Commit Graph

286 Commits

Author SHA1 Message Date
Marc Zyngier a057001e9e arm64: KVM: vgic-v3: Prevent the guest from messing with ICC_SRE_EL1
Both our GIC emulations are "strict", in the sense that we either
emulate a GICv2 or a GICv3, and not a GICv3 with GICv2 legacy
support.

But when running on a GICv3 host, we still allow the guest to
tinker with the ICC_SRE_EL1 register during its time slice:
it can switch SRE off, observe that it is off, and yet on the
next world switch, find the SRE bit to be set again. Not very
nice.

An obvious solution is to always trap accesses to ICC_SRE_EL1
(by clearing ICC_SRE_EL2.Enable), and to let the handler return
the programmed value on a read, or ignore the write.

That way, the guest can always observe that our GICv3 is SRE==1
only.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-05-31 16:12:17 +02:00
Marc Zyngier b34f2bcbf5 arm64: KVM: Make ICC_SRE_EL1 access return the configured SRE value
When we trap ICC_SRE_EL1, we handle it as RAZ/WI. It would be
more correct to actual make it RO, and return the configured
value when read.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-05-31 16:12:16 +02:00
Christoffer Dall fa89c77e89 KVM: arm/arm64: vgic-v3: Clear all dirty LRs
When saving the state of the list registers, it is critical to
reset them zero, as we could otherwise leave unexpected EOI
interrupts pending for virtual level interrupts.

Cc: stable@vger.kernel.org # v4.6+
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-05-31 16:12:09 +02:00
Linus Torvalds e28e909c36 - move kvm_stat tool from QEMU repo into tools/kvm/kvm_stat
(kvm_stat had nothing to do with QEMU in the first place -- the tool
    only interprets debugfs)
 - expose per-vm statistics in debugfs and support them in kvm_stat
   (KVM always collected per-vm statistics, but they were summarised into
    global statistics)
 
 x86:
  - fix dynamic APICv (VMX was improperly configured and a guest could
    access host's APIC MSRs, CVE-2016-4440)
  - minor fixes
 
 ARM changes from Christoffer Dall:
  "This set of changes include the new vgic, which is a reimplementation
   of our horribly broken legacy vgic implementation.  The two
   implementations will live side-by-side (with the new being the
   configured default) for one kernel release and then we'll remove the
   legacy one.
 
   Also fixes a non-critical issue with virtual abort injection to
   guests."
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull second batch of KVM updates from Radim Krčmář:
 "General:

   - move kvm_stat tool from QEMU repo into tools/kvm/kvm_stat (kvm_stat
     had nothing to do with QEMU in the first place -- the tool only
     interprets debugfs)

   - expose per-vm statistics in debugfs and support them in kvm_stat
     (KVM always collected per-vm statistics, but they were summarised
     into global statistics)

  x86:

   - fix dynamic APICv (VMX was improperly configured and a guest could
     access host's APIC MSRs, CVE-2016-4440)

   - minor fixes

  ARM changes from Christoffer Dall:

   - new vgic reimplementation of our horribly broken legacy vgic
     implementation.  The two implementations will live side-by-side
     (with the new being the configured default) for one kernel release
     and then we'll remove the legacy one.

   - fix for a non-critical issue with virtual abort injection to guests"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (70 commits)
  tools: kvm_stat: Add comments
  tools: kvm_stat: Introduce pid monitoring
  KVM: Create debugfs dir and stat files for each VM
  MAINTAINERS: Add kvm tools
  tools: kvm_stat: Powerpc related fixes
  tools: Add kvm_stat man page
  tools: Add kvm_stat vm monitor script
  kvm:vmx: more complete state update on APICv on/off
  KVM: SVM: Add more SVM_EXIT_REASONS
  KVM: Unify traced vector format
  svm: bitwise vs logical op typo
  KVM: arm/arm64: vgic-new: Synchronize changes to active state
  KVM: arm/arm64: vgic-new: enable build
  KVM: arm/arm64: vgic-new: implement mapped IRQ handling
  KVM: arm/arm64: vgic-new: Wire up irqfd injection
  KVM: arm/arm64: vgic-new: Add vgic_v2/v3_enable
  KVM: arm/arm64: vgic-new: vgic_init: implement map_resources
  KVM: arm/arm64: vgic-new: vgic_init: implement vgic_init
  KVM: arm/arm64: vgic-new: vgic_init: implement vgic_create
  KVM: arm/arm64: vgic-new: vgic_init: implement kvm_vgic_hyp_init
  ...
2016-05-27 13:41:54 -07:00
Andre Przywara efffe55af5 KVM: arm/arm64: vgic-new: enable build
Now that the new VGIC implementation has reached feature parity with
the old one, add the new files to the build system and add a Kconfig
option to switch between the two versions.
We set the default to the new version to get maximum test coverage,
in case people experience problems they can switch back to the old
behaviour if needed.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-05-20 15:40:09 +02:00
Matt Evans e4fe9e7dc3 kvm: arm64: Fix EC field in inject_abt64
The EC field of the constructed ESR is conditionally modified by ORing in
ESR_ELx_EC_DABT_LOW for a data abort.  However, ESR_ELx_EC_SHIFT is missing
from this condition.

Signed-off-by: Matt Evans <matt.evans@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-05-20 15:39:36 +02:00
Linus Torvalds 7beaa24ba4 Small release overall.
- x86: miscellaneous fixes, AVIC support (local APIC virtualization,
 AMD version)
 
 - s390: polling for interrupts after a VCPU goes to halted state is
 now enabled for s390; use hardware provided information about facility
 bits that do not need any hypervisor activity, and other fixes for
 cpu models and facilities; improve perf output; floating interrupt
 controller improvements.
 
 - MIPS: miscellaneous fixes
 
 - PPC: bugfixes only
 
 - ARM: 16K page size support, generic firmware probing layer for
 timer and GIC
 
 Christoffer Dall (KVM-ARM maintainer) says:
 "There are a few changes in this pull request touching things outside
  KVM, but they should all carry the necessary acks and it made the
  merge process much easier to do it this way."
 
 though actually the irqchip maintainers' acks didn't make it into the
 patches.  Marc Zyngier, who is both irqchip and KVM-ARM maintainer,
 later acked at http://mid.gmane.org/573351D1.4060303@arm.com
 "more formally and for documentation purposes".
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "Small release overall.

  x86:
   - miscellaneous fixes
   - AVIC support (local APIC virtualization, AMD version)

  s390:
   - polling for interrupts after a VCPU goes to halted state is now
     enabled for s390
   - use hardware provided information about facility bits that do not
     need any hypervisor activity, and other fixes for cpu models and
     facilities
   - improve perf output
   - floating interrupt controller improvements.

  MIPS:
   - miscellaneous fixes

  PPC:
   - bugfixes only

  ARM:
   - 16K page size support
   - generic firmware probing layer for timer and GIC

  Christoffer Dall (KVM-ARM maintainer) says:
    "There are a few changes in this pull request touching things
     outside KVM, but they should all carry the necessary acks and it
     made the merge process much easier to do it this way."

  though actually the irqchip maintainers' acks didn't make it into the
  patches.  Marc Zyngier, who is both irqchip and KVM-ARM maintainer,
  later acked at http://mid.gmane.org/573351D1.4060303@arm.com ('more
  formally and for documentation purposes')"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (82 commits)
  KVM: MTRR: remove MSR 0x2f8
  KVM: x86: make hwapic_isr_update and hwapic_irr_update look the same
  svm: Manage vcpu load/unload when enable AVIC
  svm: Do not intercept CR8 when enable AVIC
  svm: Do not expose x2APIC when enable AVIC
  KVM: x86: Introducing kvm_x86_ops.apicv_post_state_restore
  svm: Add VMEXIT handlers for AVIC
  svm: Add interrupt injection via AVIC
  KVM: x86: Detect and Initialize AVIC support
  svm: Introduce new AVIC VMCB registers
  KVM: split kvm_vcpu_wake_up from kvm_vcpu_kick
  KVM: x86: Introducing kvm_x86_ops VCPU blocking/unblocking hooks
  KVM: x86: Introducing kvm_x86_ops VM init/destroy hooks
  KVM: x86: Rename kvm_apic_get_reg to kvm_lapic_get_reg
  KVM: x86: Misc LAPIC changes to expose helper functions
  KVM: shrink halt polling even more for invalid wakeups
  KVM: s390: set halt polling to 80 microseconds
  KVM: halt_polling: provide a way to qualify wakeups during poll
  KVM: PPC: Book3S HV: Re-enable XICS fast path for irqfd-generated interrupts
  kvm: Conditionally register IRQ bypass consumer
  ...
2016-05-19 11:27:09 -07:00
Linus Torvalds be092017b6 arm64 updates for 4.7:
- virt_to_page/page_address optimisations
 
 - Support for NUMA systems described using device-tree
 
 - Support for hibernate/suspend-to-disk
 
 - Proper support for maxcpus= command line parameter
 
 - Detection and graceful handling of AArch64-only CPUs
 
 - Miscellaneous cleanups and non-critical fixes
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:

 - virt_to_page/page_address optimisations

 - support for NUMA systems described using device-tree

 - support for hibernate/suspend-to-disk

 - proper support for maxcpus= command line parameter

 - detection and graceful handling of AArch64-only CPUs

 - miscellaneous cleanups and non-critical fixes

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (92 commits)
  arm64: do not enforce strict 16 byte alignment to stack pointer
  arm64: kernel: Fix incorrect brk randomization
  arm64: cpuinfo: Missing NULL terminator in compat_hwcap_str
  arm64: secondary_start_kernel: Remove unnecessary barrier
  arm64: Ensure pmd_present() returns false after pmd_mknotpresent()
  arm64: Replace hard-coded values in the pmd/pud_bad() macros
  arm64: Implement pmdp_set_access_flags() for hardware AF/DBM
  arm64: Fix typo in the pmdp_huge_get_and_clear() definition
  arm64: mm: remove unnecessary EXPORT_SYMBOL_GPL
  arm64: always use STRICT_MM_TYPECHECKS
  arm64: kvm: Fix kvm teardown for systems using the extended idmap
  arm64: kaslr: increase randomization granularity
  arm64: kconfig: drop CONFIG_RTC_LIB dependency
  arm64: make ARCH_SUPPORTS_DEBUG_PAGEALLOC depend on !HIBERNATION
  arm64: hibernate: Refuse to hibernate if the boot cpu is offline
  arm64: kernel: Add support for hibernate/suspend-to-disk
  PM / Hibernate: Call flush_icache_range() on pages restored in-place
  arm64: Add new asm macro copy_page
  arm64: Promote KERNEL_START/KERNEL_END definitions to a header file
  arm64: kernel: Include _AC definition in page.h
  ...
2016-05-16 17:17:24 -07:00
Catalin Marinas 0648505324 kvm: arm64: Enable hardware updates of the Access Flag for Stage 2 page tables
The ARMv8.1 architecture extensions introduce support for hardware
updates of the access and dirty information in page table entries. With
VTCR_EL2.HA enabled (bit 21), when the CPU accesses an IPA with the
PTE_AF bit cleared in the stage 2 page table, instead of raising an
Access Flag fault to EL2 the CPU sets the actual page table entry bit
(10). To ensure that kernel modifications to the page table do not
inadvertently revert a bit set by hardware updates, certain Stage 2
software pte/pmd operations must be performed atomically.

The main user of the AF bit is the kvm_age_hva() mechanism. The
kvm_age_hva_handler() function performs a "test and clear young" action
on the pte/pmd. This needs to be atomic in respect of automatic hardware
updates of the AF bit. Since the AF bit is in the same position for both
Stage 1 and Stage 2, the patch reuses the existing
ptep_test_and_clear_young() functionality if
__HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG is defined. Otherwise, the
existing pte_young/pte_mkold mechanism is preserved.

The kvm_set_s2pte_readonly() (and the corresponding pmd equivalent) have
to perform atomic modifications in order to avoid a race with updates of
the AF bit. The arm64 implementation has been re-written using
exclusives.

Currently, kvm_set_s2pte_writable() (and pmd equivalent) take a pointer
argument and modify the pte/pmd in place. However, these functions are
only used on local variables rather than actual page table entries, so
it makes more sense to follow the pte_mkwrite() approach for stage 1
attributes. The change to kvm_s2pte_mkwrite() makes it clear that these
functions do not modify the actual page table entries.

The (pte|pmd)_mkyoung() uses on Stage 2 entries (setting the AF bit
explicitly) do not need to be modified since hardware updates of the
dirty status are not supported by KVM, so there is no possibility of
losing such information.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-05-09 22:23:08 +02:00
James Morse c612505f86 arm64: kvm: Fix kvm teardown for systems using the extended idmap
If memory is located above 1<<VA_BITS, kvm adds an extra level to its page
tables, merging the runtime tables and boot tables that contain the idmap.
This lets us avoid the trampoline dance during initialisation.

This also means there is no trampoline page mapped, so
__cpu_reset_hyp_mode() can't call __kvm_hyp_reset() in this page. The good
news is the idmap is still mapped, so we don't need the trampoline page.
The bad news is we can't call it directly as the idmap is above
HYP_PAGE_OFFSET, so its address is masked by kvm_call_hyp.

Add a function __extended_idmap_trampoline which will branch into
__kvm_hyp_reset in the idmap, change kvm_hyp_reset_entry() to return
this address if __kvm_cpu_uses_extended_idmap(). In this case
__kvm_hyp_reset() will still switch to the boot tables (which are the
merged tables that were already in use), and branch into the idmap (where
it already was).

This fixes boot failures on these systems, where we fail to execute the
missing trampoline page when tearing down kvm in init_subsystems():
[    2.508922] kvm [1]: 8-bit VMID
[    2.512057] kvm [1]: Hyp mode initialized successfully
[    2.517242] kvm [1]: interrupt-controller@e1140000 IRQ13
[    2.522622] kvm [1]: timer IRQ3
[    2.525783] Kernel panic - not syncing: HYP panic:
[    2.525783] PS:200003c9 PC:0000007ffffff820 ESR:86000005
[    2.525783] FAR:0000007ffffff820 HPFAR:00000000003ffff0 PAR:0000000000000000
[    2.525783] VCPU:          (null)
[    2.525783]
[    2.547667] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        W       4.6.0-rc5+ #1
[    2.555137] Hardware name: Default string Default string/Default string, BIOS ROD0084E 09/03/2015
[    2.563994] Call trace:
[    2.566432] [<ffffff80080888d0>] dump_backtrace+0x0/0x240
[    2.571818] [<ffffff8008088b24>] show_stack+0x14/0x20
[    2.576858] [<ffffff80083423ac>] dump_stack+0x94/0xb8
[    2.581899] [<ffffff8008152130>] panic+0x10c/0x250
[    2.586677] [<ffffff8008152024>] panic+0x0/0x250
[    2.591281] SMP: stopping secondary CPUs
[    3.649692] SMP: failed to stop secondary CPUs 0-2,4-7
[    3.654818] Kernel Offset: disabled
[    3.658293] Memory Limit: none
[    3.661337] ---[ end Kernel panic - not syncing: HYP panic:
[    3.661337] PS:200003c9 PC:0000007ffffff820 ESR:86000005
[    3.661337] FAR:0000007ffffff820 HPFAR:00000000003ffff0 PAR:0000000000000000
[    3.661337] VCPU:          (null)
[    3.661337]

Reported-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-05-03 09:50:27 +01:00
AKASHI Takahiro 67f6919766 arm64: kvm: allows kvm cpu hotplug
The current kvm implementation on arm64 does cpu-specific initialization
at system boot, and has no way to gracefully shutdown a core in terms of
kvm. This prevents kexec from rebooting the system at EL2.

This patch adds a cpu tear-down function and also puts an existing cpu-init
code into a separate function, kvm_arch_hardware_disable() and
kvm_arch_hardware_enable() respectively.
We don't need the arm64 specific cpu hotplug hook any more.

Since this patch modifies common code between arm and arm64, one stub
definition, __cpu_reset_hyp_mode(), is added on arm side to avoid
compilation errors.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
[Rebase, added separate VHE init/exit path, changed resets use of
 kvm_call_hyp() to the __version, en/disabled hardware in init_subsystems(),
 added icache maintenance to __kvm_hyp_reset() and removed lr restore, removed
 guest-enter after teardown handling]
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-28 12:05:46 +01:00
James Morse c94b0cf282 arm64: hyp/kvm: Make hyp-stub reject kvm_call_hyp()
A later patch implements kvm_arch_hardware_disable(), to remove kvm
from el2, and re-instate the hyp-stub.

This can happen while guests are running, particularly when kvm_reboot()
calls kvm_arch_hardware_disable() on each cpu. This can interrupt a guest,
remove kvm, then allow the guest to be scheduled again. This causes
kvm_call_hyp() to be run against the hyp-stub.

Change the hyp-stub to return a new exception type when this happens,
and add code to kvm's handle_exit() to tell userspace we failed to
enter the guest.

Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-28 12:05:46 +01:00
Geoff Levand ad72e59ff2 arm64: hyp/kvm: Make hyp-stub extensible
The existing arm64 hcall implementations are limited in that they only
allow for two distinct hcalls; with the x0 register either zero or not
zero.  Also, the API of the hyp-stub exception vector routines and the
KVM exception vector routines differ; hyp-stub uses a non-zero value in
x0 to implement __hyp_set_vectors, whereas KVM uses it to implement
kvm_call_hyp.

To allow for additional hcalls to be defined and to make the arm64 hcall
API more consistent across exception vector routines, change the hcall
implementations to reserve all x0 values below 0xfff for hcalls such
as {s,g}et_vectors().

Define two new preprocessor macros HVC_GET_VECTORS, and HVC_SET_VECTORS
to be used as hcall type specifiers and convert the existing
__hyp_get_vectors() and __hyp_set_vectors() routines to use these new
macros when executing an HVC call.  Also, change the corresponding
hyp-stub and KVM el1_sync exception vector routines to use these new
macros.

Signed-off-by: Geoff Levand <geoff@infradead.org>
[Merged two hcall patches, moved immediate value from esr to x0, use lr
 as a scratch register, changed limit to 0xfff]
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-28 12:05:46 +01:00
James Morse 00a44cdaba arm64: kvm: Move lr save/restore from do_el2_call into EL1
Today the 'hvc' calling KVM or the hyp-stub is expected to preserve all
registers. KVM saves/restores the registers it needs on the EL2 stack using
do_el2_call(). The hyp-stub has no stack, later patches need to be able to
be able to clobber the link register.

Move the link register save/restore to the the call sites.

Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-28 12:05:46 +01:00
Geoff Levand e7227d0e52 arm64: Cleanup SCTLR flags
We currently have macros defining flags for the arm64 sctlr registers in
both kvm_arm.h and sysreg.h.  To clean things up and simplify move the
definitions of the SCTLR_EL2 flags from kvm_arm.h to sysreg.h, rename any
SCTLR_EL1 or SCTLR_EL2 flags that are common to both registers to be
SCTLR_ELx, with 'x' indicating a common flag, and fixup all files to
include the proper header or to use the new macro names.

Signed-off-by: Geoff Levand <geoff@infradead.org>
[Restored pgtable-hwdef.h include]
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-28 12:05:46 +01:00
Suzuki K Poulose 02e0b7600f arm64: kvm: Add support for 16K pages
Now that we can handle stage-2 page tables independent
of the host page table levels, wire up the 16K page
support.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
2016-04-21 14:58:25 +02:00
Marc Zyngier 6141570c36 arm64: KVM: Warn when PARange is less than 40 bits
We always thought that 40bits of PA range would be the minimum people
would actually build. Anything less is terrifyingly small.

Turns out that we were both right and wrong. Nobody has ever built
such a system, but the ARM Foundation Model has a PARange set to 36bits.
Just because we can. Oh well. Now, the KVM API explicitely says that
we offer a 40bit PA space to the VM, so we shouldn't run KVM on
the Foundation Model at all.

That being said, this patch offers a less agressive alternative, and
loudly warns about the configuration being unsupported. You'll still
be able to run VMs (at your own risks, though).

This is just a workaround until we have a proper userspace API where
we report the PARange to userspace.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-04-06 13:33:14 +02:00
Suzuki K Poulose cb678d6016 arm64: kvm: 4.6-rc1: Fix VTCR_EL2 VS setting
When we detect support for 16bit VMID in ID_AA64MMFR1, we set the
VTCR_EL2_VS field to 1 to make use of 16bit vmids. But, with
commit 3a3604bc5e ("arm64: KVM: Switch to C-based stage2 init")
this is broken and we corrupt VTCR_EL2:T0SZ instead of updating the VS
field. VTCR_EL2_VS was actually defined to the field shift (19) and
not the real value for VS. This patch fixes the issue.

Fixes: commit 3a3604bc5e ("arm64: KVM: Switch to C-based stage2 init")
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-03-30 22:09:15 +02:00
Catalin Marinas a6cdf1c08c kvm: arm64: Disable compiler instrumentation for hypervisor code
With the recent rewrite of the arm64 KVM hypervisor code in C, enabling
certain options like KASAN would allow the compiler to generate memory
accesses or function calls to addresses not mapped at EL2. This patch
disables the compiler instrumentation on the arm64 hypervisor code for
gcov-based profiling (GCOV_KERNEL), undefined behaviour sanity checker
(UBSAN) and kernel address sanitizer (KASAN).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: <stable@vger.kernel.org> # 4.5+
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-03-21 14:02:17 +01:00
Linus Torvalds 588ab3f9af arm64 updates for 4.6:
- Initial page table creation reworked to avoid breaking large block
   mappings (huge pages) into smaller ones. The ARM architecture requires
   break-before-make in such cases to avoid TLB conflicts but that's not
   always possible on live page tables
 
 - Kernel virtual memory layout: the kernel image is no longer linked to
   the bottom of the linear mapping (PAGE_OFFSET) but at the bottom of
   the vmalloc space, allowing the kernel to be loaded (nearly) anywhere
   in physical RAM
 
 - Kernel ASLR: position independent kernel Image and modules being
   randomly mapped in the vmalloc space with the randomness is provided
   by UEFI (efi_get_random_bytes() patches merged via the arm64 tree,
   acked by Matt Fleming)
 
 - Implement relative exception tables for arm64, required by KASLR
   (initial code for ARCH_HAS_RELATIVE_EXTABLE added to lib/extable.c but
   actual x86 conversion to deferred to 4.7 because of the merge
   dependencies)
 
 - Support for the User Access Override feature of ARMv8.2: this allows
   uaccess functions (get_user etc.) to be implemented using LDTR/STTR
   instructions. Such instructions, when run by the kernel, perform
   unprivileged accesses adding an extra level of protection. The
   set_fs() macro is used to "upgrade" such instruction to privileged
   accesses via the UAO bit
 
 - Half-precision floating point support (part of ARMv8.2)
 
 - Optimisations for CPUs with or without a hardware prefetcher (using
   run-time code patching)
 
 - copy_page performance improvement to deal with 128 bytes at a time
 
 - Sanity checks on the CPU capabilities (via CPUID) to prevent
   incompatible secondary CPUs from being brought up (e.g. weird
   big.LITTLE configurations)
 
 - valid_user_regs() reworked for better sanity check of the sigcontext
   information (restored pstate information)
 
 - ACPI parking protocol implementation
 
 - CONFIG_DEBUG_RODATA enabled by default
 
 - VDSO code marked as read-only
 
 - DEBUG_PAGEALLOC support
 
 - ARCH_HAS_UBSAN_SANITIZE_ALL enabled
 
 - Erratum workaround Cavium ThunderX SoC
 
 - set_pte_at() fix for PROT_NONE mappings
 
 - Code clean-ups
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
 "Here are the main arm64 updates for 4.6.  There are some relatively
  intrusive changes to support KASLR, the reworking of the kernel
  virtual memory layout and initial page table creation.

  Summary:

   - Initial page table creation reworked to avoid breaking large block
     mappings (huge pages) into smaller ones.  The ARM architecture
     requires break-before-make in such cases to avoid TLB conflicts but
     that's not always possible on live page tables

   - Kernel virtual memory layout: the kernel image is no longer linked
     to the bottom of the linear mapping (PAGE_OFFSET) but at the bottom
     of the vmalloc space, allowing the kernel to be loaded (nearly)
     anywhere in physical RAM

   - Kernel ASLR: position independent kernel Image and modules being
     randomly mapped in the vmalloc space with the randomness is
     provided by UEFI (efi_get_random_bytes() patches merged via the
     arm64 tree, acked by Matt Fleming)

   - Implement relative exception tables for arm64, required by KASLR
     (initial code for ARCH_HAS_RELATIVE_EXTABLE added to lib/extable.c
     but actual x86 conversion to deferred to 4.7 because of the merge
     dependencies)

   - Support for the User Access Override feature of ARMv8.2: this
     allows uaccess functions (get_user etc.) to be implemented using
     LDTR/STTR instructions.  Such instructions, when run by the kernel,
     perform unprivileged accesses adding an extra level of protection.
     The set_fs() macro is used to "upgrade" such instruction to
     privileged accesses via the UAO bit

   - Half-precision floating point support (part of ARMv8.2)

   - Optimisations for CPUs with or without a hardware prefetcher (using
     run-time code patching)

   - copy_page performance improvement to deal with 128 bytes at a time

   - Sanity checks on the CPU capabilities (via CPUID) to prevent
     incompatible secondary CPUs from being brought up (e.g.  weird
     big.LITTLE configurations)

   - valid_user_regs() reworked for better sanity check of the
     sigcontext information (restored pstate information)

   - ACPI parking protocol implementation

   - CONFIG_DEBUG_RODATA enabled by default

   - VDSO code marked as read-only

   - DEBUG_PAGEALLOC support

   - ARCH_HAS_UBSAN_SANITIZE_ALL enabled

   - Erratum workaround Cavium ThunderX SoC

   - set_pte_at() fix for PROT_NONE mappings

   - Code clean-ups"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (99 commits)
  arm64: kasan: Fix zero shadow mapping overriding kernel image shadow
  arm64: kasan: Use actual memory node when populating the kernel image shadow
  arm64: Update PTE_RDONLY in set_pte_at() for PROT_NONE permission
  arm64: Fix misspellings in comments.
  arm64: efi: add missing frame pointer assignment
  arm64: make mrs_s prefixing implicit in read_cpuid
  arm64: enable CONFIG_DEBUG_RODATA by default
  arm64: Rework valid_user_regs
  arm64: mm: check at build time that PAGE_OFFSET divides the VA space evenly
  arm64: KVM: Move kvm_call_hyp back to its original localtion
  arm64: mm: treat memstart_addr as a signed quantity
  arm64: mm: list kernel sections in order
  arm64: lse: deal with clobbered IP registers after branch via PLT
  arm64: mm: dump: Use VA_START directly instead of private LOWEST_ADDR
  arm64: kconfig: add submenu for 8.2 architectural features
  arm64: kernel: acpi: fix ioremap in ACPI parking protocol cpu_postboot
  arm64: Add support for Half precision floating point
  arm64: Remove fixmap include fragility
  arm64: Add workaround for Cavium erratum 27456
  arm64: mm: Mark .rodata as RO
  ...
2016-03-17 20:03:47 -07:00
Linus Torvalds 10dc374766 One of the largest releases for KVM... Hardly any generic improvement,
but lots of architecture-specific changes.
 
 * ARM:
 - VHE support so that we can run the kernel at EL2 on ARMv8.1 systems
 - PMU support for guests
 - 32bit world switch rewritten in C
 - various optimizations to the vgic save/restore code.
 
 * PPC:
 - enabled KVM-VFIO integration ("VFIO device")
 - optimizations to speed up IPIs between vcpus
 - in-kernel handling of IOMMU hypercalls
 - support for dynamic DMA windows (DDW).
 
 * s390:
 - provide the floating point registers via sync regs;
 - separated instruction vs. data accesses
 - dirty log improvements for huge guests
 - bugfixes and documentation improvements.
 
 * x86:
 - Hyper-V VMBus hypercall userspace exit
 - alternative implementation of lowest-priority interrupts using vector
 hashing (for better VT-d posted interrupt support)
 - fixed guest debugging with nested virtualizations
 - improved interrupt tracking in the in-kernel IOAPIC
 - generic infrastructure for tracking writes to guest memory---currently
 its only use is to speedup the legacy shadow paging (pre-EPT) case, but
 in the future it will be used for virtual GPUs as well
 - much cleanup (LAPIC, kvmclock, MMU, PIT), including ubsan fixes.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "One of the largest releases for KVM...  Hardly any generic
  changes, but lots of architecture-specific updates.

  ARM:
   - VHE support so that we can run the kernel at EL2 on ARMv8.1 systems
   - PMU support for guests
   - 32bit world switch rewritten in C
   - various optimizations to the vgic save/restore code.

  PPC:
   - enabled KVM-VFIO integration ("VFIO device")
   - optimizations to speed up IPIs between vcpus
   - in-kernel handling of IOMMU hypercalls
   - support for dynamic DMA windows (DDW).

  s390:
   - provide the floating point registers via sync regs;
   - separated instruction vs.  data accesses
   - dirty log improvements for huge guests
   - bugfixes and documentation improvements.

  x86:
   - Hyper-V VMBus hypercall userspace exit
   - alternative implementation of lowest-priority interrupts using
     vector hashing (for better VT-d posted interrupt support)
   - fixed guest debugging with nested virtualizations
   - improved interrupt tracking in the in-kernel IOAPIC
   - generic infrastructure for tracking writes to guest
     memory - currently its only use is to speedup the legacy shadow
     paging (pre-EPT) case, but in the future it will be used for
     virtual GPUs as well
   - much cleanup (LAPIC, kvmclock, MMU, PIT), including ubsan fixes"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (217 commits)
  KVM: x86: remove eager_fpu field of struct kvm_vcpu_arch
  KVM: x86: disable MPX if host did not enable MPX XSAVE features
  arm64: KVM: vgic-v3: Only wipe LRs on vcpu exit
  arm64: KVM: vgic-v3: Reset LRs at boot time
  arm64: KVM: vgic-v3: Do not save an LR known to be empty
  arm64: KVM: vgic-v3: Save maintenance interrupt state only if required
  arm64: KVM: vgic-v3: Avoid accessing ICH registers
  KVM: arm/arm64: vgic-v2: Make GICD_SGIR quicker to hit
  KVM: arm/arm64: vgic-v2: Only wipe LRs on vcpu exit
  KVM: arm/arm64: vgic-v2: Reset LRs at boot time
  KVM: arm/arm64: vgic-v2: Do not save an LR known to be empty
  KVM: arm/arm64: vgic-v2: Move GICH_ELRSR saving to its own function
  KVM: arm/arm64: vgic-v2: Save maintenance interrupt state only if required
  KVM: arm/arm64: vgic-v2: Avoid accessing GICH registers
  KVM: s390: allocate only one DMA page per VM
  KVM: s390: enable STFLE interpretation only if enabled for the guest
  KVM: s390: wake up when the VCPU cpu timer expires
  KVM: s390: step the VCPU timer while in enabled wait
  KVM: s390: protect VCPU cpu timer with a seqcount
  KVM: s390: step VCPU cpu timer during kvm_run ioctl
  ...
2016-03-16 09:55:35 -07:00
Marc Zyngier b40c4892d1 arm64: KVM: vgic-v3: Only wipe LRs on vcpu exit
So far, we're always writing all possible LRs, setting the empty
ones with a zero value. This is obvious doing a low of work for
nothing, and we're better off clearing those we've actually
dirtied on the exit path (it is very rare to inject more than one
interrupt at a time anyway).

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-03-09 04:24:16 +00:00
Marc Zyngier 0d98d00b8d arm64: KVM: vgic-v3: Reset LRs at boot time
In order to let the GICv3 code be more lazy in the way it
accesses the LRs, it is necessary to start with a clean slate.

Let's reset the LRs on each CPU when the vgic is probed (which
includes a round trip to EL2...).

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-03-09 04:24:09 +00:00
Marc Zyngier 84e8b9c88d arm64: KVM: vgic-v3: Do not save an LR known to be empty
On exit, any empty LR will be signaled in ICH_ELRSR_EL2. Which
means that we do not have to save it, and we can just clear
its state in the in-memory copy.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-03-09 04:24:07 +00:00
Marc Zyngier b4344545cf arm64: KVM: vgic-v3: Save maintenance interrupt state only if required
Next on our list of useless accesses is the maintenance interrupt
status registers (ICH_MISR_EL2, ICH_EISR_EL2).

It is pointless to save them if we haven't asked for a maintenance
interrupt the first place, which can only happen for two reasons:
- Underflow: ICH_HCR_UIE will be set,
- EOI: ICH_LR_EOI will be set.

These conditions can be checked on the in-memory copies of the regs.
Should any of these two condition be valid, we must read GICH_MISR.
We can then check for ICH_MISR_EOI, and only when set read
ICH_EISR_EL2.

This means that in most case, we don't have to save them at all.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-03-09 04:24:06 +00:00
Marc Zyngier 1b8e83c04e arm64: KVM: vgic-v3: Avoid accessing ICH registers
Just like on GICv2, we're a bit hammer-happy with GICv3, and access
them more often than we should.

Adopt a policy similar to what we do for GICv2, only save/restoring
the minimal set of registers. As we don't access the registers
linearly anymore (we may skip some), the convoluted accessors become
slightly simpler, and we can drop the ugly indexing macro that
tended to confuse the reviewers.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-03-09 04:24:04 +00:00
Marc Zyngier 623eefa8d0 arm64: KVM: Switch the sys_reg search to be a binary search
Our 64bit sys_reg table is about 90 entries long (so far, and the
PMU support is likely to increase this). This means that on average,
it takes 45 comparaisons to find the right entry (and actually the
full 90 if we have to search the invariant table).

Not the most efficient thing. Specially when you think that this
table is already sorted. Switching to a binary search effectively
reduces the search to about 7 comparaisons. Slightly better!

As an added bonus, the comparison is done by comparing all the
fields at once, instead of one at a time.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:22 +00:00
Shannon Zhao bb0c70bcca arm64: KVM: Add a new vcpu device control group for PMUv3
To configure the virtual PMUv3 overflow interrupt number, we use the
vcpu kvm_device ioctl, encapsulating the KVM_ARM_VCPU_PMU_V3_IRQ
attribute within the KVM_ARM_VCPU_PMU_V3_CTRL group.

After configuring the PMUv3, call the vcpu ioctl with attribute
KVM_ARM_VCPU_PMU_V3_INIT to initialize the PMUv3.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:21 +00:00
Shannon Zhao f577f6c2a6 arm64: KVM: Introduce per-vcpu kvm device controls
In some cases it needs to get/set attributes specific to a vcpu and so
needs something else than ONE_REG.

Let's copy the KVM_DEVICE approach, and define the respective ioctls
for the vcpu file descriptor.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:21 +00:00
Shannon Zhao 808e738142 arm64: KVM: Add a new feature bit for PMUv3
To support guest PMUv3, use one bit of the VCPU INIT feature array.
Initialize the PMU when initialzing the vcpu with that bit and PMU
overflow interrupt set.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Acked-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:21 +00:00
Shannon Zhao 2aa36e9840 arm64: KVM: Reset PMU state when resetting vcpu
When resetting vcpu, it needs to reset the PMU state to initial status.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:21 +00:00
Shannon Zhao d692b8ad6e arm64: KVM: Add access handler for PMUSERENR register
This register resets as unknown in 64bit mode while it resets as zero
in 32bit mode. Here we choose to reset it as zero for consistency.

PMUSERENR_EL0 holds some bits which decide whether PMU registers can be
accessed from EL0. Add some check helpers to handle the access from EL0.

When these bits are zero, only reading PMUSERENR will trap to EL2 and
writing PMUSERENR or reading/writing other PMU registers will trap to
EL1 other than EL2 when HCR.TGE==0. To current KVM configuration
(HCR.TGE==0) there is no way to get these traps. Here we write 0xf to
physical PMUSERENR register on VM entry, so that it will trap PMU access
from EL0 to EL2. Within the register access handler we check the real
value of guest PMUSERENR register to decide whether this access is
allowed. If not allowed, return false to inject UND to guest.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:21 +00:00
Shannon Zhao 76993739cd arm64: KVM: Add helper to handle PMCR register bits
According to ARMv8 spec, when writing 1 to PMCR.E, all counters are
enabled by PMCNTENSET, while writing 0 to PMCR.E, all counters are
disabled. When writing 1 to PMCR.P, reset all event counters, not
including PMCCNTR, to zero. When writing 1 to PMCR.C, reset PMCCNTR to
zero.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:21 +00:00
Shannon Zhao 7a0adc7064 arm64: KVM: Add access handler for PMSWINC register
Add access handler which emulates writing and reading PMSWINC
register and add support for creating software increment event.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:20 +00:00
Shannon Zhao 76d883c4e6 arm64: KVM: Add access handler for PMOVSSET and PMOVSCLR register
Since the reset value of PMOVSSET and PMOVSCLR is UNKNOWN, use
reset_unknown for its reset handler. Add a handler to emulate writing
PMOVSSET or PMOVSCLR register.

When writing non-zero value to PMOVSSET, the counter and its interrupt
is enabled, kick this vcpu to sync PMU interrupt.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:20 +00:00
Shannon Zhao 9db52c78cd arm64: KVM: Add access handler for PMINTENSET and PMINTENCLR register
Since the reset value of PMINTENSET and PMINTENCLR is UNKNOWN, use
reset_unknown for its reset handler. Add a handler to emulate writing
PMINTENSET or PMINTENCLR register.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:20 +00:00
Shannon Zhao 9feb21ac57 arm64: KVM: Add access handler for event type register
These kind of registers include PMEVTYPERn, PMCCFILTR and PMXEVTYPER
which is mapped to PMEVTYPERn or PMCCFILTR.

The access handler translates all aarch32 register offsets to aarch64
ones and uses vcpu_sys_reg() to access their values to avoid taking care
of big endian.

When writing to these registers, create a perf_event for the selected
event type.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:20 +00:00
Shannon Zhao 96b0eebcc6 arm64: KVM: Add access handler for PMCNTENSET and PMCNTENCLR register
Since the reset value of PMCNTENSET and PMCNTENCLR is UNKNOWN, use
reset_unknown for its reset handler. Add a handler to emulate writing
PMCNTENSET or PMCNTENCLR register.

When writing to PMCNTENSET, call perf_event_enable to enable the perf
event. When writing to PMCNTENCLR, call perf_event_disable to disable
the perf event.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:20 +00:00
Shannon Zhao 051ff581ce arm64: KVM: Add access handler for event counter register
These kind of registers include PMEVCNTRn, PMCCNTR and PMXEVCNTR which
is mapped to PMEVCNTRn.

The access handler translates all aarch32 register offsets to aarch64
ones and uses vcpu_sys_reg() to access their values to avoid taking care
of big endian.

When reading these registers, return the sum of register value and the
value perf event counts.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:20 +00:00
Shannon Zhao a86b550530 arm64: KVM: Add access handler for PMCEID0 and PMCEID1 register
Add access handler which gets host value of PMCEID0 or PMCEID1 when
guest access these registers. Writing action to PMCEID0 or PMCEID1 is
UNDEFINED.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:19 +00:00
Shannon Zhao 3965c3ce75 arm64: KVM: Add access handler for PMSELR register
Since the reset value of PMSELR_EL0 is UNKNOWN, use reset_unknown for
its reset handler. When reading PMSELR, return the PMSELR.SEL field to
guest.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:19 +00:00
Shannon Zhao ab9468340d arm64: KVM: Add access handler for PMCR register
Add reset handler which gets host value of PMCR_EL0 and make writable
bits architecturally UNKNOWN except PMCR.E which is zero. Add an access
handler for PMCR.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:19 +00:00
Shannon Zhao 04fe472615 arm64: KVM: Define PMU data structure for each vcpu
Here we plan to support virtual PMU for guest by full software
emulation, so define some basic structs and functions preparing for
futher steps. Define struct kvm_pmc for performance monitor counter and
struct kvm_pmu for performance monitor unit for each vcpu. According to
ARMv8 spec, the PMU contains at most 32(ARMV8_PMU_MAX_COUNTERS)
counters.

Since this only supports ARM64 (or PMUv3), add a separate config symbol
for it.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:19 +00:00
Marc Zyngier 6d50d54cd8 arm64: KVM: Move vgic-v2 and timer save/restore to virt/kvm/arm/hyp
We already have virt/kvm/arm/ containing timer and vgic stuff.
Add yet another subdirectory to contain the hyp-specific files
(timer and vgic again).

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:18 +00:00
Marc Zyngier 13720a56ed arm64: KVM: Move kvm/hyp/hyp.h to include/asm/kvm_hyp.h
In order to be able to move code outside of kvm/hyp, we need to make
the global hyp.h file accessible from a standard location.

include/asm/kvm_hyp.h seems good enough.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:18 +00:00
Marc Zyngier 5f05a72aed arm64: KVM: Move most of the fault decoding to C
The fault decoding process (including computing the IPA in the case
of a permission fault) would be much better done in C code, as we
have a reasonable infrastructure to deal with the VHE/non-VHE
differences.

Let's move the whole thing to C, including the workaround for
erratum 834220, and just patch the odd ESR_EL2 access remaining
in hyp-entry.S.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:18 +00:00
Marc Zyngier 253dcbd39a arm64: KVM: VHE: Add alternative panic handling
As the kernel fully runs in HYP when VHE is enabled, we can
directly branch to the kernel's panic() implementation, and
not perform an exception return.

Add the alternative code to deal with this.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:18 +00:00
Marc Zyngier 77cb2d9133 arm64: KVM: VHE: Add fpsimd enabling on guest access
Despite the fact that a VHE enabled kernel runs at EL2, it uses
CPACR_EL1 to trap FPSIMD access. Add the required alternative
code to re-enable guest FPSIMD access when it has trapped to
EL2.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:17 +00:00
Marc Zyngier 5efe6de138 arm64: KVM: VHE: Use unified sysreg accessors for timer
Switch the timer code to the unified sysreg accessors.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:17 +00:00
Marc Zyngier 68908bf789 arm64: KVM: VHE: Implement VHE activate/deactivate_traps
Running the kernel in HYP mode requires the HCR_E2H bit to be set
at all times, and the HCR_TGE bit to be set when running as a host
(and cleared when running as a guest). At the same time, the vector
 must be set to the current role of the kernel (either host or
hypervisor), and a couple of system registers differ between VHE
and non-VHE.

We implement these by using another set of alternate functions
that get dynamically patched.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:17 +00:00
Marc Zyngier 328762247c arm64: KVM: VHE: Make __fpsimd_enabled VHE aware
As non-VHE and VHE have different ways to express the trapping of
FPSIMD registers to EL2, make __fpsimd_enabled a patchable predicate
and provide a VHE implementation.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:17 +00:00
Marc Zyngier d1526e5efc arm64: KVM: VHE: Enable minimal sysreg save/restore
We're now in a position where we can introduce VHE's minimal
save/restore, which is limited to the handful of shared sysregs.

Add the required alternative function calls that result in a
"do nothing" call on VHE, and the normal save/restore for non-VHE.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:17 +00:00
Marc Zyngier 094f8233c0 arm64: KVM: VHE: Use unified system register accessors
Use the recently introduced unified system register accessors for
those sysregs that behave differently depending on VHE being in
use or not.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:17 +00:00
Marc Zyngier 9c6c356832 arm64: KVM: VHE: Split save/restore of registers shared between guest and host
A handful of system registers are still shared between host and guest,
even while using VHE (tpidr*_el[01] and actlr_el1).

Also, some of the vcpu state (sp_el0, PC and PSTATE) must be
save/restored on entry/exit, as they are used on the host as well.

In order to facilitate the introduction of a VHE-specific sysreg
save/restore, make move the access to these registers to their
own save/restore functions.

No functional change.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:17 +00:00
Marc Zyngier edef528dc4 arm64: KVM: VHE: Differenciate host/guest sysreg save/restore
With ARMv8, host and guest share the same system register file,
making the save/restore procedure completely symetrical.
With VHE, host and guest now have different requirements, as they
use different sysregs.

In order to prepare for this, add split sysreg save/restore functions
for both host and guest. No functional changes yet.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:16 +00:00
Marc Zyngier 915ccd1dbf arm64: KVM: VHE: Introduce unified system register accessors
VHE brings its own bag of new system registers, or rather system
register accessors, as it define new ways to access both guest
and host system registers. For example, from the host:

- The host TCR_EL2 register is accessed using the TCR_EL1 accessor
- The guest TCR_EL1 register is accessed using the TCR_EL12 accessor

Obviously, this is confusing. A way to somehow reduce the complexity
of writing code for both ARMv8 and ARMv8.1 is to use a set of unified
accessors that will generate the right sysreg, depending on the mode
the CPU is running in. For example:

- read_sysreg_el1(tcr) will use TCR_EL1 on ARMv8, and TCR_EL12 on
  ARMv8.1 with VHE.
- read_sysreg_el2(tcr) will use TCR_EL2 on ARMv8, and TCR_EL1 on
  ARMv8.1 with VHE.

We end up with three sets of accessors ({read,write}_sysreg_el[012])
that can be directly used from C code. We take this opportunity to
also add the definition for the new VHE sysregs.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:16 +00:00
Marc Zyngier cedbb8b78c arm64: KVM: VHE: Patch out kern_hyp_va
The kern_hyp_va macro is pretty meaninless with VHE, as there is
only one mapping - the kernel one.

In order to keep the code readable and efficient, use runtime
patching to replace the 'and' instruction used to compute the VA
with a 'nop'.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:16 +00:00
Marc Zyngier b81125c791 arm64: KVM: VHE: Patch out use of HVC
With VHE, the host never issues an HVC instruction to get into the
KVM code, as we can simply branch there.

Use runtime code patching to simplify things a bit.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:16 +00:00
Marc Zyngier 3a3604bc5e arm64: KVM: Switch to C-based stage2 init
There is no real need to leave the stage2 initialization as part
of the early HYP bootstrap, and we can easily postpone it to
the point where we can safely run C code.

This will help VHE, which doesn't need any of this bootstrap.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 18:34:15 +00:00
Michael S. Tsirkin 4cad67fca3 arm/arm64: KVM: Fix ioctl error handling
Calling return copy_to_user(...) in an ioctl will not
do the right thing if there's a pagefault:
copy_to_user returns the number of bytes not copied
in this case.

Fix up kvm to do
	return copy_to_user(...)) ?  -EFAULT : 0;

everywhere.

Cc: stable@vger.kernel.org
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29 09:56:40 +00:00
Suzuki K Poulose 28c5dcb22f arm64: Rename cpuid_feature field extract routines
Now that we have a clear understanding of the sign of a feature,
rename the routines to reflect the sign, so that it is not misused.
The cpuid_feature_extract_field() now accepts a 'sign' parameter.

Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25 10:33:08 +00:00
Marc Zyngier fd451b90e7 arm64: KVM: vgic-v3: Restore ICH_APR0Rn_EL2 before ICH_APR1Rn_EL2
The GICv3 architecture spec says:

Writing to the active priority registers in any order other than
the following order will result in UNPREDICTABLE behavior:
- ICH_AP0R<n>_EL2.
- ICH_AP1R<n>_EL2.

So let's not pointlessly go against the rule...

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-24 17:25:58 +00:00
Ard Biesheuvel a0bf9776cd arm64: kvm: deal with kernel symbols outside of linear mapping
KVM on arm64 uses a fixed offset between the linear mapping at EL1 and
the HYP mapping at EL2. Before we can move the kernel virtual mapping
out of the linear mapping, we have to make sure that references to kernel
symbols that are accessed via the HYP mapping are translated to their
linear equivalent.

Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18 18:16:40 +00:00
Ard Biesheuvel 03336b1df9 arm64: prevent potential circular header dependencies in asm/bug.h
Currently, using BUG_ON() in header files is cumbersome, due to the fact
that asm/bug.h transitively includes a lot of other header files, resulting
in the actual BUG_ON() invocation appearing before its definition in the
preprocessor input. So let's reverse the #include dependency between
asm/bug.h and asm/debug-monitors.h, by moving the definition of BUG_BRK_IMM
from the latter to the former. Also fix up one user of asm/debug-monitors.h
which relied on a transitive include.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18 18:16:11 +00:00
Tirumalesh Chalamarla 3c5b1d92b3 arm64: KVM: Configure TCR_EL2.PS at runtime
Setting TCR_EL2.PS to 40 bits is wrong on systems with less that
less than 40 bits of physical addresses. and breaks KVM on systems
where the RAM is above 40 bits.

This patch uses ID_AA64MMFR0_EL1.PARange to set TCR_EL2.PS dynamically,
just like we already do for VTCR_EL2.PS.

[Marc: rewrote commit message, patch tidy up]

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Tirumalesh Chalamarla <tchalamarla@caviumnetworks.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-11 13:16:47 +00:00
Shannon Zhao 6327f35a20 arm64: KVM: Fix guest dead loop when register accessor returns false
Currently emulate_cp will return 0 (Handled) no matter what the accessor
returns. If register accessor returns false, it will not skip current PC
while emulate_cp return handled. Then guest will stuck in a dead loop.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-24 21:56:01 +00:00
Shannon Zhao 7769db905b arm64: KVM: Fix comments of the CP handler
Make sure the documentation reflects the actual name of the functions.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-24 21:56:00 +00:00
Dave Martin a7e0ac295d arm64: KVM: Obey RES0/1 reserved bits when setting CPTR_EL2
Some bits in CPTR are defined as RES1 in the architecture.  Setting
these bits to zero may unintentionally enable future architecture
extensions, allowing guests to use them without supervision by the host.

This would be bad: for forwards compatibility, this patch makes
sure the affected bits are always written with 1, not 0.

This patch only addresses CPTR_EL2.  Initialisation of other system
registers may still need review.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-24 21:55:58 +00:00
Marc Zyngier 8fc153cda9 arm64: KVM: Fix AArch64 guest userspace exception injection
At the moment, our fault injection is pretty limited. We always
generate a SYNC exception into EL1, as if the fault was actually
from EL1h, no matter how it was generated.

This is obviously wrong, as EL0 can generate faults of its own
(not to mention the pretty-much unused EL1t mode).

This patch fixes it by implementing section D1.10.2 of the ARMv8 ARM,
and in particular table D1-7 ("Vector offsets from vector table base
address"), which describes which vector to use depending on the source
exception level and type (synchronous, IRQ, FIQ or SError).

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Tested-by: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-24 21:55:57 +00:00
Vladimir Murzin 20475f784d arm64: KVM: Add support for 16-bit VMID
The ARMv8.1 architecture extension allows to choose between 8-bit and
16-bit of VMID, so use this capability for KVM.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-18 10:15:12 +00:00
Marc Zyngier 281243cbe0 arm64: KVM: debug: Remove spurious inline attributes
The debug trapping code is pretty heavy on the "inline" attribute,
but most functions are actually referenced in the sysreg tables,
making the inlining imposible.

Removing the useless inline qualifier seems the right thing to do,
having verified that the output code is similar.

Cc: Alex Bennée <alex.bennee@linaro.org>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-18 10:15:11 +00:00
Marc Zyngier 3ffa75cd18 arm64: KVM: Remove weak attributes
As we've now switched to the new world switch implementation,
remove the weak attributes, as nobody is supposed to override
it anymore.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-14 11:30:44 +00:00
Marc Zyngier 9d8415d6c1 arm64: KVM: Turn system register numbers to an enum
Having the system register numbers as #defines has been a pain
since day one, as the ordering is pretty fragile, and moving
things around leads to renumbering and epic conflict resolutions.

Now that we're mostly acessing the sysreg file in C, an enum is
a much better type to use, and we can clean things up a bit.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14 11:30:43 +00:00
Marc Zyngier 1ea66d27e7 arm64: KVM: Move away from the assembly version of the world switch
This is it. We remove all of the code that has now been rewritten.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14 11:30:43 +00:00
Marc Zyngier 044ac37d12 arm64: KVM: Add compatibility aliases
So far, we've implemented the new world switch with a completely
different namespace, so that we could have both implementation
compiled in.

Let's take things one step further by adding weak aliases that
have the same names as the original implementation. The weak
attributes allows the new implementation to be overriden by the
old one, and everything still work.

At a later point, we'll be able to simply drop the old code, and
everything will hopefully keep working, thanks to the aliases we
have just added. This also saves us repainting all the callers.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14 11:30:42 +00:00
Marc Zyngier 53fd5b6487 arm64: KVM: Add panic handling
Add the panic handler, together with the small bits of assembly
code to call the kernel's panic implementation.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14 11:30:42 +00:00
Marc Zyngier 2b28162cf6 arm64: KVM: HYP mode entry points
Add the entry points for HYP mode (both for hypercalls and
exception handling).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14 11:30:42 +00:00
Marc Zyngier 5eec0a91e3 arm64: KVM: Implement TLB handling
Implement the TLB handling as a direct translation of the assembly
code version.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14 11:30:41 +00:00
Marc Zyngier c13d1683df arm64: KVM: Implement fpsimd save/restore
Implement the fpsimd save restore, keeping the lazy part in
assembler (as returning to C would be overkill).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14 11:30:41 +00:00
Marc Zyngier be901e9b15 arm64: KVM: Implement the core world switch
Implement the core of the world switch in C. Not everything is there
yet, and there is nothing to re-enter the world switch either.

But this already outlines the code structure well enough.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14 11:30:41 +00:00
Marc Zyngier c1bf6e18e9 arm64: KVM: Add patchable function selector
KVM so far relies on code patching, and is likely to use it more
in the future. The main issue is that our alternative system works
at the instruction level, while we'd like to have alternatives at
the function level.

In order to cope with this, add the "hyp_alternate_select" macro that
outputs a brief sequence of code that in turn can be patched, allowing
an alternative function to be selected.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-14 11:30:40 +00:00
Marc Zyngier b97b66c14b arm64: KVM: Implement guest entry
Contrary to the previous patch, the guest entry is fairly different
from its assembly counterpart, mostly because it is only concerned
with saving/restoring the GP registers, and nothing else.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-14 11:30:40 +00:00
Marc Zyngier 8eb992674c arm64: KVM: Implement debug save/restore
Implement the debug save restore as a direct translation of
the assembly code version.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14 11:30:40 +00:00
Marc Zyngier c209ec85a2 arm64: KVM: Implement 32bit system register save/restore
Implement the 32bit system register save/restore as a direct
translation of the assembly code version.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14 11:30:40 +00:00
Marc Zyngier 6d6ec20fcf arm64: KVM: Implement system register save/restore
Implement the system register save/restore as a direct translation of
the assembly code version.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14 11:30:39 +00:00
Marc Zyngier 1431af367e arm64: KVM: Implement timer save/restore
Implement the timer save restore as a direct translation of
the assembly code version.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-14 11:30:39 +00:00
Marc Zyngier f68d2b1b73 arm64: KVM: Implement vgic-v3 save/restore
Implement the vgic-v3 save restore as a direct translation of
the assembly code version.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-14 11:30:39 +00:00
Marc Zyngier 06282fd2c2 arm64: KVM: Implement vgic-v2 save/restore
Implement the vgic-v2 save restore (mostly) as a direct translation
of the assembly code version.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-14 11:30:38 +00:00
Marc Zyngier c76a0a6695 arm64: KVM: Add a HYP-specific header file
In order to expose the various EL2 services that are private to
the hypervisor, add a new hyp.h file.

So far, it only contains mundane things such as section annotation
and VA manipulation.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-14 11:30:38 +00:00
Amit Tomar b19e6892a9 KVM: arm/arm64: Count guest exit due to various reasons
It would add guest exit statistics to debugfs, this can be helpful
while measuring KVM performance.

  [ Renamed some of the field names - Christoffer ]

Signed-off-by: Amit Singh Tomar <amittomer25@gmail.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14 11:30:00 +00:00
Pavel Fedin f6be563abb arm64: KVM: Get rid of old vcpu_reg()
Using oldstyle vcpu_reg() accessor is proven to be inappropriate and
unsafe on ARM64. This patch converts the rest of use cases to new
accessors and completely removes vcpu_reg() on ARM64.

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-04 16:30:03 +00:00
Pavel Fedin 2ec5be3dbf arm64: KVM: Correctly handle zero register in system register accesses
System register accesses also use zero register for Rt == 31, and
therefore using it will also result in getting SP value instead. This
patch makes them also using new accessors, introduced by the previous
patch. Since register value is no longer directly associated with storage
inside vCPU context structure, we introduce a dedicated storage for it in
struct sys_reg_params.

This refactor also gets rid of "massive hack" in kvm_handle_cp_64().

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-04 16:29:54 +00:00
Pavel Fedin 3fec037d0f arm64: KVM: Remove const from struct sys_reg_params
Further rework is going to introduce a dedicated storage for transfer
register value in struct sys_reg_params. Before doing this we have to
remove 'const' modifiers from it in all accessor functions and their
callers.

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-04 16:29:47 +00:00
Mark Rutland fbb4574ce9 arm64: kvm: report original PAR_EL1 upon panic
If we call __kvm_hyp_panic while a guest context is active, we call
__restore_sysregs before acquiring the system register values for the
panic, in the process throwing away the PAR_EL1 value at the point of
the panic.

This patch modifies __kvm_hyp_panic to stash the PAR_EL1 value prior to
restoring host register values, enabling us to report the original
values at the point of the panic.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24 18:20:58 +01:00
Mark Rutland 1d7a4e313a arm64: kvm: avoid %p in __kvm_hyp_panic
Currently __kvm_hyp_panic uses %p for values which are not pointers,
such as the ESR value. This can confusingly lead to "(null)" being
printed for the value.

Use %x instead, and only use %p for host pointers.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24 18:18:13 +01:00
Marc Zyngier 498cd5c32b arm64: KVM: Add workaround for Cortex-A57 erratum 834220
Cortex-A57 parts up to r1p2 can misreport Stage 2 translation faults
when a Stage 1 permission fault or device alignment fault should
have been reported.

This patch implements the workaround (which is to validate that the
Stage-1 translation actually succeeds) by using code patching.

Cc: stable@vger.kernel.org
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24 17:58:14 +01:00
Marc Zyngier c0f0963464 arm64: KVM: Fix AArch32 to AArch64 register mapping
When running a 32bit guest under a 64bit hypervisor, the ARMv8
architecture defines a mapping of the 32bit registers in the 64bit
space. This includes banked registers that are being demultiplexed
over the 64bit ones.

On exceptions caused by an operation involving a 32bit register, the
HW exposes the register number in the ESR_EL2 register. It was so
far understood that SW had to distinguish between AArch32 and AArch64
accesses (based on the current AArch32 mode and register number).

It turns out that I misinterpreted the ARM ARM, and the clue is in
D1.20.1: "For some exceptions, the exception syndrome given in the
ESR_ELx identifies one or more register numbers from the issued
instruction that generated the exception. Where the exception is
taken from an Exception level using AArch32 these register numbers
give the AArch64 view of the register."

Which means that the HW is already giving us the translated version,
and that we shouldn't try to interpret it at all (for example, doing
an MMIO operation from the IRQ mode using the LR register leads to
very unexpected behaviours).

The fix is thus not to perform a call to vcpu_reg32() at all from
vcpu_reg(), and use whatever register number is supplied directly.
The only case we need to find out about the mapping is when we
actively generate a register access, which only occurs when injecting
a fault in a guest.

Cc: stable@vger.kernel.org
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24 17:58:08 +01:00
Linus Torvalds 933425fb00 s390: A bunch of fixes and optimizations for interrupt and time
handling.
 
 PPC: Mostly bug fixes.
 
 ARM: No big features, but many small fixes and prerequisites including:
 - a number of fixes for the arch-timer
 - introducing proper level-triggered semantics for the arch-timers
 - a series of patches to synchronously halt a guest (prerequisite for
   IRQ forwarding)
 - some tracepoint improvements
 - a tweak for the EL2 panic handlers
 - some more VGIC cleanups getting rid of redundant state
 
 x86: quite a few changes:
 
 - support for VT-d posted interrupts (i.e. PCI devices can inject
 interrupts directly into vCPUs).  This introduces a new component (in
 virt/lib/) that connects VFIO and KVM together.  The same infrastructure
 will be used for ARM interrupt forwarding as well.
 
 - more Hyper-V features, though the main one Hyper-V synthetic interrupt
 controller will have to wait for 4.5.  These will let KVM expose Hyper-V
 devices.
 
 - nested virtualization now supports VPID (same as PCID but for vCPUs)
 which makes it quite a bit faster
 
 - for future hardware that supports NVDIMM, there is support for clflushopt,
 clwb, pcommit
 
 - support for "split irqchip", i.e. LAPIC in kernel + IOAPIC/PIC/PIT in
 userspace, which reduces the attack surface of the hypervisor
 
 - obligatory smattering of SMM fixes
 
 - on the guest side, stable scheduler clock support was rewritten to not
 require help from the hypervisor.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM updates from Paolo Bonzini:
 "First batch of KVM changes for 4.4.

  s390:
     A bunch of fixes and optimizations for interrupt and time handling.

  PPC:
     Mostly bug fixes.

  ARM:
     No big features, but many small fixes and prerequisites including:

      - a number of fixes for the arch-timer

      - introducing proper level-triggered semantics for the arch-timers

      - a series of patches to synchronously halt a guest (prerequisite
        for IRQ forwarding)

      - some tracepoint improvements

      - a tweak for the EL2 panic handlers

      - some more VGIC cleanups getting rid of redundant state

  x86:
     Quite a few changes:

      - support for VT-d posted interrupts (i.e. PCI devices can inject
        interrupts directly into vCPUs).  This introduces a new
        component (in virt/lib/) that connects VFIO and KVM together.
        The same infrastructure will be used for ARM interrupt
        forwarding as well.

      - more Hyper-V features, though the main one Hyper-V synthetic
        interrupt controller will have to wait for 4.5.  These will let
        KVM expose Hyper-V devices.

      - nested virtualization now supports VPID (same as PCID but for
        vCPUs) which makes it quite a bit faster

      - for future hardware that supports NVDIMM, there is support for
        clflushopt, clwb, pcommit

      - support for "split irqchip", i.e.  LAPIC in kernel +
        IOAPIC/PIC/PIT in userspace, which reduces the attack surface of
        the hypervisor

      - obligatory smattering of SMM fixes

      - on the guest side, stable scheduler clock support was rewritten
        to not require help from the hypervisor"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (123 commits)
  KVM: VMX: Fix commit which broke PML
  KVM: x86: obey KVM_X86_QUIRK_CD_NW_CLEARED in kvm_set_cr0()
  KVM: x86: allow RSM from 64-bit mode
  KVM: VMX: fix SMEP and SMAP without EPT
  KVM: x86: move kvm_set_irq_inatomic to legacy device assignment
  KVM: device assignment: remove pointless #ifdefs
  KVM: x86: merge kvm_arch_set_irq with kvm_set_msi_inatomic
  KVM: x86: zero apic_arb_prio on reset
  drivers/hv: share Hyper-V SynIC constants with userspace
  KVM: x86: handle SMBASE as physical address in RSM
  KVM: x86: add read_phys to x86_emulate_ops
  KVM: x86: removing unused variable
  KVM: don't pointlessly leave KVM_COMPAT=y in non-KVM configs
  KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr()
  KVM: arm/arm64: Clean up vgic_retire_lr() and surroundings
  KVM: arm/arm64: Optimize away redundant LR tracking
  KVM: s390: use simple switch statement as multiplexer
  KVM: s390: drop useless newline in debugging data
  KVM: s390: SCA must not cross page boundaries
  KVM: arm: Do not indent the arguments of DECLARE_BITMAP
  ...
2015-11-05 16:26:26 -08:00
Linus Torvalds 2dc10ad81f arm64 updates for 4.4:
- "genirq: Introduce generic irq migration for cpu hotunplugged" patch
   merged from tip/irq/for-arm to allow the arm64-specific part to be
   upstreamed via the arm64 tree
 
 - CPU feature detection reworked to cope with heterogeneous systems
   where CPUs may not have exactly the same features. The features
   reported by the kernel via internal data structures or ELF_HWCAP are
   delayed until all the CPUs are up (and before user space starts)
 
 - Support for 16KB pages, with the additional bonus of a 36-bit VA
   space, though the latter only depending on EXPERT
 
 - Implement native {relaxed, acquire, release} atomics for arm64
 
 - New ASID allocation algorithm which avoids IPI on roll-over, together
   with TLB invalidation optimisations (using local vs global where
   feasible)
 
 - KASan support for arm64
 
 - EFI_STUB clean-up and isolation for the kernel proper (required by
   KASan)
 
 - copy_{to,from,in}_user optimisations (sharing the memcpy template)
 
 - perf: moving arm64 to the arm32/64 shared PMU framework
 
 - L1_CACHE_BYTES increased to 128 to accommodate Cavium hardware
 
 - Support for the contiguous PTE hint on kernel mapping (16 consecutive
   entries may be able to use a single TLB entry)
 
 - Generic CONFIG_HZ now used on arm64
 
 - defconfig updates
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:

 - "genirq: Introduce generic irq migration for cpu hotunplugged" patch
   merged from tip/irq/for-arm to allow the arm64-specific part to be
   upstreamed via the arm64 tree

 - CPU feature detection reworked to cope with heterogeneous systems
   where CPUs may not have exactly the same features.  The features
   reported by the kernel via internal data structures or ELF_HWCAP are
   delayed until all the CPUs are up (and before user space starts)

 - Support for 16KB pages, with the additional bonus of a 36-bit VA
   space, though the latter only depending on EXPERT

 - Implement native {relaxed, acquire, release} atomics for arm64

 - New ASID allocation algorithm which avoids IPI on roll-over, together
   with TLB invalidation optimisations (using local vs global where
   feasible)

 - KASan support for arm64

 - EFI_STUB clean-up and isolation for the kernel proper (required by
   KASan)

 - copy_{to,from,in}_user optimisations (sharing the memcpy template)

 - perf: moving arm64 to the arm32/64 shared PMU framework

 - L1_CACHE_BYTES increased to 128 to accommodate Cavium hardware

 - Support for the contiguous PTE hint on kernel mapping (16 consecutive
   entries may be able to use a single TLB entry)

 - Generic CONFIG_HZ now used on arm64

 - defconfig updates

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (91 commits)
  arm64/efi: fix libstub build under CONFIG_MODVERSIONS
  ARM64: Enable multi-core scheduler support by default
  arm64/efi: move arm64 specific stub C code to libstub
  arm64: page-align sections for DEBUG_RODATA
  arm64: Fix build with CONFIG_ZONE_DMA=n
  arm64: Fix compat register mappings
  arm64: Increase the max granular size
  arm64: remove bogus TASK_SIZE_64 check
  arm64: make Timer Interrupt Frequency selectable
  arm64/mm: use PAGE_ALIGNED instead of IS_ALIGNED
  arm64: cachetype: fix definitions of ICACHEF_* flags
  arm64: cpufeature: declare enable_cpu_capabilities as static
  genirq: Make the cpuhotplug migration code less noisy
  arm64: Constify hwcap name string arrays
  arm64/kvm: Make use of the system wide safe values
  arm64/debug: Make use of the system wide safe value
  arm64: Move FP/ASIMD hwcap handling to common code
  arm64/HWCAP: Use system wide safe values
  arm64/capabilities: Make use of system wide safe value
  arm64: Delay cpu feature capability checks
  ...
2015-11-04 14:47:13 -08:00
Mark Rutland db85c55f1b arm64: kvm: restore EL1N SP for panic
If we panic in hyp mode, we inject a call to panic() into the EL1N host
kernel. If a guest context is active, we first attempt to restore the
minimal amount of state necessary to execute the host kernel with
restore_sysregs.

However, the SP is restored as part of restore_common_regs, and so we
may return to the host's panic() function with the SP of the guest. Any
calculations based on the SP will be bogus, and any attempt to access
the stack will result in recursive data aborts.

When running Linux as a guest, the guest's EL1N SP is like to be some
valid kernel address. In this case, the host kernel may use that region
as a stack for panic(), corrupting it in the process.

Avoid the problem by restoring the host SP prior to returning to the
host. To prevent misleading backtraces in the host, the FP is zeroed at
the same time. We don't need any of the other "common" registers in
order to panic successfully.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: <kvmarm@lists.cs.columbia.edu>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22 23:01:48 +02:00