This renames the kvm->arch.hpte_setup_done field to mmu_ready because
we will want to use it for radix guests too -- both for setting things
up before vcpu execution, and for excluding vcpus from executing while
MMU-related things get changed, such as in future switching the MMU
from radix to HPT mode or vice-versa.
This also moves the call to kvmppc_setup_partition_table() that was
done in kvmppc_hv_setup_htab_rma() for HPT guests, and the setting
of mmu_ready, into the caller in kvmppc_vcpu_run_hv().
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This removes the dependence of KVM on the mmu_psize_defs array (which
stores information about hardware support for various page sizes) and
the things derived from it, chiefly hpte_page_sizes[], hpte_page_size(),
hpte_actual_page_size() and get_sllp_encoding(). We also no longer
rely on the mmu_slb_size variable or the MMU_FTR_1T_SEGMENTS feature
bit.
The reason for doing this is so we can support a HPT guest on a radix
host. In a radix host, the mmu_psize_defs array contains information
about page sizes supported by the MMU in radix mode rather than the
page sizes supported by the MMU in HPT mode. Similarly, mmu_slb_size
and the MMU_FTR_1T_SEGMENTS bit are not set.
Instead we hard-code knowledge of the behaviour of the HPT MMU in the
POWER7, POWER8 and POWER9 processors (which are the only processors
supported by HV KVM) - specifically the encoding of the LP fields in
the HPT and SLB entries, and the fact that they have 32 SLB entries
and support 1TB segments.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This merges in the ppc-kvm topic branch of the powerpc tree to get the
commit that reverts the patch "KVM: PPC: Book3S HV: POWER9 does not
require secondary thread management". This is needed for subsequent
patches which will be applied on this branch.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This fixes the message:
arch/powerpc/kvm/book3s_segment.S: Assembler messages:
arch/powerpc/kvm/book3s_segment.S:330: Warning: invalid register expression
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Userland passes an array of 64 SLB descriptors to KVM_SET_SREGS,
some of which are valid (ie, SLB_ESID_V is set) and the rest are
likely all-zeroes (with QEMU at least).
Each of them is then passed to kvmppc_mmu_book3s_64_slbmte(), which
assumes to find the SLB index in the 3 lower bits of its rb argument.
When passed zeroed arguments, it happily overwrites the 0th SLB entry
with zeroes. This is exactly what happens while doing live migration
with QEMU when the destination pushes the incoming SLB descriptors to
KVM PR. When reloading the SLBs at the next synchronization, QEMU first
clears its SLB array and only restore valid ones, but the 0th one is
now gone and we cannot access the corresponding memory anymore:
(qemu) x/x $pc
c0000000000b742c: Cannot access memory
To avoid this, let's filter out non-valid SLB entries. While here, we
also force a full SLB flush before installing new entries. Since SLB
is for 64-bit only, we now build this path conditionally to avoid a
build break on 32-bit, which doesn't define SLB_ESID_V.
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
When running a guest on a POWER9 system with the in-kernel XICS
emulation disabled (for example by running QEMU with the parameter
"-machine pseries,kernel_irqchip=off"), the kernel does not pass
the XICS-related hypercalls such as H_CPPR up to userspace for
emulation there as it should.
The reason for this is that the real-mode handlers for these
hypercalls don't check whether a XICS device has been instantiated
before calling the xics-on-xive code. That code doesn't check
either, leading to potential NULL pointer dereferences because
vcpu->arch.xive_vcpu is NULL. Those dereferences won't cause an
exception in real mode but will lead to kernel memory corruption.
This fixes it by adding kvmppc_xics_enabled() checks before calling
the XICS functions.
Cc: stable@vger.kernel.org # v4.11+
Fixes: 5af5099385 ("KVM: PPC: Book3S HV: Native usage of the XIVE interrupt controller")
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Currently we use CPU_FTR_TM to decide if the CPU/kernel can support
TM (Transactional Memory), and if it's true we advertise that to
Qemu (or similar) via KVM_CAP_PPC_HTM.
PPC_FEATURE2_HTM is the user-visible feature bit, which indicates that
the CPU and kernel can support TM. Currently CPU_FTR_TM and
PPC_FEATURE2_HTM always have the same value, either true or false, so
using the former for KVM_CAP_PPC_HTM is correct.
However some Power9 CPUs can operate in a mode where TM is enabled but
TM suspended state is disabled. In this mode CPU_FTR_TM is true, but
PPC_FEATURE2_HTM is false. Instead a different PPC_FEATURE2 bit is
set, to indicate that this different mode of TM is available.
It is not safe to let guests use TM as-is, when the CPU is in this
mode. So to prevent that from happening, use PPC_FEATURE2_HTM to
determine the value of KVM_CAP_PPC_HTM.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This reverts commit 94a04bc25a.
In order to run HPT guests on a radix POWER9 host, we will have to run
the host in single-threaded mode, because POWER9 processors do not
currently support running some threads of a core in HPT mode while
others are in radix mode ("mixed mode").
That means that we will need the same mechanisms that are used on
POWER8 to make the secondary threads available to KVM, which were
disabled on POWER9 by commit 94a04bc25a.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This adds code to make sure that we don't try to access the
non-existent HPT for a radix guest using the htab file for the VM
in debugfs, a file descriptor obtained using the KVM_PPC_GET_HTAB_FD
ioctl, or via the KVM_PPC_RESIZE_HPT_{PREPARE,COMMIT} ioctls.
At present nothing bad happens if userspace does access these
interfaces on a radix guest, mostly because kvmppc_hpt_npte()
gives 0 for a radix guest, which in turn is because 1 << -4
comes out as 0 on POWER processors. However, that relies on
undefined behaviour, so it is better to be explicit about not
accessing the HPT for a radix guest.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The handlers support PR KVM from the day one; however the PR KVM's
enable/disable hcalls handler missed these ones.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Omit an extra message for a memory allocation failure in this function.
This issue was detected by using the Coccinelle software.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Use vma_pages function on vma object instead of explicit computation.
Found by coccinelle spatch "api/vma_pages.cocci"
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Use ARRAY_SIZE macro, rather than explicitly coding some variant of it
yourself.
Found with: find -type f -name "*.c" -o -name "*.h" | xargs perl -p -i -e
's/\bsizeof\s*\(\s*(\w+)\s*\)\s*\ /\s*sizeof\s*\(\s*\1\s*\[\s*0\s*\]\s*\)
/ARRAY_SIZE(\1)/g' and manual check/verification.
Signed-off-by: Thomas Meyer <thomas@m3y3r.de>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
At present, if an interrupt (i.e. an exception or trap) occurs in the
code where KVM is switching the MMU to or from guest context, we jump
to kvmppc_bad_host_intr, where we simply spin with interrupts disabled.
In this situation, it is hard to debug what happened because we get no
indication as to which interrupt occurred or where. Typically we get
a cascade of stall and soft lockup warnings from other CPUs.
In order to get more information for debugging, this adds code to
create a stack frame on the emergency stack and save register values
to it. We start half-way down the emergency stack in order to give
ourselves some chance of being able to do a stack trace on secondary
threads that are already on the emergency stack.
On POWER7 or POWER8, we then just spin, as before, because we don't
know what state the MMU context is in or what other threads are doing,
and we can't switch back to host context without coordinating with
other threads. On POWER9 we can do better; there we load up the host
MMU context and jump to C code, which prints an oops message to the
console and panics.
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
The x86 MMU if full of code that returns 0 and 1 for retry/emulate. Use
the existing RET_MMIO_PF_RETRY/RET_MMIO_PF_EMULATE enum, renaming it to
drop the MMIO part.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Entering SMM while running in guest mode wasn't working very well because several
pieces of the vcpu state were left set up for nested operation.
Some of the issues observed:
* L1 was getting unexpected VM exits (using L1 interception controls but running
in SMM execution environment)
* MMU was confused (walk_mmu was still set to nested_mmu)
* INTERCEPT_SMI was not emulated for L1 (KVM never injected SVM_EXIT_SMI)
Intel SDM actually prescribes the logical processor to "leave VMX operation" upon
entering SMM in 34.14.1 Default Treatment of SMI Delivery. AMD doesn't seem to
document this but they provide fields in the SMM state-save area to stash the
current state of SVM. What we need to do is basically get out of guest mode for
the duration of SMM. All this completely transparent to L1, i.e. L1 is not given
control and no L1 observable state changes.
To avoid code duplication this commit takes advantage of the existing nested
vmexit and run functionality, perhaps at the cost of efficiency. To get out of
guest mode, nested_svm_vmexit is called, unchanged. Re-entering is performed using
enter_svm_guest_mode.
This commit fixes running Windows Server 2016 with Hyper-V enabled in a VM with
OVMF firmware (OVMF_CODE-need-smm.fd).
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Analogous to 858e25c06f ("kvm: nVMX: Refactor nested_vmx_run()"), this commit splits
nested_svm_vmrun into two parts. The newly introduced enter_svm_guest_mode modifies the
vcpu state to transition from L1 to L2, while the code left in nested_svm_vmrun handles
the VMRUN instruction.
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Entering SMM while running in guest mode wasn't working very well because several
pieces of the vcpu state were left set up for nested operation.
Some of the issues observed:
* L1 was getting unexpected VM exits (using L1 interception controls but running
in SMM execution environment)
* SMM handler couldn't write to vmx_set_cr4 because of incorrect validity checks
predicated on nested.vmxon
* MMU was confused (walk_mmu was still set to nested_mmu)
Intel SDM actually prescribes the logical processor to "leave VMX operation" upon
entering SMM in 34.14.1 Default Treatment of SMI Delivery. What we need to do is
basically get out of guest mode and set nested.vmxon to false for the duration of
SMM. All this completely transparent to L1, i.e. L1 is not given control and no
L1 observable state changes.
To avoid code duplication this commit takes advantage of the existing nested
vmexit and run functionality, perhaps at the cost of efficiency. To get out of
guest mode, nested_vmx_vmexit with exit_reason == -1 is called, a trick already
used in vmx_leave_nested. Re-entering is cleaner, using enter_vmx_non_root_mode.
This commit fixes running Windows Server 2016 with Hyper-V enabled in a VM with
OVMF firmware (OVMF_CODE-need-smm.fd).
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Intel SDM 27.5.2 Loading Host Segment and Descriptor-Table Registers:
"The GDTR and IDTR limits are each set to FFFFH."
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Similar to NMI, there may be ISA specific reasons why an SMI cannot be
injected into the guest. This commit adds a new smi_allowed callback to
be implemented in following commits.
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Entering and exiting SMM may require ISA specific handling under certain
circumstances. This commit adds two new callbacks with empty implementations.
Actual functionality will be added in following commits.
* pre_enter_smm() is to be called when injecting an SMM, before any
SMM related vcpu state has been changed
* pre_leave_smm() is to be called when emulating the RSM instruction,
when the vcpu is in real mode and before any SMM related vcpu state
has been restored
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
It has always annoyed me a bit how SVM_EXIT_NPF is handled by
pf_interception. This is also the only reason behind the
under-documented need_unprotect argument to kvm_handle_page_fault.
Let NPF go straight to kvm_mmu_page_fault, just like VMX
does in handle_ept_violation and handle_ept_misconfig.
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Checking the mode is unnecessary, and is done without a memory barrier
separating the LAPIC write from the vcpu->mode read; in addition,
kvm_vcpu_wake_up is already doing a check for waiters on the wait queue
that has the same effect.
In practice it's safe because spin_lock has full-barrier semantics on x86,
but don't be too clever.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove redundant null checks before calling kmem_cache_destroy.
Found with make coccicheck M=arch/x86/kvm on linux-next tag
next-20170929.
Signed-off-by: Tim Hansen <devtimhansen@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
SDM mentioned:
"If either the “unrestricted guest†VM-execution control or the “mode-based
execute control for EPT†VM- execution control is 1, the “enable EPTâ€
VM-execution control must also be 1."
However, we can still observe unrestricted_guest is Y after inserting the kvm-intel.ko
w/ ept=N. It depends on later starts a guest in order that the function
vmx_compute_secondary_exec_control() can be executed, then both the module parameter
and exec control fields will be amended.
This patch fixes it by amending module parameter immediately during vmcs data setup.
Reviewed-by: Jim Mattson <jmattson@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Jim Mattson <jmattson@google.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- XCR0 is reset to 1 by RESET but not INIT
- XSS is zeroed by both RESET and INIT
- BNDCFGU, BND0-BND3, BNDCFGS, BNDSTATUS are zeroed by both RESET and INIT
This patch does this according to SDM.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Jim Mattson <jmattson@google.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Our routines look at tscdeadline and period when deciding state of a
timer. The timer is disarmed when switching between TSC deadline and
other modes, so we should set everything to disarmed state.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
preemption timer only looks at tscdeadline and could inject already
disarmed timer.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
0 should disable the timer, but start_hv_timer will recognize it as an
expired timer instead.
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The kvm slabs can consume a significant amount of system memory
and indeed in our production environment we have observed that
a lot of machines are spending significant amount of memory that
can not be left as system memory overhead. Also the allocations
from these slabs can be triggered directly by user space applications
which has access to kvm and thus a buggy application can leak
such memory. So, these caches should be accounted to kmemcg.
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Let's just name these according to the SDM. This should make it clearer
that the are used to enable exiting and not the feature itself.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Changing it afterwards doesn't make too much sense and will only result
in inconsistencies.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Setting it to 0 leads to setting it to the default value, let's document
this.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
No need for another enable_ept check. kvm->arch.ept_identity_map_addr
only has to be inititalized once. Having alloc_identity_pagetable() is
overkill and dropping BUG_ONs is always nice.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
They are inititally 0, so no need to reset them to 0.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
vcpu->cpu is not cleared when doing a vmx_vcpu_put/load, so this can be
dropped.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Without this, we won't be able to do any flushes, so let's just require
it. Should be absent in very strange configurations.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
ept_* function should only be called with enable_ept being set.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
This function is only called with enable_ept.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
vmx and svm use zalloc, so this is not necessary.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Make it a void and drop error handling code.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
And also get rid of that superfluous local variable "kvm".
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Let's just drop the return.
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
The description in the Intel SDM of how the divide configuration
register is used: "The APIC timer frequency will be the processor's bus
clock or core crystal clock frequency divided by the value specified in
the divide configuration register."
Observation of baremetal shown that when the TDCR is change, the TMCCT
does not change or make a big jump in value, but the rate at which it
count down change.
The patch update the emulation to APIC timer to so that a change to the
divide configuration would be reflected in the value of the counter and
when the next interrupt is triggered.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
[Fixed some whitespace and added a check for negative delta and running
timer. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
If we take TSC-deadline mode timer out of the picture, the Intel SDM
does not say that the timer is disable when the timer mode is change,
either from one-shot to periodic or vice versa.
After this patch, the timer is no longer disarmed on change of mode, so
the counter (TMCCT) keeps counting down.
So what does a write to LVTT changes ? On baremetal, the change of mode
is probably taken into account only when the counter reach 0. When this
happen, LVTT is use to figure out if the counter should restard counting
down from TMICT (so periodic mode) or stop counting (if one-shot mode).
This patch is based on observation of the behavior of the APIC timer on
baremetal as well as check that they does not go against the description
written in the Intel SDM.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
[Fixed rate limiting of periodic timer.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Extract the logic of limit lapic periodic timer frequency to a new function,
this function will be used by later patches.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
SDM 10.5.4.1 TSC-Deadline Mode mentioned that "Transitioning between TSC-Deadline
mode and other timer modes also disarms the timer". So the APIC Timer Initial Count
Register for one-shot/periodic mode should be reset. This patch do it.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
[Removed unnecessary definition of APIC_LVT_TIMER_MASK.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Make kvm_stat support Python 3 by changing the use of "print" to a
function rather than a statement, switching from "iteritems" and
"iterkeys" (removed in Python 3) to "items" and "keys" respectively,
and decoding bytes to strings when dealing with text.
With this change, kvm_stat is usable with Python 2.6 and greater.
Signed-off-by: Jeremy Cline <jeremy@jcline.org>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Paul Mackerras