Mikhail reported the following lockdep splat:
WARNING: possible irq lock inversion dependency detected
CPU 0/KVM/10284 just changed the state of lock:
000000000d538a88 (&st->lock){+...}, at:
speculative_store_bypass_update+0x10b/0x170
but this lock was taken by another, HARDIRQ-safe lock
in the past:
(&(&sighand->siglock)->rlock){-.-.}
and interrupts could create inverse lock ordering between them.
Possible interrupt unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&st->lock);
local_irq_disable();
lock(&(&sighand->siglock)->rlock);
lock(&st->lock);
<Interrupt>
lock(&(&sighand->siglock)->rlock);
*** DEADLOCK ***
The code path which connects those locks is:
speculative_store_bypass_update()
ssb_prctl_set()
do_seccomp()
do_syscall_64()
In svm_vcpu_run() speculative_store_bypass_update() is called with
interupts enabled via x86_virt_spec_ctrl_set_guest/host().
This is actually a false positive, because GIF=0 so interrupts are
disabled even if IF=1; however, we can easily move the invocations of
x86_virt_spec_ctrl_set_guest/host() into the interrupt disabled region to
cure it, and it's a good idea to keep the GIF=0/IF=1 area as small
and self-contained as possible.
Fixes: 1f50ddb4f4 ("x86/speculation: Handle HT correctly on AMD")
Reported-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: kvm@vger.kernel.org
Cc: x86@kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This needs a minor bug fix. The updated patch is as follows.
Thanks,
Junaid
------------------------------------------------------------------------------
kvm_mmu_invlpg() and kvm_mmu_invpcid_gva() only need to flush the TLB
entries for the specific guest virtual address, instead of flushing all
TLB entries associated with the VM.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove the implicit flush from the set_cr3 handlers, so that the
callers are able to decide whether to flush the TLB or not.
Signed-off-by: Junaid Shahid <junaids@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- Additional struct_size() conversions (Matthew, Kees)
- Explicitly reported overflow fixes (Silvio, Kees)
- Add missing kvcalloc() function (Kees)
- Treewide conversions of allocators to use either 2-factor argument
variant when available, or array_size() and array3_size() as needed (Kees)
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Merge tag 'overflow-v4.18-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull more overflow updates from Kees Cook:
"The rest of the overflow changes for v4.18-rc1.
This includes the explicit overflow fixes from Silvio, further
struct_size() conversions from Matthew, and a bug fix from Dan.
But the bulk of it is the treewide conversions to use either the
2-factor argument allocators (e.g. kmalloc(a * b, ...) into
kmalloc_array(a, b, ...) or the array_size() macros (e.g. vmalloc(a *
b) into vmalloc(array_size(a, b)).
Coccinelle was fighting me on several fronts, so I've done a bunch of
manual whitespace updates in the patches as well.
Summary:
- Error path bug fix for overflow tests (Dan)
- Additional struct_size() conversions (Matthew, Kees)
- Explicitly reported overflow fixes (Silvio, Kees)
- Add missing kvcalloc() function (Kees)
- Treewide conversions of allocators to use either 2-factor argument
variant when available, or array_size() and array3_size() as needed
(Kees)"
* tag 'overflow-v4.18-rc1-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (26 commits)
treewide: Use array_size in f2fs_kvzalloc()
treewide: Use array_size() in f2fs_kzalloc()
treewide: Use array_size() in f2fs_kmalloc()
treewide: Use array_size() in sock_kmalloc()
treewide: Use array_size() in kvzalloc_node()
treewide: Use array_size() in vzalloc_node()
treewide: Use array_size() in vzalloc()
treewide: Use array_size() in vmalloc()
treewide: devm_kzalloc() -> devm_kcalloc()
treewide: devm_kmalloc() -> devm_kmalloc_array()
treewide: kvzalloc() -> kvcalloc()
treewide: kvmalloc() -> kvmalloc_array()
treewide: kzalloc_node() -> kcalloc_node()
treewide: kzalloc() -> kcalloc()
treewide: kmalloc() -> kmalloc_array()
mm: Introduce kvcalloc()
video: uvesafb: Fix integer overflow in allocation
UBIFS: Fix potential integer overflow in allocation
leds: Use struct_size() in allocation
Convert intel uncore to struct_size
...
* ARM: lazy context-switching of FPSIMD registers on arm64, "split"
regions for vGIC redistributor
* s390: cleanups for nested, clock handling, crypto, storage keys and
control register bits
* x86: many bugfixes, implement more Hyper-V super powers,
implement lapic_timer_advance_ns even when the LAPIC timer
is emulated using the processor's VMX preemption timer. Two
security-related bugfixes at the top of the branch.
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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 update for KVM:
ARM:
- lazy context-switching of FPSIMD registers on arm64
- "split" regions for vGIC redistributor
s390:
- cleanups for nested
- clock handling
- crypto
- storage keys
- control register bits
x86:
- many bugfixes
- implement more Hyper-V super powers
- implement lapic_timer_advance_ns even when the LAPIC timer is
emulated using the processor's VMX preemption timer.
- two security-related bugfixes at the top of the branch"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (79 commits)
kvm: fix typo in flag name
kvm: x86: use correct privilege level for sgdt/sidt/fxsave/fxrstor access
KVM: x86: pass kvm_vcpu to kvm_read_guest_virt and kvm_write_guest_virt_system
KVM: x86: introduce linear_{read,write}_system
kvm: nVMX: Enforce cpl=0 for VMX instructions
kvm: nVMX: Add support for "VMWRITE to any supported field"
kvm: nVMX: Restrict VMX capability MSR changes
KVM: VMX: Optimize tscdeadline timer latency
KVM: docs: nVMX: Remove known limitations as they do not exist now
KVM: docs: mmu: KVM support exposing SLAT to guests
kvm: no need to check return value of debugfs_create functions
kvm: Make VM ioctl do valloc for some archs
kvm: Change return type to vm_fault_t
KVM: docs: mmu: Fix link to NPT presentation from KVM Forum 2008
kvm: x86: Amend the KVM_GET_SUPPORTED_CPUID API documentation
KVM: x86: hyperv: declare KVM_CAP_HYPERV_TLBFLUSH capability
KVM: x86: hyperv: simplistic HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE}_EX implementation
KVM: x86: hyperv: simplistic HVCALL_FLUSH_VIRTUAL_ADDRESS_{LIST,SPACE} implementation
KVM: introduce kvm_make_vcpus_request_mask() API
KVM: x86: hyperv: do rep check for each hypercall separately
...
The AMD document outlining the SSBD handling
124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf
mentions that if CPUID 8000_0008.EBX[24] is set we should be using
the SPEC_CTRL MSR (0x48) over the VIRT SPEC_CTRL MSR (0xC001_011f)
for speculative store bypass disable.
This in effect means we should clear the X86_FEATURE_VIRT_SSBD
flag so that we would prefer the SPEC_CTRL MSR.
See the document titled:
124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf
A copy of this document is available at
https://bugzilla.kernel.org/show_bug.cgi?id=199889
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Janakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Cc: kvm@vger.kernel.org
Cc: KarimAllah Ahmed <karahmed@amazon.de>
Cc: andrew.cooper3@citrix.com
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20180601145921.9500-3-konrad.wilk@oracle.com
The kvm struct has been bloating. For example, it's tens of kilo-bytes
for x86, which turns out to be a large amount of memory to allocate
contiguously via kzalloc. Thus, this patch does the following:
1. Uses architecture-specific routines to allocate the kvm struct via
vzalloc for x86.
2. Switches arm to __KVM_HAVE_ARCH_VM_ALLOC so that it can use vzalloc
when has_vhe() is true.
Other architectures continue to default to kalloc, as they have a
dependency on kalloc or have a small-enough struct kvm.
Signed-off-by: Marc Orr <marcorr@google.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This is a fix from reviewing the code, but it looks like it might be
able to lead to an Oops. It affects 32bit systems.
The KVM_MEMORY_ENCRYPT_REG_REGION ioctl uses a u64 for range->addr and
range->size but the high 32 bits would be truncated away on a 32 bit
system. This is harmless but it's also harmless to prevent it.
Then in sev_pin_memory() the "uaddr + ulen" calculation can wrap around.
The wrap around can happen on 32 bit or 64 bit systems, but I was only
able to figure out a problem for 32 bit systems. We would pick a number
which results in "npages" being zero. The sev_pin_memory() would then
return ZERO_SIZE_PTR without allocating anything.
I made it illegal to call sev_pin_memory() with "ulen" set to zero.
Hopefully, that doesn't cause any problems. I also changed the type of
"first" and "last" to long, just for cosmetic reasons. Otherwise on a
64 bit system you're saving "uaddr >> 12" in an int and it truncates the
high 20 bits away. The math works in the current code so far as I can
see but it's just weird.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[Brijesh noted that the code is only reachable on X86_64.]
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Expose the new virtualized architectural mechanism, VIRT_SSBD, for using
speculative store bypass disable (SSBD) under SVM. This will allow guests
to use SSBD on hardware that uses non-architectural mechanisms for enabling
SSBD.
[ tglx: Folded the migration fixup from Paolo Bonzini ]
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
AMD is proposing a VIRT_SPEC_CTRL MSR to handle the Speculative Store
Bypass Disable via MSR_AMD64_LS_CFG so that guests do not have to care
about the bit position of the SSBD bit and thus facilitate migration.
Also, the sibling coordination on Family 17H CPUs can only be done on
the host.
Extend x86_spec_ctrl_set_guest() and x86_spec_ctrl_restore_host() with an
extra argument for the VIRT_SPEC_CTRL MSR.
Hand in 0 from VMX and in SVM add a new virt_spec_ctrl member to the CPU
data structure which is going to be used in later patches for the actual
implementation.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Intel and AMD have different CPUID bits hence for those use synthetic bits
which get set on the respective vendor's in init_speculation_control(). So
that debacles like what the commit message of
c65732e4f7 ("x86/cpu: Restore CPUID_8000_0008_EBX reload")
talks about don't happen anymore.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Jörg Otte <jrg.otte@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: https://lkml.kernel.org/r/20180504161815.GG9257@pd.tnic
svm_vcpu_run() invokes x86_spec_ctrl_restore_host() after VMEXIT, but
before the host GS is restored. x86_spec_ctrl_restore_host() uses 'current'
to determine the host SSBD state of the thread. 'current' is GS based, but
host GS is not yet restored and the access causes a triple fault.
Move the call after the host GS restore.
Fixes: 885f82bfbc x86/process: Allow runtime control of Speculative Store Bypass
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Previously, we toggled between SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE
and SECONDARY_EXEC_VIRTUALIZE_APIC_ACCESSES, depending on whether or
not the EXTD bit was set in MSR_IA32_APICBASE. However, if the local
APIC is disabled, we should not set either of these APIC
virtualization control bits.
Signed-off-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Having everything in nospec-branch.h creates a hell of dependencies when
adding the prctl based switching mechanism. Move everything which is not
required in nospec-branch.h to spec-ctrl.h and fix up the includes in the
relevant files.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
A guest may modify the SPEC_CTRL MSR from the value used by the
kernel. Since the kernel doesn't use IBRS, this means a value of zero is
what is needed in the host.
But the 336996-Speculative-Execution-Side-Channel-Mitigations.pdf refers to
the other bits as reserved so the kernel should respect the boot time
SPEC_CTRL value and use that.
This allows to deal with future extensions to the SPEC_CTRL interface if
any at all.
Note: This uses wrmsrl() instead of native_wrmsl(). I does not make any
difference as paravirt will over-write the callq *0xfff.. with the wrmsrl
assembler code.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
writing nested virtualization tests.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
"Bug fixes, plus a new test case and the associated infrastructure for
writing nested virtualization tests"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
kvm: selftests: add vmx_tsc_adjust_test
kvm: x86: move MSR_IA32_TSC handling to x86.c
X86/KVM: Properly update 'tsc_offset' to represent the running guest
kvm: selftests: add -std=gnu99 cflags
x86: Add check for APIC access address for vmentry of L2 guests
KVM: X86: fix incorrect reference of trace_kvm_pi_irte_update
X86/KVM: Do not allow DISABLE_EXITS_MWAIT when LAPIC ARAT is not available
kvm: selftests: fix spelling mistake: "divisable" and "divisible"
X86/VMX: Disable VMX preemption timer if MWAIT is not intercepted
Update 'tsc_offset' on vmentry/vmexit of L2 guests to ensure that it always
captures the TSC_OFFSET of the running guest whether it is the L1 or L2
guest.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Jim Mattson <jmattson@google.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
[AMD changes, fix update_ia32_tsc_adjust_msr. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In arch/x86/kvm/trace.h, this function is declared as host_irq the
first input, and vcpu_id the second, instead of otherwise.
Signed-off-by: hu huajun <huhuajun@linux.alibaba.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
- VHE optimizations
- EL2 address space randomization
- speculative execution mitigations ("variant 3a", aka execution past invalid
privilege register access)
- bugfixes and cleanups
PPC:
- improvements for the radix page fault handler for HV KVM on POWER9
s390:
- more kvm stat counters
- virtio gpu plumbing
- documentation
- facilities improvements
x86:
- support for VMware magic I/O port and pseudo-PMCs
- AMD pause loop exiting
- support for AMD core performance extensions
- support for synchronous register access
- expose nVMX capabilities to userspace
- support for Hyper-V signaling via eventfd
- use Enlightened VMCS when running on Hyper-V
- allow userspace to disable MWAIT/HLT/PAUSE vmexits
- usual roundup of optimizations and nested virtualization bugfixes
Generic:
- API selftest infrastructure (though the only tests are for x86 as of now)
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
"ARM:
- VHE optimizations
- EL2 address space randomization
- speculative execution mitigations ("variant 3a", aka execution past
invalid privilege register access)
- bugfixes and cleanups
PPC:
- improvements for the radix page fault handler for HV KVM on POWER9
s390:
- more kvm stat counters
- virtio gpu plumbing
- documentation
- facilities improvements
x86:
- support for VMware magic I/O port and pseudo-PMCs
- AMD pause loop exiting
- support for AMD core performance extensions
- support for synchronous register access
- expose nVMX capabilities to userspace
- support for Hyper-V signaling via eventfd
- use Enlightened VMCS when running on Hyper-V
- allow userspace to disable MWAIT/HLT/PAUSE vmexits
- usual roundup of optimizations and nested virtualization bugfixes
Generic:
- API selftest infrastructure (though the only tests are for x86 as
of now)"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (174 commits)
kvm: x86: fix a prototype warning
kvm: selftests: add sync_regs_test
kvm: selftests: add API testing infrastructure
kvm: x86: fix a compile warning
KVM: X86: Add Force Emulation Prefix for "emulate the next instruction"
KVM: X86: Introduce handle_ud()
KVM: vmx: unify adjacent #ifdefs
x86: kvm: hide the unused 'cpu' variable
KVM: VMX: remove bogus WARN_ON in handle_ept_misconfig
Revert "KVM: X86: Fix SMRAM accessing even if VM is shutdown"
kvm: Add emulation for movups/movupd
KVM: VMX: raise internal error for exception during invalid protected mode state
KVM: nVMX: Optimization: Dont set KVM_REQ_EVENT when VMExit with nested_run_pending
KVM: nVMX: Require immediate-exit when event reinjected to L2 and L1 event pending
KVM: x86: Fix misleading comments on handling pending exceptions
KVM: x86: Rename interrupt.pending to interrupt.injected
KVM: VMX: No need to clear pending NMI/interrupt on inject realmode interrupt
x86/kvm: use Enlightened VMCS when running on Hyper-V
x86/hyper-v: detect nested features
x86/hyper-v: define struct hv_enlightened_vmcs and clean field bits
...
Introduce handle_ud() to handle invalid opcode, this function will be
used by later patches.
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim KrÄmář <rkrcmar@redhat.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Bring the PLE(pause loop exit) logic to AMD svm driver.
While testing, we found this helping in situations where numerous
pauses are generated. Without these patches we could see continuos
VMEXITS due to pause interceptions. Tested it on AMD EPYC server with
boot parameter idle=poll on a VM with 32 vcpus to simulate extensive
pause behaviour. Here are VMEXITS in 10 seconds interval.
Pauses 810199 504
Total 882184 325415
Signed-off-by: Babu Moger <babu.moger@amd.com>
[Prevented the window from dropping below the initial value. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
This patch adds the support for pause filtering threshold. This feature
support is indicated by CPUID Fn8000_000A_EDX. See AMD APM Vol 2 Section
15.14.4 Pause Intercept Filtering for more details.
In this mode, a 16-bit pause filter threshold field is added in VMCB.
The threshold value is a cycle count that is used to reset the pause
counter. As with simple pause filtering, VMRUN loads the pause count
value from VMCB into an internal counter. Then, on each pause instruction
the hardware checks the elapsed number of cycles since the most recent
pause instruction against the pause Filter Threshold. If the elapsed cycle
count is greater than the pause filter threshold, then the internal pause
count is reloaded from VMCB and execution continues. If the elapsed cycle
count is less than the pause filter threshold, then the internal pause
count is decremented. If the count value is less than zero and pause
intercept is enabled, a #VMEXIT is triggered. If advanced pause filtering
is supported and pause filter threshold field is set to zero, the filter
will operate in the simpler, count only mode.
Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
KVM and perf have a special backdoor mechanism to report the IP for interrupts
re-executed after vm exit. This works for the NMIs that perf normally uses.
However when perf is in timer mode it doesn't work because the timer interrupt
doesn't get this special treatment. This is common when KVM is running
nested in another hypervisor which may not implement the PMU, so only
timer mode is available.
Call the functions to set up the backdoor IP also for non NMI interrupts.
I renamed the functions to set up the backdoor IP reporting to be more
appropiate for their new use. The SVM change is only compile tested.
v2: Moved the functions inline.
For the normal interrupt case the before/after functions are now
called from x86.c, not arch specific code.
For the NMI case we still need to call it in the architecture
specific code, because it's already needed in the low level *_run
functions.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
[Removed unnecessary calls from arch handle_external_intr. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Add struct kvm_svm, which is analagous to struct vcpu_svm, along with
a helper to_kvm_svm() to retrieve kvm_svm from a struct kvm *. Move
the SVM specific variables and struct definitions out of kvm_arch
and into kvm_svm.
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add kvm_x86_ops->set_identity_map_addr and set ept_identity_map_addr
in VMX specific code so that ept_identity_map_addr can be moved out
of 'struct kvm_arch' in a future patch.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Define kvm_arch_[alloc|free]_vm in x86 as pass through functions
to new kvm_x86_ops vm_alloc and vm_free, and move the current
allocation logic as-is to SVM and VMX. Vendor specific alloc/free
functions set the stage for SVM/VMX wrappers of 'struct kvm',
which will allow us to move the growing number of SVM/VMX specific
member variables out of 'struct kvm_arch'.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Allow to disable pause loop exit/pause filtering on a per VM basis.
If some VMs have dedicated host CPUs, they won't be negatively affected
due to needlessly intercepted PAUSE instructions.
Thanks to Jan H. Schönherr's initial patch.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If host CPUs are dedicated to a VM, we can avoid VM exits on HLT.
This patch adds the per-VM capability to disable them.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Allowing a guest to execute MWAIT without interception enables a guest
to put a (physical) CPU into a power saving state, where it takes
longer to return from than what may be desired by the host.
Don't give a guest that power over a host by default. (Especially,
since nothing prevents a guest from using MWAIT even when it is not
advertised via CPUID.)
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
If KVM enable_vmware_backdoor module parameter is set,
the commit change VMX to now intercept #GP instead of being directly
deliviered from CPU to guest.
It is done to support access to VMware Backdoor I/O ports
even if TSS I/O permission denies it.
In that case:
1. A #GP will be raised and intercepted.
2. #GP intercept handler will simulate I/O port access instruction.
3. I/O port access instruction simulation will allow access to VMware
backdoor ports specifically even if TSS I/O permission bitmap denies it.
Note that the above change introduce slight performance hit as now #GPs
are now not deliviered directly from CPU to guest but instead
cause #VMExit and instruction emulation.
However, this behavior is introduced only when enable_vmware_backdoor
KVM module parameter is set.
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Add kvm_fast_pio() to consolidate duplicate code in VMX and SVM.
Unexport kvm_fast_pio_in() and kvm_fast_pio_out().
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
x86:
- fix NULL dereference when using userspace lapic
- optimize spectre v1 mitigations by allowing guests to use LFENCE
- make microcode revision configurable to prevent guests from
unnecessarily blacklisting spectre v2 mitigation features
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Radim Krčmář:
"x86:
- fix NULL dereference when using userspace lapic
- optimize spectre v1 mitigations by allowing guests to use LFENCE
- make microcode revision configurable to prevent guests from
unnecessarily blacklisting spectre v2 mitigation feature"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: fix vcpu initialization with userspace lapic
KVM: X86: Allow userspace to define the microcode version
KVM: X86: Introduce kvm_get_msr_feature()
KVM: SVM: Add MSR-based feature support for serializing LFENCE
KVM: x86: Add a framework for supporting MSR-based features
Linux (among the others) has checks to make sure that certain features
aren't enabled on a certain family/model/stepping if the microcode version
isn't greater than or equal to a known good version.
By exposing the real microcode version, we're preventing buggy guests that
don't check that they are running virtualized (i.e., they should trust the
hypervisor) from disabling features that are effectively not buggy.
Suggested-by: Filippo Sironi <sironi@amazon.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
In order to determine if LFENCE is a serializing instruction on AMD
processors, MSR 0xc0011029 (MSR_F10H_DECFG) must be read and the state
of bit 1 checked. This patch will add support to allow a guest to
properly make this determination.
Add the MSR feature callback operation to svm.c and add MSR 0xc0011029
to the list of MSR-based features. If LFENCE is serializing, then the
feature is supported, allowing the hypervisor to set the value of the
MSR that guest will see. Support is also added to write (hypervisor only)
and read the MSR value for the guest. A write by the guest will result in
a #GP. A read by the guest will return the value as set by the host. In
this way, the support to expose the feature to the guest is controlled by
the hypervisor.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Provide a new KVM capability that allows bits within MSRs to be recognized
as features. Two new ioctls are added to the /dev/kvm ioctl routine to
retrieve the list of these MSRs and then retrieve their values. A kvm_x86_ops
callback is used to determine support for the listed MSR-based features.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[Tweaked documentation. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Pull x86 fixes from Thomas Gleixner:
"Yet another pile of melted spectrum related changes:
- sanitize the array_index_nospec protection mechanism: Remove the
overengineered array_index_nospec_mask_check() magic and allow
const-qualified types as index to avoid temporary storage in a
non-const local variable.
- make the microcode loader more robust by properly propagating error
codes. Provide information about new feature bits after micro code
was updated so administrators can act upon.
- optimizations of the entry ASM code which reduce code footprint and
make the code simpler and faster.
- fix the {pmd,pud}_{set,clear}_flags() implementations to work
properly on paravirt kernels by removing the address translation
operations.
- revert the harmful vmexit_fill_RSB() optimization
- use IBRS around firmware calls
- teach objtool about retpolines and add annotations for indirect
jumps and calls.
- explicitly disable jumplabel patching in __init code and handle
patching failures properly instead of silently ignoring them.
- remove indirect paravirt calls for writing the speculation control
MSR as these calls are obviously proving the same attack vector
which is tried to be mitigated.
- a few small fixes which address build issues with recent compiler
and assembler versions"
* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits)
KVM/VMX: Optimize vmx_vcpu_run() and svm_vcpu_run() by marking the RDMSR path as unlikely()
KVM/x86: Remove indirect MSR op calls from SPEC_CTRL
objtool, retpolines: Integrate objtool with retpoline support more closely
x86/entry/64: Simplify ENCODE_FRAME_POINTER
extable: Make init_kernel_text() global
jump_label: Warn on failed jump_label patching attempt
jump_label: Explicitly disable jump labels in __init code
x86/entry/64: Open-code switch_to_thread_stack()
x86/entry/64: Move ASM_CLAC to interrupt_entry()
x86/entry/64: Remove 'interrupt' macro
x86/entry/64: Move the switch_to_thread_stack() call to interrupt_entry()
x86/entry/64: Move ENTER_IRQ_STACK from interrupt macro to interrupt_entry
x86/entry/64: Move PUSH_AND_CLEAR_REGS from interrupt macro to helper function
x86/speculation: Move firmware_restrict_branch_speculation_*() from C to CPP
objtool: Add module specific retpoline rules
objtool: Add retpoline validation
objtool: Use existing global variables for options
x86/mm/sme, objtool: Annotate indirect call in sme_encrypt_execute()
x86/boot, objtool: Annotate indirect jump in secondary_startup_64()
x86/paravirt, objtool: Annotate indirect calls
...
The SEV LAUNCH_SECRET command fails with error code 'invalid param'
because we missed filling the guest and header system physical address
while issuing the command.
Fixes: 9f5b5b950a (KVM: SVM: Add support for SEV LAUNCH_SECRET command)
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-kernel@vger.kernel.org
Cc: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
RSM instruction is used by the SMM handler to return from SMM mode.
Currently, rsm causes a #UD - which results in instruction fetch, decode,
and emulate. By installing the RSM intercept we can avoid the instruction
fetch since we know that #VMEXIT was due to rsm.
The patch is required for the SEV guest, because in case of SEV guest
memory is encrypted with guest-specific key and hypervisor will not
able to fetch the instruction bytes from the guest memory.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Using the access_ok() to validate the input before issuing the SEV
command does not buy us anything in this case. If userland is
giving us a garbage pointer then copy_to_user() will catch it when we try
to return the measurement.
Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Fixes: 0d0736f763 (KVM: SVM: Add support for KVM_SEV_LAUNCH_MEASURE ...)
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: linux-kernel@vger.kernel.org
Cc: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
vmx_vcpu_run() and svm_vcpu_run() are large functions, and giving
branch hints to the compiler can actually make a substantial cycle
difference by keeping the fast path contiguous in memory.
With this optimization, the retpoline-guest/retpoline-host case is
about 50 cycles faster.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: KarimAllah Ahmed <karahmed@amazon.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm@vger.kernel.org
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20180222154318.20361-3-pbonzini@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Having a paravirt indirect call in the IBRS restore path is not a
good idea, since we are trying to protect from speculative execution
of bogus indirect branch targets. It is also slower, so use
native_wrmsrl() on the vmentry path too.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: KarimAllah Ahmed <karahmed@amazon.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kvm@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: d28b387fb7
Link: http://lkml.kernel.org/r/20180222154318.20361-2-pbonzini@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
ARM:
- Include icache invalidation optimizations, improving VM startup time
- Support for forwarded level-triggered interrupts, improving
performance for timers and passthrough platform devices
- A small fix for power-management notifiers, and some cosmetic changes
PPC:
- Add MMIO emulation for vector loads and stores
- Allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
requiring the complex thread synchronization of older CPU versions
- Improve the handling of escalation interrupts with the XIVE interrupt
controller
- Support decrement register migration
- Various cleanups and bugfixes.
s390:
- Cornelia Huck passed maintainership to Janosch Frank
- Exitless interrupts for emulated devices
- Cleanup of cpuflag handling
- kvm_stat counter improvements
- VSIE improvements
- mm cleanup
x86:
- Hypervisor part of SEV
- UMIP, RDPID, and MSR_SMI_COUNT emulation
- Paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit
- Allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more AVX512
features
- Show vcpu id in its anonymous inode name
- Many fixes and cleanups
- Per-VCPU MSR bitmaps (already merged through x86/pti branch)
- Stable KVM clock when nesting on Hyper-V (merged through x86/hyperv)
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Merge tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Radim Krčmář:
"ARM:
- icache invalidation optimizations, improving VM startup time
- support for forwarded level-triggered interrupts, improving
performance for timers and passthrough platform devices
- a small fix for power-management notifiers, and some cosmetic
changes
PPC:
- add MMIO emulation for vector loads and stores
- allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without
requiring the complex thread synchronization of older CPU versions
- improve the handling of escalation interrupts with the XIVE
interrupt controller
- support decrement register migration
- various cleanups and bugfixes.
s390:
- Cornelia Huck passed maintainership to Janosch Frank
- exitless interrupts for emulated devices
- cleanup of cpuflag handling
- kvm_stat counter improvements
- VSIE improvements
- mm cleanup
x86:
- hypervisor part of SEV
- UMIP, RDPID, and MSR_SMI_COUNT emulation
- paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit
- allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more
AVX512 features
- show vcpu id in its anonymous inode name
- many fixes and cleanups
- per-VCPU MSR bitmaps (already merged through x86/pti branch)
- stable KVM clock when nesting on Hyper-V (merged through
x86/hyperv)"
* tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (197 commits)
KVM: PPC: Book3S: Add MMIO emulation for VMX instructions
KVM: PPC: Book3S HV: Branch inside feature section
KVM: PPC: Book3S HV: Make HPT resizing work on POWER9
KVM: PPC: Book3S HV: Fix handling of secondary HPTEG in HPT resizing code
KVM: PPC: Book3S PR: Fix broken select due to misspelling
KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs()
KVM: PPC: Book3S PR: Fix svcpu copying with preemption enabled
KVM: PPC: Book3S HV: Drop locks before reading guest memory
kvm: x86: remove efer_reload entry in kvm_vcpu_stat
KVM: x86: AMD Processor Topology Information
x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested
kvm: embed vcpu id to dentry of vcpu anon inode
kvm: Map PFN-type memory regions as writable (if possible)
x86/kvm: Make it compile on 32bit and with HYPYERVISOR_GUEST=n
KVM: arm/arm64: Fixup userspace irqchip static key optimization
KVM: arm/arm64: Fix userspace_irqchip_in_use counting
KVM: arm/arm64: Fix incorrect timer_is_pending logic
MAINTAINERS: update KVM/s390 maintainers
MAINTAINERS: add Halil as additional vfio-ccw maintainer
MAINTAINERS: add David as a reviewer for KVM/s390
...
[ Based on a patch from Paolo Bonzini <pbonzini@redhat.com> ]
... basically doing exactly what we do for VMX:
- Passthrough SPEC_CTRL to guests (if enabled in guest CPUID)
- Save and restore SPEC_CTRL around VMExit and VMEntry only if the guest
actually used it.
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jun Nakajima <jun.nakajima@intel.com>
Cc: kvm@vger.kernel.org
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Link: https://lkml.kernel.org/r/1517669783-20732-1-git-send-email-karahmed@amazon.de
The Indirect Branch Predictor Barrier (IBPB) is an indirect branch
control mechanism. It keeps earlier branches from influencing
later ones.
Unlike IBRS and STIBP, IBPB does not define a new mode of operation.
It's a command that ensures predicted branch targets aren't used after
the barrier. Although IBRS and IBPB are enumerated by the same CPUID
enumeration, IBPB is very different.
IBPB helps mitigate against three potential attacks:
* Mitigate guests from being attacked by other guests.
- This is addressed by issing IBPB when we do a guest switch.
* Mitigate attacks from guest/ring3->host/ring3.
These would require a IBPB during context switch in host, or after
VMEXIT. The host process has two ways to mitigate
- Either it can be compiled with retpoline
- If its going through context switch, and has set !dumpable then
there is a IBPB in that path.
(Tim's patch: https://patchwork.kernel.org/patch/10192871)
- The case where after a VMEXIT you return back to Qemu might make
Qemu attackable from guest when Qemu isn't compiled with retpoline.
There are issues reported when doing IBPB on every VMEXIT that resulted
in some tsc calibration woes in guest.
* Mitigate guest/ring0->host/ring0 attacks.
When host kernel is using retpoline it is safe against these attacks.
If host kernel isn't using retpoline we might need to do a IBPB flush on
every VMEXIT.
Even when using retpoline for indirect calls, in certain conditions 'ret'
can use the BTB on Skylake-era CPUs. There are other mitigations
available like RSB stuffing/clearing.
* IBPB is issued only for SVM during svm_free_vcpu().
VMX has a vmclear and SVM doesn't. Follow discussion here:
https://lkml.org/lkml/2018/1/15/146
Please refer to the following spec for more details on the enumeration
and control.
Refer here to get documentation about mitigations.
https://software.intel.com/en-us/side-channel-security-support
[peterz: rebase and changelog rewrite]
[karahmed: - rebase
- vmx: expose PRED_CMD if guest has it in CPUID
- svm: only pass through IBPB if guest has it in CPUID
- vmx: support !cpu_has_vmx_msr_bitmap()]
- vmx: support nested]
[dwmw2: Expose CPUID bit too (AMD IBPB only for now as we lack IBRS)
PRED_CMD is a write-only MSR]
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: kvm@vger.kernel.org
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Jun Nakajima <jun.nakajima@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/1515720739-43819-6-git-send-email-ashok.raj@intel.com
Link: https://lkml.kernel.org/r/1517522386-18410-3-git-send-email-karahmed@amazon.de
sync_pir_to_irr() is only called if vcpu->arch.apicv_active()==true.
In case it is false, VMX code make sure to set sync_pir_to_irr
to NULL.
Therefore, having SVM stubs allows to remove check for if
sync_pir_to_irr != NULL from all calling sites.
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
[Return highest IRR in the SVM case. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
This part of Secure Encrypted Virtualization (SEV) patch series focuses on KVM
changes required to create and manage SEV guests.
SEV is an extension to the AMD-V architecture which supports running encrypted
virtual machine (VMs) under the control of a hypervisor. Encrypted VMs have their
pages (code and data) secured such that only the guest itself has access to
unencrypted version. Each encrypted VM is associated with a unique encryption key;
if its data is accessed to a different entity using a different key the encrypted
guest's data will be incorrectly decrypted, leading to unintelligible data.
This security model ensures that hypervisor will no longer able to inspect or
alter any guest code or data.
The key management of this feature is handled by a separate processor known as
the AMD Secure Processor (AMD-SP) which is present on AMD SOCs. The SEV Key
Management Specification (see below) provides a set of commands which can be
used by hypervisor to load virtual machine keys through the AMD-SP driver.
The patch series adds a new ioctl in KVM driver (KVM_MEMORY_ENCRYPT_OP). The
ioctl will be used by qemu to issue SEV guest-specific commands defined in Key
Management Specification.
The following links provide additional details:
AMD Memory Encryption white paper:
http://amd-dev.wpengine.netdna-cdn.com/wordpress/media/2013/12/AMD_Memory_Encryption_Whitepaper_v7-Public.pdf
AMD64 Architecture Programmer's Manual:
http://support.amd.com/TechDocs/24593.pdf
SME is section 7.10
SEV is section 15.34
SEV Key Management:
http://support.amd.com/TechDocs/55766_SEV-KM API_Specification.pdf
KVM Forum Presentation:
http://www.linux-kvm.org/images/7/74/02x08A-Thomas_Lendacky-AMDs_Virtualizatoin_Memory_Encryption_Technology.pdf
SEV Guest BIOS support:
SEV support has been add to EDKII/OVMF BIOS
https://github.com/tianocore/edk2
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Thomas Gleixner