This is a note to let you know that I've just added the patch titled
Revert "KVM: nested VMX: disable perf cpuid reporting"
to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
revert-kvm-nested-vmx-disable-perf-cpuid-reporting.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0b4c208d443ba2af82b4c70f99ca8df31e9a0020 Mon Sep 17 00:00:00 2001
From: Jim Mattson <jmattson@xxxxxxxxxx>
Date: Tue, 20 Dec 2016 16:34:50 -0800
Subject: Revert "KVM: nested VMX: disable perf cpuid reporting"
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From: Jim Mattson <jmattson@xxxxxxxxxx>
commit 0b4c208d443ba2af82b4c70f99ca8df31e9a0020 upstream.
This reverts commit bc6134942dbbf31c25e9bd7c876be5da81c9e1ce.
A CPUID instruction executed in VMX non-root mode always causes a
VM-exit, regardless of the leaf being queried.
Fixes: bc6134942dbb ("KVM: nested VMX: disable perf cpuid reporting")
Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
[The issue solved by bc6134942dbb has been resolved with ff651cb613b4
("KVM: nVMX: Add nested msr load/restore algorithm").]
Signed-off-by: Radim Krčmář <rkrcmar@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/cpuid.c | 6 ------
arch/x86/kvm/vmx.c | 2 --
2 files changed, 8 deletions(-)
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -818,12 +818,6 @@ void kvm_cpuid(struct kvm_vcpu *vcpu, u3
if (!best)
best = check_cpuid_limit(vcpu, function, index);
- /*
- * Perfmon not yet supported for L2 guest.
- */
- if (is_guest_mode(vcpu) && function == 0xa)
- best = NULL;
-
if (best) {
*eax = best->eax;
*ebx = best->ebx;
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7754,8 +7754,6 @@ static bool nested_vmx_exit_handled(stru
case EXIT_REASON_TASK_SWITCH:
return true;
case EXIT_REASON_CPUID:
- if (kvm_register_read(vcpu, VCPU_REGS_RAX) == 0xa)
- return false;
return true;
case EXIT_REASON_HLT:
return nested_cpu_has(vmcs12, CPU_BASED_HLT_EXITING);
Patches currently in stable-queue which might be from jmattson@xxxxxxxxxx are
queue-4.4/revert-kvm-nested-vmx-disable-perf-cpuid-reporting.patch