Introduce KVM_CAP_X86_GUEST_LBR to allow per-VM enabling of the guest
lbr feature.
Signed-off-by: Like Xu <like.xu@xxxxxxxxx>
Signed-off-by: Wei Wang <wei.w.wang@xxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Andi Kleen <ak@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/x86.c | 10 ++++++++++
include/uapi/linux/kvm.h | 1 +
3 files changed, 13 insertions(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 8e90488..4a46e31 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -825,6 +825,8 @@ struct kvm_arch {
bool mwait_in_guest;
bool hlt_in_guest;
bool pause_in_guest;
+ bool guest_lbr_enabled;
+ struct perf_lbr_stack lbr_stack;
unsigned long irq_sources_bitmap;
s64 kvmclock_offset;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 542f631..8fdcfa9 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2927,6 +2927,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_SPLIT_IRQCHIP:
case KVM_CAP_IMMEDIATE_EXIT:
case KVM_CAP_GET_MSR_FEATURES:
+ case KVM_CAP_X86_GUEST_LBR:
r = 1;
break;
case KVM_CAP_SYNC_REGS:
@@ -4350,6 +4351,15 @@ static int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
kvm->arch.pause_in_guest = true;
r = 0;
break;
+ case KVM_CAP_X86_GUEST_LBR:
+ r = -EINVAL;
+ if (perf_get_lbr_stack(&kvm->arch.lbr_stack) < 0) {
+ pr_err("Failed to enable the guest lbr feature\n");
+ break;
+ }
+ kvm->arch.guest_lbr_enabled = true;
+ r = 0;
+ break;
default:
r = -EINVAL;
break;
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 07548de..7cf9bc0 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -952,6 +952,7 @@ struct kvm_ppc_resize_hpt {
#define KVM_CAP_S390_HPAGE_1M 156
#define KVM_CAP_NESTED_STATE 157
#define KVM_CAP_ARM_INJECT_SERROR_ESR 158
+#define KVM_CAP_X86_GUEST_LBR 159
#ifdef KVM_CAP_IRQ_ROUTING
--
2.7.4
