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From:   Wei Wang <wei.w.wang@intel.com>
To:     linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        pbonzini@redhat.com, ak@linux.intel.com
Cc:     kan.liang@intel.com, peterz@infradead.org, mingo@redhat.com,
        rkrcmar@redhat.com, like.xu@intel.com, wei.w.wang@intel.com,
        jannh@google.com, arei.gonglei@huawei.com
Subject: [PATCH v3 2/5] KVM/x86: KVM_CAP_X86_GUEST_LBR
Date:   Thu, 20 Sep 2018 18:05:56 +0800
Message-Id: <1537437959-8751-3-git-send-email-wei.w.wang@intel.com>
In-Reply-To: <1537437959-8751-1-git-send-email-wei.w.wang@intel.com>
References: <1537437959-8751-1-git-send-email-wei.w.wang@intel.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Introduce KVM_CAP_X86_GUEST_LBR to allow per-VM enabling of the guest
lbr feature.

Signed-off-by: Like Xu <like.xu@intel.com>
Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
---
 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