From 8a77e90966e92759f94087f9845d413290be0d70 Mon Sep 17 00:00:00 2001 From: Janakarajan Natarajan Date: Thu, 6 Jul 2017 15:50:44 -0500 Subject: [PATCH] KVM: SVM: Prepare for new bit definition in lbr_ctl MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The lbr_ctl variable in the vmcb control area is used to enable or disable Last Branch Record (LBR) virtualization. However, this is to be done using only bit 0 of the variable. To correct this and to prepare for a new feature, change the current usage to work only on a particular bit. Signed-off-by: Janakarajan Natarajan Reviewed-by: Paolo Bonzini Signed-off-by: Radim Krčmář --- arch/x86/include/asm/svm.h | 2 ++ arch/x86/kvm/svm.c | 4 ++-- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h index 14824fc78f7e7..d1163f64d7326 100644 --- a/arch/x86/include/asm/svm.h +++ b/arch/x86/include/asm/svm.h @@ -119,6 +119,8 @@ struct __attribute__ ((__packed__)) vmcb_control_area { #define AVIC_ENABLE_SHIFT 31 #define AVIC_ENABLE_MASK (1 << AVIC_ENABLE_SHIFT) +#define LBR_CTL_ENABLE_MASK BIT_ULL(0) + #define SVM_INTERRUPT_SHADOW_MASK 1 #define SVM_IOIO_STR_SHIFT 2 diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 3da42d7c629e1..6e72127c0d0ec 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -947,7 +947,7 @@ static void svm_enable_lbrv(struct vcpu_svm *svm) { u32 *msrpm = svm->msrpm; - svm->vmcb->control.lbr_ctl = 1; + svm->vmcb->control.lbr_ctl |= LBR_CTL_ENABLE_MASK; set_msr_interception(msrpm, MSR_IA32_LASTBRANCHFROMIP, 1, 1); set_msr_interception(msrpm, MSR_IA32_LASTBRANCHTOIP, 1, 1); set_msr_interception(msrpm, MSR_IA32_LASTINTFROMIP, 1, 1); @@ -958,7 +958,7 @@ static void svm_disable_lbrv(struct vcpu_svm *svm) { u32 *msrpm = svm->msrpm; - svm->vmcb->control.lbr_ctl = 0; + svm->vmcb->control.lbr_ctl &= ~LBR_CTL_ENABLE_MASK; set_msr_interception(msrpm, MSR_IA32_LASTBRANCHFROMIP, 0, 0); set_msr_interception(msrpm, MSR_IA32_LASTBRANCHTOIP, 0, 0); set_msr_interception(msrpm, MSR_IA32_LASTINTFROMIP, 0, 0); -- 2.39.5