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| author | Janakarajan Natarajan <Janakarajan.Natarajan@amd.com> | 2017-07-06 15:50:44 -0500 |
|---|---|---|
| committer | Radim Krčmář <rkrcmar@redhat.com> | 2017-07-12 22:38:28 +0200 |
| commit | 8a77e90966e92759f94087f9845d413290be0d70 (patch) | |
| tree | 17bb4aae92b4ebf1aa096e25c7df0d25d70cc252 | |
| parent | b742c1e6e79ddf4192d76336da2407c65ca7242f (diff) | |
| download | lwn-8a77e90966e92759f94087f9845d413290be0d70.tar.gz lwn-8a77e90966e92759f94087f9845d413290be0d70.zip | |
KVM: SVM: Prepare for new bit definition in lbr_ctl
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 <Janakarajan.Natarajan@amd.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
| -rw-r--r-- | arch/x86/include/asm/svm.h | 2 | ||||
| -rw-r--r-- | 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 14824fc78f7e..d1163f64d732 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 3da42d7c629e..6e72127c0d0e 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); |