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Commit 8a77e909 authored by Janakarajan Natarajan's avatar Janakarajan Natarajan Committed by Radim Krčmář
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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: default avatarJanakarajan Natarajan <Janakarajan.Natarajan@amd.com>
Reviewed-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: default avatarRadim Krčmář <rkrcmar@redhat.com>
parent b742c1e6

arch/x86/include/asm/svm.h

+2 −0
Original line number Diff line number Diff line
@@ -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

arch/x86/kvm/svm.c

+2 −2
Original line number Diff line number Diff line
@@ -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);