[PART1 RFC v4 10/11] svm: Do not intercept CR8 when enable AVIC

From: Suravee Suthikulpanit
Date: Thu Apr 07 2016 - 04:37:29 EST


When enable AVIC:
* Do not intercept CR8 since this should be handled by AVIC HW.
* Also, we don't need to sync cr8/V_TPR and APIC backing page.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@xxxxxxx>
---
arch/x86/kvm/svm.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 74b0751..bccf6cb 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1092,7 +1092,8 @@ static void init_vmcb(struct vcpu_svm *svm)
set_cr_intercept(svm, INTERCEPT_CR0_WRITE);
set_cr_intercept(svm, INTERCEPT_CR3_WRITE);
set_cr_intercept(svm, INTERCEPT_CR4_WRITE);
- set_cr_intercept(svm, INTERCEPT_CR8_WRITE);
+ if (!svm_vcpu_avic_enabled(svm))
+ set_cr_intercept(svm, INTERCEPT_CR8_WRITE);

set_dr_intercepts(svm);

@@ -4069,7 +4070,8 @@ static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)
{
struct vcpu_svm *svm = to_svm(vcpu);

- if (is_guest_mode(vcpu) && (vcpu->arch.hflags & HF_VINTR_MASK))
+ if ((is_guest_mode(vcpu) && (vcpu->arch.hflags & HF_VINTR_MASK)) ||
+ svm_vcpu_avic_enabled(svm))
return;

clr_cr_intercept(svm, INTERCEPT_CR8_WRITE);
@@ -4255,14 +4257,15 @@ static inline void sync_cr8_to_lapic(struct kvm_vcpu *vcpu)
static inline void sync_lapic_to_cr8(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
- u64 cr8;
+ struct kvm_lapic *apic = vcpu->arch.apic;

- if (is_guest_mode(vcpu) && (vcpu->arch.hflags & HF_VINTR_MASK))
+ if (is_guest_mode(vcpu) && (vcpu->arch.hflags & HF_VINTR_MASK) &&
+ svm_vcpu_avic_enabled(svm))
return;

- cr8 = kvm_get_cr8(vcpu);
svm->vmcb->control.int_ctl &= ~V_TPR_MASK;
- svm->vmcb->control.int_ctl |= cr8 & V_TPR_MASK;
+ svm->vmcb->control.int_ctl |= (kvm_apic_get_reg(apic,
+ APIC_TASKPRI) >> 4) & V_TPR_MASK;
}

static void svm_complete_interrupts(struct vcpu_svm *svm)
--
1.9.1