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

[Suravee Suthikulpanit]

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.suthikulpa...@amd.com>
---
 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