[PART1 RFC v2 09/10] 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 update TPR in APIC backing page when syncing CR8 before VMRUN

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com>
---
 arch/x86/kvm/svm.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 02cd8d0..5142861 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -986,6 +986,9 @@ static __init int svm_hardware_setup(void)
 
        if (avic) {
                printk(KERN_INFO "kvm: AVIC enabled\n");
+
+               /* Do not do cr8 intercept if AVIC is enabled. */
+               svm_x86_ops.update_cr8_intercept = NULL;
        } else {
                svm_x86_ops.deliver_posted_interrupt = NULL;
        }
@@ -1116,7 +1119,8 @@ 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 (!avic)
+               set_cr_intercept(svm, INTERCEPT_CR8_WRITE);
 
        set_dr_intercepts(svm);
 
@@ -4277,7 +4281,8 @@ 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)) ||
+            avic)
                return;
 
        clr_cr_intercept(svm, INTERCEPT_CR8_WRITE);
@@ -4472,8 +4477,10 @@ static inline void sync_lapic_to_cr8(struct kvm_vcpu 
*vcpu)
        if (is_guest_mode(vcpu) && (vcpu->arch.hflags & HF_VINTR_MASK))
                return;
 
-       cr8 = kvm_get_cr8(vcpu);
-       svm->vmcb->control.v_tpr = cr8 & V_TPR_MASK;
+       svm->vmcb->control.v_tpr = cr8 = kvm_get_cr8(vcpu) & V_TPR_MASK;
+
+       if (avic)
+               *(avic_get_bk_page_entry(svm, APIC_TASKPRI)) = (u32)cr8 << 4;
 }
 
 static void svm_complete_interrupts(struct vcpu_svm *svm)
-- 
1.9.1