[PART1 RFC v3 11/12] svm: Do not intercept CR8 when enable AVIC

Suravee Suthikulpanit
2016-03-18T06:13:15Z

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.suthikulpanit@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 ba84d57..d5418c3 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -984,6 +984,8 @@ static __init int svm_hardware_setup(void)

if (avic) {
printk(KERN_INFO "kvm: AVIC enabled\n");
+
+ svm_x86_ops.update_cr8_intercept = NULL;
} else {
svm_x86_ops.deliver_posted_interrupt = NULL;
}
@@ -1097,7 +1099,8 @@ 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);

@@ -4080,7 +4083,8 @@ 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);
@@ -4271,9 +4275,12 @@ 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);
+ cr8 = kvm_get_cr8(vcpu) & V_TPR_MASK;
svm->vmcb->control.int_ctl &= ~V_TPR_MASK;
- svm->vmcb->control.int_ctl |= cr8 & V_TPR_MASK;
+ svm->vmcb->control.int_ctl |= cr8;
+
+ if (svm_vcpu_avic_enabled(svm))
+ kvm_lapic_set_reg(svm->vcpu.arch.apic, APIC_TASKPRI, (u32)cr8 << 4);
}

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