The patch introduces a bitmap that will hold reasons apic should be
checked during vmexit. This is in a preparation for vp eoi patch
that will add one more check on vmexit. With the bitmap we can do
if(apic_attention) to check everything simultaneously which will
add zero overhead on the fast path.
Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 4 ++++
arch/x86/kvm/lapic.c | 12 +++++++-----
2 files changed, 11 insertions(+), 5 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f624ca7..69e39bc 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -172,6 +172,9 @@ enum {
#define DR7_FIXED_1 0x00000400
#define DR7_VOLATILE 0xffff23ff
+/* apic attention bits */
+#define KVM_APIC_CHECK_VAPIC 0
+
/*
* We don't want allocation failures within the mmu code, so we preallocate
* enough memory for a single page fault in a cache.
@@ -337,6 +340,7 @@ struct kvm_vcpu_arch {
u64 efer;
u64 apic_base;
struct kvm_lapic *apic; /* kernel irqchip context */
+ unsigned long apic_attention;
int32_t apic_arb_prio;
int mp_state;
int sipi_vector;
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 992b4ea..93c1574 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1088,6 +1088,7 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu)
apic_update_ppr(apic);
vcpu->arch.apic_arb_prio = 0;
+ vcpu->arch.apic_attention = 0;
apic_debug(KERN_INFO "%s: vcpu=%p, id=%d, base_msr="
"0x%016" PRIx64 ", base_address=0x%0lx.\n", __func__,
@@ -1287,7 +1288,7 @@ void kvm_lapic_sync_from_vapic(struct kvm_vcpu *vcpu)
u32 data;
void *vapic;
- if (!irqchip_in_kernel(vcpu->kvm) || !vcpu->arch.apic->vapic_addr)
+ if (!test_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention))
return;
vapic = kmap_atomic(vcpu->arch.apic->vapic_page);
@@ -1304,7 +1305,7 @@ void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu)
struct kvm_lapic *apic;
void *vapic;
- if (!irqchip_in_kernel(vcpu->kvm) || !vcpu->arch.apic->vapic_addr)
+ if (!test_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention))
return;
apic = vcpu->arch.apic;
@@ -1324,10 +1325,11 @@ void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu)
void kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr)
{
- if (!irqchip_in_kernel(vcpu->kvm))
- return;
-
vcpu->arch.apic->vapic_addr = vapic_addr;
+ if (vapic_addr)
+ __set_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention);
+ else
+ __clear_bit(KVM_APIC_CHECK_VAPIC, &vcpu->arch.apic_attention);
}
int kvm_x2apic_msr_write(struct kvm_vcpu *vcpu, u32 msr, u64 data)
--
1.7.7.3
--
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