KVM: correctly detect APIC SW state in kvm_apic_post_state_restore()

Commit Message

Gleb Natapov Aug. 8, 2012, 12:24 p.m. UTC

For apic_set_spiv() to track APIC SW state correctly it needs to see
previous and next values of the spurious vector register, but currently
memset() overwrite the old value before apic_set_spiv() get a chance to
do tracking. Fix it by calling apic_set_spiv() before overwriting old
value.

Signed-off-by: Gleb Natapov <[e-mail]>
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			Gleb.
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Comments

Avi Kivity Aug. 9, 2012, 9:44 a.m. UTC | #1

On 08/08/2012 03:24 PM, Gleb Natapov wrote:
> For apic_set_spiv() to track APIC SW state correctly it needs to see
> previous and next values of the spurious vector register, but currently
> memset() overwrite the old value before apic_set_spiv() get a chance to
> do tracking. Fix it by calling apic_set_spiv() before overwriting old
> value.
> 

Applied, thanks.

Patch

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index f019ca2..d72d79a 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1389,13 +1389,16 @@  int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu)
 	return vector;
 }
 
-void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu)
+void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu,
+		struct kvm_lapic_state *s)
 {
 	struct kvm_lapic *apic = vcpu->arch.apic;
 
 	kvm_lapic_set_base(vcpu, vcpu->arch.apic_base);
+	/* set SPIV separately to get count of SW disabled APICs right */
+	apic_set_spiv(apic, *((u32 *)(s->regs + APIC_SPIV)));
+	memcpy(vcpu->arch.apic->regs, s->regs, sizeof *s);
 	kvm_apic_set_version(vcpu);
-	apic_set_spiv(apic, kvm_apic_get_reg(apic, APIC_SPIV));
 
 	apic_update_ppr(apic);
 	hrtimer_cancel(&apic->lapic_timer.timer);
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 2ad9caa..615a8b0 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -54,7 +54,8 @@  int kvm_apic_local_deliver(struct kvm_lapic *apic, int lvt_type);
 
 u64 kvm_get_apic_base(struct kvm_vcpu *vcpu);
 void kvm_set_apic_base(struct kvm_vcpu *vcpu, u64 data);
-void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu);
+void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu,
+		struct kvm_lapic_state *s);
 int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu);
 
 u64 kvm_get_lapic_tscdeadline_msr(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 042754b..3c1ccea 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2345,8 +2345,7 @@  static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
 static int kvm_vcpu_ioctl_set_lapic(struct kvm_vcpu *vcpu,
 				    struct kvm_lapic_state *s)
 {
-	memcpy(vcpu->arch.apic->regs, s->regs, sizeof *s);
-	kvm_apic_post_state_restore(vcpu);
+	kvm_apic_post_state_restore(vcpu, s);
 	update_cr8_intercept(vcpu);
 
 	return 0;