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authorMatt Gingell <gingell@google.com>2015-11-17 17:32:05 +0100
committerPaolo Bonzini <pbonzini@redhat.com>2015-11-18 12:25:37 +0100
commit127a457acb2131fdb31c68c98cf11eda8ba7b380 (patch)
tree161e0007cbd4e13af7850921d1558bbf5078afad /arch/x86/kvm
parent585bb8f9a5e592f2ce7abbe5ed3112d5438d2754 (diff)
downloadlinux-127a457acb2131fdb31c68c98cf11eda8ba7b380.tar.gz
KVM: x86: fix interrupt window handling in split IRQ chip case
This patch ensures that dm_request_for_irq_injection and post_kvm_run_save are in sync, avoiding that an endless ping-pong between userspace (who correctly notices that IF=0) and the kernel (who insists that userspace handles its request for the interrupt window). To synchronize them, it also adds checks for kvm_arch_interrupt_allowed and !kvm_event_needs_reinjection. These are always needed, not just for in-kernel LAPIC. Signed-off-by: Matt Gingell <gingell@google.com> [A collage of two patches from Matt. - Paolo] Fixes: 1c1a9ce973a7863dd46767226bce2a5f12d48bc6 Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
-rw-r--r--arch/x86/kvm/x86.c33
1 files changed, 19 insertions, 14 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 00462bd63129..46ed8edad793 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2763,6 +2763,12 @@ static int kvm_vcpu_ioctl_set_lapic(struct kvm_vcpu *vcpu,
return 0;
}
+static int kvm_cpu_accept_dm_intr(struct kvm_vcpu *vcpu)
+{
+ return (!lapic_in_kernel(vcpu) ||
+ kvm_apic_accept_pic_intr(vcpu));
+}
+
static int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
struct kvm_interrupt *irq)
{
@@ -5921,12 +5927,16 @@ static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu)
if (!vcpu->run->request_interrupt_window || pic_in_kernel(vcpu->kvm))
return false;
+ if (!kvm_arch_interrupt_allowed(vcpu))
+ return false;
+
if (kvm_cpu_has_interrupt(vcpu))
return false;
- return (irqchip_split(vcpu->kvm)
- ? kvm_apic_accept_pic_intr(vcpu)
- : kvm_arch_interrupt_allowed(vcpu));
+ if (kvm_event_needs_reinjection(vcpu))
+ return false;
+
+ return kvm_cpu_accept_dm_intr(vcpu);
}
static void post_kvm_run_save(struct kvm_vcpu *vcpu)
@@ -5937,17 +5947,12 @@ static void post_kvm_run_save(struct kvm_vcpu *vcpu)
kvm_run->flags = is_smm(vcpu) ? KVM_RUN_X86_SMM : 0;
kvm_run->cr8 = kvm_get_cr8(vcpu);
kvm_run->apic_base = kvm_get_apic_base(vcpu);
- if (!irqchip_in_kernel(vcpu->kvm))
- kvm_run->ready_for_interrupt_injection =
- kvm_arch_interrupt_allowed(vcpu) &&
- !kvm_cpu_has_interrupt(vcpu) &&
- !kvm_event_needs_reinjection(vcpu);
- else if (!pic_in_kernel(vcpu->kvm))
- kvm_run->ready_for_interrupt_injection =
- kvm_apic_accept_pic_intr(vcpu) &&
- !kvm_cpu_has_interrupt(vcpu);
- else
- kvm_run->ready_for_interrupt_injection = 1;
+ kvm_run->ready_for_interrupt_injection =
+ pic_in_kernel(vcpu->kvm) ||
+ (kvm_arch_interrupt_allowed(vcpu) &&
+ !kvm_cpu_has_interrupt(vcpu) &&
+ !kvm_event_needs_reinjection(vcpu) &&
+ kvm_cpu_accept_dm_intr(vcpu));
}
static void update_cr8_intercept(struct kvm_vcpu *vcpu)