diff options
| author | Steve Rutherford <srutherford@google.com> | 2015-07-29 23:21:41 -0700 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-10-01 15:06:27 +0200 |
| commit | 7543a635aa09eb138b2cbf60ac3ff19503ae6954 (patch) | |
| tree | 94d181962c2a3f64019f182900ed216a2f0c3e73 /arch/x86/kvm | |
| parent | 49df6397edfc5a8ba8ca813b51fb9729d8e94b40 (diff) | |
KVM: x86: Add KVM exit for IOAPIC EOIs
Adds KVM_EXIT_IOAPIC_EOI which allows the kernel to EOI
level-triggered IOAPIC interrupts.
Uses a per VCPU exit bitmap to decide whether or not the IOAPIC needs
to be informed (which is identical to the EOI_EXIT_BITMAP field used
by modern x86 processors, but can also be used to elide kvm IOAPIC EOI
exits on older processors).
[Note: A prototype using ResampleFDs found that decoupling the EOI
from the VCPU's thread made it possible for the VCPU to not see a
recent EOI after reentering the guest. This does not match real
hardware.]
Compile tested for Intel x86.
Signed-off-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/lapic.c | 24 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 11 |
2 files changed, 28 insertions, 7 deletions
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index e05946c36b87..ef70f6f3a37a 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -877,15 +877,25 @@ static bool kvm_ioapic_handles_vector(struct kvm_lapic *apic, int vector) static void kvm_ioapic_send_eoi(struct kvm_lapic *apic, int vector) { - if (kvm_ioapic_handles_vector(apic, vector)) { - int trigger_mode; - if (apic_test_vector(vector, apic->regs + APIC_TMR)) - trigger_mode = IOAPIC_LEVEL_TRIG; - else - trigger_mode = IOAPIC_EDGE_TRIG; + int trigger_mode; + + /* Eoi the ioapic only if the ioapic doesn't own the vector. */ + if (!kvm_ioapic_handles_vector(apic, vector)) + return; - kvm_ioapic_update_eoi(apic->vcpu, vector, trigger_mode); + /* Request a KVM exit to inform the userspace IOAPIC. */ + if (irqchip_split(apic->vcpu->kvm)) { + apic->vcpu->arch.pending_ioapic_eoi = vector; + kvm_make_request(KVM_REQ_IOAPIC_EOI_EXIT, apic->vcpu); + return; } + + if (apic_test_vector(vector, apic->regs + APIC_TMR)) + trigger_mode = IOAPIC_LEVEL_TRIG; + else + trigger_mode = IOAPIC_EDGE_TRIG; + + kvm_ioapic_update_eoi(apic->vcpu, vector, trigger_mode); } static int apic_set_eoi(struct kvm_lapic *apic) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f720774a4797..27429daa054e 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6271,6 +6271,17 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) kvm_pmu_handle_event(vcpu); if (kvm_check_request(KVM_REQ_PMI, vcpu)) kvm_pmu_deliver_pmi(vcpu); + if (kvm_check_request(KVM_REQ_IOAPIC_EOI_EXIT, vcpu)) { + BUG_ON(vcpu->arch.pending_ioapic_eoi > 255); + if (test_bit(vcpu->arch.pending_ioapic_eoi, + (void *) vcpu->arch.eoi_exit_bitmap)) { + vcpu->run->exit_reason = KVM_EXIT_IOAPIC_EOI; + vcpu->run->eoi.vector = + vcpu->arch.pending_ioapic_eoi; + r = 0; + goto out; + } + } if (kvm_check_request(KVM_REQ_SCAN_IOAPIC, vcpu)) vcpu_scan_ioapic(vcpu); if (kvm_check_request(KVM_REQ_APIC_PAGE_RELOAD, vcpu)) |