@@ -401,10 +401,9 @@ Capability: basic
Architectures: x86, ppc, mips
Type: vcpu ioctl
Parameters: struct kvm_interrupt (in)
-Returns: 0 on success, -1 on error
+Returns: 0 on success, negative on failure.
-Queues a hardware interrupt vector to be injected. This is only
-useful if in-kernel local APIC or equivalent is not used.
+Queues a hardware interrupt vector to be injected.
/* for KVM_INTERRUPT */
struct kvm_interrupt {
@@ -414,7 +413,14 @@ struct kvm_interrupt {
X86:
-Note 'irq' is an interrupt vector, not an interrupt pin or line.
+Returns: 0 on success,
+ -EEXIST if an interrupt is already enqueued
+ -EINVAL the the irq number is invalid
+ -ENXIO if the PIC is in the kernel
+ -EFAULT if the pointer is invalid
+
+Note 'irq' is an interrupt vector, not an interrupt pin or line. This
+ioctl is useful if the in-kernel PIC is not used.
PPC:
@@ -563,6 +563,7 @@ struct kvm_vcpu_arch {
u64 eoi_exit_bitmaps[4];
int pending_ioapic_eoi;
+ int pending_external_vector;
};
struct kvm_lpage_info {
@@ -38,14 +38,27 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
EXPORT_SYMBOL(kvm_cpu_has_pending_timer);
/*
+ * check if there is a pending userspace external interrupt
+ */
+static int pending_userspace_extint(struct kvm_vcpu *v)
+{
+ return v->arch.pending_external_vector != -1;
+}
+
+/*
* check if there is pending interrupt from
* non-APIC source without intack.
*/
static int kvm_cpu_has_extint(struct kvm_vcpu *v)
{
- if (kvm_apic_accept_pic_intr(v))
- return pic_irqchip(v->kvm)->output; /* PIC */
- else
+ u8 accept = kvm_apic_accept_pic_intr(v);
+
+ if (accept) {
+ if (irqchip_split(v->kvm))
+ return pending_userspace_extint(v);
+ else
+ return pic_irqchip(v->kvm)->output;
+ } else
return 0;
}
@@ -57,7 +70,7 @@ static int kvm_cpu_has_extint(struct kvm_vcpu *v)
*/
int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
{
- if (!irqchip_in_kernel(v->kvm))
+ if (!pic_in_kernel(v->kvm))
return v->arch.interrupt.pending;
if (kvm_cpu_has_extint(v))
@@ -75,7 +88,7 @@ int kvm_cpu_has_injectable_intr(struct kvm_vcpu *v)
*/
int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
{
- if (!irqchip_in_kernel(v->kvm))
+ if (!pic_in_kernel(v->kvm))
return v->arch.interrupt.pending;
if (kvm_cpu_has_extint(v))
@@ -91,9 +104,16 @@ EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
*/
static int kvm_cpu_get_extint(struct kvm_vcpu *v)
{
- if (kvm_cpu_has_extint(v))
- return kvm_pic_read_irq(v->kvm); /* PIC */
- return -1;
+ if (kvm_cpu_has_extint(v)) {
+ if (irqchip_split(v->kvm)) {
+ int vector = v->arch.pending_external_vector;
+
+ v->arch.pending_external_vector = -1;
+ return vector;
+ } else
+ return kvm_pic_read_irq(v->kvm); /* PIC */
+ } else
+ return -1;
}
/*
@@ -103,7 +123,7 @@ int kvm_cpu_get_interrupt(struct kvm_vcpu *v)
{
int vector;
- if (!irqchip_in_kernel(v->kvm))
+ if (!pic_in_kernel(v->kvm) && v->arch.interrupt.pending)
return v->arch.interrupt.nr;
vector = kvm_cpu_get_extint(v);
@@ -83,6 +83,14 @@ static inline struct kvm_pic *pic_irqchip(struct kvm *kvm)
return kvm->arch.vpic;
}
+static inline int pic_in_kernel(struct kvm *kvm)
+{
+ int ret;
+
+ ret = (pic_irqchip(kvm) != NULL);
+ return ret;
+}
+
static inline int irqchip_split(struct kvm *kvm)
{
return kvm->arch.irqchip_split;
@@ -2675,7 +2675,14 @@ static int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
{
if (irq->irq >= KVM_NR_INTERRUPTS)
return -EINVAL;
- if (irqchip_in_kernel(vcpu->kvm))
+
+ if (irqchip_in_kernel(vcpu->kvm) && !pic_in_kernel(vcpu->kvm) &&
+ vcpu->arch.pending_external_vector == -1) {
+ vcpu->arch.pending_external_vector = irq->irq;
+ return 0;
+ } else if (irqchip_in_kernel(vcpu->kvm) && !pic_in_kernel(vcpu->kvm))
+ return -EEXIST;
+ else if (irqchip_in_kernel(vcpu->kvm))
return -ENXIO;
kvm_queue_interrupt(vcpu, irq->irq, false);
@@ -5805,9 +5812,15 @@ static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt)
*/
static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu)
{
- return (!irqchip_in_kernel(vcpu->kvm) && !kvm_cpu_has_interrupt(vcpu) &&
- vcpu->run->request_interrupt_window &&
- kvm_arch_interrupt_allowed(vcpu));
+ if (!vcpu->run->request_interrupt_window || pic_in_kernel(vcpu->kvm))
+ 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));
}
static void post_kvm_run_save(struct kvm_vcpu *vcpu)
@@ -5818,13 +5831,17 @@ 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))
+ if (irqchip_in_kernel(vcpu->kvm) && pic_in_kernel(vcpu->kvm))
kvm_run->ready_for_interrupt_injection = 1;
- else
+ else if (irqchip_in_kernel(vcpu->kvm)) {
+ kvm_run->ready_for_interrupt_injection =
+ kvm_apic_accept_pic_intr(vcpu);
+ } else {
kvm_run->ready_for_interrupt_injection =
kvm_arch_interrupt_allowed(vcpu) &&
!kvm_cpu_has_interrupt(vcpu) &&
!kvm_event_needs_reinjection(vcpu);
+ }
}
static void update_cr8_intercept(struct kvm_vcpu *vcpu)
@@ -6514,8 +6531,8 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
kvm_inject_pending_timer_irqs(vcpu);
if (dm_request_for_irq_injection(vcpu)) {
- r = -EINTR;
- vcpu->run->exit_reason = KVM_EXIT_INTR;
+ r = 0;
+ vcpu->run->exit_reason = KVM_EXIT_IRQ_WINDOW_OPEN;
++vcpu->stat.request_irq_exits;
break;
}
@@ -7400,6 +7417,8 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
kvm_async_pf_hash_reset(vcpu);
kvm_pmu_init(vcpu);
+ vcpu->arch.pending_external_vector = -1;
+
return 0;
fail_free_mce_banks:
In order to enable userspace PIC support, the userspace PIC needs to be able to inject local interrupts even when the APICs are in the kernel. KVM_INTERRUPT now supports sending local interrupts to an APIC when APICs are in the kernel. The ready_for_interrupt_request flag is now only set when the CPU/APIC will immediately accept and inject an interrupt (i.e. APIC has not masked the PIC). When the PIC wishes to initiate an INTA cycle with, say, CPU0, it kicks CPU0 out of the guest, and renedezvous with CPU0 once it arrives in userspace. When the CPU/APIC unmasks the PIC, a KVM_EXIT_IRQ_WINDOW_OPEN is triggered, so that userspace has a chance to inject a PIC interrupt if it had been pending. Overall, this design can lead to a small number of spurious userspace renedezvous. In particular, whenever the PIC transistions from low to high while it is masked and whenever the PIC becomes unmasked while it is low. Note: this does not buffer more than one local interrupt in the kernel, so the VMM needs to enter the guest in order to complete interrupt injection before injecting an additional interrupt. Compiles for x86. Can pass the KVM Unit Tests. Signed-off-by: Steve Rutherford <srutherford@google.com> --- Documentation/virtual/kvm/api.txt | 14 ++++++++++---- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/irq.c | 38 +++++++++++++++++++++++++++++--------- arch/x86/kvm/irq.h | 8 ++++++++ arch/x86/kvm/x86.c | 35 +++++++++++++++++++++++++++-------- 5 files changed, 75 insertions(+), 21 deletions(-)