[PATCH v2 05/16] Coalesce userspace/kernel irqchip interrupt injection logic.

Gleb Natapov
2009-04-21T14:45:16Z

Start to use interrupt/exception queues like VMX does.
This also fix the bug that if exit was caused by a guest
internal exception access to IDT the exception was not
reinjected.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
---
arch/x86/kvm/svm.c | 176 ++++++++++++++++++++++------------------------------
1 files changed, 75 insertions(+), 101 deletions(-)

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 52c41aa..053370d 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -70,7 +70,6 @@ module_param(npt, int, S_IRUGO);
static int nested = 0;
module_param(nested, int, S_IRUGO);

-static void kvm_reput_irq(struct vcpu_svm *svm);
static void svm_flush_tlb(struct kvm_vcpu *vcpu);

static int nested_svm_exit_handled(struct vcpu_svm *svm, bool kvm_override);
@@ -199,9 +198,7 @@ static void svm_queue_exception(struct kvm_vcpu *vcpu, unsigned nr,

static bool svm_exception_injected(struct kvm_vcpu *vcpu)
{
- struct vcpu_svm *svm = to_svm(vcpu);
-
- return !(svm->vmcb->control.exit_int_info & SVM_EXITINTINFO_VALID);
+ return false;
}

static int is_external_interrupt(u32 info)
@@ -976,12 +973,9 @@ static int svm_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg)

static int svm_get_irq(struct kvm_vcpu *vcpu)
{
- struct vcpu_svm *svm = to_svm(vcpu);
- u32 exit_int_info = svm->vmcb->control.exit_int_info;
-
- if (is_external_interrupt(exit_int_info))
- return exit_int_info & SVM_EVTINJ_VEC_MASK;
- return -1;
+ if (!vcpu->arch.interrupt.pending)
+ return -1;
+ return vcpu->arch.interrupt.nr;
}

static void load_host_msrs(struct kvm_vcpu *vcpu)
@@ -1088,17 +1082,8 @@ static void svm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long value,

static int pf_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
{
- u32 exit_int_info = svm->vmcb->control.exit_int_info;
- struct kvm *kvm = svm->vcpu.kvm;
u64 fault_address;
u32 error_code;
- bool event_injection = false;
-
- if (!irqchip_in_kernel(kvm) &&
- is_external_interrupt(exit_int_info)) {
- event_injection = true;
- kvm_push_irq(&svm->vcpu, exit_int_info & SVM_EVTINJ_VEC_MASK);
- }

fault_address = svm->vmcb->control.exit_info_2;
error_code = svm->vmcb->control.exit_info_1;
@@ -1118,9 +1103,11 @@ static int pf_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
*/
if (npt_enabled)
svm_flush_tlb(&svm->vcpu);
-
- if (!npt_enabled && event_injection)
- kvm_mmu_unprotect_page_virt(&svm->vcpu, fault_address);
+ else {
+ if (svm->vcpu.arch.interrupt.pending ||
+ svm->vcpu.arch.exception.pending)
+ kvm_mmu_unprotect_page_virt(&svm->vcpu, fault_address);
+ }
return kvm_mmu_page_fault(&svm->vcpu, fault_address, error_code);
}

@@ -2187,7 +2174,6 @@ static int handle_exit(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
}
}

- kvm_reput_irq(svm);

if (svm->vmcb->control.exit_code == SVM_EXIT_ERR) {
kvm_run->exit_reason = KVM_EXIT_FAIL_ENTRY;
@@ -2289,98 +2275,47 @@ static int svm_interrupt_allowed(struct kvm_vcpu *vcpu)
(svm->vcpu.arch.hflags & HF_GIF_MASK);
}

-static void svm_intr_assist(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
+static void enable_irq_window(struct kvm_vcpu *vcpu)
{
- struct vcpu_svm *svm = to_svm(vcpu);
- struct vmcb *vmcb = svm->vmcb;
- int intr_vector = -1;
-
- if ((vmcb->control.exit_int_info & SVM_EVTINJ_VALID) &&
- ((vmcb->control.exit_int_info & SVM_EVTINJ_TYPE_MASK) == 0)) {
- intr_vector = vmcb->control.exit_int_info &
- SVM_EVTINJ_VEC_MASK;
- vmcb->control.exit_int_info = 0;
- svm_inject_irq(svm, intr_vector);
- goto out;
- }
-
- if (vmcb->control.int_ctl & V_IRQ_MASK)
- goto out;
-
- if (!kvm_cpu_has_interrupt(vcpu))
- goto out;
-
- if (nested_svm_intr(svm))
- goto out;
-
- if (!(svm->vcpu.arch.hflags & HF_GIF_MASK))
- goto out;
-
- if (!(vmcb->save.rflags & X86_EFLAGS_IF) ||
- (vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK) ||
- (vmcb->control.event_inj & SVM_EVTINJ_VALID)) {
- /* unable to deliver irq, set pending irq */
- svm_set_vintr(svm);
- svm_inject_irq(svm, 0x0);
- goto out;
- }
- /* Okay, we can deliver the interrupt: grab it and update PIC state. */
- intr_vector = kvm_cpu_get_interrupt(vcpu);
- svm_inject_irq(svm, intr_vector);
-out:
- update_cr8_intercept(vcpu);
+ svm_set_vintr(to_svm(vcpu));
+ svm_inject_irq(to_svm(vcpu), 0x0);
}

-static void kvm_reput_irq(struct vcpu_svm *svm)
+static void svm_intr_inject(struct kvm_vcpu *vcpu)
{
- struct vmcb_control_area *control = &svm->vmcb->control;
-
- if ((control->int_ctl & V_IRQ_MASK)
- && !irqchip_in_kernel(svm->vcpu.kvm)) {
- control->int_ctl &= ~V_IRQ_MASK;
- kvm_push_irq(&svm->vcpu, control->int_vector);
+ /* try to reinject previous events if any */
+ if (vcpu->arch.interrupt.pending) {
+ svm_inject_irq(to_svm(vcpu), vcpu->arch.interrupt.nr);
+ return;
}

- svm->vcpu.arch.interrupt_window_open =
- !(control->int_state & SVM_INTERRUPT_SHADOW_MASK) &&
- (svm->vcpu.arch.hflags & HF_GIF_MASK);
-}
-
-static void svm_do_inject_vector(struct vcpu_svm *svm)
-{
- svm_inject_irq(svm, kvm_pop_irq(&svm->vcpu));
+ /* try to inject new event if pending */
+ if (kvm_cpu_has_interrupt(vcpu)) {
+ if (vcpu->arch.interrupt_window_open) {
+ kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu));
+ svm_inject_irq(to_svm(vcpu), vcpu->arch.interrupt.nr);
+ }
+ }
}

-static void do_interrupt_requests(struct kvm_vcpu *vcpu,
- struct kvm_run *kvm_run)
+static void svm_intr_assist(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
struct vcpu_svm *svm = to_svm(vcpu);
- struct vmcb_control_area *control = &svm->vmcb->control;
+ bool req_int_win = !irqchip_in_kernel(vcpu->kvm) &&
+ kvm_run->request_interrupt_window;

if (nested_svm_intr(svm))
- return;
+ goto out;

- svm->vcpu.arch.interrupt_window_open =
- (!(control->int_state & SVM_INTERRUPT_SHADOW_MASK) &&
- (svm->vmcb->save.rflags & X86_EFLAGS_IF) &&
- (svm->vcpu.arch.hflags & HF_GIF_MASK));
+ svm->vcpu.arch.interrupt_window_open = svm_interrupt_allowed(vcpu);

- if (svm->vcpu.arch.interrupt_window_open &&
- kvm_cpu_has_interrupt(&svm->vcpu))
- /*
- * If interrupts enabled, and not blocked by sti or mov ss. Good.
- */
- svm_do_inject_vector(svm);
+ svm_intr_inject(vcpu);

- /*
- * Interrupts blocked. Wait for unblock.
- */
- if (!svm->vcpu.arch.interrupt_window_open &&
- (kvm_cpu_has_interrupt(&svm->vcpu) ||
- kvm_run->request_interrupt_window))
- svm_set_vintr(svm);
- else
- svm_clear_vintr(svm);
+ if (kvm_cpu_has_interrupt(vcpu) || req_int_win)
+ enable_irq_window(vcpu);
+
+out:
+ update_cr8_intercept(vcpu);
}

static int svm_set_tss_addr(struct kvm *kvm, unsigned int addr)
@@ -2420,6 +2355,43 @@ static inline void sync_lapic_to_cr8(struct kvm_vcpu *vcpu)
svm->vmcb->control.int_ctl |= cr8 & V_TPR_MASK;
}

+static void svm_complete_interrupts(struct vcpu_svm *svm)
+{
+ u8 vector;
+ int type;
+ u32 exitintinfo = svm->vmcb->control.exit_int_info;
+
+ svm->vcpu.arch.nmi_injected = false;
+ kvm_clear_exception_queue(&svm->vcpu);
+ kvm_clear_interrupt_queue(&svm->vcpu);
+
+ if (!(exitintinfo & SVM_EXITINTINFO_VALID))
+ return;
+
+ vector = exitintinfo & SVM_EXITINTINFO_VEC_MASK;
+ type = exitintinfo & SVM_EXITINTINFO_TYPE_MASK;
+
+ switch (type) {
+ case SVM_EXITINTINFO_TYPE_NMI:
+ svm->vcpu.arch.nmi_injected = true;
+ break;
+ case SVM_EXITINTINFO_TYPE_EXEPT:
+ if (exitintinfo & SVM_EXITINTINFO_VALID_ERR) {
+ u32 err = svm->vmcb->control.exit_int_info_err;
+ kvm_queue_exception_e(&svm->vcpu, vector, err);
+
+ } else
+ kvm_queue_exception(&svm->vcpu, vector);
+ break;
+ case SVM_EXITINTINFO_TYPE_SOFT:
+ case SVM_EXITINTINFO_TYPE_INTR:
+ kvm_queue_interrupt(&svm->vcpu, vector);
+ break;
+ default:
+ break;
+ }
+}
+
#ifdef CONFIG_X86_64
#define R "r"
#else
@@ -2548,6 +2520,8 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
sync_cr8_to_lapic(vcpu);

svm->next_rip = 0;
+
+ svm_complete_interrupts(svm);
}

#undef R
@@ -2669,7 +2643,7 @@ static struct kvm_x86_ops svm_x86_ops = {
.queue_exception = svm_queue_exception,
.exception_injected = svm_exception_injected,
.inject_pending_irq = svm_intr_assist,
- .inject_pending_vectors = do_interrupt_requests,
+ .inject_pending_vectors = svm_intr_assist,
.interrupt_allowed = svm_interrupt_allowed,

.set_tss_addr = svm_set_tss_addr,
--
1.5.6.5