KVM: Check for pending events before attempting injection
Instead of blindly attempting to inject an event before each guest entry,
check for a possible event first in vcpu->requests. Sites that can trigger
event injection are modified to set KVM_REQ_EVENT:
- interrupt, nmi window opening
- ppr updates
- i8259 output changes
- local apic irr changes
- rflags updates
- gif flag set
- event set on exit
This improves non-injecting entry performance, and sets the stage for
non-atomic injection.
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 6e77471..ab1bb8f 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -67,6 +67,7 @@
if (!found)
return;
+ kvm_make_request(KVM_REQ_EVENT, found);
kvm_vcpu_kick(found);
}
}
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 77d8c0f..c6f2f15 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -259,9 +259,10 @@
static void apic_update_ppr(struct kvm_lapic *apic)
{
- u32 tpr, isrv, ppr;
+ u32 tpr, isrv, ppr, old_ppr;
int isr;
+ old_ppr = apic_get_reg(apic, APIC_PROCPRI);
tpr = apic_get_reg(apic, APIC_TASKPRI);
isr = apic_find_highest_isr(apic);
isrv = (isr != -1) ? isr : 0;
@@ -274,7 +275,10 @@
apic_debug("vlapic %p, ppr 0x%x, isr 0x%x, isrv 0x%x",
apic, ppr, isr, isrv);
- apic_set_reg(apic, APIC_PROCPRI, ppr);
+ if (old_ppr != ppr) {
+ apic_set_reg(apic, APIC_PROCPRI, ppr);
+ kvm_make_request(KVM_REQ_EVENT, apic->vcpu);
+ }
}
static void apic_set_tpr(struct kvm_lapic *apic, u32 tpr)
@@ -391,6 +395,7 @@
break;
}
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
kvm_vcpu_kick(vcpu);
break;
@@ -416,6 +421,7 @@
"INIT on a runnable vcpu %d\n",
vcpu->vcpu_id);
vcpu->arch.mp_state = KVM_MP_STATE_INIT_RECEIVED;
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
kvm_vcpu_kick(vcpu);
} else {
apic_debug("Ignoring de-assert INIT to vcpu %d\n",
@@ -430,6 +436,7 @@
result = 1;
vcpu->arch.sipi_vector = vector;
vcpu->arch.mp_state = KVM_MP_STATE_SIPI_RECEIVED;
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
kvm_vcpu_kick(vcpu);
}
break;
@@ -475,6 +482,7 @@
trigger_mode = IOAPIC_EDGE_TRIG;
if (!(apic_get_reg(apic, APIC_SPIV) & APIC_SPIV_DIRECTED_EOI))
kvm_ioapic_update_eoi(apic->vcpu->kvm, vector, trigger_mode);
+ kvm_make_request(KVM_REQ_EVENT, apic->vcpu);
}
static void apic_send_ipi(struct kvm_lapic *apic)
@@ -1152,6 +1160,7 @@
update_divide_count(apic);
start_apic_timer(apic);
apic->irr_pending = true;
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
}
void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index e0f4da0..1d2ea65 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2371,6 +2371,7 @@
svm->next_rip = kvm_rip_read(&svm->vcpu) + 3;
skip_emulated_instruction(&svm->vcpu);
+ kvm_make_request(KVM_REQ_EVENT, &svm->vcpu);
enable_gif(svm);
@@ -2763,6 +2764,7 @@
{
struct kvm_run *kvm_run = svm->vcpu.run;
+ kvm_make_request(KVM_REQ_EVENT, &svm->vcpu);
svm_clear_vintr(svm);
svm->vmcb->control.int_ctl &= ~V_IRQ_MASK;
/*
@@ -3209,8 +3211,10 @@
svm->int3_injected = 0;
- if (svm->vcpu.arch.hflags & HF_IRET_MASK)
+ if (svm->vcpu.arch.hflags & HF_IRET_MASK) {
svm->vcpu.arch.hflags &= ~(HF_NMI_MASK | HF_IRET_MASK);
+ kvm_make_request(KVM_REQ_EVENT, &svm->vcpu);
+ }
svm->vcpu.arch.nmi_injected = false;
kvm_clear_exception_queue(&svm->vcpu);
@@ -3219,6 +3223,8 @@
if (!(exitintinfo & SVM_EXITINTINFO_VALID))
return;
+ kvm_make_request(KVM_REQ_EVENT, &svm->vcpu);
+
vector = exitintinfo & SVM_EXITINTINFO_VEC_MASK;
type = exitintinfo & SVM_EXITINTINFO_TYPE_MASK;
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 1a7691a..2ce2e0b 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -3327,6 +3327,7 @@
static int handle_tpr_below_threshold(struct kvm_vcpu *vcpu)
{
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
return 1;
}
@@ -3339,6 +3340,8 @@
cpu_based_vm_exec_control &= ~CPU_BASED_VIRTUAL_INTR_PENDING;
vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
+
++vcpu->stat.irq_window_exits;
/*
@@ -3595,6 +3598,7 @@
cpu_based_vm_exec_control &= ~CPU_BASED_VIRTUAL_NMI_PENDING;
vmcs_write32(CPU_BASED_VM_EXEC_CONTROL, cpu_based_vm_exec_control);
++vcpu->stat.nmi_window_exits;
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
return 1;
}
@@ -3828,6 +3832,8 @@
if (!idtv_info_valid)
return;
+ kvm_make_request(KVM_REQ_EVENT, &vmx->vcpu);
+
vector = idt_vectoring_info & VECTORING_INFO_VECTOR_MASK;
type = idt_vectoring_info & VECTORING_INFO_TYPE_MASK;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 3ff0a8f..e719803 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -284,6 +284,8 @@
u32 prev_nr;
int class1, class2;
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
+
if (!vcpu->arch.exception.pending) {
queue:
vcpu->arch.exception.pending = true;
@@ -356,6 +358,7 @@
void kvm_inject_nmi(struct kvm_vcpu *vcpu)
{
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
vcpu->arch.nmi_pending = 1;
}
EXPORT_SYMBOL_GPL(kvm_inject_nmi);
@@ -2418,6 +2421,7 @@
return -ENXIO;
kvm_queue_interrupt(vcpu, irq->irq, false);
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
return 0;
}
@@ -2571,6 +2575,8 @@
if (events->flags & KVM_VCPUEVENT_VALID_SIPI_VECTOR)
vcpu->arch.sipi_vector = events->sipi_vector;
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
+
return 0;
}
@@ -4329,6 +4335,7 @@
toggle_interruptibility(vcpu, vcpu->arch.emulate_ctxt.interruptibility);
kvm_x86_ops->set_rflags(vcpu, vcpu->arch.emulate_ctxt.eflags);
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
memcpy(vcpu->arch.regs, c->regs, sizeof c->regs);
kvm_rip_write(vcpu, vcpu->arch.emulate_ctxt.eip);
@@ -4998,6 +5005,7 @@
int r;
bool req_int_win = !irqchip_in_kernel(vcpu->kvm) &&
vcpu->run->request_interrupt_window;
+ bool req_event;
if (vcpu->requests) {
if (kvm_check_request(KVM_REQ_MMU_RELOAD, vcpu))
@@ -5045,8 +5053,12 @@
local_irq_disable();
+ req_event = kvm_check_request(KVM_REQ_EVENT, vcpu);
+
if (!atomic_read(&vcpu->guest_mode) || vcpu->requests
|| need_resched() || signal_pending(current)) {
+ if (req_event)
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
atomic_set(&vcpu->guest_mode, 0);
smp_wmb();
local_irq_enable();
@@ -5055,17 +5067,19 @@
goto out;
}
- inject_pending_event(vcpu);
+ if (req_event || req_int_win) {
+ inject_pending_event(vcpu);
- /* enable NMI/IRQ window open exits if needed */
- if (vcpu->arch.nmi_pending)
- kvm_x86_ops->enable_nmi_window(vcpu);
- else if (kvm_cpu_has_interrupt(vcpu) || req_int_win)
- kvm_x86_ops->enable_irq_window(vcpu);
+ /* enable NMI/IRQ window open exits if needed */
+ if (vcpu->arch.nmi_pending)
+ kvm_x86_ops->enable_nmi_window(vcpu);
+ else if (kvm_cpu_has_interrupt(vcpu) || req_int_win)
+ kvm_x86_ops->enable_irq_window(vcpu);
- if (kvm_lapic_enabled(vcpu)) {
- update_cr8_intercept(vcpu);
- kvm_lapic_sync_to_vapic(vcpu);
+ if (kvm_lapic_enabled(vcpu)) {
+ update_cr8_intercept(vcpu);
+ kvm_lapic_sync_to_vapic(vcpu);
+ }
}
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
@@ -5305,6 +5319,8 @@
vcpu->arch.exception.pending = false;
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
+
return 0;
}
@@ -5368,6 +5384,7 @@
struct kvm_mp_state *mp_state)
{
vcpu->arch.mp_state = mp_state->mp_state;
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
return 0;
}
@@ -5389,6 +5406,7 @@
memcpy(vcpu->arch.regs, c->regs, sizeof c->regs);
kvm_rip_write(vcpu, vcpu->arch.emulate_ctxt.eip);
kvm_x86_ops->set_rflags(vcpu, vcpu->arch.emulate_ctxt.eflags);
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
return EMULATE_DONE;
}
EXPORT_SYMBOL_GPL(kvm_task_switch);
@@ -5459,6 +5477,8 @@
!is_protmode(vcpu))
vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
+
return 0;
}
@@ -5691,6 +5711,8 @@
vcpu->arch.dr6 = DR6_FIXED_1;
vcpu->arch.dr7 = DR7_FIXED_1;
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
+
return kvm_x86_ops->vcpu_reset(vcpu);
}
@@ -6001,6 +6023,7 @@
kvm_is_linear_rip(vcpu, vcpu->arch.singlestep_rip))
rflags |= X86_EFLAGS_TF;
kvm_x86_ops->set_rflags(vcpu, rflags);
+ kvm_make_request(KVM_REQ_EVENT, vcpu);
}
EXPORT_SYMBOL_GPL(kvm_set_rflags);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 917e68f..6022da1 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -39,6 +39,7 @@
#define KVM_REQ_KVMCLOCK_UPDATE 8
#define KVM_REQ_KICK 9
#define KVM_REQ_DEACTIVATE_FPU 10
+#define KVM_REQ_EVENT 11
#define KVM_USERSPACE_IRQ_SOURCE_ID 0