[PATCH 06/45] KVM: SVM: Add NMI injection support

From: Avi Kivity
Date: Sun May 24 2009 - 12:01:32 EST

From: Gleb Natapov <gleb@xxxxxxxxxx>

Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx>
Signed-off-by: Avi Kivity <avi@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 8 +++-
arch/x86/kvm/svm.c | 96 ++++++++++++++++++++-------------------
arch/x86/kvm/vmx.c | 79 ++++++++------------------------
arch/x86/kvm/x86.c | 71 ++++++++++++++++++++++++++++-
4 files changed, 145 insertions(+), 109 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 53533ea..dd9ecd3 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -512,10 +512,15 @@ struct kvm_x86_ops {
unsigned char *hypercall_addr);
int (*get_irq)(struct kvm_vcpu *vcpu);
void (*set_irq)(struct kvm_vcpu *vcpu, int vec);
+ void (*set_nmi)(struct kvm_vcpu *vcpu);
void (*queue_exception)(struct kvm_vcpu *vcpu, unsigned nr,
bool has_error_code, u32 error_code);
- void (*inject_pending_irq)(struct kvm_vcpu *vcpu, struct kvm_run *run);
int (*interrupt_allowed)(struct kvm_vcpu *vcpu);
+ int (*nmi_allowed)(struct kvm_vcpu *vcpu);
+ void (*enable_nmi_window)(struct kvm_vcpu *vcpu);
+ void (*enable_irq_window)(struct kvm_vcpu *vcpu);
+ void (*update_cr8_intercept)(struct kvm_vcpu *vcpu, int tpr, int irr);
+ void (*drop_interrupt_shadow)(struct kvm_vcpu *vcpu);
int (*set_tss_addr)(struct kvm *kvm, unsigned int addr);
int (*get_tdp_level)(void);
int (*get_mt_mask_shift)(void);
@@ -763,6 +768,7 @@ enum {
#define HF_GIF_MASK (1 << 0)
#define HF_HIF_MASK (1 << 1)
#define HF_VINTR_MASK (1 << 2)
+#define HF_NMI_MASK (1 << 3)

/*
* Hardware virtualization extension instructions may fault if a
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 0f53439..1807288 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1843,6 +1843,14 @@ static int cpuid_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
return 1;
}

+static int iret_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
+{
+ ++svm->vcpu.stat.nmi_window_exits;
+ svm->vmcb->control.intercept &= ~(1UL << INTERCEPT_IRET);
+ svm->vcpu.arch.hflags &= ~HF_NMI_MASK;
+ return 1;
+}
+
static int invlpg_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
{
if (emulate_instruction(&svm->vcpu, kvm_run, 0, 0, 0) != EMULATE_DONE)
@@ -1863,8 +1871,10 @@ static int cr8_write_interception(struct vcpu_svm *svm, struct kvm_run *kvm_run)
u8 cr8_prev = kvm_get_cr8(&svm->vcpu);
/* instruction emulation calls kvm_set_cr8() */
emulate_instruction(&svm->vcpu, NULL, 0, 0, 0);
- if (irqchip_in_kernel(svm->vcpu.kvm))
+ if (irqchip_in_kernel(svm->vcpu.kvm)) {
+ svm->vmcb->control.intercept_cr_write &= ~INTERCEPT_CR8_MASK;
return 1;
+ }
if (cr8_prev <= kvm_get_cr8(&svm->vcpu))
return 1;
kvm_run->exit_reason = KVM_EXIT_SET_TPR;
@@ -2120,6 +2130,7 @@ static int (*svm_exit_handlers[])(struct vcpu_svm *svm,
[SVM_EXIT_VINTR] = interrupt_window_interception,
/* [SVM_EXIT_CR0_SEL_WRITE] = emulate_on_interception, */
[SVM_EXIT_CPUID] = cpuid_interception,
+ [SVM_EXIT_IRET] = iret_interception,
[SVM_EXIT_INVD] = emulate_on_interception,
[SVM_EXIT_HLT] = halt_interception,
[SVM_EXIT_INVLPG] = invlpg_interception,
@@ -2227,6 +2238,21 @@ static void pre_svm_run(struct vcpu_svm *svm)
new_asid(svm, svm_data);
}

+static void svm_drop_interrupt_shadow(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_svm *svm = to_svm(vcpu);
+ svm->vmcb->control.int_state &= ~SVM_INTERRUPT_SHADOW_MASK;
+}
+
+static void svm_inject_nmi(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_svm *svm = to_svm(vcpu);
+
+ svm->vmcb->control.event_inj = SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_NMI;
+ vcpu->arch.hflags |= HF_NMI_MASK;
+ svm->vmcb->control.intercept |= (1UL << INTERCEPT_IRET);
+ ++vcpu->stat.nmi_injections;
+}

static inline void svm_inject_irq(struct vcpu_svm *svm, int irq)
{
@@ -2242,8 +2268,10 @@ static inline void svm_inject_irq(struct vcpu_svm *svm, int irq)
((/*control->int_vector >> 4*/ 0xf) << V_INTR_PRIO_SHIFT);
}

-static void svm_queue_irq(struct vcpu_svm *svm, unsigned nr)
+static void svm_queue_irq(struct kvm_vcpu *vcpu, unsigned nr)
{
+ struct vcpu_svm *svm = to_svm(vcpu);
+
svm->vmcb->control.event_inj = nr |
SVM_EVTINJ_VALID | SVM_EVTINJ_TYPE_INTR;
}
@@ -2254,28 +2282,26 @@ static void svm_set_irq(struct kvm_vcpu *vcpu, int irq)

nested_svm_intr(svm);

- svm_queue_irq(svm, irq);
+ svm_queue_irq(vcpu, irq);
}

-static void update_cr8_intercept(struct kvm_vcpu *vcpu)
+static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)
{
struct vcpu_svm *svm = to_svm(vcpu);
- struct vmcb *vmcb = svm->vmcb;
- int max_irr, tpr;

- if (!irqchip_in_kernel(vcpu->kvm) || vcpu->arch.apic->vapic_addr)
+ if (irr == -1)
return;

- vmcb->control.intercept_cr_write &= ~INTERCEPT_CR8_MASK;
-
- max_irr = kvm_lapic_find_highest_irr(vcpu);
- if (max_irr == -1)
- return;
-
- tpr = kvm_lapic_get_cr8(vcpu) << 4;
+ if (tpr >= irr)
+ svm->vmcb->control.intercept_cr_write |= INTERCEPT_CR8_MASK;
+}

- if (tpr >= (max_irr & 0xf0))
- vmcb->control.intercept_cr_write |= INTERCEPT_CR8_MASK;
+static int svm_nmi_allowed(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_svm *svm = to_svm(vcpu);
+ struct vmcb *vmcb = svm->vmcb;
+ return !(vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK) &&
+ !(svm->vcpu.arch.hflags & HF_NMI_MASK);
}

static int svm_interrupt_allowed(struct kvm_vcpu *vcpu)
@@ -2293,39 +2319,12 @@ static void enable_irq_window(struct kvm_vcpu *vcpu)
svm_inject_irq(to_svm(vcpu), 0x0);
}

-static void svm_intr_inject(struct kvm_vcpu *vcpu)
-{
- /* try to reinject previous events if any */
- if (vcpu->arch.interrupt.pending) {
- svm_queue_irq(to_svm(vcpu), vcpu->arch.interrupt.nr);
- return;
- }
-
- /* try to inject new event if pending */
- if (kvm_cpu_has_interrupt(vcpu)) {
- if (svm_interrupt_allowed(vcpu)) {
- kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu));
- svm_queue_irq(to_svm(vcpu), vcpu->arch.interrupt.nr);
- }
- }
-}
-
-static void svm_intr_assist(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
+static void enable_nmi_window(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
- bool req_int_win = !irqchip_in_kernel(vcpu->kvm) &&
- kvm_run->request_interrupt_window;

- if (nested_svm_intr(svm))
- goto out;
-
- svm_intr_inject(vcpu);
-
- if (kvm_cpu_has_interrupt(vcpu) || req_int_win)
+ if (svm->vmcb->control.int_state & SVM_INTERRUPT_SHADOW_MASK)
enable_irq_window(vcpu);
-
-out:
- update_cr8_intercept(vcpu);
}

static int svm_set_tss_addr(struct kvm *kvm, unsigned int addr)
@@ -2650,9 +2649,14 @@ static struct kvm_x86_ops svm_x86_ops = {
.patch_hypercall = svm_patch_hypercall,
.get_irq = svm_get_irq,
.set_irq = svm_set_irq,
+ .set_nmi = svm_inject_nmi,
.queue_exception = svm_queue_exception,
- .inject_pending_irq = svm_intr_assist,
.interrupt_allowed = svm_interrupt_allowed,
+ .nmi_allowed = svm_nmi_allowed,
+ .enable_nmi_window = enable_nmi_window,
+ .enable_irq_window = enable_irq_window,
+ .update_cr8_intercept = update_cr8_intercept,
+ .drop_interrupt_shadow = svm_drop_interrupt_shadow,

.set_tss_addr = svm_set_tss_addr,
.get_tdp_level = get_npt_level,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 116eac0..bad2413 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1314,6 +1314,9 @@ static __init int hardware_setup(void)
if (!cpu_has_vmx_flexpriority())
flexpriority_enabled = 0;

+ if (!cpu_has_vmx_tpr_shadow())
+ kvm_x86_ops->update_cr8_intercept = NULL;
+
return alloc_kvm_area();
}

@@ -2404,6 +2407,12 @@ out:
return ret;
}

+void vmx_drop_interrupt_shadow(struct kvm_vcpu *vcpu)
+{
+ vmcs_clear_bits(GUEST_INTERRUPTIBILITY_INFO,
+ GUEST_INTR_STATE_STI | GUEST_INTR_STATE_MOV_SS);
+}
+
static void enable_irq_window(struct kvm_vcpu *vcpu)
{
u32 cpu_based_vm_exec_control;
@@ -3214,21 +3223,14 @@ static int vmx_handle_exit(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
return 0;
}

-static void update_tpr_threshold(struct kvm_vcpu *vcpu)
+static void update_cr8_intercept(struct kvm_vcpu *vcpu, int tpr, int irr)
{
- int max_irr, tpr;
-
- if (!vm_need_tpr_shadow(vcpu->kvm))
- return;
-
- if (!kvm_lapic_enabled(vcpu) ||
- ((max_irr = kvm_lapic_find_highest_irr(vcpu)) == -1)) {
+ if (irr == -1 || tpr < irr) {
vmcs_write32(TPR_THRESHOLD, 0);
return;
}

- tpr = (kvm_lapic_get_cr8(vcpu) & 0x0f) << 4;
- vmcs_write32(TPR_THRESHOLD, (max_irr > tpr) ? tpr >> 4 : max_irr >> 4);
+ vmcs_write32(TPR_THRESHOLD, irr);
}

static void vmx_complete_interrupts(struct vcpu_vmx *vmx)
@@ -3300,55 +3302,6 @@ static void vmx_complete_interrupts(struct vcpu_vmx *vmx)
}
}

-static void vmx_intr_inject(struct kvm_vcpu *vcpu)
-{
- /* try to reinject previous events if any */
- if (vcpu->arch.nmi_injected) {
- vmx_inject_nmi(vcpu);
- return;
- }
-
- if (vcpu->arch.interrupt.pending) {
- vmx_inject_irq(vcpu, vcpu->arch.interrupt.nr);
- return;
- }
-
- /* try to inject new event if pending */
- if (vcpu->arch.nmi_pending) {
- if (vmx_nmi_allowed(vcpu)) {
- vcpu->arch.nmi_pending = false;
- vcpu->arch.nmi_injected = true;
- vmx_inject_nmi(vcpu);
- }
- } else if (kvm_cpu_has_interrupt(vcpu)) {
- if (vmx_interrupt_allowed(vcpu)) {
- kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu));
- vmx_inject_irq(vcpu, vcpu->arch.interrupt.nr);
- }
- }
-}
-
-static void vmx_intr_assist(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
-{
- bool req_int_win = !irqchip_in_kernel(vcpu->kvm) &&
- kvm_run->request_interrupt_window;
-
- update_tpr_threshold(vcpu);
-
- if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
- vmcs_clear_bits(GUEST_INTERRUPTIBILITY_INFO,
- GUEST_INTR_STATE_STI |
- GUEST_INTR_STATE_MOV_SS);
-
- vmx_intr_inject(vcpu);
-
- /* enable NMI/IRQ window open exits if needed */
- if (vcpu->arch.nmi_pending)
- enable_nmi_window(vcpu);
- else if (kvm_cpu_has_interrupt(vcpu) || req_int_win)
- enable_irq_window(vcpu);
-}
-
/*
* Failure to inject an interrupt should give us the information
* in IDT_VECTORING_INFO_FIELD. However, if the failure occurs
@@ -3683,9 +3636,15 @@ static struct kvm_x86_ops vmx_x86_ops = {
.patch_hypercall = vmx_patch_hypercall,
.get_irq = vmx_get_irq,
.set_irq = vmx_inject_irq,
+ .set_nmi = vmx_inject_nmi,
.queue_exception = vmx_queue_exception,
- .inject_pending_irq = vmx_intr_assist,
.interrupt_allowed = vmx_interrupt_allowed,
+ .nmi_allowed = vmx_nmi_allowed,
+ .enable_nmi_window = enable_nmi_window,
+ .enable_irq_window = enable_irq_window,
+ .update_cr8_intercept = update_cr8_intercept,
+ .drop_interrupt_shadow = vmx_drop_interrupt_shadow,
+
.set_tss_addr = vmx_set_tss_addr,
.get_tdp_level = get_ept_level,
.get_mt_mask_shift = vmx_get_mt_mask_shift,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 4bd56c7..b3ecaf8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3110,6 +3110,68 @@ static void vapic_exit(struct kvm_vcpu *vcpu)
up_read(&vcpu->kvm->slots_lock);
}

+static void update_cr8_intercept(struct kvm_vcpu *vcpu)
+{
+ int max_irr, tpr;
+
+ if (!kvm_x86_ops->update_cr8_intercept)
+ return;
+
+ max_irr = kvm_lapic_find_highest_irr(vcpu);
+
+ if (max_irr != -1)
+ max_irr >>= 4;
+
+ tpr = kvm_lapic_get_cr8(vcpu);
+
+ kvm_x86_ops->update_cr8_intercept(vcpu, tpr, max_irr);
+}
+
+static void inject_irq(struct kvm_vcpu *vcpu)
+{
+ /* try to reinject previous events if any */
+ if (vcpu->arch.nmi_injected) {
+ kvm_x86_ops->set_nmi(vcpu);
+ return;
+ }
+
+ if (vcpu->arch.interrupt.pending) {
+ kvm_x86_ops->set_irq(vcpu, vcpu->arch.interrupt.nr);
+ return;
+ }
+
+ /* try to inject new event if pending */
+ if (vcpu->arch.nmi_pending) {
+ if (kvm_x86_ops->nmi_allowed(vcpu)) {
+ vcpu->arch.nmi_pending = false;
+ vcpu->arch.nmi_injected = true;
+ kvm_x86_ops->set_nmi(vcpu);
+ }
+ } else if (kvm_cpu_has_interrupt(vcpu)) {
+ if (kvm_x86_ops->interrupt_allowed(vcpu)) {
+ kvm_queue_interrupt(vcpu, kvm_cpu_get_interrupt(vcpu));
+ kvm_x86_ops->set_irq(vcpu, vcpu->arch.interrupt.nr);
+ }
+ }
+}
+
+static void inject_pending_irq(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
+{
+ bool req_int_win = !irqchip_in_kernel(vcpu->kvm) &&
+ kvm_run->request_interrupt_window;
+
+ if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
+ kvm_x86_ops->drop_interrupt_shadow(vcpu);
+
+ inject_irq(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);
+}
+
static int vcpu_enter_guest(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
int r;
@@ -3168,9 +3230,14 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
if (vcpu->arch.exception.pending)
__queue_exception(vcpu);
else
- kvm_x86_ops->inject_pending_irq(vcpu, kvm_run);
+ inject_pending_irq(vcpu, kvm_run);

- kvm_lapic_sync_to_vapic(vcpu);
+ if (kvm_lapic_enabled(vcpu)) {
+ if (!vcpu->arch.apic->vapic_addr)
+ update_cr8_intercept(vcpu);
+ else
+ kvm_lapic_sync_to_vapic(vcpu);
+ }

up_read(&vcpu->kvm->slots_lock);

--
1.6.0.6

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/