[PATCH 35/35] KVM: x86: Add KVM_GET/SET_VCPU_EVENTS

Avi Kivity
2009-11-19T13:35:10Z

From: Jan Kiszka <jan.kiszka@web.de>

This new IOCTL exports all yet user-invisible states related to
exceptions, interrupts, and NMIs. Together with appropriate user space
changes, this fixes sporadic problems of vmsave/restore, live migration
and system reset.

[avi: future-proof abi by adding a flags field]

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
---
Documentation/kvm/api.txt | 49 +++++++++++++++++++++++++
arch/x86/include/asm/kvm.h | 28 ++++++++++++++
arch/x86/include/asm/kvm_host.h | 2 +
arch/x86/kvm/svm.c | 22 +++++++++++
arch/x86/kvm/vmx.c | 30 +++++++++++++++
arch/x86/kvm/x86.c | 77 +++++++++++++++++++++++++++++++++++++++
include/linux/kvm.h | 6 +++
7 files changed, 214 insertions(+), 0 deletions(-)

diff --git a/Documentation/kvm/api.txt b/Documentation/kvm/api.txt
index 36594ba..e1a1141 100644
--- a/Documentation/kvm/api.txt
+++ b/Documentation/kvm/api.txt
@@ -653,6 +653,55 @@ struct kvm_clock_data {
__u32 pad[9];
};

+4.29 KVM_GET_VCPU_EVENTS
+
+Capability: KVM_CAP_VCPU_EVENTS
+Architectures: x86
+Type: vm ioctl
+Parameters: struct kvm_vcpu_event (out)
+Returns: 0 on success, -1 on error
+
+Gets currently pending exceptions, interrupts, and NMIs as well as related
+states of the vcpu.
+
+struct kvm_vcpu_events {
+ struct {
+ __u8 injected;
+ __u8 nr;
+ __u8 has_error_code;
+ __u8 pad;
+ __u32 error_code;
+ } exception;
+ struct {
+ __u8 injected;
+ __u8 nr;
+ __u8 soft;
+ __u8 pad;
+ } interrupt;
+ struct {
+ __u8 injected;
+ __u8 pending;
+ __u8 masked;
+ __u8 pad;
+ } nmi;
+ __u32 sipi_vector;
+ __u32 flags; /* must be zero */
+};
+
+4.30 KVM_SET_VCPU_EVENTS
+
+Capability: KVM_CAP_VCPU_EVENTS
+Architectures: x86
+Type: vm ioctl
+Parameters: struct kvm_vcpu_event (in)
+Returns: 0 on success, -1 on error
+
+Set pending exceptions, interrupts, and NMIs as well as related states of the
+vcpu.
+
+See KVM_GET_VCPU_EVENTS for the data structure.
+
+
5. The kvm_run structure

Application code obtains a pointer to the kvm_run structure by
diff --git a/arch/x86/include/asm/kvm.h b/arch/x86/include/asm/kvm.h
index ef9b4b7..950df43 100644
--- a/arch/x86/include/asm/kvm.h
+++ b/arch/x86/include/asm/kvm.h
@@ -20,6 +20,7 @@
#define __KVM_HAVE_MCE
#define __KVM_HAVE_PIT_STATE2
#define __KVM_HAVE_XEN_HVM
+#define __KVM_HAVE_VCPU_EVENTS

/* Architectural interrupt line count. */
#define KVM_NR_INTERRUPTS 256
@@ -252,4 +253,31 @@ struct kvm_reinject_control {
__u8 pit_reinject;
__u8 reserved[31];
};
+
+/* for KVM_GET/SET_VCPU_EVENTS */
+struct kvm_vcpu_events {
+ struct {
+ __u8 injected;
+ __u8 nr;
+ __u8 has_error_code;
+ __u8 pad;
+ __u32 error_code;
+ } exception;
+ struct {
+ __u8 injected;
+ __u8 nr;
+ __u8 soft;
+ __u8 pad;
+ } interrupt;
+ struct {
+ __u8 injected;
+ __u8 pending;
+ __u8 masked;
+ __u8 pad;
+ } nmi;
+ __u32 sipi_vector;
+ __u32 flags;
+ __u32 reserved[10];
+};
+
#endif /* _ASM_X86_KVM_H */
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 26a74b7..06e0856 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -523,6 +523,8 @@ struct kvm_x86_ops {
bool has_error_code, u32 error_code);
int (*interrupt_allowed)(struct kvm_vcpu *vcpu);
int (*nmi_allowed)(struct kvm_vcpu *vcpu);
+ bool (*get_nmi_mask)(struct kvm_vcpu *vcpu);
+ void (*set_nmi_mask)(struct kvm_vcpu *vcpu, bool masked);
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);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 34b700f..3de0b37 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2499,6 +2499,26 @@ static int svm_nmi_allowed(struct kvm_vcpu *vcpu)
!(svm->vcpu.arch.hflags & HF_NMI_MASK);
}

+static bool svm_get_nmi_mask(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_svm *svm = to_svm(vcpu);
+
+ return !!(svm->vcpu.arch.hflags & HF_NMI_MASK);
+}
+
+static void svm_set_nmi_mask(struct kvm_vcpu *vcpu, bool masked)
+{
+ struct vcpu_svm *svm = to_svm(vcpu);
+
+ if (masked) {
+ svm->vcpu.arch.hflags |= HF_NMI_MASK;
+ svm->vmcb->control.intercept |= (1UL << INTERCEPT_IRET);
+ } else {
+ svm->vcpu.arch.hflags &= ~HF_NMI_MASK;
+ svm->vmcb->control.intercept &= ~(1UL << INTERCEPT_IRET);
+ }
+}
+
static int svm_interrupt_allowed(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
@@ -2946,6 +2966,8 @@ static struct kvm_x86_ops svm_x86_ops = {
.queue_exception = svm_queue_exception,
.interrupt_allowed = svm_interrupt_allowed,
.nmi_allowed = svm_nmi_allowed,
+ .get_nmi_mask = svm_get_nmi_mask,
+ .set_nmi_mask = svm_set_nmi_mask,
.enable_nmi_window = enable_nmi_window,
.enable_irq_window = enable_irq_window,
.update_cr8_intercept = update_cr8_intercept,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 22fcd27..778f059 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2639,6 +2639,34 @@ static int vmx_nmi_allowed(struct kvm_vcpu *vcpu)
GUEST_INTR_STATE_NMI));
}

+static bool vmx_get_nmi_mask(struct kvm_vcpu *vcpu)
+{
+ if (!cpu_has_virtual_nmis())
+ return to_vmx(vcpu)->soft_vnmi_blocked;
+ else
+ return !!(vmcs_read32(GUEST_INTERRUPTIBILITY_INFO) &
+ GUEST_INTR_STATE_NMI);
+}
+
+static void vmx_set_nmi_mask(struct kvm_vcpu *vcpu, bool masked)
+{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+
+ if (!cpu_has_virtual_nmis()) {
+ if (vmx->soft_vnmi_blocked != masked) {
+ vmx->soft_vnmi_blocked = masked;
+ vmx->vnmi_blocked_time = 0;
+ }
+ } else {
+ if (masked)
+ vmcs_set_bits(GUEST_INTERRUPTIBILITY_INFO,
+ GUEST_INTR_STATE_NMI);
+ else
+ vmcs_clear_bits(GUEST_INTERRUPTIBILITY_INFO,
+ GUEST_INTR_STATE_NMI);
+ }
+}
+
static int vmx_interrupt_allowed(struct kvm_vcpu *vcpu)
{
return (vmcs_readl(GUEST_RFLAGS) & X86_EFLAGS_IF) &&
@@ -3985,6 +4013,8 @@ static struct kvm_x86_ops vmx_x86_ops = {
.queue_exception = vmx_queue_exception,
.interrupt_allowed = vmx_interrupt_allowed,
.nmi_allowed = vmx_nmi_allowed,
+ .get_nmi_mask = vmx_get_nmi_mask,
+ .set_nmi_mask = vmx_set_nmi_mask,
.enable_nmi_window = enable_nmi_window,
.enable_irq_window = enable_irq_window,
.update_cr8_intercept = update_cr8_intercept,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ba8958d..35eea30 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1342,6 +1342,7 @@ int kvm_dev_ioctl_check_extension(long ext)
case KVM_CAP_SET_IDENTITY_MAP_ADDR:
case KVM_CAP_XEN_HVM:
case KVM_CAP_ADJUST_CLOCK:
+ case KVM_CAP_VCPU_EVENTS:
r = 1;
break;
case KVM_CAP_COALESCED_MMIO:
@@ -1883,6 +1884,61 @@ static int kvm_vcpu_ioctl_x86_set_mce(struct kvm_vcpu *vcpu,
return 0;
}

+static void kvm_vcpu_ioctl_x86_get_vcpu_events(struct kvm_vcpu *vcpu,
+ struct kvm_vcpu_events *events)
+{
+ vcpu_load(vcpu);
+
+ events->exception.injected = vcpu->arch.exception.pending;
+ events->exception.nr = vcpu->arch.exception.nr;
+ events->exception.has_error_code = vcpu->arch.exception.has_error_code;
+ events->exception.error_code = vcpu->arch.exception.error_code;
+
+ events->interrupt.injected = vcpu->arch.interrupt.pending;
+ events->interrupt.nr = vcpu->arch.interrupt.nr;
+ events->interrupt.soft = vcpu->arch.interrupt.soft;
+
+ events->nmi.injected = vcpu->arch.nmi_injected;
+ events->nmi.pending = vcpu->arch.nmi_pending;
+ events->nmi.masked = kvm_x86_ops->get_nmi_mask(vcpu);
+
+ events->sipi_vector = vcpu->arch.sipi_vector;
+
+ events->flags = 0;
+
+ vcpu_put(vcpu);
+}
+
+static int kvm_vcpu_ioctl_x86_set_vcpu_events(struct kvm_vcpu *vcpu,
+ struct kvm_vcpu_events *events)
+{
+ if (events->flags)
+ return -EINVAL;
+
+ vcpu_load(vcpu);
+
+ vcpu->arch.exception.pending = events->exception.injected;
+ vcpu->arch.exception.nr = events->exception.nr;
+ vcpu->arch.exception.has_error_code = events->exception.has_error_code;
+ vcpu->arch.exception.error_code = events->exception.error_code;
+
+ vcpu->arch.interrupt.pending = events->interrupt.injected;
+ vcpu->arch.interrupt.nr = events->interrupt.nr;
+ vcpu->arch.interrupt.soft = events->interrupt.soft;
+ if (vcpu->arch.interrupt.pending && irqchip_in_kernel(vcpu->kvm))
+ kvm_pic_clear_isr_ack(vcpu->kvm);
+
+ vcpu->arch.nmi_injected = events->nmi.injected;
+ vcpu->arch.nmi_pending = events->nmi.pending;
+ kvm_x86_ops->set_nmi_mask(vcpu, events->nmi.masked);
+
+ vcpu->arch.sipi_vector = events->sipi_vector;
+
+ vcpu_put(vcpu);
+
+ return 0;
+}
+
long kvm_arch_vcpu_ioctl(struct file *filp,
unsigned int ioctl, unsigned long arg)
{
@@ -2040,6 +2096,27 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
r = kvm_vcpu_ioctl_x86_set_mce(vcpu, &mce);
break;
}
+ case KVM_GET_VCPU_EVENTS: {
+ struct kvm_vcpu_events events;
+
+ kvm_vcpu_ioctl_x86_get_vcpu_events(vcpu, &events);
+
+ r = -EFAULT;
+ if (copy_to_user(argp, &events, sizeof(struct kvm_vcpu_events)))
+ break;
+ r = 0;
+ break;
+ }
+ case KVM_SET_VCPU_EVENTS: {
+ struct kvm_vcpu_events events;
+
+ r = -EFAULT;
+ if (copy_from_user(&events, argp, sizeof(struct kvm_vcpu_events)))
+ break;
+
+ r = kvm_vcpu_ioctl_x86_set_vcpu_events(vcpu, &events);
+ break;
+ }
default:
r = -EINVAL;
}
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 976f4d1..92045a9 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -489,6 +489,9 @@ struct kvm_ioeventfd {
#endif
#define KVM_CAP_ADJUST_CLOCK 39
#define KVM_CAP_INTERNAL_ERROR_DATA 40
+#ifdef __KVM_HAVE_VCPU_EVENTS
+#define KVM_CAP_VCPU_EVENTS 41
+#endif

#ifdef KVM_CAP_IRQ_ROUTING

@@ -672,6 +675,9 @@ struct kvm_clock_data {
/* IA64 stack access */
#define KVM_IA64_VCPU_GET_STACK _IOR(KVMIO, 0x9a, void *)
#define KVM_IA64_VCPU_SET_STACK _IOW(KVMIO, 0x9b, void *)
+/* Available with KVM_CAP_VCPU_EVENTS */
+#define KVM_GET_VCPU_EVENTS _IOR(KVMIO, 0x9f, struct kvm_vcpu_events)
+#define KVM_SET_VCPU_EVENTS _IOW(KVMIO, 0xa0, struct kvm_vcpu_events)

#define KVM_DEV_ASSIGN_ENABLE_IOMMU (1 << 0)

--
1.6.5.2