kvm: x86: Add support for VCPU event states

This patch extends the qemu-kvm state sync logic with support for
KVM_GET/SET_VCPU_EVENTS, giving access to yet missing exception,
interrupt and NMI states.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

kvm-all.c

@@ -61,6 +61,7 @@ struct KVMState
     int coalesced_mmio;
     int broken_set_mem_region;
     int migration_log;
+    int vcpu_events;
 #ifdef KVM_CAP_SET_GUEST_DEBUG
     struct kvm_sw_breakpoint_head kvm_sw_breakpoints;
 #endif
@@ -479,6 +480,11 @@ int kvm_init(int smp_cpus)
     }
 #endif
 
+    s->vcpu_events = 0;
+#ifdef KVM_CAP_VCPU_EVENTS
+    s->vcpu_events = kvm_check_extension(s, KVM_CAP_VCPU_EVENTS);
+#endif
+
     ret = kvm_arch_init(s, smp_cpus);
     if (ret < 0)
         goto err;
@@ -868,6 +874,11 @@ int kvm_has_sync_mmu(void)
 #endif
 }
 
+int kvm_has_vcpu_events(void)
+{
+    return kvm_state->vcpu_events;
+}
+
 void kvm_setup_guest_memory(void *start, size_t size)
 {
     if (!kvm_has_sync_mmu()) {

kvm.h

@@ -47,6 +47,7 @@ int kvm_log_stop(target_phys_addr_t phys_addr, ram_addr_t size);
 int kvm_set_migration_log(int enable);
 
 int kvm_has_sync_mmu(void);
+int kvm_has_vcpu_events(void);
 
 void kvm_setup_guest_memory(void *start, size_t size);
 

target-i386/cpu.h

@@ -693,6 +693,11 @@ typedef struct CPUX86State {
     /* For KVM */
     uint32_t mp_state;
     int32_t interrupt_injected;
+    uint8_t soft_interrupt;
+    uint8_t nmi_injected;
+    uint8_t nmi_pending;
+    uint8_t has_error_code;
+    uint32_t sipi_vector;
 
     /* in order to simplify APIC support, we leave this pointer to the
        user */

target-i386/kvm.c

@@ -225,6 +225,8 @@ int kvm_arch_init_vcpu(CPUState *env)
 void kvm_arch_reset_vcpu(CPUState *env)
 {
     env->interrupt_injected = -1;
+    env->nmi_injected = 0;
+    env->nmi_pending = 0;
 }
 
 static int kvm_has_msr_star(CPUState *env)
@@ -694,6 +696,73 @@ static int kvm_get_mp_state(CPUState *env)
     return 0;
 }
 
+static int kvm_put_vcpu_events(CPUState *env)
+{
+#ifdef KVM_CAP_VCPU_EVENTS
+    struct kvm_vcpu_events events;
+
+    if (!kvm_has_vcpu_events()) {
+        return 0;
+    }
+
+    events.exception.injected = (env->exception_index >= 0);
+    events.exception.nr = env->exception_index;
+    events.exception.has_error_code = env->has_error_code;
+    events.exception.error_code = env->error_code;
+
+    events.interrupt.injected = (env->interrupt_injected >= 0);
+    events.interrupt.nr = env->interrupt_injected;
+    events.interrupt.soft = env->soft_interrupt;
+
+    events.nmi.injected = env->nmi_injected;
+    events.nmi.pending = env->nmi_pending;
+    events.nmi.masked = !!(env->hflags2 & HF2_NMI_MASK);
+
+    events.sipi_vector = env->sipi_vector;
+
+    return kvm_vcpu_ioctl(env, KVM_SET_VCPU_EVENTS, &events);
+#else
+    return 0;
+#endif
+}
+
+static int kvm_get_vcpu_events(CPUState *env)
+{
+#ifdef KVM_CAP_VCPU_EVENTS
+    struct kvm_vcpu_events events;
+    int ret;
+
+    if (!kvm_has_vcpu_events()) {
+        return 0;
+    }
+
+    ret = kvm_vcpu_ioctl(env, KVM_GET_VCPU_EVENTS, &events);
+    if (ret < 0) {
+       return ret;
+    }
+    env->exception_index =
+       events.exception.injected ? events.exception.nr : -1;
+    env->has_error_code = events.exception.has_error_code;
+    env->error_code = events.exception.error_code;
+
+    env->interrupt_injected =
+        events.interrupt.injected ? events.interrupt.nr : -1;
+    env->soft_interrupt = events.interrupt.soft;
+
+    env->nmi_injected = events.nmi.injected;
+    env->nmi_pending = events.nmi.pending;
+    if (events.nmi.masked) {
+        env->hflags2 |= HF2_NMI_MASK;
+    } else {
+        env->hflags2 &= ~HF2_NMI_MASK;
+    }
+
+    env->sipi_vector = events.sipi_vector;
+#endif
+
+    return 0;
+}
+
 int kvm_arch_put_registers(CPUState *env)
 {
     int ret;
@@ -718,6 +787,10 @@ int kvm_arch_put_registers(CPUState *env)
     if (ret < 0)
         return ret;
 
+    ret = kvm_put_vcpu_events(env);
+    if (ret < 0)
+        return ret;
+
     return 0;
 }
 
@@ -745,6 +818,10 @@ int kvm_arch_get_registers(CPUState *env)
     if (ret < 0)
         return ret;
 
+    ret = kvm_get_vcpu_events(env);
+    if (ret < 0)
+        return ret;
+
     return 0;
 }
 

target-i386/machine.c

@@ -448,6 +448,11 @@ static const VMStateDescription vmstate_cpu = {
         VMSTATE_INT32_V(interrupt_injected, CPUState, 9),
         VMSTATE_UINT32_V(mp_state, CPUState, 9),
         VMSTATE_UINT64_V(tsc, CPUState, 9),
+        VMSTATE_UINT8_V(soft_interrupt, CPUState, 11),
+        VMSTATE_UINT8_V(nmi_injected, CPUState, 11),
+        VMSTATE_UINT8_V(nmi_pending, CPUState, 11),
+        VMSTATE_UINT8_V(has_error_code, CPUState, 11),
+        VMSTATE_UINT32_V(sipi_vector, CPUState, 11),
         /* MCE */
         VMSTATE_UINT64_V(mcg_cap, CPUState, 10),
         VMSTATE_UINT64_V(mcg_status, CPUState, 10),
@@ -456,6 +461,7 @@ static const VMStateDescription vmstate_cpu = {
         /* rdtscp */
         VMSTATE_UINT64_V(tsc_aux, CPUState, 11),
         VMSTATE_END_OF_LIST()
+        /* The above list is not sorted /wrt version numbers, watch out! */
     }
 };