3 files changed, 71 insertions, 0 deletions

diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 784a4c2..91930fd 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -449,6 +449,12 @@ static void arm_cpu_set_irq(void *opaque, int irq, int level)
         [ARM_CPU_VFIQ] = CPU_INTERRUPT_VFIQ
     };
 
+    if (level) {
+        env->irq_line_state |= mask[irq];
+    } else {
+        env->irq_line_state &= ~mask[irq];
+    }
+
     switch (irq) {
     case ARM_CPU_VIRQ:
     case ARM_CPU_VFIQ:
@@ -471,19 +477,30 @@ static void arm_cpu_kvm_set_irq(void *opaque, int irq, int level)
 {
 #ifdef CONFIG_KVM
     ARMCPU *cpu = opaque;
+    CPUARMState *env = &cpu->env;
     CPUState *cs = CPU(cpu);
     int kvm_irq = KVM_ARM_IRQ_TYPE_CPU << KVM_ARM_IRQ_TYPE_SHIFT;
+    uint32_t linestate_bit;
 
     switch (irq) {
     case ARM_CPU_IRQ:
         kvm_irq |= KVM_ARM_IRQ_CPU_IRQ;
+        linestate_bit = CPU_INTERRUPT_HARD;
         break;
     case ARM_CPU_FIQ:
         kvm_irq |= KVM_ARM_IRQ_CPU_FIQ;
+        linestate_bit = CPU_INTERRUPT_FIQ;
         break;
     default:
         g_assert_not_reached();
     }
+
+    if (level) {
+        env->irq_line_state |= linestate_bit;
+    } else {
+        env->irq_line_state &= ~linestate_bit;
+    }
+
     kvm_irq |= cs->cpu_index << KVM_ARM_IRQ_VCPU_SHIFT;
     kvm_set_irq(kvm_state, kvm_irq, level ? 1 : 0);
 #endif
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 814ff69..2a73fed 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -538,6 +538,9 @@ typedef struct CPUARMState {
         uint64_t esr;
     } serror;
 
+    /* State of our input IRQ/FIQ/VIRQ/VFIQ lines */
+    uint32_t irq_line_state;
+
     /* Thumb-2 EE state.  */
     uint32_t teecr;
     uint32_t teehbr;
diff --git a/target/arm/machine.c b/target/arm/machine.c
index 239fe4e..2033816 100644
--- a/target/arm/machine.c
+++ b/target/arm/machine.c
@@ -192,6 +192,22 @@ static const VMStateDescription vmstate_serror = {
     }
 };
 
+static bool irq_line_state_needed(void *opaque)
+{
+    return true;
+}
+
+static const VMStateDescription vmstate_irq_line_state = {
+    .name = "cpu/irq-line-state",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = irq_line_state_needed,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(env.irq_line_state, ARMCPU),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 static bool m_needed(void *opaque)
 {
     ARMCPU *cpu = opaque;
@@ -625,11 +641,44 @@ static int cpu_pre_save(void *opaque)
     return 0;
 }
 
+static int cpu_pre_load(void *opaque)
+{
+    ARMCPU *cpu = opaque;
+    CPUARMState *env = &cpu->env;
+
+    /*
+     * Pre-initialize irq_line_state to a value that's never valid as
+     * real data, so cpu_post_load() can tell whether we've seen the
+     * irq-line-state subsection in the incoming migration state.
+     */
+    env->irq_line_state = UINT32_MAX;
+
+    return 0;
+}
+
 static int cpu_post_load(void *opaque, int version_id)
 {
     ARMCPU *cpu = opaque;
+    CPUARMState *env = &cpu->env;
     int i, v;
 
+    /*
+     * Handle migration compatibility from old QEMU which didn't
+     * send the irq-line-state subsection. A QEMU without it did not
+     * implement the HCR_EL2.{VI,VF} bits as generating interrupts,
+     * so for TCG the line state matches the bits set in cs->interrupt_request.
+     * For KVM the line state is not stored in cs->interrupt_request
+     * and so this will leave irq_line_state as 0, but this is OK because
+     * we only need to care about it for TCG.
+     */
+    if (env->irq_line_state == UINT32_MAX) {
+        CPUState *cs = CPU(cpu);
+
+        env->irq_line_state = cs->interrupt_request &
+            (CPU_INTERRUPT_HARD | CPU_INTERRUPT_FIQ |
+             CPU_INTERRUPT_VIRQ | CPU_INTERRUPT_VFIQ);
+    }
+
     /* Update the values list from the incoming migration data.
      * Anything in the incoming data which we don't know about is
      * a migration failure; anything we know about but the incoming
@@ -680,6 +729,7 @@ const VMStateDescription vmstate_arm_cpu = {
     .version_id = 22,
     .minimum_version_id = 22,
     .pre_save = cpu_pre_save,
+    .pre_load = cpu_pre_load,
     .post_load = cpu_post_load,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32_ARRAY(env.regs, ARMCPU, 16),
@@ -747,6 +797,7 @@ const VMStateDescription vmstate_arm_cpu = {
         &vmstate_sve,
 #endif
         &vmstate_serror,
+        &vmstate_irq_line_state,
         NULL
     }
 };