[Qemu-devel] [PATCH] save/restore interrupt_request across snapshots

[Jan Kiszka <jan.kiszka@siemens.com>]

Save interrupt_request state along with the cpu snapshot and restore it
properly. This also solves the bug that pending interrupts before
invocation of qemu_loadvm_state can tunnel into the resumed guest,
causing invalid IRQs there.

Implementation covers ARM, CRIS, x86, and SPARC, ie. those archs that
support snapshotting so far.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
 hw/etraxfs.c           |    2 +-
 hw/pc.c                |    2 +-
 hw/sun4m.c             |    6 +++---
 hw/sun4u.c             |    2 +-
 target-arm/cpu.h       |    2 +-
 target-arm/machine.c   |   10 +++++++++-
 target-cris/machine.c  |    8 ++++++++
 target-i386/machine.c  |    9 ++++++++-
 target-sparc/machine.c |    9 ++++++++-
 9 files changed, 40 insertions(+), 10 deletions(-)

Index: b/hw/pc.c
===================================================================
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -766,7 +766,7 @@ static void pc_init1(ram_addr_t ram_size
             /* XXX: enable it in all cases */
             env->cpuid_features |= CPUID_APIC;
         }
-        register_savevm("cpu", i, 5, cpu_save, cpu_load, env);
+        register_savevm("cpu", i, 6, cpu_save, cpu_load, env);
         qemu_register_reset(main_cpu_reset, env);
         if (pci_enabled) {
             apic_init(env);
Index: b/target-i386/machine.c
===================================================================
--- a/target-i386/machine.c
+++ b/target-i386/machine.c
@@ -135,6 +135,8 @@ void cpu_save(QEMUFile *f, void *opaque)
     qemu_put_be16s(f, &env->intercept_dr_write);
     qemu_put_be32s(f, &env->intercept_exceptions);
     qemu_put_8s(f, &env->v_tpr);
+
+    qemu_put_be32s(f, (uint32_t *)&env->interrupt_request);
 }
 
 #ifdef USE_X86LDOUBLE
@@ -169,7 +171,7 @@ int cpu_load(QEMUFile *f, void *opaque, 
     uint16_t fpus, fpuc, fptag, fpregs_format;
     int32_t a20_mask;
 
-    if (version_id != 3 && version_id != 4 && version_id != 5)
+    if (version_id < 3 || version_id > 6)
         return -EINVAL;
     for(i = 0; i < CPU_NB_REGS; i++)
         qemu_get_betls(f, &env->regs[i]);
@@ -292,6 +294,11 @@ int cpu_load(QEMUFile *f, void *opaque, 
         qemu_get_be32s(f, &env->intercept_exceptions);
         qemu_get_8s(f, &env->v_tpr);
     }
+    if (version_id >= 6) {
+        qemu_get_be32s(f, (uint32_t *)&env->interrupt_request);
+    } else {
+        env->interrupt_request = 0;
+    }
     /* XXX: ensure compatiblity for halted bit ? */
     /* XXX: compute redundant hflags bits */
     env->hflags = hflags;
Index: b/hw/etraxfs.c
===================================================================
--- a/hw/etraxfs.c
+++ b/hw/etraxfs.c
@@ -67,7 +67,7 @@ void bareetraxfs_init (ram_addr_t ram_si
         cpu_model = "crisv32";
     }
     env = cpu_init(cpu_model);
-    register_savevm("cpu", 0, 1, cpu_save, cpu_load, env);
+    register_savevm("cpu", 0, 2, cpu_save, cpu_load, env);
     qemu_register_reset(main_cpu_reset, env);
 
     /* allocate RAM */
Index: b/hw/sun4m.c
===================================================================
--- a/hw/sun4m.c
+++ b/hw/sun4m.c
@@ -404,7 +404,7 @@ static void sun4m_hw_init(const struct h
             qemu_register_reset(secondary_cpu_reset, env);
             env->halted = 1;
         }
-        register_savevm("cpu", i, 4, cpu_save, cpu_load, env);
+        register_savevm("cpu", i, 5, cpu_save, cpu_load, env);
         cpu_irqs[i] = qemu_allocate_irqs(cpu_set_irq, envs[i], MAX_PILS);
         env->prom_addr = hwdef->slavio_base;
     }
@@ -579,7 +579,7 @@ static void sun4c_hw_init(const struct h
     cpu_sparc_set_id(env, 0);
 
     qemu_register_reset(main_cpu_reset, env);
-    register_savevm("cpu", 0, 4, cpu_save, cpu_load, env);
+    register_savevm("cpu", 0, 5, cpu_save, cpu_load, env);
     cpu_irqs = qemu_allocate_irqs(cpu_set_irq, env, MAX_PILS);
     env->prom_addr = hwdef->slavio_base;
 
@@ -1391,7 +1391,7 @@ static void sun4d_hw_init(const struct s
             qemu_register_reset(secondary_cpu_reset, env);
             env->halted = 1;
         }
-        register_savevm("cpu", i, 4, cpu_save, cpu_load, env);
+        register_savevm("cpu", i, 5, cpu_save, cpu_load, env);
         cpu_irqs[i] = qemu_allocate_irqs(cpu_set_irq, envs[i], MAX_PILS);
         env->prom_addr = hwdef->slavio_base;
     }
Index: b/hw/sun4u.c
===================================================================
--- a/hw/sun4u.c
+++ b/hw/sun4u.c
@@ -260,7 +260,7 @@ static void sun4u_init(ram_addr_t RAM_si
     bh = qemu_bh_new(hstick_irq, env);
     env->hstick = ptimer_init(bh);
     ptimer_set_period(env->hstick, 1ULL);
-    register_savevm("cpu", 0, 4, cpu_save, cpu_load, env);
+    register_savevm("cpu", 0, 5, cpu_save, cpu_load, env);
     qemu_register_reset(main_cpu_reset, env);
     main_cpu_reset(env);
 
Index: b/target-arm/cpu.h
===================================================================
--- a/target-arm/cpu.h
+++ b/target-arm/cpu.h
@@ -397,7 +397,7 @@ void cpu_arm_set_cp_io(CPUARMState *env,
 #define cpu_signal_handler cpu_arm_signal_handler
 #define cpu_list arm_cpu_list
 
-#define ARM_CPU_SAVE_VERSION 1
+#define ARM_CPU_SAVE_VERSION 2
 
 /* MMU modes definitions */
 #define MMU_MODE0_SUFFIX _kernel
Index: b/target-arm/machine.c
===================================================================
--- a/target-arm/machine.c
+++ b/target-arm/machine.c
@@ -113,6 +113,8 @@ void cpu_save(QEMUFile *f, void *opaque)
         qemu_put_be32(f, env->v7m.current_sp);
         qemu_put_be32(f, env->v7m.exception);
     }
+
+    qemu_put_be32s(f, (uint32_t *)&env->interrupt_request);
 }
 
 int cpu_load(QEMUFile *f, void *opaque, int version_id)
@@ -120,7 +122,7 @@ int cpu_load(QEMUFile *f, void *opaque, 
     CPUARMState *env = (CPUARMState *)opaque;
     int i;
 
-    if (version_id != ARM_CPU_SAVE_VERSION)
+    if (version_id < 1 || version_id > ARM_CPU_SAVE_VERSION)
         return -EINVAL;
 
     for (i = 0; i < 16; i++) {
@@ -209,6 +211,12 @@ int cpu_load(QEMUFile *f, void *opaque, 
         env->v7m.exception = qemu_get_be32(f);
     }
 
+    if (version_id >= 2) {
+        qemu_get_be32s(f, (uint32_t *)&env->interrupt_request);
+    } else {
+        env->interrupt_request = 0;
+    }
+
     return 0;
 }
 
Index: b/target-cris/machine.c
===================================================================
--- a/target-cris/machine.c
+++ b/target-cris/machine.c
@@ -47,6 +47,8 @@ void cpu_save(QEMUFile *f, void *opaque)
             }
         }
     }
+
+    qemu_put_be32s(f, (uint32_t *)&env->interrupt_request);
 }
 
 int cpu_load(QEMUFile *f, void *opaque, int version_id)
@@ -91,5 +93,11 @@ int cpu_load(QEMUFile *f, void *opaque, 
         }
     }
 
+    if (version_id >= 2) {
+        qemu_get_be32s(f, (uint32_t *)&env->interrupt_request);
+    } else {
+        env->interrupt_request = 0;
+    }
+
     return 0;
 }
Index: b/target-sparc/machine.c
===================================================================
--- a/target-sparc/machine.c
+++ b/target-sparc/machine.c
@@ -58,6 +58,8 @@ void cpu_save(QEMUFile *f, void *opaque)
     for(i = 0; i < 16; i++)
         qemu_put_be32s(f, &env->mmuregs[i]);
 #endif
+
+    qemu_put_be32s(f, (uint32_t *)&env->interrupt_request);
 }
 
 int cpu_load(QEMUFile *f, void *opaque, int version_id)
@@ -66,7 +68,7 @@ int cpu_load(QEMUFile *f, void *opaque, 
     int i;
     uint32_t tmp;
 
-    if (version_id != 4)
+    if (version_id < 4 || version_id > 5)
         return -EINVAL;
     for(i = 0; i < 8; i++)
         qemu_get_betls(f, &env->gregs[i]);
@@ -99,6 +101,11 @@ int cpu_load(QEMUFile *f, void *opaque, 
     for(i = 0; i < 16; i++)
         qemu_get_be32s(f, &env->mmuregs[i]);
 #endif
+    if (version_id >= 5) {
+        qemu_get_be32s(f, (uint32_t *)&env->interrupt_request);
+    } else {
+        env->interrupt_request = 0;
+    }
     tlb_flush(env, 1);
     return 0;
 }