[Qemu-devel] [PATCH 2/2] target-arm: Support save/load for 64 bit CPUs

[Peter Maydell <peter.maydell@linaro.org>]

For migration to work on 64 bit CPUs, we need to include both
the 64-bit integer register file and the PSTATE. Everything
else is either stored in the same place as existing 32-bit CPU
state or handled by the generic sysreg mechanism.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
The pstate save/load is a little ugly and suggests that we
could perhaps benefit from unifying the state storage/access
for 64-bit pstate and 32-bit PSR; however Alex had a go at
that a while back and it turns out to be trickier than it
looks. This is a pragmatic fix which makes save/load work
(and the on-the-wire state is right, at least).
---
 target-arm/machine.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/target-arm/machine.c b/target-arm/machine.c
index 6437690..c29e7a2 100644
--- a/target-arm/machine.c
+++ b/target-arm/machine.c
@@ -127,6 +127,13 @@ static int get_cpsr(QEMUFile *f, void *opaque, size_t size)
     CPUARMState *env = &cpu->env;
     uint32_t val = qemu_get_be32(f);
 
+    env->aarch64 = ((val & PSTATE_nRW) == 0);
+
+    if (is_a64(env)) {
+        pstate_write(env, val);
+        return 0;
+    }
+
     /* Avoid mode switch when restoring CPSR */
     env->uncached_cpsr = val & CPSR_M;
     cpsr_write(env, val, 0xffffffff);
@@ -137,8 +144,15 @@ static void put_cpsr(QEMUFile *f, void *opaque, size_t size)
 {
     ARMCPU *cpu = opaque;
     CPUARMState *env = &cpu->env;
+    uint32_t val;
+
+    if (is_a64(env)) {
+        val = pstate_read(env);
+    } else {
+        val = cpsr_read(env);
+    }
 
-    qemu_put_be32(f, cpsr_read(env));
+    qemu_put_be32(f, val);
 }
 
 static const VMStateInfo vmstate_cpsr = {
@@ -222,12 +236,14 @@ static int cpu_post_load(void *opaque, int version_id)
 
 const VMStateDescription vmstate_arm_cpu = {
     .name = "cpu",
-    .version_id = 21,
-    .minimum_version_id = 21,
+    .version_id = 22,
+    .minimum_version_id = 22,
     .pre_save = cpu_pre_save,
     .post_load = cpu_post_load,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32_ARRAY(env.regs, ARMCPU, 16),
+        VMSTATE_UINT64_ARRAY(env.xregs, ARMCPU, 32),
+        VMSTATE_UINT64(env.pc, ARMCPU),
         {
             .name = "cpsr",
             .version_id = 0,
-- 
1.9.1