1 files changed, 53 insertions, 1 deletions

diff --git a/target/arm/machine.c b/target/arm/machine.c
index 1f66da4a2c..3193b00b04 100644
--- a/target/arm/machine.c
+++ b/target/arm/machine.c
@@ -97,6 +97,17 @@ static bool m_needed(void *opaque)
     return arm_feature(env, ARM_FEATURE_M);
 }
 
+static const VMStateDescription vmstate_m_faultmask_primask = {
+    .name = "cpu/m/faultmask-primask",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(env.v7m.faultmask, ARMCPU),
+        VMSTATE_UINT32(env.v7m.primask, ARMCPU),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 static const VMStateDescription vmstate_m = {
     .name = "cpu/m",
     .version_id = 4,
@@ -115,6 +126,10 @@ static const VMStateDescription vmstate_m = {
         VMSTATE_UINT32(env.v7m.mpu_ctrl, ARMCPU),
         VMSTATE_INT32(env.v7m.exception, ARMCPU),
         VMSTATE_END_OF_LIST()
+    },
+    .subsections = (const VMStateDescription*[]) {
+        &vmstate_m_faultmask_primask,
+        NULL
     }
 };
 
@@ -201,6 +216,40 @@ static int get_cpsr(QEMUFile *f, void *opaque, size_t size,
     CPUARMState *env = &cpu->env;
     uint32_t val = qemu_get_be32(f);
 
+    if (arm_feature(env, ARM_FEATURE_M)) {
+        if (val & XPSR_EXCP) {
+            /* This is a CPSR format value from an older QEMU. (We can tell
+             * because values transferred in XPSR format always have zero
+             * for the EXCP field, and CPSR format will always have bit 4
+             * set in CPSR_M.) Rearrange it into XPSR format. The significant
+             * differences are that the T bit is not in the same place, the
+             * primask/faultmask info may be in the CPSR I and F bits, and
+             * we do not want the mode bits.
+             */
+            uint32_t newval = val;
+
+            newval &= (CPSR_NZCV | CPSR_Q | CPSR_IT | CPSR_GE);
+            if (val & CPSR_T) {
+                newval |= XPSR_T;
+            }
+            /* If the I or F bits are set then this is a migration from
+             * an old QEMU which still stored the M profile FAULTMASK
+             * and PRIMASK in env->daif. For a new QEMU, the data is
+             * transferred using the vmstate_m_faultmask_primask subsection.
+             */
+            if (val & CPSR_F) {
+                env->v7m.faultmask = 1;
+            }
+            if (val & CPSR_I) {
+                env->v7m.primask = 1;
+            }
+            val = newval;
+        }
+        /* Ignore the low bits, they are handled by vmstate_m. */
+        xpsr_write(env, val, ~XPSR_EXCP);
+        return 0;
+    }
+
     env->aarch64 = ((val & PSTATE_nRW) == 0);
 
     if (is_a64(env)) {
@@ -219,7 +268,10 @@ static int put_cpsr(QEMUFile *f, void *opaque, size_t size,
     CPUARMState *env = &cpu->env;
     uint32_t val;
 
-    if (is_a64(env)) {
+    if (arm_feature(env, ARM_FEATURE_M)) {
+        /* The low 9 bits are v7m.exception, which is handled by vmstate_m. */
+        val = xpsr_read(env) & ~XPSR_EXCP;
+    } else if (is_a64(env)) {
         val = pstate_read(env);
     } else {
         val = cpsr_read(env);