From: TANG Tiancheng <lyndra@linux.alibaba.com>

vmstate_riscv_cpu was missing env.stimer and env.vstimer.
Without migrating these QEMUTimer fields, active S/VS-mode
timer events are lost after snapshot or migration.

Add VMSTATE_TIMER_PTR() entries to save and restore them.

Reviewed-by: LIU Zhiwei <zhiwei_liu@linux.alibaba.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Signed-off-by: TANG Tiancheng <lyndra@linux.alibaba.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20250911-timers-v3-4-60508f640050@linux.alibaba.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 target/riscv/machine.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/target/riscv/machine.c b/target/riscv/machine.c
index 1600ec44f0..51e0567ed3 100644
--- a/target/riscv/machine.c
+++ b/target/riscv/machine.c
@@ -400,6 +400,30 @@ static const VMStateDescription vmstate_ssp = {
     }
 };
 
+static bool sstc_timer_needed(void *opaque)
+{
+    RISCVCPU *cpu = opaque;
+    CPURISCVState *env = &cpu->env;
+
+    if (!cpu->cfg.ext_sstc) {
+        return false;
+    }
+
+    return env->stimer != NULL || env->vstimer != NULL;
+}
+
+static const VMStateDescription vmstate_sstc = {
+    .name = "cpu/timer",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .needed = sstc_timer_needed,
+    .fields = (const VMStateField[]) {
+        VMSTATE_TIMER_PTR(env.stimer, RISCVCPU),
+        VMSTATE_TIMER_PTR(env.vstimer, RISCVCPU),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
 const VMStateDescription vmstate_riscv_cpu = {
     .name = "cpu",
     .version_id = 10,
@@ -476,6 +500,7 @@ const VMStateDescription vmstate_riscv_cpu = {
         &vmstate_elp,
         &vmstate_ssp,
         &vmstate_ctr,
+        &vmstate_sstc,
         NULL
     }
 };
-- 
2.51.0