[Qemu-devel] [PATCH] pseries: Implement RTAS system-reboot call

[David Gibson]

This patch adds the PAPR defined RTAS system-reboot call to the pseries
machine emulation, providing the guest with a way to trigger a reboot.
This exposes a bug in the pseries VIO code which means CRQs are not
properly reset on a system reset.  This patch also fixes that bug by
adding a suitable reset handler.

Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>

Conflicts:

        hw/spapr_vio.c
---
 hw/spapr_rtas.c |   14 ++++++++++++++
 hw/spapr_vio.c  |   33 +++++++++++++++++++++++++--------
 2 files changed, 39 insertions(+), 8 deletions(-)

diff --git a/hw/spapr_rtas.c b/hw/spapr_rtas.c
index 0946585..480a4ae 100644
--- a/hw/spapr_rtas.c
+++ b/hw/spapr_rtas.c
@@ -112,6 +112,19 @@ static void rtas_power_off(sPAPREnvironment *spapr,
     rtas_st(rets, 0, 0);
 }
 
+static void rtas_system_reboot(sPAPREnvironment *spapr,
+                               uint32_t token, uint32_t nargs,
+                               target_ulong args,
+                               uint32_t nret, target_ulong rets)
+{
+    if (nargs != 0 || nret != 1) {
+        rtas_st(rets, 0, -3);
+        return;
+    }
+    qemu_system_reset_request();
+    rtas_st(rets, 0, 0);
+}
+
 static void rtas_query_cpu_stopped_state(sPAPREnvironment *spapr,
                                          uint32_t token, uint32_t nargs,
                                          target_ulong args,
@@ -294,6 +307,7 @@ static void core_rtas_register_types(void)
     spapr_rtas_register("get-time-of-day", rtas_get_time_of_day);
     spapr_rtas_register("set-time-of-day", rtas_set_time_of_day);
     spapr_rtas_register("power-off", rtas_power_off);
+    spapr_rtas_register("system-reboot", rtas_system_reboot);
     spapr_rtas_register("query-cpu-stopped-state",
                         rtas_query_cpu_stopped_state);
     spapr_rtas_register("start-cpu", rtas_start_cpu);
diff --git a/hw/spapr_vio.c b/hw/spapr_vio.c
index dbf5a90..200f27c 100644
--- a/hw/spapr_vio.c
+++ b/hw/spapr_vio.c
@@ -435,12 +435,13 @@ static target_ulong h_reg_crq(CPUPPCState *env, 
sPAPREnvironment *spapr,
 
     /* Check if device supports CRQs */
     if (!dev->crq.SendFunc) {
+        hcall_dprintf("h_reg_crq, device does not support CRQ\n");
         return H_NOT_FOUND;
     }
 
-
     /* Already a queue ? */
     if (dev->crq.qsize) {
+        hcall_dprintf("h_reg_crq, CRQ already registered\n");
         return H_RESOURCE;
     }
     dev->crq.qladdr = queue_addr;
@@ -453,6 +454,17 @@ static target_ulong h_reg_crq(CPUPPCState *env, 
sPAPREnvironment *spapr,
     return H_SUCCESS;
 }
 
+static target_ulong free_crq(VIOsPAPRDevice *dev)
+{
+    dev->crq.qladdr = 0;
+    dev->crq.qsize = 0;
+    dev->crq.qnext = 0;
+
+    dprintf("CRQ for dev 0x%" PRIx32 " freed\n", dev->reg);
+
+    return H_SUCCESS;
+}
+
 static target_ulong h_free_crq(CPUPPCState *env, sPAPREnvironment *spapr,
                                target_ulong opcode, target_ulong *args)
 {
@@ -465,13 +477,7 @@ static target_ulong h_free_crq(CPUPPCState *env, 
sPAPREnvironment *spapr,
         return H_PARAMETER;
     }
 
-    dev->crq.qladdr = 0;
-    dev->crq.qsize = 0;
-    dev->crq.qnext = 0;
-
-    dprintf("CRQ for dev 0x" TARGET_FMT_lx " freed\n", reg);
-
-    return H_SUCCESS;
+    return free_crq(dev);
 }
 
 static target_ulong h_send_crq(CPUPPCState *env, sPAPREnvironment *spapr,
@@ -649,6 +655,15 @@ static int spapr_vio_check_reg(VIOsPAPRDevice *sdev)
     return 0;
 }
 
+static void spapr_vio_busdev_reset(void *opaque)
+{
+    VIOsPAPRDevice *dev = (VIOsPAPRDevice *)opaque;
+
+    if (dev->crq.qsize) {
+        free_crq(dev);
+    }
+}
+
 static int spapr_vio_busdev_init(DeviceState *qdev)
 {
     VIOsPAPRDevice *dev = (VIOsPAPRDevice *)qdev;
@@ -677,6 +692,8 @@ static int spapr_vio_busdev_init(DeviceState *qdev)
 
     rtce_init(dev);
 
+    qemu_register_reset(spapr_vio_busdev_reset, dev);
+
     return pc->init(dev);
 }
 
-- 
1.7.9.1