[PATCH v12 19/19] multi-process: perform device reset in the remote process

[Jagannathan Raman <jag.raman@oracle.com>]

From: Elena Ufimtseva <elena.ufimtseva@oracle.com>

Perform device reset in the remote process when QEMU performs
device reset. This is required to reset the internal state
(like registers, etc...) of emulated devices

Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 include/hw/remote/mpqemu-link.h |  1 +
 hw/remote/message.c             | 23 ++++++++++++++++++++++-
 hw/remote/proxy.c               | 20 ++++++++++++++++++++
 3 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/include/hw/remote/mpqemu-link.h b/include/hw/remote/mpqemu-link.h
index a0c5c5d..0b87293 100644
--- a/include/hw/remote/mpqemu-link.h
+++ b/include/hw/remote/mpqemu-link.h
@@ -39,6 +39,7 @@ typedef enum {
     BAR_WRITE,
     BAR_READ,
     SET_IRQFD,
+    DEVICE_RESET,
     MPQEMU_CMD_MAX,
 } MPQemuCmd;
 
diff --git a/hw/remote/message.c b/hw/remote/message.c
index a1b1018..f3af4c5 100644
--- a/hw/remote/message.c
+++ b/hw/remote/message.c
@@ -19,6 +19,7 @@
 #include "exec/memattrs.h"
 #include "hw/remote/memory.h"
 #include "hw/remote/iohub.h"
+#include "sysemu/reset.h"
 
 static void process_config_write(QIOChannel *ioc, PCIDevice *dev,
                                  MPQemuMsg *msg);
@@ -26,6 +27,8 @@ static void process_config_read(QIOChannel *ioc, PCIDevice *dev,
                                 MPQemuMsg *msg);
 static void process_bar_write(QIOChannel *ioc, MPQemuMsg *msg, Error **errp);
 static void process_bar_read(QIOChannel *ioc, MPQemuMsg *msg, Error **errp);
+static void process_device_reset_msg(QIOChannel *ioc, PCIDevice *dev,
+                                     Error **errp);
 
 void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
 {
@@ -72,7 +75,9 @@ void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
         case SET_IRQFD:
             process_set_irqfd_msg(pci_dev, &msg);
             break;
-
+        case DEVICE_RESET:
+            process_device_reset_msg(com->ioc, pci_dev, &local_err);
+            break;
         default:
             error_setg(&local_err,
                        "Unknown command (%d) received for device %s (pid=%d)",
@@ -218,3 +223,19 @@ fail:
                    "in remote process pid=%d", getpid());
     }
 }
+
+static void process_device_reset_msg(QIOChannel *ioc, PCIDevice *dev,
+                                     Error **errp)
+{
+    DeviceClass *dc = DEVICE_GET_CLASS(dev);
+    DeviceState *s = DEVICE(dev);
+    MPQemuMsg ret = { 0 };
+
+    if (dc->reset) {
+        dc->reset(s);
+    }
+
+    ret.cmd = RET_MSG;
+
+    mpqemu_msg_send(&ret, ioc, errp);
+}
diff --git a/hw/remote/proxy.c b/hw/remote/proxy.c
index a68ee66..5b7b14c 100644
--- a/hw/remote/proxy.c
+++ b/hw/remote/proxy.c
@@ -25,6 +25,7 @@
 #include "util/event_notifier-posix.c"
 
 static void probe_pci_info(PCIDevice *dev, Error **errp);
+static void proxy_device_reset(DeviceState *dev);
 
 static void proxy_set_socket(PCIProxyDev *pdev, int fd, Error **errp)
 {
@@ -199,6 +200,8 @@ static void pci_proxy_dev_class_init(ObjectClass *klass, void *data)
     k->config_read = pci_proxy_read_config;
     k->config_write = pci_proxy_write_config;
 
+    dc->reset = proxy_device_reset;
+
     device_class_set_props(dc, proxy_properties);
 }
 
@@ -356,3 +359,20 @@ static void probe_pci_info(PCIDevice *dev, Error **errp)
         }
     }
 }
+
+static void proxy_device_reset(DeviceState *dev)
+{
+    PCIProxyDev *pdev = PCI_PROXY_DEV(dev);
+    MPQemuMsg msg = { 0 };
+    Error *local_err = NULL;
+
+    msg.cmd = DEVICE_RESET;
+    msg.size = 0;
+
+    (void)mpqemu_msg_send_and_await_reply(&msg, pdev, &local_err);
+    if (local_err) {
+        error_report("Failed to send DEVICE_RESET to the remote process");
+        error_free(local_err);
+    }
+
+}
-- 
1.8.3.1