From b6cc02d98fc6df49786608e5916f3de883a9461c Mon Sep 17 00:00:00 2001
From: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Date: Fri, 29 Jan 2021 11:46:21 -0500
Subject: [PATCH] multi-process: perform device reset in the remote process

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>
Message-id: 7cb220a51f565dc0817bd76e2f540e89c2d2b850.1611938319.git.jag.raman@oracle.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/remote/message.c             | 22 ++++++++++++++++++++++
 hw/remote/proxy.c               | 19 +++++++++++++++++++
 include/hw/remote/mpqemu-link.h |  1 +
 3 files changed, 42 insertions(+)

diff --git a/hw/remote/message.c b/hw/remote/message.c
index adab040ca1..11d729845c 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, Error **errp);
@@ -26,6 +27,8 @@ static void process_config_read(QIOChannel *ioc, PCIDevice *dev,
                                 MPQemuMsg *msg, Error **errp);
 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)
 {
@@ -69,6 +72,9 @@ void coroutine_fn mpqemu_remote_msg_loop_co(void *data)
         case MPQEMU_CMD_SET_IRQFD:
             process_set_irqfd_msg(pci_dev, &msg);
             break;
+        case MPQEMU_CMD_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"
@@ -206,3 +212,19 @@ fail:
                       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 = MPQEMU_CMD_RET;
+
+    mpqemu_msg_send(&ret, ioc, errp);
+}
diff --git a/hw/remote/proxy.c b/hw/remote/proxy.c
index a082709881..4fa4be079d 100644
--- a/hw/remote/proxy.c
+++ b/hw/remote/proxy.c
@@ -26,6 +26,7 @@
 #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_intx_update(PCIDevice *pci_dev)
 {
@@ -202,6 +203,8 @@ 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);
 }
 
@@ -358,3 +361,19 @@ 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 = MPQEMU_CMD_DEVICE_RESET;
+    msg.size = 0;
+
+    mpqemu_msg_send_and_await_reply(&msg, pdev, &local_err);
+    if (local_err) {
+        error_report_err(local_err);
+    }
+
+}
diff --git a/include/hw/remote/mpqemu-link.h b/include/hw/remote/mpqemu-link.h
index 71d206f00e..4ec0915885 100644
--- a/include/hw/remote/mpqemu-link.h
+++ b/include/hw/remote/mpqemu-link.h
@@ -40,6 +40,7 @@ typedef enum {
     MPQEMU_CMD_BAR_WRITE,
     MPQEMU_CMD_BAR_READ,
     MPQEMU_CMD_SET_IRQFD,
+    MPQEMU_CMD_DEVICE_RESET,
     MPQEMU_CMD_MAX,
 } MPQemuCmd;