[PATCH v7 12/21] multi-process: Connect Proxy Object with device in the remote process

[elena . ufimtseva]

From: Jagannathan Raman <jag.ra...@oracle.com>

Send a message to the remote process to connect PCI device with the
corresponding Proxy object in QEMU

Signed-off-by: Elena Ufimtseva <elena.ufimts...@oracle.com>
Signed-off-by: John G Johnson <john.g.john...@oracle.com>
Signed-off-by: Jagannathan Raman <jag.ra...@oracle.com>
---
 hw/i386/remote-msg.c     | 39 +++++++++++++++++++++++++++++++++++++++
 hw/pci/proxy.c           | 28 ++++++++++++++++++++++++++++
 include/hw/pci/proxy.h   |  1 +
 include/io/mpqemu-link.h |  1 +
 io/mpqemu-link.c         |  8 ++++++++
 5 files changed, 77 insertions(+)

diff --git a/hw/i386/remote-msg.c b/hw/i386/remote-msg.c
index 58e24ab2ad..68f50866bb 100644
--- a/hw/i386/remote-msg.c
+++ b/hw/i386/remote-msg.c
@@ -6,6 +6,11 @@
 #include "io/mpqemu-link.h"
 #include "qapi/error.h"
 #include "sysemu/runstate.h"
+#include "io/channel-util.h"
+#include "hw/pci/pci.h"
+
+static void process_connect_dev_msg(MPQemuMsg *msg, QIOChannel *com,
+                                    Error **errp);
 
 gboolean mpqemu_process_msg(QIOChannel *ioc, GIOCondition cond,
                             gpointer opaque)
@@ -34,6 +39,9 @@ gboolean mpqemu_process_msg(QIOChannel *ioc, GIOCondition 
cond,
     }
 
     switch (msg.cmd) {
+    case CONNECT_DEV:
+        process_connect_dev_msg(&msg, ioc, &local_err);
+        break;
     default:
         error_setg(&local_err, "Unknown command (%d) received from proxy \
                    in remote process pid=%d", msg.cmd, getpid());
@@ -50,3 +58,34 @@ gboolean mpqemu_process_msg(QIOChannel *ioc, GIOCondition 
cond,
 
     return TRUE;
 }
+
+static void process_connect_dev_msg(MPQemuMsg *msg, QIOChannel *com,
+                                    Error **errp)
+{
+    char *devid = (char *)msg->data2;
+    QIOChannel *dioc = NULL;
+    DeviceState *dev = NULL;
+    MPQemuMsg ret = { 0 };
+    int rc = 0;
+
+    g_assert(devid && (devid[msg->size - 1] == '\0'));
+
+    dev = qdev_find_recursive(sysbus_get_default(), devid);
+    if (!dev || !object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
+        rc = 0xff;
+        goto exit;
+    }
+
+    dioc = qio_channel_new_fd(msg->fds[0], errp);
+
+    qio_channel_add_watch(dioc, G_IO_IN | G_IO_HUP, mpqemu_process_msg,
+                          (void *)dev, NULL);
+
+exit:
+    ret.cmd = RET_MSG;
+    ret.bytestream = 0;
+    ret.data1.u64 = rc;
+    ret.size = sizeof(ret.data1);
+
+    mpqemu_msg_send(&ret, com);
+}
diff --git a/hw/pci/proxy.c b/hw/pci/proxy.c
index 6d62399c52..16649ed0ec 100644
--- a/hw/pci/proxy.c
+++ b/hw/pci/proxy.c
@@ -15,10 +15,38 @@
 #include "io/channel-util.h"
 #include "hw/qdev-properties.h"
 #include "monitor/monitor.h"
+#include "io/mpqemu-link.h"
 
 static void proxy_set_socket(PCIProxyDev *pdev, int fd, Error **errp)
 {
+    DeviceState *dev = DEVICE(pdev);
+    MPQemuMsg msg = { 0 };
+    int fds[2];
+    Error *local_err = NULL;
+
     pdev->com = qio_channel_new_fd(fd, errp);
+
+    if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds)) {
+        error_setg(errp, "Failed to create proxy channel with fd %d", fd);
+        return;
+    }
+
+    msg.cmd = CONNECT_DEV;
+    msg.bytestream = 1;
+    msg.data2 = (uint8_t *)dev->id;
+    msg.size = strlen(dev->id) + 1;
+    msg.num_fds = 1;
+    msg.fds[0] = fds[1];
+
+    (void)mpqemu_msg_send_reply_co(&msg, pdev->com, &local_err);
+    if (local_err) {
+        error_setg(errp, "Failed to send DEV_CONNECT to the remote process");
+        close(fds[0]);
+    } else {
+        pdev->dev = qio_channel_new_fd(fds[0], errp);
+    }
+
+    close(fds[1]);
 }
 
 static Property proxy_properties[] = {
diff --git a/include/hw/pci/proxy.h b/include/hw/pci/proxy.h
index c1c7142fa2..72dd7e0944 100644
--- a/include/hw/pci/proxy.h
+++ b/include/hw/pci/proxy.h
@@ -30,6 +30,7 @@ typedef struct PCIProxyDev {
     PCIDevice parent_dev;
     char *fd;
     QIOChannel *com;
+    QIOChannel *dev;
 } PCIProxyDev;
 
 typedef struct PCIProxyDevClass {
diff --git a/include/io/mpqemu-link.h b/include/io/mpqemu-link.h
index c6d2b6bf8b..d620806c17 100644
--- a/include/io/mpqemu-link.h
+++ b/include/io/mpqemu-link.h
@@ -36,6 +36,7 @@
 typedef enum {
     INIT = 0,
     SYNC_SYSMEM,
+    CONNECT_DEV,
     RET_MSG,
     MAX = INT_MAX,
 } MPQemuCmd;
diff --git a/io/mpqemu-link.c b/io/mpqemu-link.c
index 5887c8c6c0..54df3b254e 100644
--- a/io/mpqemu-link.c
+++ b/io/mpqemu-link.c
@@ -234,6 +234,14 @@ bool mpqemu_msg_valid(MPQemuMsg *msg)
             return false;
         }
         break;
+    case CONNECT_DEV:
+        if ((msg->num_fds != 1) ||
+            (msg->fds[0] == -1) ||
+            (msg->fds[0] == -1) ||
+            !msg->bytestream) {
+            return false;
+        }
+        break;
     default:
         break;
     }
-- 
2.25.GIT