[PATCH v10 09/19] multi-process: setup memory manager for remote device

[elena.ufimtseva@oracle.com]

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

SyncSysMemMsg message format is defined. It is used to send
file descriptors of the RAM regions to remote device.
RAM on the remote device is configured with a set of file descriptors.
Old RAM regions are deleted and new regions, each with an fd, is
added to the RAM.

Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Signed-off-by: John G Johnson <john.g.johnson@oracle.com>
Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 MAINTAINERS                     |  2 ++
 hw/i386/meson.build             |  1 +
 hw/i386/remote-memory.c         | 58 +++++++++++++++++++++++++++++++++
 include/hw/i386/remote-memory.h | 19 +++++++++++
 include/io/mpqemu-link.h        | 13 ++++++++
 io/mpqemu-link.c                | 11 +++++++
 6 files changed, 104 insertions(+)
 create mode 100644 hw/i386/remote-memory.c
 create mode 100644 include/hw/i386/remote-memory.h

diff --git a/MAINTAINERS b/MAINTAINERS
index ac8eefaa3f..14b8c005fc 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3050,6 +3050,8 @@ F: include/io/mpqemu-link.h
 F: hw/i386/remote-msg.c
 F: include/hw/i386/remote-obj.h
 F: hw/i386/remote-obj.c
+F: include/hw/i386/remote-memory.h
+F: hw/i386/remote-memory.c
 
 Build and test automation
 -------------------------
diff --git a/hw/i386/meson.build b/hw/i386/meson.build
index 7b35f35d86..36e151c80a 100644
--- a/hw/i386/meson.build
+++ b/hw/i386/meson.build
@@ -26,6 +26,7 @@ i386_ss.add(when: 'CONFIG_PC', if_true: files(
 i386_ss.add(when: 'CONFIG_MPQEMU', if_true: files('remote.c'))
 i386_ss.add(when: 'CONFIG_MPQEMU', if_true: files('remote-msg.c'))
 i386_ss.add(when: 'CONFIG_MPQEMU', if_true: files('remote-obj.c'))
+i386_ss.add(when: 'CONFIG_MPQEMU', if_true: files('remote-memory.c'))
 
 subdir('kvm')
 subdir('xen')
diff --git a/hw/i386/remote-memory.c b/hw/i386/remote-memory.c
new file mode 100644
index 0000000000..27bc8a7674
--- /dev/null
+++ b/hw/i386/remote-memory.c
@@ -0,0 +1,58 @@
+/*
+ * Memory manager for remote device
+ *
+ * Copyright © 2018, 2020 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+
+#include "hw/i386/remote-memory.h"
+#include "exec/address-spaces.h"
+#include "exec/ram_addr.h"
+#include "qapi/error.h"
+
+void remote_sysmem_reconfig(MPQemuMsg *msg, Error **errp)
+{
+    SyncSysmemMsg *sysmem_info = &msg->data.sync_sysmem;
+    MemoryRegion *sysmem, *subregion, *next;
+    static unsigned int suffix;
+    Error *local_err = NULL;
+    char *name;
+    int region;
+
+    sysmem = get_system_memory();
+
+    memory_region_transaction_begin();
+
+    QTAILQ_FOREACH_SAFE(subregion, &sysmem->subregions, subregions_link, next) {
+        if (subregion->ram) {
+            memory_region_del_subregion(sysmem, subregion);
+            object_unparent(OBJECT(subregion));
+        }
+    }
+
+    for (region = 0; region < msg->num_fds; region++) {
+        subregion = g_new(MemoryRegion, 1);
+        name = g_strdup_printf("remote-mem-%u", suffix++);
+        memory_region_init_ram_from_fd(subregion, NULL,
+                                       name, sysmem_info->sizes[region],
+                                       RAM_SHARED, msg->fds[region],
+                                       sysmem_info->offsets[region],
+                                       &local_err);
+        g_free(name);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            break;
+        }
+
+        memory_region_add_subregion(sysmem, sysmem_info->gpas[region],
+                                    subregion);
+    }
+
+    memory_region_transaction_commit();
+}
diff --git a/include/hw/i386/remote-memory.h b/include/hw/i386/remote-memory.h
new file mode 100644
index 0000000000..aab3e4d85d
--- /dev/null
+++ b/include/hw/i386/remote-memory.h
@@ -0,0 +1,19 @@
+/*
+ * Memory manager for remote device
+ *
+ * Copyright © 2018, 2020 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef REMOTE_MEMORY_H
+#define REMOTE_MEMORY_H
+
+#include "exec/hwaddr.h"
+#include "io/mpqemu-link.h"
+
+void remote_sysmem_reconfig(MPQemuMsg *msg, Error **errp);
+
+#endif
diff --git a/include/io/mpqemu-link.h b/include/io/mpqemu-link.h
index 3505e062dd..e33181ad80 100644
--- a/include/io/mpqemu-link.h
+++ b/include/io/mpqemu-link.h
@@ -14,6 +14,7 @@
 #include "qom/object.h"
 #include "qemu/thread.h"
 #include "io/channel.h"
+#include "exec/hwaddr.h"
 
 #define REMOTE_MAX_FDS 8
 
@@ -24,12 +25,22 @@
  *
  * MPQemuCmd enum type to specify the command to be executed on the remote
  * device.
+ *
+ * SYNC_SYSMEM      Shares QEMU's RAM with remote device's RAM
  */
 typedef enum {
     MPQEMU_CMD_INIT,
+    SYNC_SYSMEM,
+    RET_MSG,
     MPQEMU_CMD_MAX,
 } MPQemuCmd;
 
+typedef struct {
+    hwaddr gpas[REMOTE_MAX_FDS];
+    uint64_t sizes[REMOTE_MAX_FDS];
+    off_t offsets[REMOTE_MAX_FDS];
+} SyncSysmemMsg;
+
 /**
  * MPQemuMsg:
  * @cmd: The remote command
@@ -40,12 +51,14 @@ typedef enum {
  * MPQemuMsg Format of the message sent to the remote device from QEMU.
  *
  */
+
 typedef struct {
     int cmd;
     size_t size;
 
     union {
         uint64_t u64;
+        SyncSysmemMsg sync_sysmem;
     } data;
 
     int fds[REMOTE_MAX_FDS];
diff --git a/io/mpqemu-link.c b/io/mpqemu-link.c
index 42df2af229..8d966820a0 100644
--- a/io/mpqemu-link.c
+++ b/io/mpqemu-link.c
@@ -226,5 +226,16 @@ bool mpqemu_msg_valid(MPQemuMsg *msg)
         }
     }
 
+     /* Verify message specific fields. */
+    switch (msg->cmd) {
+    case SYNC_SYSMEM:
+        if (msg->num_fds == 0 || msg->size != sizeof(SyncSysmemMsg)) {
+            return false;
+        }
+        break;
+    default:
+        break;
+    }
+
     return true;
 }
-- 
2.25.GIT