[PATCH v6 15/36] multi-process: setup memory manager for remote device

[elena.ufimtseva@oracle.com]

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

sync_sysmem_msg_t 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>
---
 MAINTAINERS              |  2 ++
 Makefile.target          |  2 ++
 exec.c                   | 17 +++++++++++
 include/exec/ram_addr.h  |  2 ++
 include/io/mpqemu-link.h | 12 ++++++++
 include/remote/memory.h  | 20 +++++++++++++
 io/mpqemu-link.c         | 13 +++++++++
 remote/memory.c          | 63 ++++++++++++++++++++++++++++++++++++++++
 8 files changed, 131 insertions(+)
 create mode 100644 include/remote/memory.h
 create mode 100644 remote/memory.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 970cdfc2ef..7b46ec2e71 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2823,6 +2823,8 @@ F: include/remote/pcihost.h
 F: remote/pcihost.c
 F: include/remote/machine.h
 F: remote/machine.c
+F: include/remote/memory.h
+F: remote/memory.c
 
 Build and test automation
 -------------------------
diff --git a/Makefile.target b/Makefile.target
index 70fa1eeca5..500fa07fda 100644
--- a/Makefile.target
+++ b/Makefile.target
@@ -143,6 +143,8 @@ remote-pci-tgt-obj-$(CONFIG_MPQEMU) += stubs/replay.o
 remote-pci-tgt-obj-$(CONFIG_MPQEMU) += stubs/xen-mapcache.o
 remote-pci-tgt-obj-$(CONFIG_MPQEMU) += stubs/audio.o
 remote-pci-tgt-obj-$(CONFIG_MPQEMU) += stubs/monitor.o
+
+remote-pci-tgt-obj-$(CONFIG_MPQEMU) += remote/memory.o
 endif
 
 #########################################################
diff --git a/exec.c b/exec.c
index 3bdad9d058..523e77dd09 100644
--- a/exec.c
+++ b/exec.c
@@ -2359,6 +2359,23 @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
 
     return block;
 }
+
+void qemu_ram_init_from_fd(MemoryRegion *mr, int fd, uint64_t size,
+                           ram_addr_t offset, Error **errp)
+{
+    char *name = g_strdup_printf("%d", fd);
+
+    memory_region_init(mr, NULL, name, size);
+    mr->ram = true;
+    mr->terminates = true;
+    mr->destructor = NULL;
+    mr->align = 0;
+    mr->ram_block = qemu_ram_alloc_from_fd(size, mr, RAM_SHARED, fd, offset,
+                                           errp);
+    mr->dirty_log_mask = tcg_enabled() ? (1 << DIRTY_MEMORY_CODE) : 0;
+
+    g_free(name);
+}
 #endif
 
 static
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 1b9f489ff0..d9d7314f51 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -122,6 +122,8 @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
 RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr,
                                  uint32_t ram_flags, int fd,
                                  off_t offset, Error **errp);
+void qemu_ram_init_from_fd(MemoryRegion *mr, int fd, uint64_t size,
+                           ram_addr_t offset, Error **errp);
 
 RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
                                   MemoryRegion *mr, Error **errp);
diff --git a/include/io/mpqemu-link.h b/include/io/mpqemu-link.h
index ef95599bca..d46cb81058 100644
--- a/include/io/mpqemu-link.h
+++ b/include/io/mpqemu-link.h
@@ -16,6 +16,8 @@
 
 #include "qom/object.h"
 #include "qemu/thread.h"
+#include "exec/cpu-common.h"
+#include "exec/hwaddr.h"
 
 #define TYPE_MPQEMU_LINK "mpqemu-link"
 #define MPQEMU_LINK(obj) \
@@ -27,15 +29,23 @@
 
 /**
  * mpqemu_cmd_t:
+ * SYNC_SYSMEM      Shares QEMU's RAM with remote device's RAM
  *
  * proc_cmd_t enum type to specify the command to be executed on the remote
  * device.
  */
 typedef enum {
     INIT = 0,
+    SYNC_SYSMEM,
     MAX,
 } mpqemu_cmd_t;
 
+typedef struct {
+    hwaddr gpas[REMOTE_MAX_FDS];
+    uint64_t sizes[REMOTE_MAX_FDS];
+    ram_addr_t offsets[REMOTE_MAX_FDS];
+} sync_sysmem_msg_t;
+
 /**
  * MPQemuMsg:
  * @cmd: The remote command
@@ -49,6 +59,7 @@ typedef enum {
  * MPQemuMsg Format of the message sent to the remote device from QEMU.
  *
  */
+
 typedef struct {
     mpqemu_cmd_t cmd;
     int bytestream;
@@ -56,6 +67,7 @@ typedef struct {
 
     union {
         uint64_t u64;
+        sync_sysmem_msg_t sync_sysmem;
     } data1;
 
     int fds[REMOTE_MAX_FDS];
diff --git a/include/remote/memory.h b/include/remote/memory.h
new file mode 100644
index 0000000000..e2e479bb6f
--- /dev/null
+++ b/include/remote/memory.h
@@ -0,0 +1,20 @@
+/*
+ * 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 "qemu/osdep.h"
+#include "exec/hwaddr.h"
+#include "io/mpqemu-link.h"
+
+void remote_sysmem_reconfig(MPQemuMsg *msg, Error **errp);
+
+#endif
diff --git a/io/mpqemu-link.c b/io/mpqemu-link.c
index fa9b3a66b1..330a6deffe 100644
--- a/io/mpqemu-link.c
+++ b/io/mpqemu-link.c
@@ -348,6 +348,19 @@ bool mpqemu_msg_valid(MPQemuMsg *msg)
             }
         }
     }
+     /* Verify message specific fields. */
+    switch (msg->cmd) {
+    case SYNC_SYSMEM:
+        if (msg->num_fds == 0 || msg->bytestream != 0) {
+            return false;
+        }
+        if (msg->size != sizeof(msg->data1)) {
+            return false;
+        }
+        break;
+    default:
+        break;
+    }
 
     return true;
 }
diff --git a/remote/memory.c b/remote/memory.c
new file mode 100644
index 0000000000..2c8b7bb42f
--- /dev/null
+++ b/remote/memory.c
@@ -0,0 +1,63 @@
+/*
+ * 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 <stdint.h>
+#include <sys/types.h>
+
+#include "qemu/osdep.h"
+#include "qemu/queue.h"
+#include "qemu-common.h"
+#include "remote/memory.h"
+#include "exec/memory.h"
+#include "exec/address-spaces.h"
+#include "cpu.h"
+#include "exec/ram_addr.h"
+#include "io/mpqemu-link.h"
+#include "qemu/main-loop.h"
+#include "qapi/error.h"
+
+void remote_sysmem_reconfig(MPQemuMsg *msg, Error **errp)
+{
+    sync_sysmem_msg_t *sysmem_info = &msg->data1.sync_sysmem;
+    MemoryRegion *sysmem, *subregion, *next;
+    Error *local_err = NULL;
+    int region;
+
+    sysmem = get_system_memory();
+
+    qemu_mutex_lock_iothread();
+
+    memory_region_transaction_begin();
+
+    QTAILQ_FOREACH_SAFE(subregion, &sysmem->subregions, subregions_link, next) {
+        if (subregion->ram) {
+            memory_region_del_subregion(sysmem, subregion);
+            qemu_ram_free(subregion->ram_block);
+        }
+    }
+
+    for (region = 0; region < msg->num_fds; region++) {
+        subregion = g_new(MemoryRegion, 1);
+        qemu_ram_init_from_fd(subregion, msg->fds[region],
+                              sysmem_info->sizes[region],
+                              sysmem_info->offsets[region], &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            break;
+        }
+
+        memory_region_add_subregion(sysmem, sysmem_info->gpas[region],
+                                    subregion);
+    }
+
+    memory_region_transaction_commit();
+
+    qemu_mutex_unlock_iothread();
+}
-- 
2.25.GIT