[PATCH RFC v2 09/16] vfio-user: region read/write

[Elena Ufimtseva]

From: John Johnson <john.g.johnson@oracle.com>

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>
---
 hw/vfio/user-protocol.h | 12 ++++++++++++
 hw/vfio/user.h          |  4 ++++
 hw/vfio/common.c        | 16 +++++++++++++--
 hw/vfio/user.c          | 43 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 73 insertions(+), 2 deletions(-)

diff --git a/hw/vfio/user-protocol.h b/hw/vfio/user-protocol.h
index 104bf4ff31..56904cf872 100644
--- a/hw/vfio/user-protocol.h
+++ b/hw/vfio/user-protocol.h
@@ -109,4 +109,16 @@ typedef struct {
     uint64_t offset;
 } VFIOUserRegionInfo;
 
+/*
+ * VFIO_USER_REGION_READ
+ * VFIO_USER_REGION_WRITE
+ */
+typedef struct {
+    VFIOUserHdr hdr;
+    uint64_t offset;
+    uint32_t region;
+    uint32_t count;
+    char data[];
+} VFIOUserRegionRW;
+
 #endif /* VFIO_USER_PROTOCOL_H */
diff --git a/hw/vfio/user.h b/hw/vfio/user.h
index f0122539ba..02f832a173 100644
--- a/hw/vfio/user.h
+++ b/hw/vfio/user.h
@@ -74,5 +74,9 @@ int vfio_user_validate_version(VFIODevice *vbasedev, Error 
**errp);
 int vfio_user_get_info(VFIODevice *vbasedev);
 int vfio_user_get_region_info(VFIODevice *vbasedev, int index,
                               struct vfio_region_info *info, VFIOUserFDs *fds);
+int vfio_user_region_read(VFIODevice *vbasedev, uint32_t index, uint64_t 
offset,
+                          uint32_t count, void *data);
+int vfio_user_region_write(VFIODevice *vbasedev, uint32_t index,
+                           uint64_t offset, uint32_t count, void *data);
 
 #endif /* VFIO_USER_H */
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 7d667b0533..a8b1ea9358 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -215,6 +215,7 @@ void vfio_region_write(void *opaque, hwaddr addr,
         uint32_t dword;
         uint64_t qword;
     } buf;
+    int ret;
 
     switch (size) {
     case 1:
@@ -234,7 +235,12 @@ void vfio_region_write(void *opaque, hwaddr addr,
         break;
     }
 
-    if (pwrite(vbasedev->fd, &buf, size, region->fd_offset + addr) != size) {
+    if (vbasedev->proxy != NULL) {
+        ret = vfio_user_region_write(vbasedev, region->nr, addr, size, &data);
+    } else {
+        ret = pwrite(vbasedev->fd, &buf, size, region->fd_offset + addr);
+    }
+    if (ret != size) {
         error_report("%s(%s:region%d+0x%"HWADDR_PRIx", 0x%"PRIx64
                      ",%d) failed: %m",
                      __func__, vbasedev->name, region->nr,
@@ -266,8 +272,14 @@ uint64_t vfio_region_read(void *opaque,
         uint64_t qword;
     } buf;
     uint64_t data = 0;
+    int ret;
 
-    if (pread(vbasedev->fd, &buf, size, region->fd_offset + addr) != size) {
+    if (vbasedev->proxy != NULL) {
+        ret = vfio_user_region_read(vbasedev, region->nr, addr, size, &buf);
+    } else {
+        ret = pread(vbasedev->fd, &buf, size, region->fd_offset + addr);
+    }
+    if (ret != size) {
         error_report("%s(%s:region%d+0x%"HWADDR_PRIx", %d) failed: %m",
                      __func__, vbasedev->name, region->nr,
                      addr, size);
diff --git a/hw/vfio/user.c b/hw/vfio/user.c
index 91b51f37df..83235b2411 100644
--- a/hw/vfio/user.c
+++ b/hw/vfio/user.c
@@ -767,3 +767,46 @@ int vfio_user_get_region_info(VFIODevice *vbasedev, int 
index,
     memcpy(info, &msgp->argsz, info->argsz);
     return 0;
 }
+
+int vfio_user_region_read(VFIODevice *vbasedev, uint32_t index, uint64_t 
offset,
+                                 uint32_t count, void *data)
+{
+    g_autofree VFIOUserRegionRW *msgp = NULL;
+    int size = sizeof(*msgp) + count;
+
+    msgp = g_malloc0(size);
+    vfio_user_request_msg(&msgp->hdr, VFIO_USER_REGION_READ, sizeof(*msgp), 0);
+    msgp->offset = offset;
+    msgp->region = index;
+    msgp->count = count;
+
+    vfio_user_send_recv(vbasedev->proxy, &msgp->hdr, NULL, size, 0);
+    if (msgp->hdr.flags & VFIO_USER_ERROR) {
+        return -msgp->hdr.error_reply;
+    } else if (msgp->count > count) {
+        return -E2BIG;
+    } else {
+        memcpy(data, &msgp->data, msgp->count);
+    }
+
+    return msgp->count;
+}
+
+int vfio_user_region_write(VFIODevice *vbasedev, uint32_t index,
+                           uint64_t offset, uint32_t count, void *data)
+{
+    g_autofree VFIOUserRegionRW *msgp = NULL;
+    int size = sizeof(*msgp) + count;
+
+    msgp = g_malloc0(size);
+    vfio_user_request_msg(&msgp->hdr, VFIO_USER_REGION_WRITE, size,
+                          VFIO_USER_NO_REPLY);
+    msgp->offset = offset;
+    msgp->region = index;
+    msgp->count = count;
+    memcpy(&msgp->data, data, count);
+
+    vfio_user_send(vbasedev->proxy, &msgp->hdr, NULL);
+
+    return count;
+}
-- 
2.25.1