[v5,07/21] vhost: add vhost_set_log_base op

diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
index 72d1392..88d33fd 100644
--- a/hw/virtio/vhost-backend.c
+++ b/hw/virtio/vhost-backend.c
@@ -11,6 +11,7 @@ 
 #include "hw/virtio/vhost.h"
 #include "hw/virtio/vhost-backend.h"
 #include "qemu/error-report.h"
+#include "linux/vhost.h"
 
 #include <sys/ioctl.h>
 
@@ -49,12 +50,19 @@  static int vhost_kernel_get_vq_index(struct vhost_dev *dev, int idx)
     return idx - dev->vq_index;
 }
 
+static int vhost_set_log_base(struct vhost_dev *dev, uint64_t base)
+{
+    return vhost_kernel_call(dev, VHOST_SET_LOG_BASE, &base);
+}
+
 static const VhostOps kernel_ops = {
         .backend_type = VHOST_BACKEND_TYPE_KERNEL,
         .vhost_call = vhost_kernel_call,
         .vhost_backend_init = vhost_kernel_init,
         .vhost_backend_cleanup = vhost_kernel_cleanup,
         .vhost_backend_get_vq_index = vhost_kernel_get_vq_index,
+
+        .vhost_set_log_base = vhost_set_log_base,
 };
 
 int vhost_set_backend_type(struct vhost_dev *dev, VhostBackendType backend_type)
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index b11c0d2..fd4fcbf 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -242,7 +242,6 @@  static int vhost_user_call(struct vhost_dev *dev, unsigned long int request,
         break;
 
     case VHOST_USER_SET_FEATURES:
-    case VHOST_USER_SET_LOG_BASE:
     case VHOST_USER_SET_PROTOCOL_FEATURES:
         msg.u64 = *((__u64 *) arg);
         msg.size = sizeof(m.u64);
@@ -367,6 +366,20 @@  static int vhost_user_call(struct vhost_dev *dev, unsigned long int request,
     return 0;
 }
 
+static int vhost_set_log_base(struct vhost_dev *dev, uint64_t base)
+{
+    VhostUserMsg msg = {
+        .request = VHOST_USER_SET_LOG_BASE,
+        .flags = VHOST_USER_VERSION,
+        .u64 = base,
+        .size = sizeof(m.u64),
+    };
+
+    vhost_user_write(dev, &msg, NULL, 0);
+
+    return 0;
+}
+
 static int vhost_user_init(struct vhost_dev *dev, void *opaque)
 {
     unsigned long long features;
@@ -447,4 +460,6 @@  const VhostOps user_ops = {
         .vhost_backend_cleanup = vhost_user_cleanup,
         .vhost_backend_get_vq_index = vhost_user_get_vq_index,
         .vhost_backend_set_vring_enable = vhost_user_set_vring_enable,
+
+        .vhost_set_log_base = vhost_set_log_base,
 };
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 7bc3862..7f01cd6 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -366,7 +366,7 @@  static inline void vhost_dev_log_resize(struct vhost_dev* dev, uint64_t size)
 
     /* inform backend of log switching, this must be done before
        releasing the current log, to ensure no logging is lost */
-    r = dev->vhost_ops->vhost_call(dev, VHOST_SET_LOG_BASE, &log_base);
+    r = dev->vhost_ops->vhost_set_log_base(dev, log_base);
     assert(r >= 0);
     vhost_log_put(dev, true);
     dev->log = log;
@@ -1171,8 +1171,8 @@  int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
         hdev->log_size = vhost_get_log_size(hdev);
         hdev->log = vhost_log_get(hdev->log_size, share);
         log_base = (uintptr_t)hdev->log->log;
-        r = hdev->vhost_ops->vhost_call(hdev, VHOST_SET_LOG_BASE,
-                                        hdev->log_size ? &log_base : NULL);
+        r = hdev->vhost_ops->vhost_set_log_base(hdev,
+                                                hdev->log_size ? log_base : 0);
         if (r < 0) {
             r = -errno;
             goto fail_log;
diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
index 3a0f6e2..c6b688a 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -27,13 +27,18 @@  typedef int (*vhost_backend_cleanup)(struct vhost_dev *dev);
 typedef int (*vhost_backend_get_vq_index)(struct vhost_dev *dev, int idx);
 typedef int (*vhost_backend_set_vring_enable)(struct vhost_dev *dev, int enable);
 
+typedef int (*vhost_set_log_base_op)(struct vhost_dev *dev, uint64_t base);
+
 typedef struct VhostOps {
     VhostBackendType backend_type;
     vhost_call vhost_call;
+
     vhost_backend_init vhost_backend_init;
     vhost_backend_cleanup vhost_backend_cleanup;
     vhost_backend_get_vq_index vhost_backend_get_vq_index;
     vhost_backend_set_vring_enable vhost_backend_set_vring_enable;
+
+    vhost_set_log_base_op vhost_set_log_base;
 } VhostOps;
 
 extern const VhostOps user_ops;