[Qemu-devel] [PATCH v4 11/22] vhost-user: send log shm fd along with log_base

[marcandre . lureau]

From: Marc-André Lureau <address@hidden>

Send the shm for the dirty pages logging if the backend supports
VHOST_USER_PROTOCOL_F_LOG_SHMFD.

Signed-off-by: Marc-André Lureau <address@hidden>
---
 hw/virtio/vhost-backend.c         |  3 ++-
 hw/virtio/vhost-user.c            | 17 ++++++++++++++---
 hw/virtio/vhost.c                 |  5 +++--
 include/hw/virtio/vhost-backend.h |  4 +++-
 4 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
index bf2d1d4..3f2d6ea 100644
--- a/hw/virtio/vhost-backend.c
+++ b/hw/virtio/vhost-backend.c
@@ -66,7 +66,8 @@ static int vhost_scsi_get_abi_version(struct vhost_dev *dev, 
int *version)
     return vhost_kernel_call(dev, VHOST_SCSI_GET_ABI_VERSION, version);
 }
 
-static int vhost_set_log_base(struct vhost_dev *dev, uint64_t base)
+static int vhost_set_log_base(struct vhost_dev *dev, uint64_t base,
+                              struct vhost_log *log)
 {
     return vhost_kernel_call(dev, VHOST_SET_LOG_BASE, &base);
 }
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index d3334f5..3cb5559 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -26,7 +26,9 @@
 #define VHOST_MEMORY_MAX_NREGIONS    8
 
 #define VHOST_USER_F_PROTOCOL_FEATURES 30
-#define VHOST_USER_PROTOCOL_FEATURE_MASK 0x0ULL
+
+#define VHOST_USER_PROTOCOL_FEATURE_MASK 0x1ULL
+#define VHOST_USER_PROTOCOL_F_LOG_SHMFD 0
 
 typedef enum VhostUserRequest {
     VHOST_USER_NONE = 0,
@@ -182,8 +184,11 @@ static int vhost_scsi_get_abi_version(struct vhost_dev 
*dev, int *version)
     return -1;
 }
 
-static int vhost_set_log_base(struct vhost_dev *dev, uint64_t base)
+static int vhost_set_log_base(struct vhost_dev *dev, uint64_t base,
+                              struct vhost_log *log)
 {
+    int fds[VHOST_MEMORY_MAX_NREGIONS];
+    size_t fd_num = 0;
     VhostUserMsg msg = {
         .request = VHOST_USER_SET_LOG_BASE,
         .flags = VHOST_USER_VERSION,
@@ -191,7 +196,13 @@ static int vhost_set_log_base(struct vhost_dev *dev, 
uint64_t base)
         .size = sizeof(m.u64),
     };
 
-    vhost_user_write(dev, &msg, NULL, 0);
+    if (virtio_has_feature(dev->protocol_features,
+                           VHOST_USER_PROTOCOL_F_LOG_SHMFD) &&
+        log->fd != -1) {
+        fds[fd_num++] = log->fd;
+    }
+
+    vhost_user_write(dev, &msg, fds, fd_num);
 
     return 0;
 }
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 83ef164..0fa7b69 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -359,7 +359,7 @@ 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_set_log_base(dev, log_base);
+    r = dev->vhost_ops->vhost_set_log_base(dev, log_base, log);
     assert(r >= 0);
     vhost_log_put(dev, true);
     dev->log = log;
@@ -1167,7 +1167,8 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice 
*vdev)
         hdev->log = vhost_log_get(hdev->log_size, share);
         log_base = (uintptr_t)hdev->log->log;
         r = hdev->vhost_ops->vhost_set_log_base(hdev,
-                                                hdev->log_size ? log_base : 0);
+                                                hdev->log_size ? log_base : 0,
+                                                hdev->log);
         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 42cfb87..a87f0b3 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -20,6 +20,7 @@ typedef enum VhostBackendType {
 
 struct vhost_dev;
 struct vhost_memory;
+struct vhost_log;
 struct vhost_vring_file;
 struct vhost_vring_state;
 struct vhost_vring_addr;
@@ -36,7 +37,8 @@ typedef int (*vhost_scsi_clear_endpoint_op)(struct vhost_dev 
*dev,
                                             struct vhost_scsi_target *target);
 typedef int (*vhost_scsi_get_abi_version_op)(struct vhost_dev *dev,
                                              int *version);
-typedef int (*vhost_set_log_base_op)(struct vhost_dev *dev, uint64_t base);
+typedef int (*vhost_set_log_base_op)(struct vhost_dev *dev, uint64_t base,
+                                     struct vhost_log *log);
 typedef int (*vhost_set_mem_table_op)(struct vhost_dev *dev,
                                       struct vhost_memory *mem);
 typedef int (*vhost_set_vring_addr_op)(struct vhost_dev *dev,
-- 
2.4.3