Re: [Qemu-devel] [PATCH v2 3/4] contrib/libvhost-user: enable virtio config space messages

2017-08-09 Thread Marc-André Lureau 
Hi

- Original Message -
> Enable VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG/VHOST_USER_SET_CONFIG_FD
> messages in libvhost-user library, users can implement their own I/O target
> based on the library. This enable the virtio config space delivered between
> Qemu host device and the I/O target, also event notifier is added in case
> of virtio config space changed.
> 
> Signed-off-by: Changpeng Liu 
> ---
>  contrib/libvhost-user/libvhost-user.c | 51
>  +++
>  contrib/libvhost-user/libvhost-user.h | 14 ++
>  2 files changed, 65 insertions(+)
> 
> diff --git a/contrib/libvhost-user/libvhost-user.c
> b/contrib/libvhost-user/libvhost-user.c
> index 9efb9da..002cf15 100644
> --- a/contrib/libvhost-user/libvhost-user.c
> +++ b/contrib/libvhost-user/libvhost-user.c
> @@ -63,6 +63,9 @@ vu_request_to_string(int req)
>  REQ(VHOST_USER_SET_VRING_ENABLE),
>  REQ(VHOST_USER_SEND_RARP),
>  REQ(VHOST_USER_INPUT_GET_CONFIG),
> +REQ(VHOST_USER_GET_CONFIG),
> +REQ(VHOST_USER_SET_CONFIG),
> +REQ(VHOST_USER_SET_CONFIG_FD),
>  REQ(VHOST_USER_MAX),
>  };
>  #undef REQ
> @@ -744,6 +747,43 @@ vu_set_vring_enable_exec(VuDev *dev, VhostUserMsg *vmsg)
>  }
>  
>  static bool
> +vu_get_config(VuDev *dev, VhostUserMsg *vmsg)
> +{
> +if (dev->iface->get_config) {
> +dev->iface->get_config(dev, vmsg->payload.config, vmsg->size);

better check the return value on error to avoid sending garbage back to master.

> +}
> +
> +return true;
> +}
> +
> +static bool
> +vu_set_config(VuDev *dev, VhostUserMsg *vmsg)
> +{
> +if (dev->iface->set_config) {
> +dev->iface->set_config(dev, vmsg->payload.config, vmsg->size);

you could perhaps make that function return void instead (since error isn't 
reported to master)


> +}
> +
> +return false;
> +}
> +
> +static bool
> +vu_set_config_fd(VuDev *dev, VhostUserMsg *vmsg)
> +{
> +   if (vmsg->fd_num != 1) {
> +vu_panic(dev, "Invalid config_fd message");
> +return false;
> +}
> +
> +if (dev->config_fd != -1) {
> +close(dev->config_fd);
> +}
> +dev->config_fd = vmsg->fds[0];
> +DPRINT("Got config_fd: %d\n", vmsg->fds[0]);
> +
> +return false;
> +}
> +
> +static bool
>  vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
>  {
>  int do_reply = 0;
> @@ -806,6 +846,12 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
>  return vu_get_queue_num_exec(dev, vmsg);
>  case VHOST_USER_SET_VRING_ENABLE:
>  return vu_set_vring_enable_exec(dev, vmsg);
> +case VHOST_USER_GET_CONFIG:
> +return vu_get_config(dev, vmsg);
> +case VHOST_USER_SET_CONFIG:
> +return vu_set_config(dev, vmsg);
> +case VHOST_USER_SET_CONFIG_FD:
> +return vu_set_config_fd(dev, vmsg);
>  default:
>  vmsg_close_fds(vmsg);
>  vu_panic(dev, "Unhandled request: %d", vmsg->request);
> @@ -878,6 +924,10 @@ vu_deinit(VuDev *dev)
>  
>  vu_close_log(dev);
>  
> +if (dev->config_fd != -1) {
> +close(dev->config_fd);
> +}
> +
>  if (dev->sock != -1) {
>  close(dev->sock);
>  }
> @@ -907,6 +957,7 @@ vu_init(VuDev *dev,
>  dev->remove_watch = remove_watch;
>  dev->iface = iface;
>  dev->log_call_fd = -1;
> +dev->config_fd = -1;
>  for (i = 0; i < VHOST_MAX_NR_VIRTQUEUE; i++) {
>  dev->vq[i] = (VuVirtq) {
>  .call_fd = -1, .kick_fd = -1, .err_fd = -1,
> diff --git a/contrib/libvhost-user/libvhost-user.h
> b/contrib/libvhost-user/libvhost-user.h
> index 53ef222..899dee1 100644
> --- a/contrib/libvhost-user/libvhost-user.h
> +++ b/contrib/libvhost-user/libvhost-user.h
> @@ -30,6 +30,8 @@
>  
>  #define VHOST_MEMORY_MAX_NREGIONS 8
>  
> +#define VHOST_USER_MAX_CONFIG_SIZE 256
> +
>  enum VhostUserProtocolFeature {
>  VHOST_USER_PROTOCOL_F_MQ = 0,
>  VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
> @@ -62,6 +64,9 @@ typedef enum VhostUserRequest {
>  VHOST_USER_SET_VRING_ENABLE = 18,
>  VHOST_USER_SEND_RARP = 19,
>  VHOST_USER_INPUT_GET_CONFIG = 20,
> +VHOST_USER_GET_CONFIG = 24,
> +VHOST_USER_SET_CONFIG = 25,
> +VHOST_USER_SET_CONFIG_FD = 26,
>  VHOST_USER_MAX
>  } VhostUserRequest;
>  
> @@ -105,6 +110,7 @@ typedef struct VhostUserMsg {
>  struct vhost_vring_addr addr;
>  VhostUserMemory memory;
>  VhostUserLog log;
> +uint8_t config[VHOST_USER_MAX_CONFIG_SIZE];
>  } payload;
>  
>  int fds[VHOST_MEMORY_MAX_NREGIONS];
> @@ -132,6 +138,9 @@ typedef void (*vu_set_features_cb) (VuDev *dev, uint64_t
> features);
>  typedef int (*vu_process_msg_cb) (VuDev *dev, VhostUserMsg *vmsg,
>int *do_reply);
>  typedef void (*vu_queue_set_started_cb) (VuDev *dev, int qidx, bool
>  started);
> +typedef int (*vu_get_config_cb) (VuDev *dev, uint8_t *config, size_t len);
> +typedef int (*vu_set_config_cb)

[Qemu-devel] [PATCH v2 3/4] contrib/libvhost-user: enable virtio config space messages

2017-08-09 Thread Changpeng Liu 
Enable VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG/VHOST_USER_SET_CONFIG_FD
messages in libvhost-user library, users can implement their own I/O target
based on the library. This enable the virtio config space delivered between
Qemu host device and the I/O target, also event notifier is added in case
of virtio config space changed.

Signed-off-by: Changpeng Liu 
---
 contrib/libvhost-user/libvhost-user.c | 51 +++
 contrib/libvhost-user/libvhost-user.h | 14 ++
 2 files changed, 65 insertions(+)

diff --git a/contrib/libvhost-user/libvhost-user.c 
b/contrib/libvhost-user/libvhost-user.c
index 9efb9da..002cf15 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -63,6 +63,9 @@ vu_request_to_string(int req)
 REQ(VHOST_USER_SET_VRING_ENABLE),
 REQ(VHOST_USER_SEND_RARP),
 REQ(VHOST_USER_INPUT_GET_CONFIG),
+REQ(VHOST_USER_GET_CONFIG),
+REQ(VHOST_USER_SET_CONFIG),
+REQ(VHOST_USER_SET_CONFIG_FD),
 REQ(VHOST_USER_MAX),
 };
 #undef REQ
@@ -744,6 +747,43 @@ vu_set_vring_enable_exec(VuDev *dev, VhostUserMsg *vmsg)
 }
 
 static bool
+vu_get_config(VuDev *dev, VhostUserMsg *vmsg)
+{
+if (dev->iface->get_config) {
+dev->iface->get_config(dev, vmsg->payload.config, vmsg->size);
+}
+
+return true;
+}
+
+static bool
+vu_set_config(VuDev *dev, VhostUserMsg *vmsg)
+{
+if (dev->iface->set_config) {
+dev->iface->set_config(dev, vmsg->payload.config, vmsg->size);
+}
+
+return false;
+}
+
+static bool
+vu_set_config_fd(VuDev *dev, VhostUserMsg *vmsg)
+{
+   if (vmsg->fd_num != 1) {
+vu_panic(dev, "Invalid config_fd message");
+return false;
+}
+
+if (dev->config_fd != -1) {
+close(dev->config_fd);
+}
+dev->config_fd = vmsg->fds[0];
+DPRINT("Got config_fd: %d\n", vmsg->fds[0]);
+
+return false;
+}
+
+static bool
 vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
 {
 int do_reply = 0;
@@ -806,6 +846,12 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
 return vu_get_queue_num_exec(dev, vmsg);
 case VHOST_USER_SET_VRING_ENABLE:
 return vu_set_vring_enable_exec(dev, vmsg);
+case VHOST_USER_GET_CONFIG:
+return vu_get_config(dev, vmsg);
+case VHOST_USER_SET_CONFIG:
+return vu_set_config(dev, vmsg);
+case VHOST_USER_SET_CONFIG_FD:
+return vu_set_config_fd(dev, vmsg);
 default:
 vmsg_close_fds(vmsg);
 vu_panic(dev, "Unhandled request: %d", vmsg->request);
@@ -878,6 +924,10 @@ vu_deinit(VuDev *dev)
 
 vu_close_log(dev);
 
+if (dev->config_fd != -1) {
+close(dev->config_fd);
+}
+
 if (dev->sock != -1) {
 close(dev->sock);
 }
@@ -907,6 +957,7 @@ vu_init(VuDev *dev,
 dev->remove_watch = remove_watch;
 dev->iface = iface;
 dev->log_call_fd = -1;
+dev->config_fd = -1;
 for (i = 0; i < VHOST_MAX_NR_VIRTQUEUE; i++) {
 dev->vq[i] = (VuVirtq) {
 .call_fd = -1, .kick_fd = -1, .err_fd = -1,
diff --git a/contrib/libvhost-user/libvhost-user.h 
b/contrib/libvhost-user/libvhost-user.h
index 53ef222..899dee1 100644
--- a/contrib/libvhost-user/libvhost-user.h
+++ b/contrib/libvhost-user/libvhost-user.h
@@ -30,6 +30,8 @@
 
 #define VHOST_MEMORY_MAX_NREGIONS 8
 
+#define VHOST_USER_MAX_CONFIG_SIZE 256
+
 enum VhostUserProtocolFeature {
 VHOST_USER_PROTOCOL_F_MQ = 0,
 VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
@@ -62,6 +64,9 @@ typedef enum VhostUserRequest {
 VHOST_USER_SET_VRING_ENABLE = 18,
 VHOST_USER_SEND_RARP = 19,
 VHOST_USER_INPUT_GET_CONFIG = 20,
+VHOST_USER_GET_CONFIG = 24,
+VHOST_USER_SET_CONFIG = 25,
+VHOST_USER_SET_CONFIG_FD = 26,
 VHOST_USER_MAX
 } VhostUserRequest;
 
@@ -105,6 +110,7 @@ typedef struct VhostUserMsg {
 struct vhost_vring_addr addr;
 VhostUserMemory memory;
 VhostUserLog log;
+uint8_t config[VHOST_USER_MAX_CONFIG_SIZE];
 } payload;
 
 int fds[VHOST_MEMORY_MAX_NREGIONS];
@@ -132,6 +138,9 @@ typedef void (*vu_set_features_cb) (VuDev *dev, uint64_t 
features);
 typedef int (*vu_process_msg_cb) (VuDev *dev, VhostUserMsg *vmsg,
   int *do_reply);
 typedef void (*vu_queue_set_started_cb) (VuDev *dev, int qidx, bool started);
+typedef int (*vu_get_config_cb) (VuDev *dev, uint8_t *config, size_t len);
+typedef int (*vu_set_config_cb) (VuDev *dev, const uint8_t *config,
+ size_t len);
 
 typedef struct VuDevIface {
 /* called by VHOST_USER_GET_FEATURES to get the features bitmask */
@@ -148,6 +157,10 @@ typedef struct VuDevIface {
 vu_process_msg_cb process_msg;
 /* tells when queues can be processed */
 vu_queue_set_started_cb queue_set_started;
+/* get the config space of the device */
+vu_get_config_cb get_config;
+/* set the config space of the device */
+