[Qemu-devel] [PATCH v8 3/4] contrib/libvhost-user: enable virtio config space messages

Changpeng Liu posted 4 patches 7 years, 9 months ago
There is a newer version of this series
[Qemu-devel] [PATCH v8 3/4] contrib/libvhost-user: enable virtio config space messages
Posted by Changpeng Liu 7 years, 9 months ago
Enable VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG 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.

Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
---
 contrib/libvhost-user/libvhost-user.c | 54 +++++++++++++++++++++++++++++++++++
 contrib/libvhost-user/libvhost-user.h | 34 +++++++++++++++++++++-
 2 files changed, 87 insertions(+), 1 deletion(-)

diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
index f409bd3..9e12eb1 100644
--- a/contrib/libvhost-user/libvhost-user.c
+++ b/contrib/libvhost-user/libvhost-user.c
@@ -84,6 +84,8 @@ vu_request_to_string(unsigned int req)
         REQ(VHOST_USER_SET_SLAVE_REQ_FD),
         REQ(VHOST_USER_IOTLB_MSG),
         REQ(VHOST_USER_SET_VRING_ENDIAN),
+        REQ(VHOST_USER_GET_CONFIG),
+        REQ(VHOST_USER_SET_CONFIG),
         REQ(VHOST_USER_MAX),
     };
 #undef REQ
@@ -798,6 +800,53 @@ vu_set_slave_req_fd(VuDev *dev, VhostUserMsg *vmsg)
 }
 
 static bool
+vu_get_config(VuDev *dev, VhostUserMsg *vmsg)
+{
+    int ret = -1;
+
+    if (dev->iface->get_config) {
+        ret = dev->iface->get_config(dev, vmsg->payload.config.region,
+                                     vmsg->payload.config.size);
+    }
+
+    if (ret) {
+        /* resize to zero to indicate an error to master */
+        vmsg->size = 0;
+    }
+
+    return true;
+}
+
+static bool
+vu_set_config(VuDev *dev, VhostUserMsg *vmsg)
+{
+    int ret = -1;
+    bool reply_supported = !!(dev->protocol_features &
+                             (1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK));
+
+    if (dev->iface->set_config) {
+        ret = dev->iface->set_config(dev, vmsg->payload.config.region,
+                                     vmsg->payload.config.offset,
+                                     vmsg->payload.config.size,
+                                     vmsg->payload.config.flags);
+    }
+
+    vmsg->size = sizeof(vmsg->payload.u64);
+    if (!ret) {
+        vmsg->payload.u64 = 0;
+    } else {
+        /* indicate an error in case reply supported */
+        vmsg->payload.u64 = 1;
+    }
+
+    if (reply_supported) {
+        return true;
+    }
+
+    return false;
+}
+
+static bool
 vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
 {
     int do_reply = 0;
@@ -862,6 +911,10 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
         return vu_set_vring_enable_exec(dev, vmsg);
     case VHOST_USER_SET_SLAVE_REQ_FD:
         return vu_set_slave_req_fd(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_NONE:
         break;
     default:
@@ -970,6 +1023,7 @@ vu_init(VuDev *dev,
     dev->iface = iface;
     dev->log_call_fd = -1;
     dev->slave_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 2f5864b..b38959e 100644
--- a/contrib/libvhost-user/libvhost-user.h
+++ b/contrib/libvhost-user/libvhost-user.h
@@ -30,6 +30,16 @@
 
 #define VHOST_MEMORY_MAX_NREGIONS 8
 
+typedef enum VhostSetConfigType {
+    VHOST_SET_CONFIG_TYPE_MASTER = 0,
+    VHOST_SET_CONFIG_TYPE_MIGRATION = 1,
+} VhostSetConfigType;
+
+/*
+ * Maximum size of virtio device config space
+ */
+#define VHOST_USER_MAX_CONFIG_SIZE 256
+
 enum VhostUserProtocolFeature {
     VHOST_USER_PROTOCOL_F_MQ = 0,
     VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
@@ -38,7 +48,6 @@ enum VhostUserProtocolFeature {
     VHOST_USER_PROTOCOL_F_NET_MTU = 4,
     VHOST_USER_PROTOCOL_F_SLAVE_REQ = 5,
     VHOST_USER_PROTOCOL_F_CROSS_ENDIAN = 6,
-
     VHOST_USER_PROTOCOL_F_MAX
 };
 
@@ -69,6 +78,8 @@ typedef enum VhostUserRequest {
     VHOST_USER_SET_SLAVE_REQ_FD = 21,
     VHOST_USER_IOTLB_MSG = 22,
     VHOST_USER_SET_VRING_ENDIAN = 23,
+    VHOST_USER_GET_CONFIG = 24,
+    VHOST_USER_SET_CONFIG = 25,
     VHOST_USER_MAX
 } VhostUserRequest;
 
@@ -90,6 +101,18 @@ typedef struct VhostUserLog {
     uint64_t mmap_offset;
 } VhostUserLog;
 
+typedef struct VhostUserConfig {
+    uint32_t offset;
+    uint32_t size;
+    uint32_t flags;
+    uint8_t region[VHOST_USER_MAX_CONFIG_SIZE];
+} VhostUserConfig;
+
+static VhostUserConfig c __attribute__ ((unused));
+#define VHOST_USER_CONFIG_HDR_SIZE (sizeof(c.offset) \
+                                   + sizeof(c.size) \
+                                   + sizeof(c.flags))
+
 #if defined(_WIN32)
 # define VU_PACKED __attribute__((gcc_struct, packed))
 #else
@@ -112,6 +135,7 @@ typedef struct VhostUserMsg {
         struct vhost_vring_addr addr;
         VhostUserMemory memory;
         VhostUserLog log;
+        VhostUserConfig config;
     } payload;
 
     int fds[VHOST_MEMORY_MAX_NREGIONS];
@@ -140,6 +164,10 @@ 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 bool (*vu_queue_is_processed_in_order_cb) (VuDev *dev, int qidx);
+typedef int (*vu_get_config_cb) (VuDev *dev, uint8_t *config, uint32_t len);
+typedef int (*vu_set_config_cb) (VuDev *dev, const uint8_t *data,
+                                 uint32_t offset, uint32_t size,
+                                 uint32_t flags);
 
 typedef struct VuDevIface {
     /* called by VHOST_USER_GET_FEATURES to get the features bitmask */
@@ -162,6 +190,10 @@ typedef struct VuDevIface {
      * on unmanaged exit/crash.
      */
     vu_queue_is_processed_in_order_cb queue_is_processed_in_order;
+    /* get the config space of the device */
+    vu_get_config_cb get_config;
+    /* set the config space of the device */
+    vu_set_config_cb set_config;
 } VuDevIface;
 
 typedef void (*vu_queue_handler_cb) (VuDev *dev, int qidx);
-- 
1.9.3


Re: [Qemu-devel] [PATCH v8 3/4] contrib/libvhost-user: enable virtio config space messages
Posted by Marc-André Lureau 7 years, 9 months ago
Hi

On Tue, Jan 2, 2018 at 4:55 AM, Changpeng Liu <changpeng.liu@intel.com> wrote:
> Enable VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG 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.
>
> Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
> ---
>  contrib/libvhost-user/libvhost-user.c | 54 +++++++++++++++++++++++++++++++++++
>  contrib/libvhost-user/libvhost-user.h | 34 +++++++++++++++++++++-
>  2 files changed, 87 insertions(+), 1 deletion(-)
>
> diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-user.c
> index f409bd3..9e12eb1 100644
> --- a/contrib/libvhost-user/libvhost-user.c
> +++ b/contrib/libvhost-user/libvhost-user.c
> @@ -84,6 +84,8 @@ vu_request_to_string(unsigned int req)
>          REQ(VHOST_USER_SET_SLAVE_REQ_FD),
>          REQ(VHOST_USER_IOTLB_MSG),
>          REQ(VHOST_USER_SET_VRING_ENDIAN),
> +        REQ(VHOST_USER_GET_CONFIG),
> +        REQ(VHOST_USER_SET_CONFIG),
>          REQ(VHOST_USER_MAX),
>      };
>  #undef REQ
> @@ -798,6 +800,53 @@ vu_set_slave_req_fd(VuDev *dev, VhostUserMsg *vmsg)
>  }
>
>  static bool
> +vu_get_config(VuDev *dev, VhostUserMsg *vmsg)
> +{
> +    int ret = -1;
> +
> +    if (dev->iface->get_config) {
> +        ret = dev->iface->get_config(dev, vmsg->payload.config.region,
> +                                     vmsg->payload.config.size);
> +    }
> +
> +    if (ret) {
> +        /* resize to zero to indicate an error to master */
> +        vmsg->size = 0;
> +    }
> +
> +    return true;
> +}
> +
> +static bool
> +vu_set_config(VuDev *dev, VhostUserMsg *vmsg)
> +{
> +    int ret = -1;
> +    bool reply_supported = !!(dev->protocol_features &
> +                             (1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK));
> +

None of the other messages in libvhost-user support the REPLY_ACK
flag. Do you need it? If not, please drop it.

If you need it, it's a better idea to make the reply explicit and
mandatory in the protocol for SET_CONFIG.

> +    if (dev->iface->set_config) {
> +        ret = dev->iface->set_config(dev, vmsg->payload.config.region,
> +                                     vmsg->payload.config.offset,
> +                                     vmsg->payload.config.size,
> +                                     vmsg->payload.config.flags);
> +    }
> +
> +    vmsg->size = sizeof(vmsg->payload.u64);
> +    if (!ret) {
> +        vmsg->payload.u64 = 0;
> +    } else {
> +        /* indicate an error in case reply supported */
> +        vmsg->payload.u64 = 1;
> +    }
> +
> +    if (reply_supported) {
> +        return true;
> +    }
> +
> +    return false;
> +}
> +
> +static bool
>  vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
>  {
>      int do_reply = 0;
> @@ -862,6 +911,10 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
>          return vu_set_vring_enable_exec(dev, vmsg);
>      case VHOST_USER_SET_SLAVE_REQ_FD:
>          return vu_set_slave_req_fd(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_NONE:
>          break;
>      default:
> @@ -970,6 +1023,7 @@ vu_init(VuDev *dev,
>      dev->iface = iface;
>      dev->log_call_fd = -1;
>      dev->slave_fd = -1;
> +

unrelated coding style change, please drop

>      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 2f5864b..b38959e 100644
> --- a/contrib/libvhost-user/libvhost-user.h
> +++ b/contrib/libvhost-user/libvhost-user.h
> @@ -30,6 +30,16 @@
>
>  #define VHOST_MEMORY_MAX_NREGIONS 8
>
> +typedef enum VhostSetConfigType {
> +    VHOST_SET_CONFIG_TYPE_MASTER = 0,
> +    VHOST_SET_CONFIG_TYPE_MIGRATION = 1,
> +} VhostSetConfigType;
> +
> +/*
> + * Maximum size of virtio device config space
> + */
> +#define VHOST_USER_MAX_CONFIG_SIZE 256
> +
>  enum VhostUserProtocolFeature {
>      VHOST_USER_PROTOCOL_F_MQ = 0,
>      VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
> @@ -38,7 +48,6 @@ enum VhostUserProtocolFeature {
>      VHOST_USER_PROTOCOL_F_NET_MTU = 4,
>      VHOST_USER_PROTOCOL_F_SLAVE_REQ = 5,
>      VHOST_USER_PROTOCOL_F_CROSS_ENDIAN = 6,
> -


unrelated coding style change, please drop

>      VHOST_USER_PROTOCOL_F_MAX
>  };
>
> @@ -69,6 +78,8 @@ typedef enum VhostUserRequest {
>      VHOST_USER_SET_SLAVE_REQ_FD = 21,
>      VHOST_USER_IOTLB_MSG = 22,
>      VHOST_USER_SET_VRING_ENDIAN = 23,
> +    VHOST_USER_GET_CONFIG = 24,
> +    VHOST_USER_SET_CONFIG = 25,
>      VHOST_USER_MAX
>  } VhostUserRequest;
>
> @@ -90,6 +101,18 @@ typedef struct VhostUserLog {
>      uint64_t mmap_offset;
>  } VhostUserLog;
>
> +typedef struct VhostUserConfig {
> +    uint32_t offset;
> +    uint32_t size;
> +    uint32_t flags;
> +    uint8_t region[VHOST_USER_MAX_CONFIG_SIZE];
> +} VhostUserConfig;
> +
> +static VhostUserConfig c __attribute__ ((unused));
> +#define VHOST_USER_CONFIG_HDR_SIZE (sizeof(c.offset) \
> +                                   + sizeof(c.size) \
> +                                   + sizeof(c.flags))
> +
>  #if defined(_WIN32)
>  # define VU_PACKED __attribute__((gcc_struct, packed))
>  #else
> @@ -112,6 +135,7 @@ typedef struct VhostUserMsg {
>          struct vhost_vring_addr addr;
>          VhostUserMemory memory;
>          VhostUserLog log;
> +        VhostUserConfig config;
>      } payload;
>
>      int fds[VHOST_MEMORY_MAX_NREGIONS];
> @@ -140,6 +164,10 @@ 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 bool (*vu_queue_is_processed_in_order_cb) (VuDev *dev, int qidx);
> +typedef int (*vu_get_config_cb) (VuDev *dev, uint8_t *config, uint32_t len);
> +typedef int (*vu_set_config_cb) (VuDev *dev, const uint8_t *data,
> +                                 uint32_t offset, uint32_t size,
> +                                 uint32_t flags);
>
>  typedef struct VuDevIface {
>      /* called by VHOST_USER_GET_FEATURES to get the features bitmask */
> @@ -162,6 +190,10 @@ typedef struct VuDevIface {
>       * on unmanaged exit/crash.
>       */
>      vu_queue_is_processed_in_order_cb queue_is_processed_in_order;
> +    /* get the config space of the device */
> +    vu_get_config_cb get_config;
> +    /* set the config space of the device */
> +    vu_set_config_cb set_config;
>  } VuDevIface;
>
>  typedef void (*vu_queue_handler_cb) (VuDev *dev, int qidx);
> --
> 1.9.3
>


-- 
Marc-André Lureau

Re: [Qemu-devel] [PATCH v8 3/4] contrib/libvhost-user: enable virtio config space messages
Posted by Liu, Changpeng 7 years, 9 months ago

> -----Original Message-----
> From: Marc-André Lureau [mailto:marcandre.lureau@gmail.com]
> Sent: Tuesday, January 2, 2018 11:30 PM
> To: Liu, Changpeng <changpeng.liu@intel.com>
> Cc: QEMU <qemu-devel@nongnu.org>; Harris, James R <james.r.harris@intel.com>;
> Michael S. Tsirkin <mst@redhat.com>; Stefan Hajnoczi <stefanha@gmail.com>;
> Paolo Bonzini <pbonzini@redhat.com>; Felipe Franciosi <felipe@nutanix.com>
> Subject: Re: [Qemu-devel] [PATCH v8 3/4] contrib/libvhost-user: enable virtio
> config space messages
> 
> Hi
> 
> On Tue, Jan 2, 2018 at 4:55 AM, Changpeng Liu <changpeng.liu@intel.com> wrote:
> > Enable VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG 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.
> >
> > Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
> > ---
> >  contrib/libvhost-user/libvhost-user.c | 54
> +++++++++++++++++++++++++++++++++++
> >  contrib/libvhost-user/libvhost-user.h | 34 +++++++++++++++++++++-
> >  2 files changed, 87 insertions(+), 1 deletion(-)
> >
> > diff --git a/contrib/libvhost-user/libvhost-user.c b/contrib/libvhost-user/libvhost-
> user.c
> > index f409bd3..9e12eb1 100644
> > --- a/contrib/libvhost-user/libvhost-user.c
> > +++ b/contrib/libvhost-user/libvhost-user.c
> > @@ -84,6 +84,8 @@ vu_request_to_string(unsigned int req)
> >          REQ(VHOST_USER_SET_SLAVE_REQ_FD),
> >          REQ(VHOST_USER_IOTLB_MSG),
> >          REQ(VHOST_USER_SET_VRING_ENDIAN),
> > +        REQ(VHOST_USER_GET_CONFIG),
> > +        REQ(VHOST_USER_SET_CONFIG),
> >          REQ(VHOST_USER_MAX),
> >      };
> >  #undef REQ
> > @@ -798,6 +800,53 @@ vu_set_slave_req_fd(VuDev *dev, VhostUserMsg *vmsg)
> >  }
> >
> >  static bool
> > +vu_get_config(VuDev *dev, VhostUserMsg *vmsg)
> > +{
> > +    int ret = -1;
> > +
> > +    if (dev->iface->get_config) {
> > +        ret = dev->iface->get_config(dev, vmsg->payload.config.region,
> > +                                     vmsg->payload.config.size);
> > +    }
> > +
> > +    if (ret) {
> > +        /* resize to zero to indicate an error to master */
> > +        vmsg->size = 0;
> > +    }
> > +
> > +    return true;
> > +}
> > +
> > +static bool
> > +vu_set_config(VuDev *dev, VhostUserMsg *vmsg)
> > +{
> > +    int ret = -1;
> > +    bool reply_supported = !!(dev->protocol_features &
> > +                             (1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK));
> > +
> 
> None of the other messages in libvhost-user support the REPLY_ACK
> flag. Do you need it? If not, please drop it.
Ok, will drop it.
> 
> If you need it, it's a better idea to make the reply explicit and
> mandatory in the protocol for SET_CONFIG.
> 
> > +    if (dev->iface->set_config) {
> > +        ret = dev->iface->set_config(dev, vmsg->payload.config.region,
> > +                                     vmsg->payload.config.offset,
> > +                                     vmsg->payload.config.size,
> > +                                     vmsg->payload.config.flags);
> > +    }
> > +
> > +    vmsg->size = sizeof(vmsg->payload.u64);
> > +    if (!ret) {
> > +        vmsg->payload.u64 = 0;
> > +    } else {
> > +        /* indicate an error in case reply supported */
> > +        vmsg->payload.u64 = 1;
> > +    }
> > +
> > +    if (reply_supported) {
> > +        return true;
> > +    }
> > +
> > +    return false;
> > +}
> > +
> > +static bool
> >  vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
> >  {
> >      int do_reply = 0;
> > @@ -862,6 +911,10 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg)
> >          return vu_set_vring_enable_exec(dev, vmsg);
> >      case VHOST_USER_SET_SLAVE_REQ_FD:
> >          return vu_set_slave_req_fd(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_NONE:
> >          break;
> >      default:
> > @@ -970,6 +1023,7 @@ vu_init(VuDev *dev,
> >      dev->iface = iface;
> >      dev->log_call_fd = -1;
> >      dev->slave_fd = -1;
> > +
> 
> unrelated coding style change, please drop
Thanks.
> 
> >      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 2f5864b..b38959e 100644
> > --- a/contrib/libvhost-user/libvhost-user.h
> > +++ b/contrib/libvhost-user/libvhost-user.h
> > @@ -30,6 +30,16 @@
> >
> >  #define VHOST_MEMORY_MAX_NREGIONS 8
> >
> > +typedef enum VhostSetConfigType {
> > +    VHOST_SET_CONFIG_TYPE_MASTER = 0,
> > +    VHOST_SET_CONFIG_TYPE_MIGRATION = 1,
> > +} VhostSetConfigType;
> > +
> > +/*
> > + * Maximum size of virtio device config space
> > + */
> > +#define VHOST_USER_MAX_CONFIG_SIZE 256
> > +
> >  enum VhostUserProtocolFeature {
> >      VHOST_USER_PROTOCOL_F_MQ = 0,
> >      VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
> > @@ -38,7 +48,6 @@ enum VhostUserProtocolFeature {
> >      VHOST_USER_PROTOCOL_F_NET_MTU = 4,
> >      VHOST_USER_PROTOCOL_F_SLAVE_REQ = 5,
> >      VHOST_USER_PROTOCOL_F_CROSS_ENDIAN = 6,
> > -
> 
> 
> unrelated coding style change, please drop
Thanks.
> 
> >      VHOST_USER_PROTOCOL_F_MAX
> >  };
> >
> > @@ -69,6 +78,8 @@ typedef enum VhostUserRequest {
> >      VHOST_USER_SET_SLAVE_REQ_FD = 21,
> >      VHOST_USER_IOTLB_MSG = 22,
> >      VHOST_USER_SET_VRING_ENDIAN = 23,
> > +    VHOST_USER_GET_CONFIG = 24,
> > +    VHOST_USER_SET_CONFIG = 25,
> >      VHOST_USER_MAX
> >  } VhostUserRequest;
> >
> > @@ -90,6 +101,18 @@ typedef struct VhostUserLog {
> >      uint64_t mmap_offset;
> >  } VhostUserLog;
> >
> > +typedef struct VhostUserConfig {
> > +    uint32_t offset;
> > +    uint32_t size;
> > +    uint32_t flags;
> > +    uint8_t region[VHOST_USER_MAX_CONFIG_SIZE];
> > +} VhostUserConfig;
> > +
> > +static VhostUserConfig c __attribute__ ((unused));
> > +#define VHOST_USER_CONFIG_HDR_SIZE (sizeof(c.offset) \
> > +                                   + sizeof(c.size) \
> > +                                   + sizeof(c.flags))
> > +
> >  #if defined(_WIN32)
> >  # define VU_PACKED __attribute__((gcc_struct, packed))
> >  #else
> > @@ -112,6 +135,7 @@ typedef struct VhostUserMsg {
> >          struct vhost_vring_addr addr;
> >          VhostUserMemory memory;
> >          VhostUserLog log;
> > +        VhostUserConfig config;
> >      } payload;
> >
> >      int fds[VHOST_MEMORY_MAX_NREGIONS];
> > @@ -140,6 +164,10 @@ 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 bool (*vu_queue_is_processed_in_order_cb) (VuDev *dev, int qidx);
> > +typedef int (*vu_get_config_cb) (VuDev *dev, uint8_t *config, uint32_t len);
> > +typedef int (*vu_set_config_cb) (VuDev *dev, const uint8_t *data,
> > +                                 uint32_t offset, uint32_t size,
> > +                                 uint32_t flags);
> >
> >  typedef struct VuDevIface {
> >      /* called by VHOST_USER_GET_FEATURES to get the features bitmask */
> > @@ -162,6 +190,10 @@ typedef struct VuDevIface {
> >       * on unmanaged exit/crash.
> >       */
> >      vu_queue_is_processed_in_order_cb queue_is_processed_in_order;
> > +    /* get the config space of the device */
> > +    vu_get_config_cb get_config;
> > +    /* set the config space of the device */
> > +    vu_set_config_cb set_config;
> >  } VuDevIface;
> >
> >  typedef void (*vu_queue_handler_cb) (VuDev *dev, int qidx);
> > --
> > 1.9.3
> >
> 
> 
> --
> Marc-André Lureau