diff mbox series

[v3,3/5] vhost_user: Add frontend command for shmem config

Message ID 20240912145335.129447-4-aesteve@redhat.com (mailing list archive)
State New, archived
Headers show
Series vhost-user: Add SHMEM_MAP/UNMAP requests | expand

Commit Message

Albert Esteve Sept. 12, 2024, 2:53 p.m. UTC 
The frontend can use this command to retrieve
VIRTIO Shared Memory Regions configuration from
the backend. The response contains the number of
shared memory regions, their size, and shmid.

This is useful when the frontend is unaware of
specific backend type and configuration,
for example, in the `vhost-user-device` case.

Signed-off-by: Albert Esteve <aesteve@redhat.com>
---
 hw/virtio/vhost-user.c            | 45 +++++++++++++++++++++++++++++++
 include/hw/virtio/vhost-backend.h |  6 +++++
 include/hw/virtio/vhost-user.h    |  1 +
 3 files changed, 52 insertions(+)

Comments

Stefan Hajnoczi Sept. 17, 2024, 7:48 a.m. UTC | #1 
On Thu, Sep 12, 2024 at 04:53:33PM +0200, Albert Esteve wrote:
> The frontend can use this command to retrieve
> VIRTIO Shared Memory Regions configuration from
> the backend. The response contains the number of
> shared memory regions, their size, and shmid.
> 
> This is useful when the frontend is unaware of
> specific backend type and configuration,
> for example, in the `vhost-user-device` case.
> 
> Signed-off-by: Albert Esteve <aesteve@redhat.com>
> ---
>  hw/virtio/vhost-user.c            | 45 +++++++++++++++++++++++++++++++
>  include/hw/virtio/vhost-backend.h |  6 +++++
>  include/hw/virtio/vhost-user.h    |  1 +
>  3 files changed, 52 insertions(+)
> 
> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> index de0bb35257..83f5c02bea 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -57,6 +57,8 @@
>   */
>  #define VHOST_USER_MAX_CONFIG_SIZE 256
>  
> +#define VHOST_USER_MAX_SHMEM_REGIONS 256
> +
>  #define VHOST_USER_PROTOCOL_FEATURE_MASK ((1 << VHOST_USER_PROTOCOL_F_MAX) - 1)
>  
>  typedef enum VhostUserRequest {
> @@ -104,6 +106,7 @@ typedef enum VhostUserRequest {
>      VHOST_USER_GET_SHARED_OBJECT = 41,
>      VHOST_USER_SET_DEVICE_STATE_FD = 42,
>      VHOST_USER_CHECK_DEVICE_STATE = 43,
> +    VHOST_USER_GET_SHMEM_CONFIG = 44,
>      VHOST_USER_MAX
>  } VhostUserRequest;
>  
> @@ -138,6 +141,12 @@ typedef struct VhostUserMemRegMsg {
>      VhostUserMemoryRegion region;
>  } VhostUserMemRegMsg;
>  
> +typedef struct VhostUserShMemConfig {
> +    uint32_t nregions;
> +    uint32_t padding;
> +    uint64_t memory_sizes[VHOST_MEMORY_BASELINE_NREGIONS];
> +} VhostUserShMemConfig;
> +
>  typedef struct VhostUserLog {
>      uint64_t mmap_size;
>      uint64_t mmap_offset;
> @@ -245,6 +254,7 @@ typedef union {
>          VhostUserShared object;
>          VhostUserTransferDeviceState transfer_state;
>          VhostUserMMap mmap;
> +        VhostUserShMemConfig shmem;
>  } VhostUserPayload;
>  
>  typedef struct VhostUserMsg {
> @@ -3134,6 +3144,40 @@ static int vhost_user_check_device_state(struct vhost_dev *dev, Error **errp)
>      return 0;
>  }
>  
> +static int vhost_user_get_shmem_config(struct vhost_dev *dev,
> +                                       int *nregions,
> +                                       uint64_t *memory_sizes,
> +                                       Error **errp)
> +{
> +    int ret;
> +    VhostUserMsg msg = {
> +        .hdr.request = VHOST_USER_GET_SHMEM_CONFIG,
> +        .hdr.flags = VHOST_USER_VERSION,
> +    };
> +
> +    if (!virtio_has_feature(dev->protocol_features,
> +                            VHOST_USER_PROTOCOL_F_SHMEM)) {
> +        return 0;
> +    }
> +
> +    ret = vhost_user_write(dev, &msg, NULL, 0);
> +    if (ret < 0) {
> +        return ret;
> +    }
> +
> +    ret = vhost_user_read(dev, &msg);
> +    if (ret < 0) {
> +        return ret;
> +    }
> +
> +    assert(msg.payload.shmem.nregions <= VHOST_USER_MAX_SHMEM_REGIONS);
> +    *nregions = msg.payload.shmem.nregions;
> +    memcpy(memory_sizes,
> +           &msg.payload.shmem.memory_sizes,
> +           sizeof(uint64_t) * VHOST_MEMORY_BASELINE_NREGIONS);
> +    return 0;
> +}
> +
>  const VhostOps user_ops = {
>          .backend_type = VHOST_BACKEND_TYPE_USER,
>          .vhost_backend_init = vhost_user_backend_init,
> @@ -3172,4 +3216,5 @@ const VhostOps user_ops = {
>          .vhost_supports_device_state = vhost_user_supports_device_state,
>          .vhost_set_device_state_fd = vhost_user_set_device_state_fd,
>          .vhost_check_device_state = vhost_user_check_device_state,
> +        .vhost_get_shmem_config = vhost_user_get_shmem_config,
>  };
> diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
> index 70c2e8ffee..f9c2955420 100644
> --- a/include/hw/virtio/vhost-backend.h
> +++ b/include/hw/virtio/vhost-backend.h
> @@ -159,6 +159,11 @@ typedef int (*vhost_set_device_state_fd_op)(struct vhost_dev *dev,
>                                              int *reply_fd,
>                                              Error **errp);
>  typedef int (*vhost_check_device_state_op)(struct vhost_dev *dev, Error **errp);
> +typedef int (*vhost_get_shmem_config_op)(struct vhost_dev *dev,
> +                                         int *nregions,
> +                                         uint64_t *memory_sizes,

VHOST_USER_MAX_SHMEM_REGIONS is defined inside vhost-user.c and not
visible here. However, vhost_get_shmem_config_op() assumes the caller
knows the maximum number of memory_sizes[] array elements.

I think a constant should be declared in the VIRTIO header files and a
doc comment is needed here stating that memory_sizes[] must be at least
VIRTIO_MAX_SHMEM_REGIONS.

> +                                         Error **errp);
> +
>  
>  typedef struct VhostOps {
>      VhostBackendType backend_type;
> @@ -214,6 +219,7 @@ typedef struct VhostOps {
>      vhost_supports_device_state_op vhost_supports_device_state;
>      vhost_set_device_state_fd_op vhost_set_device_state_fd;
>      vhost_check_device_state_op vhost_check_device_state;
> +    vhost_get_shmem_config_op vhost_get_shmem_config;
>  } VhostOps;
>  
>  int vhost_backend_update_device_iotlb(struct vhost_dev *dev,
> diff --git a/include/hw/virtio/vhost-user.h b/include/hw/virtio/vhost-user.h
> index 324cd8663a..d4bb2c3958 100644
> --- a/include/hw/virtio/vhost-user.h
> +++ b/include/hw/virtio/vhost-user.h
> @@ -32,6 +32,7 @@ enum VhostUserProtocolFeature {
>      /* Feature 17 reserved for VHOST_USER_PROTOCOL_F_XEN_MMAP. */
>      VHOST_USER_PROTOCOL_F_SHARED_OBJECT = 18,
>      VHOST_USER_PROTOCOL_F_DEVICE_STATE = 19,
> +    VHOST_USER_PROTOCOL_F_SHMEM = 20,
>      VHOST_USER_PROTOCOL_F_MAX
>  };
>  
> -- 
> 2.45.2
>
Stefan Hajnoczi Sept. 17, 2024, 7:50 a.m. UTC | #2 
On Thu, Sep 12, 2024 at 04:53:33PM +0200, Albert Esteve wrote:
> The frontend can use this command to retrieve
> VIRTIO Shared Memory Regions configuration from
> the backend. The response contains the number of
> shared memory regions, their size, and shmid.
> 
> This is useful when the frontend is unaware of
> specific backend type and configuration,
> for example, in the `vhost-user-device` case.
> 
> Signed-off-by: Albert Esteve <aesteve@redhat.com>
> ---
>  hw/virtio/vhost-user.c            | 45 +++++++++++++++++++++++++++++++
>  include/hw/virtio/vhost-backend.h |  6 +++++
>  include/hw/virtio/vhost-user.h    |  1 +
>  3 files changed, 52 insertions(+)
> 
> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> index de0bb35257..83f5c02bea 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -57,6 +57,8 @@
>   */
>  #define VHOST_USER_MAX_CONFIG_SIZE 256
>  
> +#define VHOST_USER_MAX_SHMEM_REGIONS 256
> +
>  #define VHOST_USER_PROTOCOL_FEATURE_MASK ((1 << VHOST_USER_PROTOCOL_F_MAX) - 1)
>  
>  typedef enum VhostUserRequest {
> @@ -104,6 +106,7 @@ typedef enum VhostUserRequest {
>      VHOST_USER_GET_SHARED_OBJECT = 41,
>      VHOST_USER_SET_DEVICE_STATE_FD = 42,
>      VHOST_USER_CHECK_DEVICE_STATE = 43,
> +    VHOST_USER_GET_SHMEM_CONFIG = 44,
>      VHOST_USER_MAX
>  } VhostUserRequest;
>  
> @@ -138,6 +141,12 @@ typedef struct VhostUserMemRegMsg {
>      VhostUserMemoryRegion region;
>  } VhostUserMemRegMsg;
>  
> +typedef struct VhostUserShMemConfig {
> +    uint32_t nregions;
> +    uint32_t padding;
> +    uint64_t memory_sizes[VHOST_MEMORY_BASELINE_NREGIONS];

I think this should be VHOST_USER_MAX_SHMEM_REGIONS.

> +} VhostUserShMemConfig;
> +
>  typedef struct VhostUserLog {
>      uint64_t mmap_size;
>      uint64_t mmap_offset;
> @@ -245,6 +254,7 @@ typedef union {
>          VhostUserShared object;
>          VhostUserTransferDeviceState transfer_state;
>          VhostUserMMap mmap;
> +        VhostUserShMemConfig shmem;
>  } VhostUserPayload;
>  
>  typedef struct VhostUserMsg {
> @@ -3134,6 +3144,40 @@ static int vhost_user_check_device_state(struct vhost_dev *dev, Error **errp)
>      return 0;
>  }
>  
> +static int vhost_user_get_shmem_config(struct vhost_dev *dev,
> +                                       int *nregions,
> +                                       uint64_t *memory_sizes,
> +                                       Error **errp)
> +{
> +    int ret;
> +    VhostUserMsg msg = {
> +        .hdr.request = VHOST_USER_GET_SHMEM_CONFIG,
> +        .hdr.flags = VHOST_USER_VERSION,
> +    };
> +
> +    if (!virtio_has_feature(dev->protocol_features,
> +                            VHOST_USER_PROTOCOL_F_SHMEM)) {
> +        return 0;
> +    }
> +
> +    ret = vhost_user_write(dev, &msg, NULL, 0);
> +    if (ret < 0) {
> +        return ret;
> +    }
> +
> +    ret = vhost_user_read(dev, &msg);
> +    if (ret < 0) {
> +        return ret;
> +    }
> +
> +    assert(msg.payload.shmem.nregions <= VHOST_USER_MAX_SHMEM_REGIONS);
> +    *nregions = msg.payload.shmem.nregions;
> +    memcpy(memory_sizes,
> +           &msg.payload.shmem.memory_sizes,
> +           sizeof(uint64_t) * VHOST_MEMORY_BASELINE_NREGIONS);
> +    return 0;
> +}
> +
>  const VhostOps user_ops = {
>          .backend_type = VHOST_BACKEND_TYPE_USER,
>          .vhost_backend_init = vhost_user_backend_init,
> @@ -3172,4 +3216,5 @@ const VhostOps user_ops = {
>          .vhost_supports_device_state = vhost_user_supports_device_state,
>          .vhost_set_device_state_fd = vhost_user_set_device_state_fd,
>          .vhost_check_device_state = vhost_user_check_device_state,
> +        .vhost_get_shmem_config = vhost_user_get_shmem_config,
>  };
> diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
> index 70c2e8ffee..f9c2955420 100644
> --- a/include/hw/virtio/vhost-backend.h
> +++ b/include/hw/virtio/vhost-backend.h
> @@ -159,6 +159,11 @@ typedef int (*vhost_set_device_state_fd_op)(struct vhost_dev *dev,
>                                              int *reply_fd,
>                                              Error **errp);
>  typedef int (*vhost_check_device_state_op)(struct vhost_dev *dev, Error **errp);
> +typedef int (*vhost_get_shmem_config_op)(struct vhost_dev *dev,
> +                                         int *nregions,
> +                                         uint64_t *memory_sizes,
> +                                         Error **errp);
> +
>  
>  typedef struct VhostOps {
>      VhostBackendType backend_type;
> @@ -214,6 +219,7 @@ typedef struct VhostOps {
>      vhost_supports_device_state_op vhost_supports_device_state;
>      vhost_set_device_state_fd_op vhost_set_device_state_fd;
>      vhost_check_device_state_op vhost_check_device_state;
> +    vhost_get_shmem_config_op vhost_get_shmem_config;
>  } VhostOps;
>  
>  int vhost_backend_update_device_iotlb(struct vhost_dev *dev,
> diff --git a/include/hw/virtio/vhost-user.h b/include/hw/virtio/vhost-user.h
> index 324cd8663a..d4bb2c3958 100644
> --- a/include/hw/virtio/vhost-user.h
> +++ b/include/hw/virtio/vhost-user.h
> @@ -32,6 +32,7 @@ enum VhostUserProtocolFeature {
>      /* Feature 17 reserved for VHOST_USER_PROTOCOL_F_XEN_MMAP. */
>      VHOST_USER_PROTOCOL_F_SHARED_OBJECT = 18,
>      VHOST_USER_PROTOCOL_F_DEVICE_STATE = 19,
> +    VHOST_USER_PROTOCOL_F_SHMEM = 20,
>      VHOST_USER_PROTOCOL_F_MAX
>  };
>  
> -- 
> 2.45.2
>
diff mbox series

Patch

diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index de0bb35257..83f5c02bea 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -57,6 +57,8 @@ 
  */
 #define VHOST_USER_MAX_CONFIG_SIZE 256
 
+#define VHOST_USER_MAX_SHMEM_REGIONS 256
+
 #define VHOST_USER_PROTOCOL_FEATURE_MASK ((1 << VHOST_USER_PROTOCOL_F_MAX) - 1)
 
 typedef enum VhostUserRequest {
@@ -104,6 +106,7 @@  typedef enum VhostUserRequest {
     VHOST_USER_GET_SHARED_OBJECT = 41,
     VHOST_USER_SET_DEVICE_STATE_FD = 42,
     VHOST_USER_CHECK_DEVICE_STATE = 43,
+    VHOST_USER_GET_SHMEM_CONFIG = 44,
     VHOST_USER_MAX
 } VhostUserRequest;
 
@@ -138,6 +141,12 @@  typedef struct VhostUserMemRegMsg {
     VhostUserMemoryRegion region;
 } VhostUserMemRegMsg;
 
+typedef struct VhostUserShMemConfig {
+    uint32_t nregions;
+    uint32_t padding;
+    uint64_t memory_sizes[VHOST_MEMORY_BASELINE_NREGIONS];
+} VhostUserShMemConfig;
+
 typedef struct VhostUserLog {
     uint64_t mmap_size;
     uint64_t mmap_offset;
@@ -245,6 +254,7 @@  typedef union {
         VhostUserShared object;
         VhostUserTransferDeviceState transfer_state;
         VhostUserMMap mmap;
+        VhostUserShMemConfig shmem;
 } VhostUserPayload;
 
 typedef struct VhostUserMsg {
@@ -3134,6 +3144,40 @@  static int vhost_user_check_device_state(struct vhost_dev *dev, Error **errp)
     return 0;
 }
 
+static int vhost_user_get_shmem_config(struct vhost_dev *dev,
+                                       int *nregions,
+                                       uint64_t *memory_sizes,
+                                       Error **errp)
+{
+    int ret;
+    VhostUserMsg msg = {
+        .hdr.request = VHOST_USER_GET_SHMEM_CONFIG,
+        .hdr.flags = VHOST_USER_VERSION,
+    };
+
+    if (!virtio_has_feature(dev->protocol_features,
+                            VHOST_USER_PROTOCOL_F_SHMEM)) {
+        return 0;
+    }
+
+    ret = vhost_user_write(dev, &msg, NULL, 0);
+    if (ret < 0) {
+        return ret;
+    }
+
+    ret = vhost_user_read(dev, &msg);
+    if (ret < 0) {
+        return ret;
+    }
+
+    assert(msg.payload.shmem.nregions <= VHOST_USER_MAX_SHMEM_REGIONS);
+    *nregions = msg.payload.shmem.nregions;
+    memcpy(memory_sizes,
+           &msg.payload.shmem.memory_sizes,
+           sizeof(uint64_t) * VHOST_MEMORY_BASELINE_NREGIONS);
+    return 0;
+}
+
 const VhostOps user_ops = {
         .backend_type = VHOST_BACKEND_TYPE_USER,
         .vhost_backend_init = vhost_user_backend_init,
@@ -3172,4 +3216,5 @@  const VhostOps user_ops = {
         .vhost_supports_device_state = vhost_user_supports_device_state,
         .vhost_set_device_state_fd = vhost_user_set_device_state_fd,
         .vhost_check_device_state = vhost_user_check_device_state,
+        .vhost_get_shmem_config = vhost_user_get_shmem_config,
 };
diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
index 70c2e8ffee..f9c2955420 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -159,6 +159,11 @@  typedef int (*vhost_set_device_state_fd_op)(struct vhost_dev *dev,
                                             int *reply_fd,
                                             Error **errp);
 typedef int (*vhost_check_device_state_op)(struct vhost_dev *dev, Error **errp);
+typedef int (*vhost_get_shmem_config_op)(struct vhost_dev *dev,
+                                         int *nregions,
+                                         uint64_t *memory_sizes,
+                                         Error **errp);
+
 
 typedef struct VhostOps {
     VhostBackendType backend_type;
@@ -214,6 +219,7 @@  typedef struct VhostOps {
     vhost_supports_device_state_op vhost_supports_device_state;
     vhost_set_device_state_fd_op vhost_set_device_state_fd;
     vhost_check_device_state_op vhost_check_device_state;
+    vhost_get_shmem_config_op vhost_get_shmem_config;
 } VhostOps;
 
 int vhost_backend_update_device_iotlb(struct vhost_dev *dev,
diff --git a/include/hw/virtio/vhost-user.h b/include/hw/virtio/vhost-user.h
index 324cd8663a..d4bb2c3958 100644
--- a/include/hw/virtio/vhost-user.h
+++ b/include/hw/virtio/vhost-user.h
@@ -32,6 +32,7 @@  enum VhostUserProtocolFeature {
     /* Feature 17 reserved for VHOST_USER_PROTOCOL_F_XEN_MMAP. */
     VHOST_USER_PROTOCOL_F_SHARED_OBJECT = 18,
     VHOST_USER_PROTOCOL_F_DEVICE_STATE = 19,
+    VHOST_USER_PROTOCOL_F_SHMEM = 20,
     VHOST_USER_PROTOCOL_F_MAX
 };