Re: [PATCH v5 2/4] vhost_user: header defines for add/rem mem region

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 11/13/25 1:44 PM, Pravin M Bathija wrote:
> The changes in this file cover the enum message requests for
> supporting add/remove memory regions. The front-end vhost-user
> client sends messages like get max memory slots, add memory region
> and remove memory region which are covered in these changes which
> are on the vhost-user back-end. The changes also include data structure
> definition of memory region to be added/removed. The data structure
> VhostUserMsg has been changed to include the memory region.
> 
> Signed-off-by: Pravin M Bathija <pravin.bathija@dell.com>
> ---
>   lib/vhost/vhost_user.h | 10 ++++++++++
>   1 file changed, 10 insertions(+)
> 
> diff --git a/lib/vhost/vhost_user.h b/lib/vhost/vhost_user.h
> index ef486545ba..5a0e747b58 100644
> --- a/lib/vhost/vhost_user.h
> +++ b/lib/vhost/vhost_user.h
> @@ -32,6 +32,7 @@
>   					 (1ULL << VHOST_USER_PROTOCOL_F_BACKEND_SEND_FD) | \
>   					 (1ULL << VHOST_USER_PROTOCOL_F_HOST_NOTIFIER) | \
>   					 (1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT) | \
> +					 (1ULL << VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS) | \

It should be enabled only once the feature is actually implemented,
otherwise bisection may fail.

>   					 (1ULL << VHOST_USER_PROTOCOL_F_STATUS))
>   
>   typedef enum VhostUserRequest {
> @@ -67,6 +68,9 @@ typedef enum VhostUserRequest {
>   	VHOST_USER_POSTCOPY_END = 30,
>   	VHOST_USER_GET_INFLIGHT_FD = 31,
>   	VHOST_USER_SET_INFLIGHT_FD = 32,
> +	VHOST_USER_GET_MAX_MEM_SLOTS = 36,
> +	VHOST_USER_ADD_MEM_REG = 37,
> +	VHOST_USER_REM_MEM_REG = 38,
>   	VHOST_USER_SET_STATUS = 39,
>   	VHOST_USER_GET_STATUS = 40,
>   } VhostUserRequest;
> @@ -91,6 +95,11 @@ typedef struct VhostUserMemory {
>   	VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS];
>   } VhostUserMemory;
>   
> +typedef struct VhostUserSingleMemReg {
> +	uint64_t padding;
> +	VhostUserMemoryRegion region;
> +} VhostUserSingleMemReg;
> +
>   typedef struct VhostUserLog {
>   	uint64_t mmap_size;
>   	uint64_t mmap_offset;
> @@ -186,6 +195,7 @@ typedef struct __rte_packed_begin VhostUserMsg {
>   		struct vhost_vring_state state;
>   		struct vhost_vring_addr addr;
>   		VhostUserMemory memory;
> +		VhostUserSingleMemReg memory_single;
>   		VhostUserLog    log;
>   		struct vhost_iotlb_msg iotlb;
>   		VhostUserCryptoSessionParam crypto_session;