vduse: add vq group asid support

Add support for assigning Address Space Identifiers (ASIDs) to each VQ
group.  This enables mapping each group into a distinct memory space.

The vq group to ASID association is protected by a rwlock now.  But the
mutex domain_lock keeps protecting the domains of all ASIDs, as some
operations like the one related with the bounce buffer size still
requires to lock all the ASIDs.

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20260119143306.1818855-12-eperezma@redhat.com>

1 files changed, 63 insertions, 3 deletions

diff --git a/include/uapi/linux/vduse.h b/include/uapi/linux/vduse.h
index a3d51cf6df3a..68b4287f9fac 100644
--- a/include/uapi/linux/vduse.h
+++ b/include/uapi/linux/vduse.h
@@ -32,6 +32,7 @@
  * @vq_num: the number of virtqueues
  * @vq_align: the allocation alignment of virtqueue's metadata
  * @ngroups: number of vq groups that VDUSE device declares
+ * @nas: number of address spaces that VDUSE device declares
  * @reserved: for future use, needs to be initialized to zero
  * @config_size: the size of the configuration space
  * @config: the buffer of the configuration space
@@ -47,7 +48,8 @@ struct vduse_dev_config {
 	__u32 vq_num;
 	__u32 vq_align;
 	__u32 ngroups; /* if VDUSE_API_VERSION >= 1 */
-	__u32 reserved[12];
+	__u32 nas; /* if VDUSE_API_VERSION >= 1 */
+	__u32 reserved[11];
 	__u32 config_size;
 	__u8 config[];
 };
@@ -167,6 +169,16 @@ struct vduse_vq_state_packed {
 };
 
 /**
+ * struct vduse_vq_group_asid - virtqueue group ASID
+ * @group: Index of the virtqueue group
+ * @asid: Address space ID of the group
+ */
+struct vduse_vq_group_asid {
+	__u32 group;
+	__u32 asid;
+};
+
+/**
  * struct vduse_vq_info - information of a virtqueue
  * @index: virtqueue index
  * @num: the size of virtqueue
@@ -225,6 +237,7 @@ struct vduse_vq_eventfd {
  * @uaddr: start address of userspace memory, it must be aligned to page size
  * @iova: start of the IOVA region
  * @size: size of the IOVA region
+ * @asid: Address space ID of the IOVA region
  * @reserved: for future use, needs to be initialized to zero
  *
  * Structure used by VDUSE_IOTLB_REG_UMEM and VDUSE_IOTLB_DEREG_UMEM
@@ -234,7 +247,8 @@ struct vduse_iova_umem {
 	__u64 uaddr;
 	__u64 iova;
 	__u64 size;
-	__u64 reserved[3];
+	__u32 asid;
+	__u32 reserved[5];
 };
 
 /* Register userspace memory for IOVA regions */
@@ -248,6 +262,7 @@ struct vduse_iova_umem {
  * @start: start of the IOVA region
  * @last: last of the IOVA region
  * @capability: capability of the IOVA region
+ * @asid: Address space ID of the IOVA region, only if device API version >= 1
  * @reserved: for future use, needs to be initialized to zero
  *
  * Structure used by VDUSE_IOTLB_GET_INFO ioctl to get information of
@@ -258,7 +273,8 @@ struct vduse_iova_info {
 	__u64 last;
 #define VDUSE_IOVA_CAP_UMEM (1 << 0)
 	__u64 capability;
-	__u64 reserved[3];
+	__u32 asid; /* Only if device API version >= 1 */
+	__u32 reserved[5];
 };
 
 /*
@@ -267,6 +283,28 @@ struct vduse_iova_info {
  */
 #define VDUSE_IOTLB_GET_INFO	_IOWR(VDUSE_BASE, 0x1a, struct vduse_iova_info)
 
+/**
+ * struct vduse_iotlb_entry_v2 - entry of IOTLB to describe one IOVA region
+ *
+ * @v1: the original vduse_iotlb_entry
+ * @asid: address space ID of the IOVA region
+ * @reserved: for future use, needs to be initialized to zero
+ *
+ * Structure used by VDUSE_IOTLB_GET_FD2 ioctl to find an overlapped IOVA region.
+ */
+struct vduse_iotlb_entry_v2 {
+	struct vduse_iotlb_entry v1;
+	__u32 asid;
+	__u32 reserved[12];
+};
+
+/*
+ * Same as VDUSE_IOTLB_GET_FD but with vduse_iotlb_entry_v2 argument that
+ * support extra fields.
+ */
+#define VDUSE_IOTLB_GET_FD2	_IOWR(VDUSE_BASE, 0x1b, struct vduse_iotlb_entry_v2)
+
+
 /* The control messages definition for read(2)/write(2) on /dev/vduse/$NAME */
 
 /**
@@ -275,11 +313,14 @@ struct vduse_iova_info {
  * @VDUSE_SET_STATUS: set the device status
  * @VDUSE_UPDATE_IOTLB: Notify userspace to update the memory mapping for
  *                      specified IOVA range via VDUSE_IOTLB_GET_FD ioctl
+ * @VDUSE_SET_VQ_GROUP_ASID: Notify userspace to update the address space of a
+ *                           virtqueue group.
  */
 enum vduse_req_type {
 	VDUSE_GET_VQ_STATE,
 	VDUSE_SET_STATUS,
 	VDUSE_UPDATE_IOTLB,
+	VDUSE_SET_VQ_GROUP_ASID,
 };
 
 /**
@@ -315,6 +356,18 @@ struct vduse_iova_range {
 };
 
 /**
+ * struct vduse_iova_range_v2 - IOVA range [start, last] if API_VERSION >= 1
+ * @start: start of the IOVA range
+ * @last: last of the IOVA range
+ * @asid: address space ID of the IOVA range
+ */
+struct vduse_iova_range_v2 {
+	__u64 start;
+	__u64 last;
+	__u32 asid;
+};
+
+/**
  * struct vduse_dev_request - control request
  * @type: request type
  * @request_id: request id
@@ -322,6 +375,8 @@ struct vduse_iova_range {
  * @vq_state: virtqueue state, only index field is available
  * @s: device status
  * @iova: IOVA range for updating
+ * @iova_v2: IOVA range for updating if API_VERSION >= 1
+ * @vq_group_asid: ASID of a virtqueue group
  * @padding: padding
  *
  * Structure used by read(2) on /dev/vduse/$NAME.
@@ -334,6 +389,11 @@ struct vduse_dev_request {
 		struct vduse_vq_state vq_state;
 		struct vduse_dev_status s;
 		struct vduse_iova_range iova;
+		/* Following members but padding exist only if vduse api
+		 * version >= 1
+		 */
+		struct vduse_iova_range_v2 iova_v2;
+		struct vduse_vq_group_asid vq_group_asid;
 		__u32 padding[32];
 	};
 };