Commit 4a44a5ed authored by Stefano Garzarella's avatar Stefano Garzarella Committed by Michael S. Tsirkin
Browse files

vdpa_sim_blk: add support for discard and write-zeroes 



Expose VIRTIO_BLK_F_DISCARD and VIRTIO_BLK_F_WRITE_ZEROES features
to the drivers and handle VIRTIO_BLK_T_DISCARD and
VIRTIO_BLK_T_WRITE_ZEROES requests checking ranges and flags.

The simulator behaves like a ramdisk, so for VIRTIO_BLK_F_DISCARD
does nothing, while for VIRTIO_BLK_T_WRITE_ZEROES sets to 0 the
specified region.

Signed-off-by: default avatarStefano Garzarella <sgarzare@redhat.com>
Message-Id: <20220811083632.77525-5-sgarzare@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 518083d2

drivers/vdpa/vdpa_sim/vdpa_sim_blk.c

+73 −1
Original line number Diff line number Diff line
@@ -30,11 +30,14 @@ 
				 (1ULL << VIRTIO_BLK_F_SEG_MAX)  | \

				 (1ULL << VIRTIO_BLK_F_BLK_SIZE) | \

				 (1ULL << VIRTIO_BLK_F_TOPOLOGY) | \

				 (1ULL << VIRTIO_BLK_F_MQ))

				 (1ULL << VIRTIO_BLK_F_MQ)       | \

				 (1ULL << VIRTIO_BLK_F_DISCARD)  | \

				 (1ULL << VIRTIO_BLK_F_WRITE_ZEROES))



#define VDPASIM_BLK_CAPACITY	0x40000

#define VDPASIM_BLK_SIZE_MAX	0x1000

#define VDPASIM_BLK_SEG_MAX	32

#define VDPASIM_BLK_DWZ_MAX_SECTORS UINT_MAX



/* 1 virtqueue, 1 address space, 1 virtqueue group */

#define VDPASIM_BLK_VQ_NUM	1
@@ -193,6 +196,64 @@ static bool vdpasim_blk_handle_req(struct vdpasim *vdpasim, 
		/* nothing to do */

		break;



	case VIRTIO_BLK_T_DISCARD:

	case VIRTIO_BLK_T_WRITE_ZEROES: {

		struct virtio_blk_discard_write_zeroes range;

		u32 num_sectors, flags;



		if (to_pull != sizeof(range)) {

			dev_dbg(&vdpasim->vdpa.dev,

				"discard/write_zeroes header len: 0x%zx [expected: 0x%zx]\n",

				to_pull, sizeof(range));

			status = VIRTIO_BLK_S_IOERR;

			break;

		}



		bytes = vringh_iov_pull_iotlb(&vq->vring, &vq->out_iov, &range,

					      to_pull);

		if (bytes < 0) {

			dev_dbg(&vdpasim->vdpa.dev,

				"vringh_iov_pull_iotlb() error: %zd offset: 0x%llx len: 0x%zx\n",

				bytes, offset, to_pull);

			status = VIRTIO_BLK_S_IOERR;

			break;

		}



		sector = le64_to_cpu(range.sector);

		offset = sector << SECTOR_SHIFT;

		num_sectors = le32_to_cpu(range.num_sectors);

		flags = le32_to_cpu(range.flags);



		if (type == VIRTIO_BLK_T_DISCARD && flags != 0) {

			dev_dbg(&vdpasim->vdpa.dev,

				"discard unexpected flags set - flags: 0x%x\n",

				flags);

			status = VIRTIO_BLK_S_UNSUPP;

			break;

		}



		if (type == VIRTIO_BLK_T_WRITE_ZEROES &&

		    flags & ~VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP) {

			dev_dbg(&vdpasim->vdpa.dev,

				"write_zeroes unexpected flags set - flags: 0x%x\n",

				flags);

			status = VIRTIO_BLK_S_UNSUPP;

			break;

		}



		if (!vdpasim_blk_check_range(vdpasim, sector, num_sectors,

					     VDPASIM_BLK_DWZ_MAX_SECTORS)) {

			status = VIRTIO_BLK_S_IOERR;

			break;

		}



		if (type == VIRTIO_BLK_T_WRITE_ZEROES) {

			memset(vdpasim->buffer + offset, 0,

			       num_sectors << SECTOR_SHIFT);

		}



		break;

	}

	default:

		dev_dbg(&vdpasim->vdpa.dev,

			"Unsupported request type %d\n", type);
@@ -281,6 +342,17 @@ static void vdpasim_blk_get_config(struct vdpasim *vdpasim, void *config) 
	blk_config->min_io_size = cpu_to_vdpasim16(vdpasim, 1);

	blk_config->opt_io_size = cpu_to_vdpasim32(vdpasim, 1);

	blk_config->blk_size = cpu_to_vdpasim32(vdpasim, SECTOR_SIZE);

	/* VIRTIO_BLK_F_DISCARD */

	blk_config->discard_sector_alignment =

		cpu_to_vdpasim32(vdpasim, SECTOR_SIZE);

	blk_config->max_discard_sectors =

		cpu_to_vdpasim32(vdpasim, VDPASIM_BLK_DWZ_MAX_SECTORS);

	blk_config->max_discard_seg = cpu_to_vdpasim32(vdpasim, 1);

	/* VIRTIO_BLK_F_WRITE_ZEROES */

	blk_config->max_write_zeroes_sectors =

		cpu_to_vdpasim32(vdpasim, VDPASIM_BLK_DWZ_MAX_SECTORS);

	blk_config->max_write_zeroes_seg = cpu_to_vdpasim32(vdpasim, 1);



}



static void vdpasim_blk_mgmtdev_release(struct device *dev)