Hi Dmitry, On Sun, Sep 18, 2022 at 10:29:21PM -0400, Dmitry Fomichev wrote: > The zone-specific code in the patch is heavily influenced by NVMe ZNS > code in drivers/nvme/host/zns.c, but it is simpler because the proposed > virtio ZBD draft only covers the zoned device features that are > relevant to the zoned functionality provided by Linux block layer. > There is a parallel work going on to support non-po2 zone sizes in Linux block layer and drivers[1]. I don't see any reason why we shouldn't make the calculations generic here instead of putting the constraint on zone sectors to be po2 as the virtio spec also supports it. I took a quick look, and changing the calculations from po2 specific to generic will not be in the hot path and can be trivially changed. I have suggested the changes inline to make the virtio blk driver zone size agnostic. I haven't tested the changes but it is very similar to the changes I did in the drivers/nvme/host/zns.c in my patch series[2]. [1] https://lore.kernel.org/linux-block/20220912082204.51189-1-p.raghav@xxxxxxxxxxx/ [2] https://lore.kernel.org/linux-block/20220912082204.51189-6-p.raghav@xxxxxxxxxxx/ > Co-developed-by: Stefan Hajnoczi <stefanha@xxxxxxxxx> > Signed-off-by: Stefan Hajnoczi <stefanha@xxxxxxxxx> > Signed-off-by: Dmitry Fomichev <dmitry.fomichev@xxxxxxx> > --- > drivers/block/virtio_blk.c | 381 ++++++++++++++++++++++++++++++-- > include/uapi/linux/virtio_blk.h | 106 +++++++++ > 2 files changed, 469 insertions(+), 18 deletions(-) > <snip> > +#ifdef CONFIG_BLK_DEV_ZONED > +static void *virtblk_alloc_report_buffer(struct virtio_blk *vblk, > + unsigned int nr_zones, > + unsigned int zone_sectors, > + size_t *buflen) > +{ > + struct request_queue *q = vblk->disk->queue; > + size_t bufsize; > + void *buf; > + - nr_zones = min_t(unsigned int, nr_zones, - get_capacity(vblk->disk) >> ilog2(zone_sectors)); + nr_zones = min_t(unsigned int, nr_zones, + div64_u64(get_capacity(vblk->disk), zone_sectors)); > + > + bufsize = sizeof(struct virtio_blk_zone_report) + > + nr_zones * sizeof(struct virtio_blk_zone_descriptor); > + bufsize = min_t(size_t, bufsize, > + queue_max_hw_sectors(q) << SECTOR_SHIFT); > + bufsize = min_t(size_t, bufsize, queue_max_segments(q) << PAGE_SHIFT); > + > + while (bufsize >= sizeof(struct virtio_blk_zone_report)) { > + buf = __vmalloc(bufsize, GFP_KERNEL | __GFP_NORETRY); > + if (buf) { > + *buflen = bufsize; > + return buf; > + } > + bufsize >>= 1; > + } > + > + return NULL; > +} > + > +static int virtblk_submit_zone_report(struct virtio_blk *vblk, > + char *report_buf, size_t report_len, > + sector_t sector) > +{ > + struct request_queue *q = vblk->disk->queue; > + struct request *req; > + struct virtblk_req *vbr; > + int err; > + > + req = blk_mq_alloc_request(q, REQ_OP_DRV_IN, 0); > + if (IS_ERR(req)) > + return PTR_ERR(req); > + > + vbr = blk_mq_rq_to_pdu(req); > + vbr->in_hdr_len = sizeof(vbr->status); > + vbr->out_hdr.type = cpu_to_virtio32(vblk->vdev, VIRTIO_BLK_T_ZONE_REPORT); > + vbr->out_hdr.sector = cpu_to_virtio64(vblk->vdev, sector); > + > + err = blk_rq_map_kern(q, req, report_buf, report_len, GFP_KERNEL); > + if (err) > + goto out; > + > + blk_execute_rq(req, false); > + err = blk_status_to_errno(virtblk_result(vbr->status)); > +out: > + blk_mq_free_request(req); > + return err; > +} > + > +static int virtblk_parse_zone(struct virtio_blk *vblk, > + struct virtio_blk_zone_descriptor *entry, > + unsigned int idx, unsigned int zone_sectors, > + report_zones_cb cb, void *data) > +{ > + struct blk_zone zone = { }; > + > + if (entry->z_type != VIRTIO_BLK_ZT_SWR && > + entry->z_type != VIRTIO_BLK_ZT_SWP && > + entry->z_type != VIRTIO_BLK_ZT_CONV) { > + dev_err(&vblk->vdev->dev, "invalid zone type %#x\n", > + entry->z_type); > + return -EINVAL; > + } > + > + zone.type = entry->z_type; > + zone.cond = entry->z_state; > + zone.len = zone_sectors; > + zone.capacity = le64_to_cpu(entry->z_cap); > + zone.start = le64_to_cpu(entry->z_start); > + if (zone.cond == BLK_ZONE_COND_FULL) > + zone.wp = zone.start + zone.len; > + else > + zone.wp = le64_to_cpu(entry->z_wp); > + > + return cb(&zone, idx, data); > +} > + > +static int virtblk_report_zones(struct gendisk *disk, sector_t sector, > + unsigned int nr_zones, report_zones_cb cb, > + void *data) > +{ > + struct virtio_blk *vblk = disk->private_data; > + struct virtio_blk_zone_report *report; > + unsigned int zone_sectors = vblk->zone_sectors; > + unsigned int nz, i; > + int ret, zone_idx = 0; > + size_t buflen; + u64 remainder; > + > + if (WARN_ON_ONCE(!vblk->zone_sectors)) > + return -EOPNOTSUPP; > + > + report = virtblk_alloc_report_buffer(vblk, nr_zones, > + zone_sectors, &buflen); > + if (!report) > + return -ENOMEM; > + - sector &= ~(zone_sectors - 1); + div64_u64_rem(sector, zone_sectors, &remainder); + sector -= remainder; > + while (zone_idx < nr_zones && sector < get_capacity(vblk->disk)) { > + memset(report, 0, buflen); > + > + ret = virtblk_submit_zone_report(vblk, (char *)report, > + buflen, sector); > + if (ret) { > + if (ret > 0) > + ret = -EIO; > + goto out_free; > + } > + > + nz = min((unsigned int)le64_to_cpu(report->nr_zones), nr_zones); > + if (!nz) > + break; > + > + for (i = 0; i < nz && zone_idx < nr_zones; i++) { > + ret = virtblk_parse_zone(vblk, &report->zones[i], > + zone_idx, zone_sectors, cb, data); > + if (ret) > + goto out_free; > + zone_idx++; > + } > + > + sector += zone_sectors * nz; > + } > + > + if (zone_idx > 0) > + ret = zone_idx; > + else > + ret = -EINVAL; > +out_free: > + kvfree(report); > + return ret; > +} > + <snip> > +static int virtblk_probe_zoned_device(struct virtio_device *vdev, > + struct virtio_blk *vblk, > + struct request_queue *q) > +{ <snip> > + blk_queue_physical_block_size(q, le32_to_cpu(v)); > + blk_queue_io_min(q, le32_to_cpu(v)); > + > + dev_dbg(&vdev->dev, "write granularity = %u\n", le32_to_cpu(v)); > + - /* - * virtio ZBD specification doesn't require zones to be a power of - * two sectors in size, but the code in this driver expects that. - */ - virtio_cread(vdev, struct virtio_blk_config, zoned.zone_sectors, &v); - if (v == 0 || !is_power_of_2(v)) { - dev_err(&vdev->dev, - "zoned device with non power of two zone size %u\n", v); - return -ENODEV; - } > + > + dev_dbg(&vdev->dev, "zone sectors = %u\n", le32_to_cpu(v)); > + vblk->zone_sectors = le32_to_cpu(v); > + > + if (virtio_has_feature(vdev, VIRTIO_BLK_F_DISCARD)) { > + dev_warn(&vblk->vdev->dev, > + "ignoring negotiated F_DISCARD for zoned device\n"); > + blk_queue_max_discard_sectors(q, 0); > + } > + > + ret = blk_revalidate_disk_zones(vblk->disk, NULL); > + if (!ret) { > + virtio_cread(vdev, struct virtio_blk_config, > + zoned.max_append_sectors, &v); > + if (!v) { > + dev_warn(&vdev->dev, "zero max_append_sectors reported\n"); > + return -ENODEV; > + } > + blk_queue_max_zone_append_sectors(q, le32_to_cpu(v)); > + dev_dbg(&vdev->dev, "max append sectors = %u\n", le32_to_cpu(v)); > + > + } > + > + return ret; > +} > + -- Pankaj Raghav
