From patchwork Mon Apr 1 12:17:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Durrant X-Patchwork-Id: 1072711 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=citrix.com Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 44Xrx01FQlz9sPB for ; Mon, 1 Apr 2019 23:19:00 +1100 (AEDT) Received: from localhost ([127.0.0.1]:57879 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hAvty-0004yw-5e for incoming@patchwork.ozlabs.org; Mon, 01 Apr 2019 08:18:58 -0400 Received: from eggs.gnu.org ([209.51.188.92]:50296) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hAvt6-0004xh-AD for qemu-devel@nongnu.org; Mon, 01 Apr 2019 08:18:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hAvt4-0005i6-W5 for qemu-devel@nongnu.org; Mon, 01 Apr 2019 08:18:04 -0400 Received: from smtp03.citrix.com ([162.221.156.55]:31515) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hAvt4-0005hH-LK; Mon, 01 Apr 2019 08:18:02 -0400 X-IronPort-AV: E=Sophos;i="5.60,296,1549929600"; d="scan'208";a="82370742" From: Paul Durrant To: , , Date: Mon, 1 Apr 2019 13:17:19 +0100 Message-ID: <20190401121719.27208-1-paul.durrant@citrix.com> X-Mailer: git-send-email 2.20.1.2.gb21ebb6 MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 162.221.156.55 Subject: [Qemu-devel] [PATCH v3] xen-block: scale sector based quantities correctly X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Stefano Stabellini , Max Reitz , Paul Durrant , Stefan Hajnoczi , Anthony Perard Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" The Xen blkif protocol requires that sector based quantities should be interpreted strictly as multiples of 512 bytes. Specifically: "first_sect and last_sect in blkif_request_segment, as well as sector_number in blkif_request, are always expressed in 512-byte units." Commit fcab2b464e06 "xen: add header and build dataplane/xen-block.c" incorrectly modified behaviour to use the block device logical_block_size property as the scale, instead of correctly shifting values by the hardcoded BDRV_SECTOR_BITS (and hence scaling them to 512 byte units). This patch undoes that change and restores compliance with the spec. Furthermore, this patch also restores the original xen_disk behaviour of advertizing a hardcoded 'sector-size' value of 512 in xenstore and scaling 'sectors' accordingly. The realize() method is also modified to fail if logical_block_size is set to anything other than 512. Signed-off-by: Paul Durrant Reviewed-by: Anthony PERARD --- Cc: Stefan Hajnoczi Cc: Stefano Stabellini Cc: Anthony Perard Cc: Kevin Wolf Cc: Max Reitz v3: - Expand commit comment with more explanation - Enforce logical_block_size == 512 --- hw/block/dataplane/xen-block.c | 28 +++++++++++++--------------- hw/block/xen-block.c | 10 ++++++++-- hw/block/xen_blkif.h | 2 ++ 3 files changed, 23 insertions(+), 17 deletions(-) diff --git a/hw/block/dataplane/xen-block.c b/hw/block/dataplane/xen-block.c index f1523c5b45..bb8f1186e4 100644 --- a/hw/block/dataplane/xen-block.c +++ b/hw/block/dataplane/xen-block.c @@ -49,7 +49,6 @@ struct XenBlockDataPlane { unsigned int *ring_ref; unsigned int nr_ring_ref; void *sring; - int64_t file_blk; int protocol; blkif_back_rings_t rings; int more_work; @@ -168,7 +167,7 @@ static int xen_block_parse_request(XenBlockRequest *request) goto err; } - request->start = request->req.sector_number * dataplane->file_blk; + request->start = request->req.sector_number * XEN_BLKIF_SECTOR_SIZE; for (i = 0; i < request->req.nr_segments; i++) { if (i == BLKIF_MAX_SEGMENTS_PER_REQUEST) { error_report("error: nr_segments too big"); @@ -178,14 +177,14 @@ static int xen_block_parse_request(XenBlockRequest *request) error_report("error: first > last sector"); goto err; } - if (request->req.seg[i].last_sect * dataplane->file_blk >= + if (request->req.seg[i].last_sect * XEN_BLKIF_SECTOR_SIZE >= XC_PAGE_SIZE) { error_report("error: page crossing"); goto err; } len = (request->req.seg[i].last_sect - - request->req.seg[i].first_sect + 1) * dataplane->file_blk; + request->req.seg[i].first_sect + 1) * XEN_BLKIF_SECTOR_SIZE; request->size += len; } if (request->start + request->size > blk_getlength(dataplane->blk)) { @@ -205,7 +204,6 @@ static int xen_block_copy_request(XenBlockRequest *request) XenDevice *xendev = dataplane->xendev; XenDeviceGrantCopySegment segs[BLKIF_MAX_SEGMENTS_PER_REQUEST]; int i, count; - int64_t file_blk = dataplane->file_blk; bool to_domain = (request->req.operation == BLKIF_OP_READ); void *virt = request->buf; Error *local_err = NULL; @@ -220,16 +218,17 @@ static int xen_block_copy_request(XenBlockRequest *request) if (to_domain) { segs[i].dest.foreign.ref = request->req.seg[i].gref; segs[i].dest.foreign.offset = request->req.seg[i].first_sect * - file_blk; + XEN_BLKIF_SECTOR_SIZE; segs[i].source.virt = virt; } else { segs[i].source.foreign.ref = request->req.seg[i].gref; segs[i].source.foreign.offset = request->req.seg[i].first_sect * - file_blk; + XEN_BLKIF_SECTOR_SIZE; segs[i].dest.virt = virt; } segs[i].len = (request->req.seg[i].last_sect - - request->req.seg[i].first_sect + 1) * file_blk; + request->req.seg[i].first_sect + 1) * + XEN_BLKIF_SECTOR_SIZE; virt += segs[i].len; } @@ -331,22 +330,22 @@ static bool xen_block_split_discard(XenBlockRequest *request, XenBlockDataPlane *dataplane = request->dataplane; int64_t byte_offset; int byte_chunk; - uint64_t byte_remaining, limit; + uint64_t byte_remaining; uint64_t sec_start = sector_number; uint64_t sec_count = nr_sectors; /* Wrap around, or overflowing byte limit? */ if (sec_start + sec_count < sec_count || - sec_start + sec_count > INT64_MAX / dataplane->file_blk) { + sec_start + sec_count > INT64_MAX / XEN_BLKIF_SECTOR_SIZE) { return false; } - limit = BDRV_REQUEST_MAX_SECTORS * dataplane->file_blk; - byte_offset = sec_start * dataplane->file_blk; - byte_remaining = sec_count * dataplane->file_blk; + byte_offset = sec_start * XEN_BLKIF_SECTOR_SIZE; + byte_remaining = sec_count * XEN_BLKIF_SECTOR_SIZE; do { - byte_chunk = byte_remaining > limit ? limit : byte_remaining; + byte_chunk = byte_remaining > BDRV_REQUEST_MAX_BYTES ? + BDRV_REQUEST_MAX_BYTES : byte_remaining; request->aio_inflight++; blk_aio_pdiscard(dataplane->blk, byte_offset, byte_chunk, xen_block_complete_aio, request); @@ -632,7 +631,6 @@ XenBlockDataPlane *xen_block_dataplane_create(XenDevice *xendev, XenBlockDataPlane *dataplane = g_new0(XenBlockDataPlane, 1); dataplane->xendev = xendev; - dataplane->file_blk = conf->logical_block_size; dataplane->blk = conf->blk; QLIST_INIT(&dataplane->inflight); diff --git a/hw/block/xen-block.c b/hw/block/xen-block.c index a848849f48..522385561a 100644 --- a/hw/block/xen-block.c +++ b/hw/block/xen-block.c @@ -149,7 +149,7 @@ static void xen_block_set_size(XenBlockDevice *blockdev) const char *type = object_get_typename(OBJECT(blockdev)); XenBlockVdev *vdev = &blockdev->props.vdev; BlockConf *conf = &blockdev->props.conf; - int64_t sectors = blk_getlength(conf->blk) / conf->logical_block_size; + int64_t sectors = blk_getlength(conf->blk) / XEN_BLKIF_SECTOR_SIZE; XenDevice *xendev = XEN_DEVICE(blockdev); trace_xen_block_size(type, vdev->disk, vdev->partition, sectors); @@ -223,6 +223,12 @@ static void xen_block_realize(XenDevice *xendev, Error **errp) blkconf_blocksizes(conf); + if (conf->logical_block_size != XEN_BLKIF_SECTOR_SIZE) { + error_setg(errp, "logical_block_size != %u not supported", + XEN_BLKIF_SECTOR_SIZE); + return; + } + if (conf->logical_block_size > conf->physical_block_size) { error_setg( errp, "logical_block_size > physical_block_size not supported"); @@ -253,7 +259,7 @@ static void xen_block_realize(XenDevice *xendev, Error **errp) blockdev->device_type); xen_device_backend_printf(xendev, "sector-size", "%u", - conf->logical_block_size); + XEN_BLKIF_SECTOR_SIZE); xen_block_set_size(blockdev); diff --git a/hw/block/xen_blkif.h b/hw/block/xen_blkif.h index 3e6e1ea365..a353693ea0 100644 --- a/hw/block/xen_blkif.h +++ b/hw/block/xen_blkif.h @@ -143,4 +143,6 @@ static inline void blkif_get_x86_64_req(blkif_request_t *dst, } } +#define XEN_BLKIF_SECTOR_SIZE 512 + #endif /* XEN_BLKIF_H */