From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57093) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zwums-0000d7-Jw for qemu-devel@nongnu.org; Thu, 12 Nov 2015 11:31:51 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zwumo-0007L5-74 for qemu-devel@nongnu.org; Thu, 12 Nov 2015 11:31:50 -0500 Received: from mx-v6.kamp.de ([2a02:248:0:51::16]:44826 helo=mx01.kamp.de) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zwumn-0007Kq-Tb for qemu-devel@nongnu.org; Thu, 12 Nov 2015 11:31:46 -0500 From: Peter Lieven Date: Thu, 12 Nov 2015 17:30:43 +0100 Message-Id: <1447345846-15624-4-git-send-email-pl@kamp.de> In-Reply-To: <1447345846-15624-1-git-send-email-pl@kamp.de> References: <1447345846-15624-1-git-send-email-pl@kamp.de> Subject: [Qemu-devel] [PATCH V4 3/6] ide: add support for IDEBufferedRequest List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, qemu-block@nongnu.org Cc: kwolf@redhat.com, famz@redhat.com, stefanha@gmail.com, jcody@redhat.com, Peter Lieven , jsnow@redhat.com this patch adds a new aio readv compatible function which copies all data through a bounce buffer. These buffered requests can be flagged as orphaned which means that their original callback has already been invoked and the request has just not been completed by the backend storage. The bounce buffer guarantees that guest memory corruption is avoided when such a orphaned request is completed by the backend at a later stage. This trick only works for read requests as a write request completed at a later stage might corrupt data as there is no way to control if and what data has already been written to the storage. Signed-off-by: Peter Lieven --- hw/ide/core.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ hw/ide/internal.h | 14 ++++++++++++++ 2 files changed, 61 insertions(+) diff --git a/hw/ide/core.c b/hw/ide/core.c index 364ba21..7ca67bc 100644 --- a/hw/ide/core.c +++ b/hw/ide/core.c @@ -561,6 +561,53 @@ static bool ide_sect_range_ok(IDEState *s, return true; } +static void ide_buffered_readv_cb(void *opaque, int ret) +{ + IDEBufferedRequest *req = opaque; + if (!req->orphaned) { + if (!ret) { + qemu_iovec_from_buf(req->original_qiov, 0, req->iov.iov_base, + req->original_qiov->size); + } + req->original_cb(req->original_opaque, ret); + } + QLIST_REMOVE(req, list); + qemu_vfree(req->iov.iov_base); + g_free(req); +} + +#define MAX_BUFFERED_REQS 16 + +BlockAIOCB *ide_buffered_readv(IDEState *s, int64_t sector_num, + QEMUIOVector *iov, int nb_sectors, + BlockCompletionFunc *cb, void *opaque) +{ + BlockAIOCB *aioreq; + IDEBufferedRequest *req; + int c = 0; + + QLIST_FOREACH(req, &s->buffered_requests, list) { + c++; + } + if (c > MAX_BUFFERED_REQS) { + return blk_abort_aio_request(s->blk, cb, opaque, -EIO); + } + + req = g_new0(IDEBufferedRequest, 1); + req->original_qiov = iov; + req->original_cb = cb; + req->original_opaque = opaque; + req->iov.iov_base = qemu_blockalign(blk_bs(s->blk), iov->size); + req->iov.iov_len = iov->size; + qemu_iovec_init_external(&req->qiov, &req->iov, 1); + + aioreq = blk_aio_readv(s->blk, sector_num, &req->qiov, nb_sectors, + ide_buffered_readv_cb, req); + + QLIST_INSERT_HEAD(&s->buffered_requests, req, list); + return aioreq; +} + static void ide_sector_read(IDEState *s); static void ide_sector_read_cb(void *opaque, int ret) diff --git a/hw/ide/internal.h b/hw/ide/internal.h index e4629b0..2d1e2d2 100644 --- a/hw/ide/internal.h +++ b/hw/ide/internal.h @@ -343,6 +343,16 @@ enum ide_dma_cmd { #define ide_cmd_is_read(s) \ ((s)->dma_cmd == IDE_DMA_READ) +typedef struct IDEBufferedRequest { + QLIST_ENTRY(IDEBufferedRequest) list; + struct iovec iov; + QEMUIOVector qiov; + QEMUIOVector *original_qiov; + BlockCompletionFunc *original_cb; + void *original_opaque; + bool orphaned; +} IDEBufferedRequest; + /* NOTE: IDEState represents in fact one drive */ struct IDEState { IDEBus *bus; @@ -396,6 +406,7 @@ struct IDEState { BlockAIOCB *pio_aiocb; struct iovec iov; QEMUIOVector qiov; + QLIST_HEAD(, IDEBufferedRequest) buffered_requests; /* ATA DMA state */ uint64_t io_buffer_offset; int32_t io_buffer_size; @@ -572,6 +583,9 @@ void ide_set_inactive(IDEState *s, bool more); BlockAIOCB *ide_issue_trim(BlockBackend *blk, int64_t sector_num, QEMUIOVector *qiov, int nb_sectors, BlockCompletionFunc *cb, void *opaque); +BlockAIOCB *ide_buffered_readv(IDEState *s, int64_t sector_num, + QEMUIOVector *iov, int nb_sectors, + BlockCompletionFunc *cb, void *opaque); /* hw/ide/atapi.c */ void ide_atapi_cmd(IDEState *s); -- 1.9.1