From cd08d22a0da022d99fe6cfddb7de680abf66c8be Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Tue, 5 Dec 2023 13:19:59 -0500 Subject: [PATCH 082/101] scsi: assert that callbacks run in the correct AioContext RH-Author: Kevin Wolf RH-MergeRequest: 214: Remove AioContext lock RH-Jira: RHEL-15965 RH-Acked-by: Miroslav Rezanina RH-Acked-by: Stefan Hajnoczi RH-Commit: [13/26] d2fd5065c3b72d9d2f4e37efee39fe12eba0f0a9 (kmwolf/centos-qemu-kvm) Since the removal of AioContext locking, the correctness of the code relies on running requests from a single AioContext at any given time. Add assertions that verify that callbacks are invoked in the correct AioContext. Signed-off-by: Stefan Hajnoczi Message-ID: <20231205182011.1976568-3-stefanha@redhat.com> Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- hw/scsi/scsi-disk.c | 14 ++++++++++++++ system/dma-helpers.c | 3 +++ 2 files changed, 17 insertions(+) diff --git a/hw/scsi/scsi-disk.c b/hw/scsi/scsi-disk.c index 2c1bbb3530..a5048e0aaf 100644 --- a/hw/scsi/scsi-disk.c +++ b/hw/scsi/scsi-disk.c @@ -273,6 +273,10 @@ static void scsi_aio_complete(void *opaque, int ret) SCSIDiskReq *r = (SCSIDiskReq *)opaque; SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev); + /* The request must only run in the BlockBackend's AioContext */ + assert(blk_get_aio_context(s->qdev.conf.blk) == + qemu_get_current_aio_context()); + assert(r->req.aiocb != NULL); r->req.aiocb = NULL; @@ -370,8 +374,13 @@ static void scsi_dma_complete(void *opaque, int ret) static void scsi_read_complete_noio(SCSIDiskReq *r, int ret) { + SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev); uint32_t n; + /* The request must only run in the BlockBackend's AioContext */ + assert(blk_get_aio_context(s->qdev.conf.blk) == + qemu_get_current_aio_context()); + assert(r->req.aiocb == NULL); if (scsi_disk_req_check_error(r, ret, false)) { goto done; @@ -496,8 +505,13 @@ static void scsi_read_data(SCSIRequest *req) static void scsi_write_complete_noio(SCSIDiskReq *r, int ret) { + SCSIDiskState *s = DO_UPCAST(SCSIDiskState, qdev, r->req.dev); uint32_t n; + /* The request must only run in the BlockBackend's AioContext */ + assert(blk_get_aio_context(s->qdev.conf.blk) == + qemu_get_current_aio_context()); + assert (r->req.aiocb == NULL); if (scsi_disk_req_check_error(r, ret, false)) { goto done; diff --git a/system/dma-helpers.c b/system/dma-helpers.c index 528117f256..9b221cf94e 100644 --- a/system/dma-helpers.c +++ b/system/dma-helpers.c @@ -119,6 +119,9 @@ static void dma_blk_cb(void *opaque, int ret) trace_dma_blk_cb(dbs, ret); + /* DMAAIOCB is not thread-safe and must be accessed only from dbs->ctx */ + assert(ctx == qemu_get_current_aio_context()); + dbs->acb = NULL; dbs->offset += dbs->iov.size; -- 2.39.3