qemu-kvm/SOURCES/kvm-scsi-assert-that-callbacks-run-in-the-correct-AioCon.patch

89 lines
3.0 KiB
Diff

From cd08d22a0da022d99fe6cfddb7de680abf66c8be Mon Sep 17 00:00:00 2001
From: Stefan Hajnoczi <stefanha@redhat.com>
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 <kwolf@redhat.com>
RH-MergeRequest: 214: Remove AioContext lock
RH-Jira: RHEL-15965
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
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 <stefanha@redhat.com>
Message-ID: <20231205182011.1976568-3-stefanha@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
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