You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
113 lines
3.5 KiB
113 lines
3.5 KiB
From 92aff3cc1a412de01e9563802fa48848eae5283f Mon Sep 17 00:00:00 2001
|
|
From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= <clg@redhat.com>
|
|
Date: Thu, 21 Dec 2023 16:58:41 +0100
|
|
Subject: [PATCH 065/101] backends/iommufd: Remove mutex
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
RH-Author: Eric Auger <eric.auger@redhat.com>
|
|
RH-MergeRequest: 211: IOMMUFD backend backport
|
|
RH-Jira: RHEL-19302 RHEL-21057
|
|
RH-Acked-by: Cédric Le Goater <clg@redhat.com>
|
|
RH-Acked-by: Sebastian Ott <sebott@redhat.com>
|
|
RH-Commit: [64/67] 65518432b18f18ceadafe1b0698cdaa962e84f61 (eauger1/centos-qemu-kvm)
|
|
|
|
Coverity reports a concurrent data access violation because be->users
|
|
is being accessed in iommufd_backend_can_be_deleted() without holding
|
|
the mutex.
|
|
|
|
However, these routines are called from the QEMU main thread when a
|
|
device is created. In this case, the code paths should be protected by
|
|
the BQL lock and it should be safe to drop the IOMMUFD backend mutex.
|
|
Simply remove it.
|
|
|
|
Fixes: CID 1531550
|
|
Fixes: CID 1531549
|
|
Reviewed-by: Eric Auger <eric.auger@redhat.com>
|
|
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
|
|
Signed-off-by: Cédric Le Goater <clg@redhat.com>
|
|
(cherry picked from commit 19368b1905b4b917e915526fcbd5bfa3f7439451)
|
|
Signed-off-by: Eric Auger <eric.auger@redhat.com>
|
|
---
|
|
backends/iommufd.c | 7 -------
|
|
include/sysemu/iommufd.h | 2 --
|
|
2 files changed, 9 deletions(-)
|
|
|
|
diff --git a/backends/iommufd.c b/backends/iommufd.c
|
|
index 393c0d9a37..1ef683c7b0 100644
|
|
--- a/backends/iommufd.c
|
|
+++ b/backends/iommufd.c
|
|
@@ -29,7 +29,6 @@ static void iommufd_backend_init(Object *obj)
|
|
be->fd = -1;
|
|
be->users = 0;
|
|
be->owned = true;
|
|
- qemu_mutex_init(&be->lock);
|
|
}
|
|
|
|
static void iommufd_backend_finalize(Object *obj)
|
|
@@ -52,10 +51,8 @@ static void iommufd_backend_set_fd(Object *obj, const char *str, Error **errp)
|
|
error_prepend(errp, "Could not parse remote object fd %s:", str);
|
|
return;
|
|
}
|
|
- qemu_mutex_lock(&be->lock);
|
|
be->fd = fd;
|
|
be->owned = false;
|
|
- qemu_mutex_unlock(&be->lock);
|
|
trace_iommu_backend_set_fd(be->fd);
|
|
}
|
|
|
|
@@ -79,7 +76,6 @@ int iommufd_backend_connect(IOMMUFDBackend *be, Error **errp)
|
|
{
|
|
int fd, ret = 0;
|
|
|
|
- qemu_mutex_lock(&be->lock);
|
|
if (be->owned && !be->users) {
|
|
fd = qemu_open_old("/dev/iommu", O_RDWR);
|
|
if (fd < 0) {
|
|
@@ -93,13 +89,11 @@ int iommufd_backend_connect(IOMMUFDBackend *be, Error **errp)
|
|
out:
|
|
trace_iommufd_backend_connect(be->fd, be->owned,
|
|
be->users, ret);
|
|
- qemu_mutex_unlock(&be->lock);
|
|
return ret;
|
|
}
|
|
|
|
void iommufd_backend_disconnect(IOMMUFDBackend *be)
|
|
{
|
|
- qemu_mutex_lock(&be->lock);
|
|
if (!be->users) {
|
|
goto out;
|
|
}
|
|
@@ -110,7 +104,6 @@ void iommufd_backend_disconnect(IOMMUFDBackend *be)
|
|
}
|
|
out:
|
|
trace_iommufd_backend_disconnect(be->fd, be->users);
|
|
- qemu_mutex_unlock(&be->lock);
|
|
}
|
|
|
|
int iommufd_backend_alloc_ioas(IOMMUFDBackend *be, uint32_t *ioas_id,
|
|
diff --git a/include/sysemu/iommufd.h b/include/sysemu/iommufd.h
|
|
index 9c5524b0ed..9af27ebd6c 100644
|
|
--- a/include/sysemu/iommufd.h
|
|
+++ b/include/sysemu/iommufd.h
|
|
@@ -2,7 +2,6 @@
|
|
#define SYSEMU_IOMMUFD_H
|
|
|
|
#include "qom/object.h"
|
|
-#include "qemu/thread.h"
|
|
#include "exec/hwaddr.h"
|
|
#include "exec/cpu-common.h"
|
|
|
|
@@ -19,7 +18,6 @@ struct IOMMUFDBackend {
|
|
/*< protected >*/
|
|
int fd; /* /dev/iommu file descriptor */
|
|
bool owned; /* is the /dev/iommu opened internally */
|
|
- QemuMutex lock;
|
|
uint32_t users;
|
|
|
|
/*< public >*/
|
|
--
|
|
2.39.3
|
|
|