b60d6a584c
- target/i386: csv: Release CSV3 shared pages after unmapping DMA - target/i386: Add new CPU model ClearwaterForest - target/i386: add sha512, sm3, sm4 feature bits - docs: Add GNR, SRF and CWF CPU models - target/i386: Export BHI_NO bit to guests - target/i386: Introduce SierraForest-v2 model - vdpa/iommufd:Implement DMA mapping through the iommufd interface - vdpa/iommufd:Introduce vdpa-iommufd module - vdpa/iommufd:support associating iommufd backend for vDPA devices - Kconfig/iommufd/VDPA: Update IOMMUFD module configuration dependencies The vDPA module can also use IOMMUFD like the VFIO module. - backends/iommufd: Get rid of qemu_open_old() - backends/iommufd: Make iommufd_backend_*() return bool - backends/iommufd: Fix missing ERRP_GUARD() for error_prepend() - backends/iommufd: Remove mutex - backends/iommufd: Remove check on number of backend users - hw/intc: Add extioi ability of 256 vcpu interrupt routing - hw/rtc: Fixed loongson rtc emulation errors - hw/loongarch/boot: Adjust the loading position of the initrd - target/loongarch: Fix the cpu unplug resource leak - target/loongarch: fix vcpu reset command word issue - vdpa:Fix dirty page bitmap synchronization not done after suspend for vdpa devices Signed-off-by: Jiabo Feng <fengjiabo1@huawei.com> (cherry picked from commit a5212066e7516ff2a316e1b2feaa75dd5ee4d17a)
104 lines
3.1 KiB
Diff
104 lines
3.1 KiB
Diff
From 1e6734af14b3223a7d7e304262c96051ddf8637f Mon Sep 17 00:00:00 2001
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From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= <clg@redhat.com>
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Date: Thu, 21 Dec 2023 16:58:41 +0100
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Subject: [PATCH] backends/iommufd: Remove mutex
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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Coverity reports a concurrent data access violation because be->users
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is being accessed in iommufd_backend_can_be_deleted() without holding
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the mutex.
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However, these routines are called from the QEMU main thread when a
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device is created. In this case, the code paths should be protected by
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the BQL lock and it should be safe to drop the IOMMUFD backend mutex.
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Simply remove it.
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Fixes: CID 1531550
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Fixes: CID 1531549
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Reviewed-by: Eric Auger <eric.auger@redhat.com>
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Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
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Signed-off-by: Cédric Le Goater <clg@redhat.com>
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---
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backends/iommufd.c | 7 -------
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include/sysemu/iommufd.h | 2 --
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2 files changed, 9 deletions(-)
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diff --git a/backends/iommufd.c b/backends/iommufd.c
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index f17a846aab..3cbf11fc8b 100644
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--- a/backends/iommufd.c
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+++ b/backends/iommufd.c
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@@ -30,7 +30,6 @@ static void iommufd_backend_init(Object *obj)
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be->fd = -1;
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be->users = 0;
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be->owned = true;
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- qemu_mutex_init(&be->lock);
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}
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static void iommufd_backend_finalize(Object *obj)
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@@ -53,10 +52,8 @@ static void iommufd_backend_set_fd(Object *obj, const char *str, Error **errp)
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error_prepend(errp, "Could not parse remote object fd %s:", str);
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return;
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}
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- qemu_mutex_lock(&be->lock);
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be->fd = fd;
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be->owned = false;
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- qemu_mutex_unlock(&be->lock);
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trace_iommu_backend_set_fd(be->fd);
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}
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@@ -80,7 +77,6 @@ int iommufd_backend_connect(IOMMUFDBackend *be, Error **errp)
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{
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int fd, ret = 0;
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- qemu_mutex_lock(&be->lock);
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if (be->owned && !be->users) {
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fd = qemu_open_old("/dev/iommu", O_RDWR);
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if (fd < 0) {
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@@ -94,13 +90,11 @@ int iommufd_backend_connect(IOMMUFDBackend *be, Error **errp)
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out:
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trace_iommufd_backend_connect(be->fd, be->owned,
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be->users, ret);
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- qemu_mutex_unlock(&be->lock);
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return ret;
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}
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void iommufd_backend_disconnect(IOMMUFDBackend *be)
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{
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- qemu_mutex_lock(&be->lock);
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if (!be->users) {
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goto out;
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}
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@@ -111,7 +105,6 @@ void iommufd_backend_disconnect(IOMMUFDBackend *be)
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}
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out:
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trace_iommufd_backend_disconnect(be->fd, be->users);
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- qemu_mutex_unlock(&be->lock);
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}
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int iommufd_backend_alloc_ioas(IOMMUFDBackend *be, uint32_t *ioas_id,
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diff --git a/include/sysemu/iommufd.h b/include/sysemu/iommufd.h
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index 29afaa429d..908c94d811 100644
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--- a/include/sysemu/iommufd.h
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+++ b/include/sysemu/iommufd.h
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@@ -15,7 +15,6 @@
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#define SYSEMU_IOMMUFD_H
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#include "qom/object.h"
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-#include "qemu/thread.h"
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#include "exec/hwaddr.h"
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#include "exec/cpu-common.h"
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#include "sysemu/host_iommu_device.h"
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@@ -33,7 +32,6 @@ struct IOMMUFDBackend {
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/*< protected >*/
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int fd; /* /dev/iommu file descriptor */
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bool owned; /* is the /dev/iommu opened internally */
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- QemuMutex lock;
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uint32_t users;
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/*< public >*/
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--
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2.41.0.windows.1
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