From 881c999e302e7ee1212b47c523a2cf442c549417 Mon Sep 17 00:00:00 2001 From: Zhenzhong Duan Date: Mon, 13 Jun 2022 14:10:09 +0800 Subject: [PATCH 02/17] virtio-iommu: Use recursive lock to avoid deadlock RH-Author: Eric Auger RH-MergeRequest: 105: virtio-iommu: Fix bypass mode for assigned devices RH-Commit: [2/5] 67dce1eecb49555f728f119f8efac00417ff65bf (eauger1/centos-qemu-kvm) RH-Bugzilla: 2100106 RH-Acked-by: Miroslav Rezanina RH-Acked-by: Peter Xu RH-Acked-by: Cornelia Huck Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2100106 When switching address space with mutex lock hold, mapping will be replayed for assigned device. This will trigger relock deadlock. Also release the mutex resource in unrealize routine. Signed-off-by: Zhenzhong Duan Message-Id: <20220613061010.2674054-3-zhenzhong.duan@intel.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin (cherry picked from commit 08f2030a2e46f1e93d186b3a683e5caef1df562b) Signed-off-by: Eric Auger --- hw/virtio/virtio-iommu.c | 20 +++++++++++--------- include/hw/virtio/virtio-iommu.h | 2 +- 2 files changed, 12 insertions(+), 10 deletions(-) diff --git a/hw/virtio/virtio-iommu.c b/hw/virtio/virtio-iommu.c index 5e99e6c62b..440a1c28a7 100644 --- a/hw/virtio/virtio-iommu.c +++ b/hw/virtio/virtio-iommu.c @@ -79,7 +79,7 @@ static bool virtio_iommu_device_bypassed(IOMMUDevice *sdev) sid = virtio_iommu_get_bdf(sdev); - qemu_mutex_lock(&s->mutex); + qemu_rec_mutex_lock(&s->mutex); /* need to check bypass before system reset */ if (!s->endpoints) { bypassed = s->config.bypass; @@ -94,7 +94,7 @@ static bool virtio_iommu_device_bypassed(IOMMUDevice *sdev) } unlock: - qemu_mutex_unlock(&s->mutex); + qemu_rec_mutex_unlock(&s->mutex); return bypassed; } @@ -746,7 +746,7 @@ static void virtio_iommu_handle_command(VirtIODevice *vdev, VirtQueue *vq) tail.status = VIRTIO_IOMMU_S_DEVERR; goto out; } - qemu_mutex_lock(&s->mutex); + qemu_rec_mutex_lock(&s->mutex); switch (head.type) { case VIRTIO_IOMMU_T_ATTACH: tail.status = virtio_iommu_handle_attach(s, iov, iov_cnt); @@ -775,7 +775,7 @@ static void virtio_iommu_handle_command(VirtIODevice *vdev, VirtQueue *vq) default: tail.status = VIRTIO_IOMMU_S_UNSUPP; } - qemu_mutex_unlock(&s->mutex); + qemu_rec_mutex_unlock(&s->mutex); out: sz = iov_from_buf(elem->in_sg, elem->in_num, 0, @@ -863,7 +863,7 @@ static IOMMUTLBEntry virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr, sid = virtio_iommu_get_bdf(sdev); trace_virtio_iommu_translate(mr->parent_obj.name, sid, addr, flag); - qemu_mutex_lock(&s->mutex); + qemu_rec_mutex_lock(&s->mutex); ep = g_tree_lookup(s->endpoints, GUINT_TO_POINTER(sid)); if (!ep) { @@ -947,7 +947,7 @@ static IOMMUTLBEntry virtio_iommu_translate(IOMMUMemoryRegion *mr, hwaddr addr, trace_virtio_iommu_translate_out(addr, entry.translated_addr, sid); unlock: - qemu_mutex_unlock(&s->mutex); + qemu_rec_mutex_unlock(&s->mutex); return entry; } @@ -1036,7 +1036,7 @@ static void virtio_iommu_replay(IOMMUMemoryRegion *mr, IOMMUNotifier *n) sid = virtio_iommu_get_bdf(sdev); - qemu_mutex_lock(&s->mutex); + qemu_rec_mutex_lock(&s->mutex); if (!s->endpoints) { goto unlock; @@ -1050,7 +1050,7 @@ static void virtio_iommu_replay(IOMMUMemoryRegion *mr, IOMMUNotifier *n) g_tree_foreach(ep->domain->mappings, virtio_iommu_remap, mr); unlock: - qemu_mutex_unlock(&s->mutex); + qemu_rec_mutex_unlock(&s->mutex); } static int virtio_iommu_notify_flag_changed(IOMMUMemoryRegion *iommu_mr, @@ -1169,7 +1169,7 @@ static void virtio_iommu_device_realize(DeviceState *dev, Error **errp) virtio_add_feature(&s->features, VIRTIO_IOMMU_F_PROBE); virtio_add_feature(&s->features, VIRTIO_IOMMU_F_BYPASS_CONFIG); - qemu_mutex_init(&s->mutex); + qemu_rec_mutex_init(&s->mutex); s->as_by_busptr = g_hash_table_new_full(NULL, NULL, NULL, g_free); @@ -1197,6 +1197,8 @@ static void virtio_iommu_device_unrealize(DeviceState *dev) g_tree_destroy(s->endpoints); } + qemu_rec_mutex_destroy(&s->mutex); + virtio_delete_queue(s->req_vq); virtio_delete_queue(s->event_vq); virtio_cleanup(vdev); diff --git a/include/hw/virtio/virtio-iommu.h b/include/hw/virtio/virtio-iommu.h index 102eeefa73..2ad5ee320b 100644 --- a/include/hw/virtio/virtio-iommu.h +++ b/include/hw/virtio/virtio-iommu.h @@ -58,7 +58,7 @@ struct VirtIOIOMMU { ReservedRegion *reserved_regions; uint32_t nb_reserved_regions; GTree *domains; - QemuMutex mutex; + QemuRecMutex mutex; GTree *endpoints; bool boot_bypass; }; -- 2.31.1