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2026-01-08vhost/vsock: improve RCU read sections around vhost_vsock_get()Stefano Garzarella1-4/+11
[ Upstream commit d8ee3cfdc89b75dc059dc21c27bef2c1440f67eb ] vhost_vsock_get() uses hash_for_each_possible_rcu() to find the `vhost_vsock` associated with the `guest_cid`. hash_for_each_possible_rcu() should only be called within an RCU read section, as mentioned in the following comment in include/linux/rculist.h: /** * hlist_for_each_entry_rcu - iterate over rcu list of given type * @pos: the type * to use as a loop cursor. * @head: the head for your list. * @member: the name of the hlist_node within the struct. * @cond: optional lockdep expression if called from non-RCU protection. * * This list-traversal primitive may safely run concurrently with * the _rcu list-mutation primitives such as hlist_add_head_rcu() * as long as the traversal is guarded by rcu_read_lock(). */ Currently, all calls to vhost_vsock_get() are between rcu_read_lock() and rcu_read_unlock() except for calls in vhost_vsock_set_cid() and vhost_vsock_reset_orphans(). In both cases, the current code is safe, but we can make improvements to make it more robust. About vhost_vsock_set_cid(), when building the kernel with CONFIG_PROVE_RCU_LIST enabled, we get the following RCU warning when the user space issues `ioctl(dev, VHOST_VSOCK_SET_GUEST_CID, ...)` : WARNING: suspicious RCU usage 6.18.0-rc7 #62 Not tainted ----------------------------- drivers/vhost/vsock.c:74 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by rpc-libvirtd/3443: #0: ffffffffc05032a8 (vhost_vsock_mutex){+.+.}-{4:4}, at: vhost_vsock_dev_ioctl+0x2ff/0x530 [vhost_vsock] stack backtrace: CPU: 2 UID: 0 PID: 3443 Comm: rpc-libvirtd Not tainted 6.18.0-rc7 #62 PREEMPT(none) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-7.fc42 06/10/2025 Call Trace: <TASK> dump_stack_lvl+0x75/0xb0 dump_stack+0x14/0x1a lockdep_rcu_suspicious.cold+0x4e/0x97 vhost_vsock_get+0x8f/0xa0 [vhost_vsock] vhost_vsock_dev_ioctl+0x307/0x530 [vhost_vsock] __x64_sys_ioctl+0x4f2/0xa00 x64_sys_call+0xed0/0x1da0 do_syscall_64+0x73/0xfa0 entry_SYSCALL_64_after_hwframe+0x76/0x7e ... </TASK> This is not a real problem, because the vhost_vsock_get() caller, i.e. vhost_vsock_set_cid(), holds the `vhost_vsock_mutex` used by the hash table writers. Anyway, to prevent that warning, add lockdep_is_held() condition to hash_for_each_possible_rcu() to verify that either the caller is in an RCU read section or `vhost_vsock_mutex` is held when CONFIG_PROVE_RCU_LIST is enabled; and also clarify the comment for vhost_vsock_get() to better describe the locking requirements and the scope of the returned pointer validity. About vhost_vsock_reset_orphans(), currently this function is only called via vsock_for_each_connected_socket(), which holds the `vsock_table_lock` spinlock (which is also an RCU read-side critical section). However, add an explicit RCU read lock there to make the code more robust and explicit about the RCU requirements, and to prevent issues if the calling context changes in the future or if vhost_vsock_reset_orphans() is called from other contexts. Fixes: 834e772c8db0 ("vhost/vsock: fix use-after-free in network stack callers") Cc: stefanha@redhat.com Signed-off-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20251126133826.142496-1-sgarzare@redhat.com> Message-ID: <20251126210313.GA499503@fedora> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-18vhost: Fix kthread worker cgroup failure handlingMike Christie1-1/+3
[ Upstream commit f3f64c2eaffbc3169bbe1e5d1e897e6dacc839d1 ] If we fail to attach to a cgroup we are leaking the id. This adds a new goto to free the id. Fixes: 7d9896e9f6d0 ("vhost: Reintroduce kthread API and add mode selection") Signed-off-by: Mike Christie <michael.christie@oracle.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Message-Id: <20251101194358.13605-1-michael.christie@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15vhost: vringh: Modify the return value checkzhang jiao1-3/+4
[ Upstream commit 82a8d0fda55b35361ee7f35b54fa2b66d7847d2b ] The return value of copy_from_iter and copy_to_iter can't be negative, check whether the copied lengths are equal. Fixes: 309bba39c945 ("vringh: iterate on iotlb_translate to handle large translations") Cc: "Stefano Garzarella" <sgarzare@redhat.com> Signed-off-by: zhang jiao <zhangjiao2@cmss.chinamobile.com> Message-Id: <20250910091739.2999-1-zhangjiao2@cmss.chinamobile.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15vhost: vringh: Fix copy_to_iter return value checkMichael S. Tsirkin1-3/+4
[ Upstream commit 439263376c2c4e126cac0d07e4987568de4eaba5 ] The return value of copy_to_iter can't be negative, check whether the copied length is equal to the requested length instead of checking for negative values. Cc: zhang jiao <zhangjiao2@cmss.chinamobile.com> Link: https://lore.kernel.org/all/20250910091739.2999-1-zhangjiao2@cmss.chinamobile.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Simon Horman <horms@kernel.org> Fixes: 309bba39c945 ("vringh: iterate on iotlb_translate to handle large translations") Link: https://patch.msgid.link/cd637504a6e3967954a9e80fc1b75e8c0978087b.1758723310.git.mst@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-04vhost/net: Protect ubufs with rcu read lock in vhost_net_ubuf_put()Nikolay Kuratov1-2/+7
commit dd54bcf86c91a4455b1f95cbc8e9ac91205f3193 upstream. When operating on struct vhost_net_ubuf_ref, the following execution sequence is theoretically possible: CPU0 is finalizing DMA operation CPU1 is doing VHOST_NET_SET_BACKEND // ubufs->refcount == 2 vhost_net_ubuf_put() vhost_net_ubuf_put_wait_and_free(oldubufs) vhost_net_ubuf_put_and_wait() vhost_net_ubuf_put() int r = atomic_sub_return(1, &ubufs->refcount); // r = 1 int r = atomic_sub_return(1, &ubufs->refcount); // r = 0 wait_event(ubufs->wait, !atomic_read(&ubufs->refcount)); // no wait occurs here because condition is already true kfree(ubufs); if (unlikely(!r)) wake_up(&ubufs->wait); // use-after-free This leads to use-after-free on ubufs access. This happens because CPU1 skips waiting for wake_up() when refcount is already zero. To prevent that use a read-side RCU critical section in vhost_net_ubuf_put(), as suggested by Hillf Danton. For this lock to take effect, free ubufs with kfree_rcu(). Cc: stable@vger.kernel.org Fixes: 0ad8b480d6ee9 ("vhost: fix ref cnt checking deadlock") Reported-by: Andrey Ryabinin <arbn@yandex-team.com> Suggested-by: Hillf Danton <hdanton@sina.com> Signed-off-by: Nikolay Kuratov <kniv@yandex-team.ru> Message-Id: <20250805130917.727332-1-kniv@yandex-team.ru> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28vhost/vsock: Avoid allocating arbitrarily-sized SKBsWill Deacon1-2/+4
commit 10a886aaed293c4db3417951f396827216299e3d upstream. vhost_vsock_alloc_skb() returns NULL for packets advertising a length larger than VIRTIO_VSOCK_MAX_PKT_BUF_SIZE in the packet header. However, this is only checked once the SKB has been allocated and, if the length in the packet header is zero, the SKB may not be freed immediately. Hoist the size check before the SKB allocation so that an iovec larger than VIRTIO_VSOCK_MAX_PKT_BUF_SIZE + the header size is rejected outright. The subsequent check on the length field in the header can then simply check that the allocated SKB is indeed large enough to hold the packet. Cc: <stable@vger.kernel.org> Fixes: 71dc9ec9ac7d ("virtio/vsock: replace virtio_vsock_pkt with sk_buff") Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Will Deacon <will@kernel.org> Message-Id: <20250717090116.11987-2-will@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-20vhost: fail early when __vhost_add_used() failsJason Wang1-0/+3
[ Upstream commit b4ba1207d45adaafa2982c035898b36af2d3e518 ] This patch fails vhost_add_used_n() early when __vhost_add_used() fails to make sure used idx is not updated with stale used ring information. Reported-by: Eugenio Pérez <eperezma@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Message-Id: <20250714084755.11921-2-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Tested-by: Lei Yang <leiyang@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15vhost: Reintroduce kthread API and add mode selectionCindy Lu3-18/+266
[ Upstream commit 7d9896e9f6d02d8aa85e63f736871f96c59a5263 ] Since commit 6e890c5d5021 ("vhost: use vhost_tasks for worker threads"), the vhost uses vhost_task and operates as a child of the owner thread. This is required for correct CPU usage accounting, especially when using containers. However, this change has caused confusion for some legacy userspace applications, and we didn't notice until it's too late. Unfortunately, it's too late to revert - we now have userspace depending both on old and new behaviour :( To address the issue, reintroduce kthread mode for vhost workers and provide a configuration to select between kthread and task worker. - Add 'fork_owner' parameter to vhost_dev to let users select kthread or task mode. Default mode is task mode(VHOST_FORK_OWNER_TASK). - Reintroduce kthread mode support: * Bring back the original vhost_worker() implementation, and renamed to vhost_run_work_kthread_list(). * Add cgroup support for the kthread * Introduce struct vhost_worker_ops: - Encapsulates create / stop / wake‑up callbacks. - vhost_worker_create() selects the proper ops according to inherit_owner. - Userspace configuration interface: * New IOCTLs: - VHOST_SET_FORK_FROM_OWNER lets userspace select task mode (VHOST_FORK_OWNER_TASK) or kthread mode (VHOST_FORK_OWNER_KTHREAD) - VHOST_GET_FORK_FROM_OWNER reads the current worker mode * Expose module parameter 'fork_from_owner_default' to allow system administrators to configure the default mode for vhost workers * Kconfig option CONFIG_VHOST_ENABLE_FORK_OWNER_CONTROL controls whether these IOCTLs and the parameter are available - The VHOST_NEW_WORKER functionality requires fork_owner to be set to true, with validation added to ensure proper configuration This partially reverts or improves upon: commit 6e890c5d5021 ("vhost: use vhost_tasks for worker threads") commit 1cdaafa1b8b4 ("vhost: replace single worker pointer with xarray") Fixes: 6e890c5d5021 ("vhost: use vhost_tasks for worker threads"), Signed-off-by: Cindy Lu <lulu@redhat.com> Message-Id: <20250714071333.59794-2-lulu@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Tested-by: Lei Yang <leiyang@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15vhost-scsi: Fix log flooding with target does not exist errorsMike Christie1-3/+1
[ Upstream commit 69cd720a8a5e9ef0f05ce5dd8c9ea6e018245c82 ] As part of the normal initiator side scanning the guest's scsi layer will loop over all possible targets and send an inquiry. Since the max number of targets for virtio-scsi is 256, this can result in 255 error messages about targets not existing if you only have a single target. When there's more than 1 vhost-scsi device each with a single target, then you get N * 255 log messages. It looks like the log message was added by accident in: commit 3f8ca2e115e5 ("vhost/scsi: Extract common handling code from control queue handler") when we added common helpers. Then in: commit 09d7583294aa ("vhost/scsi: Use common handling code in request queue handler") we converted the scsi command processing path to use the new helpers so we started to see the extra log messages during scanning. The patches were just making some code common but added the vq_err call and I'm guessing the patch author forgot to enable the vq_err call (vq_err is implemented by pr_debug which defaults to off). So this patch removes the call since it's expected to hit this path during device discovery. Fixes: 09d7583294aa ("vhost/scsi: Use common handling code in request queue handler") Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Message-Id: <20250611210113.10912-1-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-29vhost-scsi: Return queue full for page alloc failures during copyMike Christie1-6/+9
[ Upstream commit 891b99eab0f89dbe08d216f4ab71acbeaf7a3102 ] This has us return queue full if we can't allocate a page during the copy operation so the initiator can retry. Signed-off-by: Mike Christie <michael.christie@oracle.com> Message-Id: <20241203191705.19431-5-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-29vhost-scsi: protect vq->log_used with vq->mutexDongli Zhang1-0/+8
[ Upstream commit f591cf9fce724e5075cc67488c43c6e39e8cbe27 ] The vhost-scsi completion path may access vq->log_base when vq->log_used is already set to false. vhost-thread QEMU-thread vhost_scsi_complete_cmd_work() -> vhost_add_used() -> vhost_add_used_n() if (unlikely(vq->log_used)) QEMU disables vq->log_used via VHOST_SET_VRING_ADDR. mutex_lock(&vq->mutex); vq->log_used = false now! mutex_unlock(&vq->mutex); QEMU gfree(vq->log_base) log_used() -> log_write(vq->log_base) Assuming the VMM is QEMU. The vq->log_base is from QEMU userpace and can be reclaimed via gfree(). As a result, this causes invalid memory writes to QEMU userspace. The control queue path has the same issue. Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Mike Christie <michael.christie@oracle.com> Message-Id: <20250403063028.16045-2-dongli.zhang@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02vhost-scsi: Fix vhost_scsi_send_status()Dongli Zhang1-7/+11
[ Upstream commit 58465d86071b61415e25fb054201f61e83d21465 ] Although the support of VIRTIO_F_ANY_LAYOUT + VIRTIO_F_VERSION_1 was signaled by the commit 664ed90e621c ("vhost/scsi: Set VIRTIO_F_ANY_LAYOUT + VIRTIO_F_VERSION_1 feature bits"), vhost_scsi_send_bad_target() still assumes the response in a single descriptor. Similar issue in vhost_scsi_send_bad_target() has been fixed in previous commit. In addition, similar issue for vhost_scsi_complete_cmd_work() has been fixed by the commit 6dd88fd59da8 ("vhost-scsi: unbreak any layout for response"). Fixes: 3ca51662f818 ("vhost-scsi: Add better resource allocation failure handling") Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Mike Christie <michael.christie@oracle.com> Message-Id: <20250403063028.16045-4-dongli.zhang@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02vhost-scsi: Fix vhost_scsi_send_bad_target()Dongli Zhang1-11/+37
[ Upstream commit b182687135474d7ed905a07cc6cb2734b359e13e ] Although the support of VIRTIO_F_ANY_LAYOUT + VIRTIO_F_VERSION_1 was signaled by the commit 664ed90e621c ("vhost/scsi: Set VIRTIO_F_ANY_LAYOUT + VIRTIO_F_VERSION_1 feature bits"), vhost_scsi_send_bad_target() still assumes the response in a single descriptor. In addition, although vhost_scsi_send_bad_target() is used by both I/O queue and control queue, the response header is always virtio_scsi_cmd_resp. It is required to use virtio_scsi_ctrl_tmf_resp or virtio_scsi_ctrl_an_resp for control queue. Fixes: 664ed90e621c ("vhost/scsi: Set VIRTIO_F_ANY_LAYOUT + VIRTIO_F_VERSION_1 feature bits") Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Mike Christie <michael.christie@oracle.com> Message-Id: <20250403063028.16045-3-dongli.zhang@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-05-02vhost-scsi: Add better resource allocation failure handlingMike Christie1-3/+25
[ Upstream commit 3ca51662f8186b569b8fb282242c20ccbb3993c2 ] If we can't allocate mem to map in data for a request or can't find a tag for a command, we currently drop the command. This leads to the error handler running to clean it up. Instead of dropping the command this has us return an error telling the initiator that it queued more commands than we can handle. The initiator will then reduce how many commands it will send us and retry later. Signed-off-by: Mike Christie <michael.christie@oracle.com> Message-Id: <20241203191705.19431-4-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Stefan Hajnoczi <stefanha@redhat.com> Stable-dep-of: b18268713547 ("vhost-scsi: Fix vhost_scsi_send_bad_target()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10vhost-scsi: Fix handling of multiple calls to vhost_scsi_set_endpointMike Christie1-12/+13
[ Upstream commit 5dd639a1646ef5fe8f4bf270fad47c5c3755b9b6 ] If vhost_scsi_set_endpoint is called multiple times without a vhost_scsi_clear_endpoint between them, we can hit multiple bugs found by Haoran Zhang: 1. Use-after-free when no tpgs are found: This fixes a use after free that occurs when vhost_scsi_set_endpoint is called more than once and calls after the first call do not find any tpgs to add to the vs_tpg. When vhost_scsi_set_endpoint first finds tpgs to add to the vs_tpg array match=true, so we will do: vhost_vq_set_backend(vq, vs_tpg); ... kfree(vs->vs_tpg); vs->vs_tpg = vs_tpg; If vhost_scsi_set_endpoint is called again and no tpgs are found match=false so we skip the vhost_vq_set_backend call leaving the pointer to the vs_tpg we then free via: kfree(vs->vs_tpg); vs->vs_tpg = vs_tpg; If a scsi request is then sent we do: vhost_scsi_handle_vq -> vhost_scsi_get_req -> vhost_vq_get_backend which sees the vs_tpg we just did a kfree on. 2. Tpg dir removal hang: This patch fixes an issue where we cannot remove a LIO/target layer tpg (and structs above it like the target) dir due to the refcount dropping to -1. The problem is that if vhost_scsi_set_endpoint detects a tpg is already in the vs->vs_tpg array or if the tpg has been removed so target_depend_item fails, the undepend goto handler will do target_undepend_item on all tpgs in the vs_tpg array dropping their refcount to 0. At this time vs_tpg contains both the tpgs we have added in the current vhost_scsi_set_endpoint call as well as tpgs we added in previous calls which are also in vs->vs_tpg. Later, when vhost_scsi_clear_endpoint runs it will do target_undepend_item on all the tpgs in the vs->vs_tpg which will drop their refcount to -1. Userspace will then not be able to remove the tpg and will hang when it tries to do rmdir on the tpg dir. 3. Tpg leak: This fixes a bug where we can leak tpgs and cause them to be un-removable because the target name is overwritten when vhost_scsi_set_endpoint is called multiple times but with different target names. The bug occurs if a user has called VHOST_SCSI_SET_ENDPOINT and setup a vhost-scsi device to target/tpg mapping, then calls VHOST_SCSI_SET_ENDPOINT again with a new target name that has tpgs we haven't seen before (target1 has tpg1 but target2 has tpg2). When this happens we don't teardown the old target tpg mapping and just overwrite the target name and the vs->vs_tpg array. Later when we do vhost_scsi_clear_endpoint, we are passed in either target1 or target2's name and we will only match that target's tpgs when we loop over the vs->vs_tpg. We will then return from the function without doing target_undepend_item on the tpgs. Because of all these bugs, it looks like being able to call vhost_scsi_set_endpoint multiple times was never supported. The major user, QEMU, already has checks to prevent this use case. So to fix the issues, this patch prevents vhost_scsi_set_endpoint from being called if it's already successfully added tpgs. To add, remove or change the tpg config or target name, you must do a vhost_scsi_clear_endpoint first. Fixes: 25b98b64e284 ("vhost scsi: alloc cmds per vq instead of session") Fixes: 4f7f46d32c98 ("tcm_vhost: Use vq->private_data to indicate if the endpoint is setup") Reported-by: Haoran Zhang <wh1sper@zju.edu.cn> Closes: https://lore.kernel.org/virtualization/e418a5ee-45ca-4d18-9b5d-6f8b6b1add8e@oracle.com/T/#me6c0041ce376677419b9b2563494172a01487ecb Signed-off-by: Mike Christie <michael.christie@oracle.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-Id: <20250129210922.121533-1-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-22vhost: return task creation error instead of NULLKeith Busch1-1/+1
[ Upstream commit cb380909ae3b1ebf14d6a455a4f92d7916d790cb ] Lets callers distinguish why the vhost task creation failed. No one currently cares why it failed, so no real runtime change from this patch, but that will not be the case for long. Signed-off-by: Keith Busch <kbusch@kernel.org> Message-ID: <20250227230631.303431-2-kbusch@meta.com> Reviewed-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-10-07Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds1-12/+15
Pull virtio fixes from Michael Tsirkin: "Several small bugfixes all over the place. Most notably, fixes the vsock allocation with GFP_KERNEL in atomic context, which has been triggering warnings for lots of testers" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: vhost/scsi: null-ptr-dereference in vhost_scsi_get_req() vsock/virtio: use GFP_ATOMIC under RCU read lock virtio_console: fix misc probe bugs virtio_ring: tag event_triggered as racy for KCSAN vdpa/octeon_ep: Fix format specifier for pointers in debug messages
2024-10-07vhost/scsi: null-ptr-dereference in vhost_scsi_get_req()Haoran Zhang1-12/+15
Since commit 3f8ca2e115e5 ("vhost/scsi: Extract common handling code from control queue handler") a null pointer dereference bug can be triggered when guest sends an SCSI AN request. In vhost_scsi_ctl_handle_vq(), `vc.target` is assigned with `&v_req.tmf.lun[1]` within a switch-case block and is then passed to vhost_scsi_get_req() which extracts `vc->req` and `tpg`. However, for a `VIRTIO_SCSI_T_AN_*` request, tpg is not required, so `vc.target` is set to NULL in this branch. Later, in vhost_scsi_get_req(), `vc->target` is dereferenced without being checked, leading to a null pointer dereference bug. This bug can be triggered from guest. When this bug occurs, the vhost_worker process is killed while holding `vq->mutex` and the corresponding tpg will remain occupied indefinitely. Below is the KASAN report: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 PID: 840 Comm: poc Not tainted 6.10.0+ #1 Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:vhost_scsi_get_req+0x165/0x3a0 Code: 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 2b 02 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 65 30 4c 89 e2 48 c1 ea 03 <0f> b6 04 02 4c 89 e2 83 e2 07 38 d0 7f 08 84 c0 0f 85 be 01 00 00 RSP: 0018:ffff888017affb50 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff88801b000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888017affcb8 RBP: ffff888017affb80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888017affc88 R14: ffff888017affd1c R15: ffff888017993000 FS: 000055556e076500(0000) GS:ffff88806b100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200027c0 CR3: 0000000010ed0004 CR4: 0000000000370ef0 Call Trace: <TASK> ? show_regs+0x86/0xa0 ? die_addr+0x4b/0xd0 ? exc_general_protection+0x163/0x260 ? asm_exc_general_protection+0x27/0x30 ? vhost_scsi_get_req+0x165/0x3a0 vhost_scsi_ctl_handle_vq+0x2a4/0xca0 ? __pfx_vhost_scsi_ctl_handle_vq+0x10/0x10 ? __switch_to+0x721/0xeb0 ? __schedule+0xda5/0x5710 ? __kasan_check_write+0x14/0x30 ? _raw_spin_lock+0x82/0xf0 vhost_scsi_ctl_handle_kick+0x52/0x90 vhost_run_work_list+0x134/0x1b0 vhost_task_fn+0x121/0x350 ... </TASK> ---[ end trace 0000000000000000 ]--- Let's add a check in vhost_scsi_get_req. Fixes: 3f8ca2e115e5 ("vhost/scsi: Extract common handling code from control queue handler") Signed-off-by: Haoran Zhang <wh1sper@zju.edu.cn> [whitespace fixes] Signed-off-by: Mike Christie <michael.christie@oracle.com> Message-Id: <b26d7ddd-b098-4361-88f8-17ca7f90adf7@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-10-03move asm/unaligned.h to linux/unaligned.hAl Viro1-1/+1
asm/unaligned.h is always an include of asm-generic/unaligned.h; might as well move that thing to linux/unaligned.h and include that - there's nothing arch-specific in that header. auto-generated by the following: for i in `git grep -l -w asm/unaligned.h`; do sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i done for i in `git grep -l -w asm-generic/unaligned.h`; do sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i done git mv include/asm-generic/unaligned.h include/linux/unaligned.h git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
2024-09-26Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds1-3/+13
Pull virtio updates from Michael Tsirkin: "Several new features here: - virtio-balloon supports new stats - vdpa supports setting mac address - vdpa/mlx5 suspend/resume as well as MKEY ops are now faster - virtio_fs supports new sysfs entries for queue info - virtio/vsock performance has been improved And fixes, cleanups all over the place" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (34 commits) vsock/virtio: avoid queuing packets when intermediate queue is empty vsock/virtio: refactor virtio_transport_send_pkt_work fw_cfg: Constify struct kobj_type vdpa/mlx5: Postpone MR deletion vdpa/mlx5: Introduce init/destroy for MR resources vdpa/mlx5: Rename mr_mtx -> lock vdpa/mlx5: Extract mr members in own resource struct vdpa/mlx5: Rename function vdpa/mlx5: Delete direct MKEYs in parallel vdpa/mlx5: Create direct MKEYs in parallel MAINTAINERS: add virtio-vsock driver in the VIRTIO CORE section virtio_fs: add sysfs entries for queue information virtio_fs: introduce virtio_fs_put_locked helper vdpa: Remove unused declarations vdpa/mlx5: Parallelize VQ suspend/resume for CVQ MQ command vdpa/mlx5: Small improvement for change_num_qps() vdpa/mlx5: Keep notifiers during suspend but ignore vdpa/mlx5: Parallelize device resume vdpa/mlx5: Parallelize device suspend vdpa/mlx5: Use async API for vq modify commands ...
2024-09-10vhost_vdpa: assign irq bypass producer token correctlyJason Wang1-3/+13
We used to call irq_bypass_unregister_producer() in vhost_vdpa_setup_vq_irq() which is problematic as we don't know if the token pointer is still valid or not. Actually, we use the eventfd_ctx as the token so the life cycle of the token should be bound to the VHOST_SET_VRING_CALL instead of vhost_vdpa_setup_vq_irq() which could be called by set_status(). Fixing this by setting up irq bypass producer's token when handling VHOST_SET_VRING_CALL and un-registering the producer before calling vhost_vring_ioctl() to prevent a possible use after free as eventfd could have been released in vhost_vring_ioctl(). And such registering and unregistering will only be done if DRIVER_OK is set. Reported-by: Dragos Tatulea <dtatulea@nvidia.com> Tested-by: Dragos Tatulea <dtatulea@nvidia.com> Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com> Fixes: 2cf1ba9a4d15 ("vhost_vdpa: implement IRQ offloading in vhost_vdpa") Signed-off-by: Jason Wang <jasowang@redhat.com> Message-Id: <20240816031900.18013-1-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-08-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-7/+1
Cross-merge networking fixes after downstream PR. No conflicts or adjacent changes. Link: https://patch.msgid.link/20240808170148.3629934-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-06Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds1-7/+1
Pull virtio fix from Michael Tsirkin: "Fix a single, long-standing issue with kick pass-through vdpa" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: vhost-vdpa: switch to use vmf_insert_pfn() in the fault handler
2024-08-02vsock/virtio: add SIOCOUTQ support for all virtio based transportsLuigi Leonardi1-1/+3
Introduce support for virtio_transport_unsent_bytes ioctl for virtio_transport, vhost_vsock and vsock_loopback. For all transports the unsent bytes counter is incremented in virtio_transport_get_credit. In virtio_transport (G2H) and in vhost-vsock (H2G) the counter is decremented when the skbuff is consumed. In vsock_loopback the same skbuff is passed from the transmitter to the receiver, so the counter is decremented before queuing the skbuff to the receiver. Signed-off-by: Luigi Leonardi <luigi.leonardi@outlook.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2024-07-26vhost-vdpa: switch to use vmf_insert_pfn() in the fault handlerJason Wang1-7/+1
remap_pfn_page() should not be called in the fault handler as it may change the vma->flags which may trigger lockdep warning since the vma write lock is not held. Actually there's no need to modify the vma->flags as it has been set in the mmap(). So this patch switches to use vmf_insert_pfn() instead. Reported-by: Dragos Tatulea <dtatulea@nvidia.com> Tested-by: Dragos Tatulea <dtatulea@nvidia.com> Fixes: ddd89d0a059d ("vhost_vdpa: support doorbell mapping via mmap") Cc: stable@vger.kernel.org Signed-off-by: Jason Wang <jasowang@redhat.com> Message-Id: <20240701033159.18133-1-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
2024-07-19Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds3-65/+45
Pull virtio updates from Michael Tsirkin: "Several new features here: - Virtio find vqs API has been reworked (required to fix the scalability issue we have with adminq, which I hope to merge later in the cycle) - vDPA driver for Marvell OCTEON - virtio fs performance improvement - mlx5 migration speedups Fixes, cleanups all over the place" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (56 commits) virtio: rename virtio_find_vqs_info() to virtio_find_vqs() virtio: remove unused virtio_find_vqs() and virtio_find_vqs_ctx() helpers virtio: convert the rest virtio_find_vqs() users to virtio_find_vqs_info() virtio_balloon: convert to use virtio_find_vqs_info() virtiofs: convert to use virtio_find_vqs_info() scsi: virtio_scsi: convert to use virtio_find_vqs_info() virtio_net: convert to use virtio_find_vqs_info() virtio_crypto: convert to use virtio_find_vqs_info() virtio_console: convert to use virtio_find_vqs_info() virtio_blk: convert to use virtio_find_vqs_info() virtio: rename find_vqs_info() op to find_vqs() virtio: remove the original find_vqs() op virtio: call virtio_find_vqs_info() from virtio_find_single_vq() directly virtio: convert find_vqs() op implementations to find_vqs_info() virtio_pci: convert vp_*find_vqs() ops to find_vqs_info() virtio: introduce virtio_queue_info struct and find_vqs_info() config op virtio: make virtio_find_single_vq() call virtio_find_vqs() virtio: make virtio_find_vqs() call virtio_find_vqs_ctx() caif_virtio: use virtio_find_single_vq() for single virtqueue finding vdpa/mlx5: Don't enable non-active VQs in .set_vq_ready() ...
2024-07-09vringh: add MODULE_DESCRIPTION()Jeff Johnson1-0/+1
Fix the allmodconfig 'make w=1' issue: WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/vhost/vringh.o Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com> Message-Id: <20240516-md-vringh-v1-1-31bf37779a5a@quicinc.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2024-07-09vhost: move smp_rmb() into vhost_get_avail_idx()Michael S. Tsirkin1-63/+42
All callers of vhost_get_avail_idx() use smp_rmb() to order the available ring entry read and avail_idx read. Make vhost_get_avail_idx() call smp_rmb() itself whenever the avail_idx is accessed. This way, the callers don't need to worry about the memory barrier. As a side benefit, we also validate the index on all paths now, which will hopefully help prevent/catch earlier future bugs. Note that current code is inconsistent in how the errors are handled. They are treated as an empty ring in some places, but as non-empty ring in other places. This patch doesn't attempt to change the existing behaviour. No functional change intended. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Acked-by: Will Deacon <will@kernel.org> Message-Id: <20240429232748.642356-1-gshan@redhat.com>
2024-07-04vhost/vsock: always initialize seqpacket_allowMichael S. Tsirkin1-2/+2
There are two issues around seqpacket_allow: 1. seqpacket_allow is not initialized when socket is created. Thus if features are never set, it will be read uninitialized. 2. if VIRTIO_VSOCK_F_SEQPACKET is set and then cleared, then seqpacket_allow will not be cleared appropriately (existing apps I know about don't usually do this but it's legal and there's no way to be sure no one relies on this). To fix: - initialize seqpacket_allow after allocation - set it unconditionally in set_features Reported-by: syzbot+6c21aeb59d0e82eb2782@syzkaller.appspotmail.com Reported-by: Jeongjun Park <aha310510@gmail.com> Fixes: ced7b713711f ("vhost/vsock: support SEQPACKET for transport"). Tested-by: Arseny Krasnov <arseny.krasnov@kaspersky.com> Cc: David S. Miller <davem@davemloft.net> Cc: Stefan Hajnoczi <stefanha@redhat.com> Message-ID: <20240422100010-mutt-send-email-mst@kernel.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Eugenio Pérez <eperezma@redhat.com> Acked-by: Jakub Kicinski <kuba@kernel.org>
2024-07-04vhost-vdpa: Use iommu_paging_domain_alloc()Lu Baolu1-8/+6
Replace iommu_domain_alloc() with iommu_paging_domain_alloc(). Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Link: https://lore.kernel.org/r/20240610085555.88197-5-baolu.lu@linux.intel.com Signed-off-by: Will Deacon <will@kernel.org>
2024-05-23Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds4-65/+140
Pull virtio updates from Michael Tsirkin: "Several new features here: - virtio-net is finally supported in vduse - virtio (balloon and mem) interaction with suspend is improved - vhost-scsi now handles signals better/faster And fixes, cleanups all over the place" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (48 commits) virtio-pci: Check if is_avq is NULL virtio: delete vq in vp_find_vqs_msix() when request_irq() fails MAINTAINERS: add Eugenio Pérez as reviewer vhost-vdpa: Remove usage of the deprecated ida_simple_xx() API vp_vdpa: don't allocate unused msix vectors sound: virtio: drop owner assignment fuse: virtio: drop owner assignment scsi: virtio: drop owner assignment rpmsg: virtio: drop owner assignment nvdimm: virtio_pmem: drop owner assignment wifi: mac80211_hwsim: drop owner assignment vsock/virtio: drop owner assignment net: 9p: virtio: drop owner assignment net: virtio: drop owner assignment net: caif: virtio: drop owner assignment misc: nsm: drop owner assignment iommu: virtio: drop owner assignment drm/virtio: drop owner assignment gpio: virtio: drop owner assignment firmware: arm_scmi: virtio: drop owner assignment ...
2024-05-22vhost-vdpa: Remove usage of the deprecated ida_simple_xx() APIChristophe JAILLET1-3/+3
ida_alloc() and ida_free() should be preferred to the deprecated ida_simple_get() and ida_simple_remove(). Note that the upper limit of ida_simple_get() is exclusive, but the one of ida_alloc_max() is inclusive. So a -1 has been added when needed. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Reviewed-by: Simon Horman <horms@kernel.org> Message-Id: <67c2edf49788c27d5f7a49fc701520b9fcf739b5.1713088999.git.christophe.jaillet@wanadoo.fr> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2024-05-22vhost_task: Handle SIGKILL by flushing work and exitingMike Christie2-4/+52
Instead of lingering until the device is closed, this has us handle SIGKILL by: 1. marking the worker as killed so we no longer try to use it with new virtqueues and new flush operations. 2. setting the virtqueue to worker mapping so no new works are queued. 3. running all the exiting works. Suggested-by: Edward Adam Davis <eadavis@qq.com> Reported-and-tested-by: syzbot+98edc2df894917b3431f@syzkaller.appspotmail.com Message-Id: <tencent_546DA49414E876EEBECF2C78D26D242EE50A@qq.com> Signed-off-by: Mike Christie <michael.christie@oracle.com> Message-Id: <20240316004707.45557-9-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-05-22vhost: Release worker mutex during flushesMike Christie1-14/+30
In the next patches where the worker can be killed while in use, we need to be able to take the worker mutex and kill queued works for new IO and flushes, and set some new flags to prevent new __vhost_vq_attach_worker calls from swapping in/out killed workers. If we are holding the worker mutex during a flush and the flush's work is still in the queue, the worker code that will handle the SIGKILL cleanup won't be able to take the mutex and perform it's cleanup. So this patch has us drop the worker mutex while waiting for the flush to complete. Signed-off-by: Mike Christie <michael.christie@oracle.com> Message-Id: <20240316004707.45557-8-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-05-22vhost: Use virtqueue mutex for swapping workerMike Christie1-6/+12
__vhost_vq_attach_worker uses the vhost_dev mutex to serialize the swapping of a virtqueue's worker. This was done for simplicity because we are already holding that mutex. In the next patches where the worker can be killed while in use, we need finer grained locking because some drivers will hold the vhost_dev mutex while flushing. However in the SIGKILL handler in the next patches, we will need to be able to swap workers (set current one to NULL), kill queued works and stop new flushes while flushes are in progress. To prepare us, this has us use the virtqueue mutex for swapping workers instead of the vhost_dev one. Signed-off-by: Mike Christie <michael.christie@oracle.com> Message-Id: <20240316004707.45557-7-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-05-22vhost_scsi: Handle vhost_vq_work_queue failures for TMFsMike Christie1-1/+2
vhost_vq_work_queue will never fail when queueing the TMF's response handling because a guest can only send us TMFs when the device is fully setup so there is always a worker at that time. In the next patches we will modify the worker code so it handles SIGKILL by exiting before outstanding commands/TMFs have sent their responses. In that case vhost_vq_work_queue can fail when we try to send a response. This has us just free the TMF's resources since at this time the guest won't be able to get a response even if we could send it. Signed-off-by: Mike Christie <michael.christie@oracle.com> Message-Id: <20240316004707.45557-6-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-05-22vhost: Remove vhost_vq_flushMike Christie2-13/+0
vhost_vq_flush is no longer used so remove it. Signed-off-by: Mike Christie <michael.christie@oracle.com> Message-Id: <20240316004707.45557-5-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-05-22vhost-scsi: Use system wq to flush dev for TMFsMike Christie1-20/+19
We flush all the workers that are not also used by the ctl vq to make sure that responses queued by LIO before the TMF response are sent before the TMF response. This requires a special vhost_vq_flush function which, in the next patches where we handle SIGKILL killing workers while in use, will require extra locking/complexity. To avoid that, this patch has us flush the entire device from the system work queue, then queue up sending the response from there. This is a little less optimal since we now flush all workers but this will be ok since commands have already timed out and perf is not a concern. Signed-off-by: Mike Christie <michael.christie@oracle.com> Message-Id: <20240316004707.45557-4-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-05-22vhost-scsi: Handle vhost_vq_work_queue failures for cmdsMike Christie1-1/+12
In the next patches we will support the vhost_task being killed while in use. The problem for vhost-scsi is that we can't free some structs until we get responses for commands we have submitted to the target layer and we currently process the responses from the vhost_task. This has just drop the responses and free the command's resources. When all commands have completed then operations like flush will be woken up and we can complete device release and endpoint cleanup. Signed-off-by: Mike Christie <michael.christie@oracle.com> Message-Id: <20240316004707.45557-3-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-05-22vhost-scsi: Handle vhost_vq_work_queue failures for eventsMike Christie1-5/+12
Currently, we can try to queue an event's work before the vhost_task is created. When this happens we just drop it in vhost_scsi_do_plug before even calling vhost_vq_work_queue. During a device shutdown we do the same thing after vhost_scsi_clear_endpoint has cleared the backends. In the next patches we will be able to kill the vhost_task before we have cleared the endpoint. In that case, vhost_vq_work_queue can fail and we will leak the event's memory. This has handle the failure by just freeing the event. This is safe to do, because vhost_vq_work_queue will only return failure for us when the vhost_task is killed and so userspace will not be able to handle events if we sent them. Signed-off-by: Mike Christie <michael.christie@oracle.com> Message-Id: <20240316004707.45557-2-michael.christie@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-04-23net: extend ubuf_info callback to ops structurePavel Begunkov1-2/+6
We'll need to associate additional callbacks with ubuf_info, introduce a structure holding ubuf_info callbacks. Apart from a more smarter io_uring notification management introduced in next patches, it can be used to generalise msg_zerocopy_put_abort() and also store ->sg_from_iter, which is currently passed in struct msghdr. Reviewed-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/all/a62015541de49c0e2a8a0377a1d5d0a5aeb07016.1713369317.git.asml.silence@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-08vhost: correct misleading printing informationXianting Tian1-1/+1
Guest moved avail idx not used idx when we need to print log if '(vq->avail_idx - last_avail_idx) > vq->num', so fix it. Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com> Message-Id: <20240311082109.46773-1-xianting.tian@linux.alibaba.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-04-08vhost: Add smp_rmb() in vhost_enable_notify()Gavin Shan1-1/+11
A smp_rmb() has been missed in vhost_enable_notify(), inspired by Will. Otherwise, it's not ensured the available ring entries pushed by guest can be observed by vhost in time, leading to stale available ring entries fetched by vhost in vhost_get_vq_desc(), as reported by Yihuang Yu on NVidia's grace-hopper (ARM64) platform. /home/gavin/sandbox/qemu.main/build/qemu-system-aarch64 \ -accel kvm -machine virt,gic-version=host -cpu host \ -smp maxcpus=1,cpus=1,sockets=1,clusters=1,cores=1,threads=1 \ -m 4096M,slots=16,maxmem=64G \ -object memory-backend-ram,id=mem0,size=4096M \ : \ -netdev tap,id=vnet0,vhost=true \ -device virtio-net-pci,bus=pcie.8,netdev=vnet0,mac=52:54:00:f1:26:b0 : guest# netperf -H 10.26.1.81 -l 60 -C -c -t UDP_STREAM virtio_net virtio0: output.0:id 100 is not a head! Add the missed smp_rmb() in vhost_enable_notify(). When it returns true, it means there's still pending tx buffers. Since it might read indices, so it still can bypass the smp_rmb() in vhost_get_vq_desc(). Note that it should be safe until vq->avail_idx is changed by commit d3bb267bbdcb ("vhost: cache avail index in vhost_enable_notify()"). Fixes: d3bb267bbdcb ("vhost: cache avail index in vhost_enable_notify()") Cc: <stable@kernel.org> # v5.18+ Reported-by: Yihuang Yu <yihyu@redhat.com> Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Gavin Shan <gshan@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20240328002149.1141302-3-gshan@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
2024-04-08vhost: Add smp_rmb() in vhost_vq_avail_empty()Gavin Shan1-1/+11
A smp_rmb() has been missed in vhost_vq_avail_empty(), spotted by Will. Otherwise, it's not ensured the available ring entries pushed by guest can be observed by vhost in time, leading to stale available ring entries fetched by vhost in vhost_get_vq_desc(), as reported by Yihuang Yu on NVidia's grace-hopper (ARM64) platform. /home/gavin/sandbox/qemu.main/build/qemu-system-aarch64 \ -accel kvm -machine virt,gic-version=host -cpu host \ -smp maxcpus=1,cpus=1,sockets=1,clusters=1,cores=1,threads=1 \ -m 4096M,slots=16,maxmem=64G \ -object memory-backend-ram,id=mem0,size=4096M \ : \ -netdev tap,id=vnet0,vhost=true \ -device virtio-net-pci,bus=pcie.8,netdev=vnet0,mac=52:54:00:f1:26:b0 : guest# netperf -H 10.26.1.81 -l 60 -C -c -t UDP_STREAM virtio_net virtio0: output.0:id 100 is not a head! Add the missed smp_rmb() in vhost_vq_avail_empty(). When tx_can_batch() returns true, it means there's still pending tx buffers. Since it might read indices, so it still can bypass the smp_rmb() in vhost_get_vq_desc(). Note that it should be safe until vq->avail_idx is changed by commit 275bf960ac697 ("vhost: better detection of available buffers"). Fixes: 275bf960ac69 ("vhost: better detection of available buffers") Cc: <stable@kernel.org> # v4.11+ Reported-by: Yihuang Yu <yihyu@redhat.com> Suggested-by: Will Deacon <will@kernel.org> Signed-off-by: Gavin Shan <gshan@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Message-Id: <20240328002149.1141302-2-gshan@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
2024-03-19Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds2-0/+17
Pull virtio updates from Michael Tsirkin: - Per vq sizes in vdpa - Info query for block devices support in vdpa - DMA sync callbacks in vduse - Fixes, cleanups * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (35 commits) virtio_net: rename free_old_xmit_skbs to free_old_xmit virtio_net: unify the code for recycling the xmit ptr virtio-net: add cond_resched() to the command waiting loop virtio-net: convert rx mode setting to use workqueue virtio: packed: fix unmap leak for indirect desc table vDPA: report virtio-blk flush info to user space vDPA: report virtio-block read-only info to user space vDPA: report virtio-block write zeroes configuration to user space vDPA: report virtio-block discarding configuration to user space vDPA: report virtio-block topology info to user space vDPA: report virtio-block MQ info to user space vDPA: report virtio-block max segments in a request to user space vDPA: report virtio-block block-size to user space vDPA: report virtio-block max segment size to user space vDPA: report virtio-block capacity to user space virtio: make virtio_bus const vdpa: make vdpa_bus const vDPA/ifcvf: implement vdpa_config_ops.get_vq_num_min vDPA/ifcvf: get_max_vq_size to return max size virtio_vdpa: create vqs with the actual size ...
2024-03-19vDPA: introduce get_vq_size to vdpa_config_opsZhu Lingshan1-0/+8
This commit introduces a new interface get_vq_size to vDPA config ops, this new interface intends to report the size of a specific virtqueue Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com> Message-Id: <20240202163905.8834-3-lingshan.zhu@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-03-19vdpa: skip suspend/resume ops if not DRIVER_OKSteve Sistare1-0/+6
If a vdpa device is not in state DRIVER_OK, then there is no driver state to preserve, so no need to call the suspend and resume driver ops. Suggested-by: Eugenio Perez Martin <eperezma@redhat.com>" Signed-off-by: Steve Sistare <steven.sistare@oracle.com> Message-Id: <1707834358-165470-1-git-send-email-steven.sistare@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Eugenio Pérez <eperezma@redhat.com>
2024-03-19vhost: Added pad cleanup if vnet_hdr is not present.Andrew Melnychenko1-0/+3
When the Qemu launched with vhost but without tap vnet_hdr, vhost tries to copy vnet_hdr from socket iter with size 0 to the page that may contain some trash. That trash can be interpreted as unpredictable values for vnet_hdr. That leads to dropping some packets and in some cases to stalling vhost routine when the vhost_net tries to process packets and fails in a loop. Qemu options: -netdev tap,vhost=on,vnet_hdr=off,... Signed-off-by: Andrew Melnychenko <andrew@daynix.com> Message-Id: <20240115194840.1183077-1-andrew@daynix.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-03-05vhost/net: remove vhost_net_page_frag_refill()Yunsheng Lin1-64/+27
The page frag in vhost_net_page_frag_refill() uses the 'struct page_frag' from skb_page_frag_refill(), but it's implementation is similar to page_frag_alloc_align() now. This patch removes vhost_net_page_frag_refill() by using 'struct page_frag_cache' instead of 'struct page_frag', and allocating frag using page_frag_alloc_align(). The added benefit is that not only unifying the page frag implementation a little, but also having about 0.5% performance boost testing by using the vhost_net_test introduced in the last patch. Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-03-05page_frag: unify gfp bits for order 3 page allocationYunsheng Lin1-1/+1
Currently there seems to be three page frag implementations which all try to allocate order 3 page, if that fails, it then fail back to allocate order 0 page, and each of them all allow order 3 page allocation to fail under certain condition by using specific gfp bits. The gfp bits for order 3 page allocation are different between different implementation, __GFP_NOMEMALLOC is or'd to forbid access to emergency reserves memory for __page_frag_cache_refill(), but it is not or'd in other implementions, __GFP_DIRECT_RECLAIM is masked off to avoid direct reclaim in vhost_net_page_frag_refill(), but it is not masked off in __page_frag_cache_refill(). This patch unifies the gfp bits used between different implementions by or'ing __GFP_NOMEMALLOC and masking off __GFP_DIRECT_RECLAIM for order 3 page allocation to avoid possible pressure for mm. Leave the gfp unifying for page frag implementation in sock.c for now as suggested by Paolo Abeni. Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> CC: Alexander Duyck <alexander.duyck@gmail.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>