user/sven/linux.git/drivers/virtio, branch v4.19.280

virtio_mmio: Restore guest page size on resume

2022-07-21T19:09:30Z

[ Upstream commit e0c2ce8217955537dd5434baeba061f209797119 ] Virtio devices might lose their state when the VMM is restarted after a suspend to disk (hibernation) cycle. This means that the guest page size register must be restored for the virtio_mmio legacy interface, since otherwise the virtio queues are not functional. This is particularly problematic for QEMU that currently still defaults to using the legacy interface for virtio_mmio. Write the guest page size register again in virtio_mmio_restore() to make legacy virtio_mmio devices work correctly after hibernation. Signed-off-by: Stephan Gerhold Message-Id: <20220621110621.3638025-3-stephan.gerhold@kernkonzept.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

virtio_mmio: Add missing PM calls to freeze/restore

2022-07-21T19:09:29Z

[ Upstream commit ed7ac37fde33ccd84e4bd2b9363c191f925364c7 ] Most virtio drivers provide freeze/restore callbacks to finish up device usage before suspend and to reinitialize the virtio device after resume. However, these callbacks are currently only called when using virtio_pci. virtio_mmio does not have any PM ops defined. This causes problems for example after suspend to disk (hibernation), since the virtio devices might lose their state after the VMM is restarted. Calling virtio_device_freeze()/restore() ensures that the virtio devices are re-initialized correctly. Fix this by implementing the dev_pm_ops for virtio_mmio, similar to virtio_pci_common. Signed-off-by: Stephan Gerhold Message-Id: <20220621110621.3638025-2-stephan.gerhold@kernkonzept.com> Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

virtio-pci: Remove wrong address verification in vp_del_vqs()

2022-06-25T09:49:17Z

commit 7e415282b41bf0d15c6e0fe268f822d9b083f2f7 upstream. GCC 12 enhanced -Waddress when comparing array address to null [0], which warns: drivers/virtio/virtio_pci_common.c: In function ‘vp_del_vqs’: drivers/virtio/virtio_pci_common.c:257:29: warning: the comparison will always evaluate as ‘true’ for the pointer operand in ‘vp_dev->msix_affinity_masks + (sizetype)((long unsigned int)i * 256)’ must not be NULL [-Waddress] 257 | if (vp_dev->msix_affinity_masks[i]) | ^~~~~~ In fact, the verification is comparing the result of a pointer arithmetic, the address "msix_affinity_masks + i", which will always evaluate to true. Under the hood, free_cpumask_var() calls kfree(), which is safe to pass NULL, not requiring non-null verification. So remove the verification to make compiler happy (happy compiler, happy life). [0] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102103 Signed-off-by: Murilo Opsfelder Araujo Message-Id: <20220415023002.49805-1-muriloo@linux.ibm.com> Signed-off-by: Michael S. Tsirkin Acked-by: Christophe de Dinechin Cc: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman

virtio-mmio: fix missing put_device() when vm_cmdline_parent registration failed

2022-06-25T09:49:15Z

[ Upstream commit a58a7f97ba11391d2d0d408e0b24f38d86ae748e ] The reference must be released when device_register(&vm_cmdline_parent) failed. Add the corresponding 'put_device()' in the error handling path. Signed-off-by: chengkaitao Message-Id: <20220602005542.16489-1-chengkaitao@didiglobal.com> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Signed-off-by: Sasha Levin

virtio: acknowledge all features before access

2022-03-16T12:20:27Z

commit 4fa59ede95195f267101a1b8916992cf3f245cdb upstream. The feature negotiation was designed in a way that makes it possible for devices to know which config fields will be accessed by drivers. This is broken since commit 404123c2db79 ("virtio: allow drivers to validate features") with fallout in at least block and net. We have a partial work-around in commit 2f9a174f918e ("virtio: write back F_VERSION_1 before validate") which at least lets devices find out which format should config space have, but this is a partial fix: guests should not access config space without acknowledging features since otherwise we'll never be able to change the config space format. To fix, split finalize_features from virtio_finalize_features and call finalize_features with all feature bits before validation, and then - if validation changed any bits - once again after. Since virtio_finalize_features no longer writes out features rename it to virtio_features_ok - since that is what it does: checks that features are ok with the device. As a side effect, this also reduces the amount of hypervisor accesses - we now only acknowledge features once unless we are clearing any features when validating (which is uncommon). IRC I think that this was more or less always the intent in the spec but unfortunately the way the spec is worded does not say this explicitly, I plan to address this at the spec level, too. Acked-by: Jason Wang Cc: stable@vger.kernel.org Fixes: 404123c2db79 ("virtio: allow drivers to validate features") Fixes: 2f9a174f918e ("virtio: write back F_VERSION_1 before validate") Cc: "Halil Pasic" Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman

virtio: unexport virtio_finalize_features

2022-03-16T12:20:27Z

commit 838d6d3461db0fdbf33fc5f8a69c27b50b4a46da upstream. virtio_finalize_features is only used internally within virtio. No reason to export it. Signed-off-by: Michael S. Tsirkin Reviewed-by: Cornelia Huck Acked-by: Jason Wang Signed-off-by: Greg Kroah-Hartman

virtio: write back F_VERSION_1 before validate

2021-10-20T09:23:02Z

commit 2f9a174f918e29608564c7a4e8329893ab604fb4 upstream. The virtio specification virtio-v1.1-cs01 states: "Transitional devices MUST detect Legacy drivers by detecting that VIRTIO_F_VERSION_1 has not been acknowledged by the driver." This is exactly what QEMU as of 6.1 has done relying solely on VIRTIO_F_VERSION_1 for detecting that. However, the specification also says: "... the driver MAY read (but MUST NOT write) the device-specific configuration fields to check that it can support the device ..." before setting FEATURES_OK. In that case, any transitional device relying solely on VIRTIO_F_VERSION_1 for detecting legacy drivers will return data in legacy format. In particular, this implies that it is in big endian format for big endian guests. This naturally confuses the driver which expects little endian in the modern mode. It is probably a good idea to amend the spec to clarify that VIRTIO_F_VERSION_1 can only be relied on after the feature negotiation is complete. Before validate callback existed, config space was only read after FEATURES_OK. However, we already have two regressions, so let's address this here as well. The regressions affect the VIRTIO_NET_F_MTU feature of virtio-net and the VIRTIO_BLK_F_BLK_SIZE feature of virtio-blk for BE guests when virtio 1.0 is used on both sides. The latter renders virtio-blk unusable with DASD backing, because things simply don't work with the default. See Fixes tags for relevant commits. For QEMU, we can work around the issue by writing out the feature bits with VIRTIO_F_VERSION_1 bit set. We (ab)use the finalize_features config op for this. This isn't enough to address all vhost devices since these do not get the features until FEATURES_OK, however it looks like the affected devices actually never handled the endianness for legacy mode correctly, so at least that's not a regression. No devices except virtio net and virtio blk seem to be affected. Long term the right thing to do is to fix the hypervisors. Cc: #v4.11 Signed-off-by: Halil Pasic Fixes: 82e89ea077b9 ("virtio-blk: Add validation for block size in config space") Fixes: fe36cbe0671e ("virtio_net: clear MTU when out of range") Reported-by: markver@us.ibm.com Reviewed-by: Cornelia Huck Link: https://lore.kernel.org/r/20211011053921.1198936-1-pasic@linux.ibm.com Signed-off-by: Michael S. Tsirkin Signed-off-by: Greg Kroah-Hartman

virtio_pci: Support surprise removal of virtio pci device

2021-09-03T07:58:02Z

[ Upstream commit 43bb40c5b92659966bdf4bfe584fde0a3575a049 ] When a virtio pci device undergo surprise removal (aka async removal in PCIe spec), mark the device as broken so that any upper layer drivers can abort any outstanding operation. When a virtio net pci device undergo surprise removal which is used by a NetworkManager, a below call trace was observed. kernel:watchdog: BUG: soft lockup - CPU#1 stuck for 26s! [kworker/1:1:27059] watchdog: BUG: soft lockup - CPU#1 stuck for 52s! [kworker/1:1:27059] CPU: 1 PID: 27059 Comm: kworker/1:1 Tainted: G S W I L 5.13.0-hotplug+ #8 Hardware name: Dell Inc. PowerEdge R640/0H28RR, BIOS 2.9.4 11/06/2020 Workqueue: events linkwatch_event RIP: 0010:virtnet_send_command+0xfc/0x150 [virtio_net] Call Trace: virtnet_set_rx_mode+0xcf/0x2a7 [virtio_net] ? __hw_addr_create_ex+0x85/0xc0 __dev_mc_add+0x72/0x80 igmp6_group_added+0xa7/0xd0 ipv6_mc_up+0x3c/0x60 ipv6_find_idev+0x36/0x80 addrconf_add_dev+0x1e/0xa0 addrconf_dev_config+0x71/0x130 addrconf_notify+0x1f5/0xb40 ? rtnl_is_locked+0x11/0x20 ? __switch_to_asm+0x42/0x70 ? finish_task_switch+0xaf/0x2c0 ? raw_notifier_call_chain+0x3e/0x50 raw_notifier_call_chain+0x3e/0x50 netdev_state_change+0x67/0x90 linkwatch_do_dev+0x3c/0x50 __linkwatch_run_queue+0xd2/0x220 linkwatch_event+0x21/0x30 process_one_work+0x1c8/0x370 worker_thread+0x30/0x380 ? process_one_work+0x370/0x370 kthread+0x118/0x140 ? set_kthread_struct+0x40/0x40 ret_from_fork+0x1f/0x30 Hence, add the ability to abort the command on surprise removal which prevents infinite loop and system lockup. Signed-off-by: Parav Pandit Link: https://lore.kernel.org/r/20210721142648.1525924-5-parav@nvidia.com Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

virtio: Improve vq->broken access to avoid any compiler optimization

2021-09-03T07:58:02Z

[ Upstream commit 60f0779862e4ab943810187752c462e85f5fa371 ] Currently vq->broken field is read by virtqueue_is_broken() in busy loop in one context by virtnet_send_command(). vq->broken is set to true in other process context by virtio_break_device(). Reader and writer are accessing it without any synchronization. This may lead to a compiler optimization which may result to optimize reading vq->broken only once. Hence, force reading vq->broken on each invocation of virtqueue_is_broken() and also force writing it so that such update is visible to the readers. It is a theoretical fix that isn't yet encountered in the field. Signed-off-by: Parav Pandit Link: https://lore.kernel.org/r/20210721142648.1525924-2-parav@nvidia.com Signed-off-by: Michael S. Tsirkin Signed-off-by: Sasha Levin

virtio_ring: Avoid loop when vq is broken in virtqueue_poll

2020-08-26T08:31:01Z

[ Upstream commit 481a0d7422db26fb63e2d64f0652667a5c6d0f3e ] The loop may exist if vq->broken is true, virtqueue_get_buf_ctx_packed or virtqueue_get_buf_ctx_split will return NULL, so virtnet_poll will reschedule napi to receive packet, it will lead cpu usage(si) to 100%. call trace as below: virtnet_poll virtnet_receive virtqueue_get_buf_ctx virtqueue_get_buf_ctx_packed virtqueue_get_buf_ctx_split virtqueue_napi_complete virtqueue_poll //return true virtqueue_napi_schedule //it will reschedule napi to fix this, return false if vq is broken in virtqueue_poll. Signed-off-by: Mao Wenan Acked-by: Michael S. Tsirkin Link: https://lore.kernel.org/r/1596354249-96204-1-git-send-email-wenan.mao@linux.alibaba.com Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang Signed-off-by: Sasha Levin