kernel.git/drivers/vhost/vdpa.c, branch linux-6.7.y

eventfd: simplify eventfd_signal()

2024-04-03T13:11:23Z

[ Upstream commit 3652117f854819a148ff0fbe4492587d3520b5e5 ] Ever since the eventfd type was introduced back in 2007 in commit e1ad7468c77d ("signal/timer/event: eventfd core") the eventfd_signal() function only ever passed 1 as a value for @n. There's no point in keeping that additional argument. Link: https://lore.kernel.org/r/20231122-vfs-eventfd-signal-v2-2-bd549b14ce0c@kernel.org Acked-by: Xu Yilun Acked-by: Andrew Donnellan # ocxl Acked-by: Eric Farman # s390 Reviewed-by: Jan Kara Reviewed-by: Jens Axboe Signed-off-by: Christian Brauner Stable-dep-of: 675daf435e9f ("vfio/platform: Create persistent IRQ handlers") Signed-off-by: Sasha Levin

vhost-vdpa: fix use after free in vhost_vdpa_probe()

2023-11-01T13:31:16Z

The put_device() calls vhost_vdpa_release_dev() which calls ida_simple_remove() and frees "v". So this call to ida_simple_remove() is a use after free and a double free. Fixes: ebe6a354fa7e ("vhost-vdpa: Call ida_simple_remove() when failed") Signed-off-by: Dan Carpenter Message-Id: Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang

vhost-vdpa: clean iotlb map during reset for older userspace

2023-11-01T13:20:00Z

Using .compat_reset op from the previous patch, the buggy .reset behaviour can be kept as-is on older userspace apps, which don't ack the IOTLB_PERSIST backend feature. As this compatibility quirk is limited to those drivers that used to be buggy in the past, it won't affect change the behaviour or affect ABI on the setups with API compliant driver. The separation of .compat_reset from the regular .reset allows vhost-vdpa able to know which driver had broken behaviour before, so it can apply the corresponding compatibility quirk to the individual driver whenever needed. Compared to overloading the existing .reset with flags, .compat_reset won't cause any extra burden to the implementation of every compliant driver. [mst: squashed in two fixup commits] Message-Id: <1697880319-4937-6-git-send-email-si-wei.liu@oracle.com> Message-Id: <1698102863-21122-1-git-send-email-si-wei.liu@oracle.com> Reported-by: Dragos Tatulea Tested-by: Dragos Tatulea Message-Id: <1698275594-19204-1-git-send-email-si-wei.liu@oracle.com> Reported-by: Lei Yang Signed-off-by: Si-Wei Liu Signed-off-by: Michael S. Tsirkin Tested-by: Lei Yang

vhost-vdpa: introduce IOTLB_PERSIST backend feature bit

2023-11-01T13:20:00Z

Userspace needs this feature flag to distinguish if vhost-vdpa iotlb in the kernel can be trusted to persist IOTLB mapping across vDPA reset. Without it, userspace has no way to tell apart if it's running on an older kernel, which could silently drop all iotlb mapping across vDPA reset, especially with broken parent driver implementation for the .reset driver op. The broken driver may incorrectly drop all mappings of its own as part of .reset, which inadvertently ends up with corrupted mapping state between vhost-vdpa userspace and the kernel. As a workaround, to make the mapping behaviour predictable across reset, userspace has to pro-actively remove all mappings before vDPA reset, and then restore all the mappings afterwards. This workaround is done unconditionally on top of all parent drivers today, due to the parent driver implementation issue and no means to differentiate. This workaround had been utilized in QEMU since day one when the corresponding vhost-vdpa userspace backend came to the world. There are 3 cases that backend may claim this feature bit on for: - parent device that has to work with platform IOMMU - parent device with on-chip IOMMU that has the expected .reset_map support in driver - parent device with vendor specific IOMMU implementation with persistent IOTLB mapping already that has to specifically declare this backend feature The reason why .reset_map is being one of the pre-condition for persistent iotlb is because without it, vhost-vdpa can't switch back iotlb to the initial state later on, especially for the on-chip IOMMU case which starts with identity mapping at device creation. virtio-vdpa requires on-chip IOMMU to perform 1:1 passthrough translation from PA to IOVA as-is to begin with, and .reset_map is the only means to turn back iotlb to the identity mapping mode after vhost-vdpa is gone. The difference in behavior did not matter as QEMU unmaps all the memory unregistering the memory listener at vhost_vdpa_dev_start( started = false), but the backend acknowledging this feature flag allows QEMU to make sure it is safe to skip this unmap & map in the case of vhost stop & start cycle. In that sense, this feature flag is actually a signal for userspace to know that the driver bug has been solved. Not offering it indicates that userspace cannot trust the kernel will retain the maps. Signed-off-by: Si-Wei Liu Acked-by: Eugenio Pérez Message-Id: <1697880319-4937-4-git-send-email-si-wei.liu@oracle.com> Signed-off-by: Michael S. Tsirkin Tested-by: Lei Yang

vhost-vdpa: reset vendor specific mapping to initial state in .release

2023-11-01T13:19:59Z

Devices with on-chip IOMMU or vendor specific IOTLB implementation may need to restore iotlb mapping to the initial or default state using the .reset_map op, as it's desirable for some parent devices to not work with DMA ops and maintain a simple IOMMU model with .reset_map. In particular, device reset should not cause mapping to go away on such IOTLB model, so persistent mapping is implied across reset. Before the userspace process using vhost-vdpa is gone, give it a chance to reset iotlb back to the initial state in vhost_vdpa_cleanup(). Signed-off-by: Si-Wei Liu Acked-by: Eugenio Pérez Message-Id: <1697880319-4937-3-git-send-email-si-wei.liu@oracle.com> Signed-off-by: Michael S. Tsirkin Tested-by: Lei Yang

vhost-vdpa: uAPI to get dedicated descriptor group id

2023-11-01T13:19:55Z

With _F_DESC_ASID backend feature, the device can now support the VHOST_VDPA_GET_VRING_DESC_GROUP ioctl, and it may expose the descriptor table (including avail and used ring) in a different group than the buffers it contains. This new uAPI will fetch the group ID of the descriptor table. Signed-off-by: Si-Wei Liu Acked-by: Eugenio Pérez Acked-by: Jason Wang Message-Id: <20231018171456.1624030-6-dtatulea@nvidia.com> Signed-off-by: Michael S. Tsirkin Reviewed-by: Si-Wei Liu Tested-by: Si-Wei Liu Tested-by: Lei Yang

vhost-vdpa: introduce descriptor group backend feature

2023-11-01T13:19:55Z

Userspace knows if the device has dedicated descriptor group or not by checking this feature bit. It's only exposed if the vdpa driver backend implements the .get_vq_desc_group() operation callback. Userspace trying to negotiate this feature when it or the dependent _F_IOTLB_ASID feature hasn't been exposed will result in an error. Signed-off-by: Si-Wei Liu Acked-by: Eugenio Pérez Acked-by: Jason Wang Message-Id: <20231018171456.1624030-5-dtatulea@nvidia.com> Signed-off-by: Michael S. Tsirkin Reviewed-by: Si-Wei Liu Tested-by: Si-Wei Liu Tested-by: Lei Yang

vdpa: add get_backend_features vdpa operation

2023-09-03T22:10:22Z

This operation allow vdpa parent to expose its own backend feature bits. Next patches introduce a feature not compatible with all parent drivers: the ability to enable vq after driver_ok. Each parent must declare if it allows it or not. Signed-off-by: Eugenio Pérez Acked-by: Shannon Nelson Message-Id: <20230609092127.170673-4-eperezma@redhat.com> Signed-off-by: Michael S. Tsirkin

vdpa: accept VHOST_BACKEND_F_ENABLE_AFTER_DRIVER_OK backend feature

2023-09-03T22:10:22Z

Accepting VHOST_BACKEND_F_ENABLE_AFTER_DRIVER_OK backend feature if userland sets it. Signed-off-by: Eugenio Pérez Acked-by: Shannon Nelson Message-Id: <20230609092127.170673-3-eperezma@redhat.com> Signed-off-by: Michael S. Tsirkin

Merge tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-06-28T17:28:11Z

Pull mm updates from Andrew Morton: - Yosry Ahmed brought back some cgroup v1 stats in OOM logs - Yosry has also eliminated cgroup's atomic rstat flushing - Nhat Pham adds the new cachestat() syscall. It provides userspace with the ability to query pagecache status - a similar concept to mincore() but more powerful and with improved usability - Mel Gorman provides more optimizations for compaction, reducing the prevalence of page rescanning - Lorenzo Stoakes has done some maintanance work on the get_user_pages() interface - Liam Howlett continues with cleanups and maintenance work to the maple tree code. Peng Zhang also does some work on maple tree - Johannes Weiner has done some cleanup work on the compaction code - David Hildenbrand has contributed additional selftests for get_user_pages() - Thomas Gleixner has contributed some maintenance and optimization work for the vmalloc code - Baolin Wang has provided some compaction cleanups, - SeongJae Park continues maintenance work on the DAMON code - Huang Ying has done some maintenance on the swap code's usage of device refcounting - Christoph Hellwig has some cleanups for the filemap/directio code - Ryan Roberts provides two patch series which yield some rationalization of the kernel's access to pte entries - use the provided APIs rather than open-coding accesses - Lorenzo Stoakes has some fixes to the interaction between pagecache and directio access to file mappings - John Hubbard has a series of fixes to the MM selftesting code - ZhangPeng continues the folio conversion campaign - Hugh Dickins has been working on the pagetable handling code, mainly with a view to reducing the load on the mmap_lock - Catalin Marinas has reduced the arm64 kmalloc() minimum alignment from 128 to 8 - Domenico Cerasuolo has improved the zswap reclaim mechanism by reorganizing the LRU management - Matthew Wilcox provides some fixups to make gfs2 work better with the buffer_head code - Vishal Moola also has done some folio conversion work - Matthew Wilcox has removed the remnants of the pagevec code - their functionality is migrated over to struct folio_batch * tag 'mm-stable-2023-06-24-19-15' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (380 commits) mm/hugetlb: remove hugetlb_set_page_subpool() mm: nommu: correct the range of mmap_sem_read_lock in task_mem() hugetlb: revert use of page_cache_next_miss() Revert "page cache: fix page_cache_next/prev_miss off by one" mm/vmscan: fix root proactive reclaim unthrottling unbalanced node mm: memcg: rename and document global_reclaim() mm: kill [add|del]_page_to_lru_list() mm: compaction: convert to use a folio in isolate_migratepages_block() mm: zswap: fix double invalidate with exclusive loads mm: remove unnecessary pagevec includes mm: remove references to pagevec mm: rename invalidate_mapping_pagevec to mapping_try_invalidate mm: remove struct pagevec net: convert sunrpc from pagevec to folio_batch i915: convert i915_gpu_error to use a folio_batch pagevec: rename fbatch_count() mm: remove check_move_unevictable_pages() drm: convert drm_gem_put_pages() to use a folio_batch i915: convert shmem_sg_free_table() to use a folio_batch scatterlist: add sg_set_folio() ...