kernel/linux.git/drivers/virtio, branch linux-5.11.y

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2020-12-24T20:06:46+00:00

Pull virtio updates from Michael Tsirkin: - vdpa sim refactoring - virtio mem: Big Block Mode support - misc cleanus, fixes * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (61 commits) vdpa: Use simpler version of ida allocation vdpa: Add missing comment for virtqueue count uapi: virtio_ids: add missing device type IDs from OASIS spec uapi: virtio_ids.h: consistent indentions vhost scsi: fix error return code in vhost_scsi_set_endpoint() virtio_ring: Fix two use after free bugs virtio_net: Fix error code in probe() virtio_ring: Cut and paste bugs in vring_create_virtqueue_packed() tools/virtio: add barrier for aarch64 tools/virtio: add krealloc_array tools/virtio: include asm/bug.h vdpa/mlx5: Use write memory barrier after updating CQ index vdpa: split vdpasim to core and net modules vdpa_sim: split vdpasim_virtqueue's iov field in out_iov and in_iov vdpa_sim: make vdpasim->buffer size configurable vdpa_sim: use kvmalloc to allocate vdpasim->buffer vdpa_sim: set vringh notify callback vdpa_sim: add set_config callback in vdpasim_dev_attr vdpa_sim: add get_config callback in vdpasim_dev_attr vdpa_sim: make 'config' generic and usable for any device type ...

virtio_ring: Fix two use after free bugs

2020-12-18T21:14:31+00:00

The "vq" struct is added to the "vdev->vqs" list prematurely. If we encounter an error later in the function then the "vq" is freed, but since it is still on the list that could lead to a use after free bug. Fixes: cbeedb72b97a ("virtio_ring: allocate desc state for split ring separately") Reported-by: Robert Buhren Reported-by: Felicitas Hetzelt Signed-off-by: Dan Carpenter Link: https://lore.kernel.org/r/X8pGaG/zkI3jk8mk@mwanda Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang

virtio_ring: Cut and paste bugs in vring_create_virtqueue_packed()

2020-12-18T21:14:30+00:00

There is a copy and paste bug in the error handling of this code and it uses "ring_dma_addr" three times instead of "device_event_dma_addr" and "driver_event_dma_addr". Fixes: 1ce9e6055fa0 (" virtio_ring: introduce packed ring support") Reported-by: Robert Buhren Reported-by: Felicitas Hetzelt Signed-off-by: Dan Carpenter Link: https://lore.kernel.org/r/X8pGRJlEzyn+04u2@mwanda Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang

virtio-mem: Big Block Mode (BBM) - safe memory hotunplug

2020-12-18T21:14:28+00:00

Let's add a safe mechanism to unplug memory, avoiding long/endless loops when trying to offline memory - similar to in SBM. Fake-offline all memory (via alloc_contig_range()) before trying to offline+remove it. Use this mode as default, but allow to enable the other mode explicitly (which could give better memory hotunplug guarantees in some environments). The "unsafe" mode can be enabled e.g., via virtio_mem.bbm_safe_unplug=0 on the cmdline. Reviewed-by: Wei Yang Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Pankaj Gupta Cc: Michal Hocko Cc: Oscar Salvador Cc: Wei Yang Cc: Andrew Morton Signed-off-by: David Hildenbrand Link: https://lore.kernel.org/r/20201112133815.13332-30-david@redhat.com Signed-off-by: Michael S. Tsirkin

virtio-mem: Big Block Mode (BBM) - basic memory hotunplug

2020-12-18T21:14:28+00:00

Let's try to unplug completely offline big blocks first. Then, (if enabled via unplug_offline) try to offline and remove whole big blocks. No locking necessary - we can deal with concurrent onlining/offlining just fine. Note1: This is sub-optimal and might be dangerous in some environments: we could end up in an infinite loop when offlining (e.g., long-term pinnings), similar as with DIMMs. We'll introduce safe memory hotunplug via fake-offlining next, and use this basic mode only when explicitly enabled. Note2: Without ZONE_MOVABLE, memory unplug will be extremely unreliable with bigger block sizes. Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Pankaj Gupta Cc: Michal Hocko Cc: Oscar Salvador Cc: Wei Yang Cc: Andrew Morton Signed-off-by: David Hildenbrand Link: https://lore.kernel.org/r/20201112133815.13332-29-david@redhat.com Signed-off-by: Michael S. Tsirkin

virtio-mem: allow to force Big Block Mode (BBM) and set the big block size

2020-12-18T21:14:27+00:00

Let's allow to force BBM, even if subblocks would be possible. Take care of properly calculating the first big block id, because the start address might no longer be aligned to the big block size. Also, allow to manually configure the size of Big Blocks. Reviewed-by: Wei Yang Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Pankaj Gupta Cc: Michal Hocko Cc: Oscar Salvador Cc: Wei Yang Cc: Andrew Morton Signed-off-by: David Hildenbrand Link: https://lore.kernel.org/r/20201112133815.13332-27-david@redhat.com Signed-off-by: Michael S. Tsirkin

virtio-mem: Big Block Mode (BBM) memory hotplug

2020-12-18T21:14:27+00:00

Currently, we do not support device block sizes that exceed the Linux memory block size. For example, having a device block size of 1 GiB (e.g., gigantic pages in the hypervisor) won't work with 128 MiB Linux memory blocks. Let's implement Big Block Mode (BBM), whereby we add/remove at least one Linux memory block at a time. With a 1 GiB device block size, a Big Block (BB) will cover 8 Linux memory blocks. We'll keep registering the online_page_callback machinery, it will be used for safe memory hotunplug in BBM next. Note: BBM is properly prepared for variable-sized Linux memory blocks that we might see in the future. So we won't care how many Linux memory blocks a big block actually spans, and how the memory notifier is called. Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Pankaj Gupta Cc: Michal Hocko Cc: Oscar Salvador Cc: Wei Yang Cc: Andrew Morton Signed-off-by: David Hildenbrand Link: https://lore.kernel.org/r/20201112133815.13332-26-david@redhat.com Signed-off-by: Michael S. Tsirkin

virtio-mem: factor out adding/removing memory from Linux

2020-12-18T21:14:27+00:00

Let's use wrappers for the low-level functions that dev_dbg/dev_warn and work on addr + size, such that we can reuse them for adding/removing in other granularity. We only warn when adding memory failed, because that's something to pay attention to. We won't warn when removing failed, we'll reuse that in racy context soon (and we do have proper BUG_ON() statements in the current cases where it must never happen). Reviewed-by: Wei Yang Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Pankaj Gupta Signed-off-by: David Hildenbrand Link: https://lore.kernel.org/r/20201112133815.13332-25-david@redhat.com Signed-off-by: Michael S. Tsirkin

virtio-mem: memory notifier callbacks are specific to Sub Block Mode (SBM)

2020-12-18T21:14:27+00:00

Let's rename accordingly. Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Pankaj Gupta Signed-off-by: David Hildenbrand Link: https://lore.kernel.org/r/20201112133815.13332-24-david@redhat.com Signed-off-by: Michael S. Tsirkin

virito-mem: existing (un)plug functions are specific to Sub Block Mode (SBM)

2020-12-18T21:14:27+00:00

Let's rename them accordingly. virtio_mem_plug_request() and virtio_mem_unplug_request() will be handled separately. Reviewed-by: Wei Yang Cc: "Michael S. Tsirkin" Cc: Jason Wang Cc: Pankaj Gupta Signed-off-by: David Hildenbrand Link: https://lore.kernel.org/r/20201112133815.13332-23-david@redhat.com Signed-off-by: Michael S. Tsirkin