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2020-08-14virtio: pci: constify ioreadX() iomem argument (as in generic implementation)Krzysztof Kozlowski
The ioreadX() helpers have inconsistent interface. On some architectures void *__iomem address argument is a pointer to const, on some not. Implementations of ioreadX() do not modify the memory under the address so they can be converted to a "const" version for const-safety and consistency among architectures. Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Cc: Allen Hubbe <allenbh@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dave Jiang <dave.jiang@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Helge Deller <deller@gmx.de> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Jakub Kicinski <kuba@kernel.org> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Jon Mason <jdmason@kudzu.us> Cc: Kalle Valo <kvalo@codeaurora.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Richard Henderson <rth@twiddle.net> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200709072837.5869-5-krzk@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-11Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds
Pull virtio updates from Michael Tsirkin: - IRQ bypass support for vdpa and IFC - MLX5 vdpa driver - Endianness fixes for virtio drivers - Misc other fixes * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (71 commits) vdpa/mlx5: fix up endian-ness for mtu vdpa: Fix pointer math bug in vdpasim_get_config() vdpa/mlx5: Fix pointer math in mlx5_vdpa_get_config() vdpa/mlx5: fix memory allocation failure checks vdpa/mlx5: Fix uninitialised variable in core/mr.c vdpa_sim: init iommu lock virtio_config: fix up warnings on parisc vdpa/mlx5: Add VDPA driver for supported mlx5 devices vdpa/mlx5: Add shared memory registration code vdpa/mlx5: Add support library for mlx5 VDPA implementation vdpa/mlx5: Add hardware descriptive header file vdpa: Modify get_vq_state() to return error code net/vdpa: Use struct for set/get vq state vdpa: remove hard coded virtq num vdpasim: support batch updating vhost-vdpa: support IOTLB batching hints vhost-vdpa: support get/set backend features vhost: generialize backend features setting/getting vhost-vdpa: refine ioctl pre-processing vDPA: dont change vq irq after DRIVER_OK ...
2020-08-05virtio_pci_modern: Fix the comment of virtio_pci_find_capability()Liao Pingfang
Fix the comment of virtio_pci_find_capability() by adding missing comment for the last parameter: bars. Fixes: 59a5b0f7bf74 ("virtio-pci: alloc only resources actually used.") Signed-off-by: Liao Pingfang <liao.pingfang@zte.com.cn> Signed-off-by: Yi Wang <wang.yi59@zte.com.cn> Link: https://lore.kernel.org/r/1596455545-43556-1-git-send-email-wang.yi59@zte.com.cn Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2020-08-05virtio_ring: Avoid loop when vq is broken in virtqueue_pollMao Wenan
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 <wenan.mao@linux.alibaba.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Link: https://lore.kernel.org/r/1596354249-96204-1-git-send-email-wenan.mao@linux.alibaba.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2020-08-05virtio_mem: convert to LE accessorsMichael S. Tsirkin
Virtio mem is modern-only. Use LE accessors for config space. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05virtio_input: convert to LE accessorsMichael S. Tsirkin
Virtio input is modern-only. Use LE accessors for config space. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05virtio_balloon: use LE config space accessesMichael S. Tsirkin
Balloon is LE, it's cleaner to access it as such directly. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05virtio_vdpa: legacy features handlingMichael S. Tsirkin
We normally expect vdpa to use the modern interface. However for consistency, let's use same APIs as vhost for legacy guests. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-05virtio_balloon: fix sparse warningMichael S. Tsirkin
balloon uses virtio32_to_cpu instead of cpu_to_virtio32 to convert a native endian number to virtio. No practical difference but makes sparse warn. Fix it up. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
2020-08-04Merge tag 'uninit-macro-v5.9-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull uninitialized_var() macro removal from Kees Cook: "This is long overdue, and has hidden too many bugs over the years. The series has several "by hand" fixes, and then a trivial treewide replacement. - Clean up non-trivial uses of uninitialized_var() - Update documentation and checkpatch for uninitialized_var() removal - Treewide removal of uninitialized_var()" * tag 'uninit-macro-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: compiler: Remove uninitialized_var() macro treewide: Remove uninitialized_var() usage checkpatch: Remove awareness of uninitialized_var() macro mm/debug_vm_pgtable: Remove uninitialized_var() usage f2fs: Eliminate usage of uninitialized_var() macro media: sur40: Remove uninitialized_var() usage KVM: PPC: Book3S PR: Remove uninitialized_var() usage clk: spear: Remove uninitialized_var() usage clk: st: Remove uninitialized_var() usage spi: davinci: Remove uninitialized_var() usage ide: Remove uninitialized_var() usage rtlwifi: rtl8192cu: Remove uninitialized_var() usage b43: Remove uninitialized_var() usage drbd: Remove uninitialized_var() usage x86/mm/numa: Remove uninitialized_var() usage docs: deprecated.rst: Add uninitialized_var()
2020-08-03virtio: virtio_has_iommu_quirk -> virtio_has_dma_quirkMichael S. Tsirkin
Now that the corresponding feature bit has been renamed, rename the quirk too - it's about special ways to do DMA, not necessarily about the IOMMU. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-08-03virtio: VIRTIO_F_IOMMU_PLATFORM -> VIRTIO_F_ACCESS_PLATFORMMichael S. Tsirkin
Rename the bit to match latest virtio spec. Add a compat macro to avoid breaking existing userspace. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com>
2020-07-30virtio-mem: Fix build error due to improper use 'select'Weilong Chen
As noted in: https://www.kernel.org/doc/Documentation/kbuild/kconfig-language.txt "select should be used with care. select will force a symbol to a value without visiting the dependencies." Config VIRTIO_MEM should not select CONTIG_ALLOC directly. Otherwise it will cause an error: https://bugzilla.kernel.org/show_bug.cgi?id=208245 Signed-off-by: Weilong Chen <chenweilong@huawei.com> Link: https://lore.kernel.org/r/20200619080333.194753-1-chenweilong@huawei.com Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: David Hildenbrand <david@redhat.com>
2020-07-29virtio_balloon: fix up endian-ness for free cmd idMichael S. Tsirkin
free cmd id is read using virtio endian, spec says all fields in balloon are LE. Fix it up. Fixes: 86a559787e6f ("virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT") Cc: stable@vger.kernel.org Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Wei Wang <wei.w.wang@intel.com> Acked-by: David Hildenbrand <david@redhat.com>
2020-07-29virtio-balloon: Document byte ordering of poison_valAlexander Duyck
The poison_val field in the virtio_balloon_config is treated as a little-endian field by the host. Since we are currently only having to deal with a single byte poison value this isn't a problem, however if the value should ever expand it would cause byte ordering issues. Document that in the code so that we know that if the value should ever expand we need to byte swap the value on big-endian architectures. Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Link: https://lore.kernel.org/r/20200713203539.17140.71425.stgit@localhost.localdomain Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: David Hildenbrand <david@redhat.com>
2020-07-24Merge tag 'pci-v5.8-fixes-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci into master Pull PCI fixes from Bjorn Helgaas: - Reject invalid IRQ 0 command line argument for virtio_mmio because IRQ 0 now generates warnings (Bjorn Helgaas) - Revert "PCI/PM: Assume ports without DLL Link Active train links in 100 ms", which broke nouveau (Bjorn Helgaas) * tag 'pci-v5.8-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: Revert "PCI/PM: Assume ports without DLL Link Active train links in 100 ms" virtio-mmio: Reject invalid IRQ 0 command line argument
2020-07-22virtio-mmio: Reject invalid IRQ 0 command line argumentBjorn Helgaas
The "virtio_mmio.device=" command line argument allows a user to specify the size, address, and IRQ of a virtio device. Previously the only requirement for the IRQ was that it be an unsigned integer. Zero is an unsigned integer but an invalid IRQ number, and after a85a6c86c25be ("driver core: platform: Clarify that IRQ 0 is invalid"), attempts to use IRQ 0 cause warnings. If the user specifies IRQ 0, return failure instead of registering a device with IRQ 0. Fixes: a85a6c86c25be ("driver core: platform: Clarify that IRQ 0 is invalid") Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Jason Wang <jasowang@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com>
2020-07-16treewide: Remove uninitialized_var() usageKees Cook
Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var\(([^\)]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs Signed-off-by: Kees Cook <keescook@chromium.org>
2020-06-22virtio-mem: add memory via add_memory_driver_managed()David Hildenbrand
Virtio-mem managed memory is always detected and added by the virtio-mem driver, never using something like the firmware-provided memory map. This is the case after an ordinary system reboot, and has to be guaranteed after kexec. Especially, virtio-mem added memory resources can contain inaccessible parts ("unblocked memory blocks"), blindly forwarding them to a kexec kernel is dangerous, as unplugged memory will get accessed (esp. written). Let's use the new way of adding special driver-managed memory introduced in commit 7b7b27214bba ("mm/memory_hotplug: introduce add_memory_driver_managed()"). This will result in no entries in /sys/firmware/memmap ("raw firmware- provided memory map"), the memory resource will be flagged IORESOURCE_MEM_DRIVER_MANAGED (esp., kexec_file_load() will not place kexec images on this memory), and it is exposed as "System RAM (virtio_mem)" in /proc/iomem, so esp. kexec-tools can properly handle it. Example /proc/iomem before this change: [...] 140000000-333ffffff : virtio0 140000000-147ffffff : System RAM 334000000-533ffffff : virtio1 338000000-33fffffff : System RAM 340000000-347ffffff : System RAM 348000000-34fffffff : System RAM [...] Example /proc/iomem after this change: [...] 140000000-333ffffff : virtio0 140000000-147ffffff : System RAM (virtio_mem) 334000000-533ffffff : virtio1 338000000-33fffffff : System RAM (virtio_mem) 340000000-347ffffff : System RAM (virtio_mem) 348000000-34fffffff : System RAM (virtio_mem) [...] Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: teawater <teawaterz@linux.alibaba.com> Fixes: 5f1f79bbc9e26 ("virtio-mem: Paravirtualized memory hotplug") Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200611093518.5737-1-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
2020-06-22virtio-mem: silence a static checker warningDan Carpenter
Smatch complains that "rc" can be uninitialized if we hit the "break;" statement on the first iteration through the loop. I suspect that this can't happen in real life, but returning a zero literal is cleaner and silence the static checker warning. Fixes: 5f1f79bbc9e2 ("virtio-mem: Paravirtualized memory hotplug") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Link: https://lore.kernel.org/r/20200610085911.GC5439@mwanda Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-14treewide: replace '---help---' in Kconfig files with 'help'Masahiro Yamada
Since commit 84af7a6194e4 ("checkpatch: kconfig: prefer 'help' over '---help---'"), the number of '---help---' has been gradually decreasing, but there are still more than 2400 instances. This commit finishes the conversion. While I touched the lines, I also fixed the indentation. There are a variety of indentation styles found. a) 4 spaces + '---help---' b) 7 spaces + '---help---' c) 8 spaces + '---help---' d) 1 space + 1 tab + '---help---' e) 1 tab + '---help---' (correct indentation) f) 1 tab + 1 space + '---help---' g) 1 tab + 2 spaces + '---help---' In order to convert all of them to 1 tab + 'help', I ran the following commend: $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/' Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-09virtio_mem: convert device block size into 64bitMichael S. Tsirkin
If subblock size is large (e.g. 1G) 32 bit math involving it can overflow. Rather than try to catch all instances of that, let's tweak block size to 64 bit. It ripples through UAPI which is an ABI change, but it's not too late to make it, and it will allow supporting >4Gbyte blocks while might become necessary down the road. Fixes: 5f1f79bbc9e26 ("virtio-mem: Paravirtualized memory hotplug") Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: David Hildenbrand <david@redhat.com>
2020-06-08virtio-mem: drop unnecessary initializationMichael S. Tsirkin
rc is initialized to -ENIVAL but that's never used. Drop it. Fixes: 5f1f79bbc9e2 ("virtio-mem: Paravirtualized memory hotplug") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: David Hildenbrand <david@redhat.com>
2020-06-04virtio-mem: Don't rely on implicit compiler padding for requestsDavid Hildenbrand
The compiler will add padding after the last member, make that explicit. The size of a request is always 24 bytes. The size of a response always 10 bytes. Add compile-time checks. Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: teawater <teawaterz@linux.alibaba.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200515101402.16597-1-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-04virtio-mem: Try to unplug the complete online memory block firstDavid Hildenbrand
Right now, we always try to unplug single subblocks when processing an online memory block. Let's try to unplug the complete online memory block first, in case it is fully plugged and the unplug request is large enough. Fallback to single subblocks in case the memory block cannot get unplugged as a whole. Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200507140139.17083-16-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-04virtio-mem: Use -ETXTBSY as error code if the device is busyDavid Hildenbrand
Let's be able to distinguish if the device or if memory is busy. Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200507140139.17083-15-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-04virtio-mem: Unplug subblocks right-to-leftDavid Hildenbrand
We unplug blocks right-to-left, let's also unplug subblocks within a block right-to-left. Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200507140139.17083-14-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-04virtio-mem: Drop manual check for already present memoryDavid Hildenbrand
Registering our parent resource will fail if any memory is still present (e.g., because somebody unloaded the driver and tries to reload it). No need for the manual check. Move our "unplug all" handling to after registering the resource. Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200507140139.17083-13-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-04virtio-mem: Add parent resource for all added "System RAM"David Hildenbrand
Let's add a parent resource, named after the virtio device (inspired by drivers/dax/kmem.c). This allows user space to identify which memory belongs to which virtio-mem device. With this change and two virtio-mem devices: :/# cat /proc/iomem 00000000-00000fff : Reserved 00001000-0009fbff : System RAM [...] 140000000-333ffffff : virtio0 140000000-147ffffff : System RAM 148000000-14fffffff : System RAM 150000000-157ffffff : System RAM [...] 334000000-3033ffffff : virtio1 338000000-33fffffff : System RAM 340000000-347ffffff : System RAM 348000000-34fffffff : System RAM [...] Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200507140139.17083-12-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
2020-06-04virtio-mem: Better retry handlingDavid Hildenbrand
Let's start with a retry interval of 5 seconds and double the time until we reach 5 minutes, in case we keep getting errors. Reset the retry interval in case we succeeded. The two main reasons for having to retry are - The hypervisor is busy and cannot process our request - We cannot reach the desired requested_size (esp., not enough memory can get unplugged because we can't allocate any subblocks). Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200507140139.17083-11-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-04virtio-mem: Offline and remove completely unplugged memory blocksDavid Hildenbrand
Let's offline+remove memory blocks once all subblocks are unplugged. We can use the new Linux MM interface for that. As no memory is in use anymore, this shouldn't take a long time and shouldn't fail. There might be corner cases where the offlining could still fail (especially, if another notifier NACKs the offlining request). Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200507140139.17083-10-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-04virtio-mem: Allow to offline partially unplugged memory blocksDavid Hildenbrand
Dropping the reference count of PageOffline() pages during MEM_GOING_ONLINE allows offlining code to skip them. However, we also have to clear PG_reserved, because PG_reserved pages get detected as unmovable right away. Take care of restoring the reference count when offlining is canceled. Clarify why we don't have to perform any action when unloading the driver. Also, let's add a warning if anybody is still holding a reference to unplugged pages when offlining. Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200507140139.17083-8-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-04virtio-mem: Paravirtualized memory hotunplug part 2David Hildenbrand
We also want to unplug online memory (contained in online memory blocks and, therefore, managed by the buddy), and eventually replug it later. When requested to unplug memory, we use alloc_contig_range() to allocate subblocks in online memory blocks (so we are the owner) and send them to our hypervisor. When requested to plug memory, we can replug such memory using free_contig_range() after asking our hypervisor. We also want to mark all allocated pages PG_offline, so nobody will touch them. To differentiate pages that were never onlined when onlining the memory block from pages allocated via alloc_contig_range(), we use PageDirty(). Based on this flag, virtio_mem_fake_online() can either online the pages for the first time or use free_contig_range(). It is worth noting that there are no guarantees on how much memory can actually get unplugged again. All device memory might completely be fragmented with unmovable data, such that no subblock can get unplugged. We are not touching the ZONE_MOVABLE. If memory is onlined to the ZONE_MOVABLE, it can only get unplugged after that memory was offlined manually by user space. In normal operation, virtio-mem memory is suggested to be onlined to ZONE_NORMAL. In the future, we will try to make unplug more likely to succeed. Add a module parameter to control if online memory shall be touched. As we want to access alloc_contig_range()/free_contig_range() from kernel module context, export the symbols. Note: Whenever virtio-mem uses alloc_contig_range(), all affected pages are on the same node, in the same zone, and contain no holes. Acked-by: Michal Hocko <mhocko@suse.com> # to export contig range allocator API Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200507140139.17083-6-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-04virtio-mem: Paravirtualized memory hotunplug part 1David Hildenbrand
Unplugging subblocks of memory blocks that are offline is easy. All we have to do is watch out for concurrent onlining activity. Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200507140139.17083-5-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-04virtio-mem: Allow to specify an ACPI PXM as nidDavid Hildenbrand
We want to allow to specify (similar as for a DIMM), to which node a virtio-mem device (and, therefore, its memory) belongs. Add a new virtio-mem feature flag and export pxm_to_node, so it can be used in kernel module context. Acked-by: Michal Hocko <mhocko@suse.com> # for the export Acked-by: "Rafael J. Wysocki" <rafael@kernel.org> # for the export Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Len Brown <lenb@kernel.org> Cc: linux-acpi@vger.kernel.org Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200507140139.17083-4-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-04virtio-mem: Paravirtualized memory hotplugDavid Hildenbrand
Each virtio-mem device owns exactly one memory region. It is responsible for adding/removing memory from that memory region on request. When the device driver starts up, the requested amount of memory is queried and then plugged to Linux. On request, further memory can be plugged or unplugged. This patch only implements the plugging part. On x86-64, memory can currently be plugged in 4MB ("subblock") granularity. When required, a new memory block will be added (e.g., usually 128MB on x86-64) in order to plug more subblocks. Only x86-64 was tested for now. The online_page callback is used to keep unplugged subblocks offline when onlining memory - similar to the Hyper-V balloon driver. Unplugged pages are marked PG_offline, to tell dump tools (e.g., makedumpfile) to skip them. User space is usually responsible for onlining the added memory. The memory hotplug notifier is used to synchronize virtio-mem activity against memory onlining/offlining. Each virtio-mem device can belong to a NUMA node, which allows us to easily add/remove small chunks of memory to/from a specific NUMA node by using multiple virtio-mem devices. Something that works even when the guest has no idea about the NUMA topology. One way to view virtio-mem is as a "resizable DIMM" or a DIMM with many "sub-DIMMS". This patch directly introduces the basic infrastructure to implement memory unplug. Especially the memory block states and subblock bitmaps will be heavily used there. Notes: - In case memory is to be onlined by user space, we limit the amount of offline memory blocks, to not run out of memory. This is esp. an issue if memory is added faster than it is getting onlined. - Suspend/Hibernate is not supported due to the way virtio-mem devices behave. Limited support might be possible in the future. - Reloading the device driver is not supported. Reviewed-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Tested-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Michal Hocko <mhocko@kernel.org> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Len Brown <lenb@kernel.org> Cc: linux-acpi@vger.kernel.org Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20200507140139.17083-2-david@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-04virtio-balloon: Disable free page reporting if page poison reporting is not ↵Alexander Duyck
enabled We should disable free page reporting if page poisoning is enabled but we cannot report it via the balloon interface. This way we can avoid the possibility of corrupting guest memory. Normally the page poisoning feature should always be present when free page reporting is enabled on the hypervisor, however this allows us to correctly handle a case of the virtio-balloon device being possibly misconfigured. Fixes: 5d757c8d518d ("virtio-balloon: add support for providing free page reports to host") Cc: stable@vger.kernel.org Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Link: https://lore.kernel.org/r/20200508173732.17877.85060.stgit@localhost.localdomain Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-02virtio-mmio: Delete an error message in vm_find_vqs()Markus Elfring
The function “platform_get_irq” can log an error already. Thus omit a redundant message for the exception handling in the calling function. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Link: https://lore.kernel.org/r/9e27bc4a-cfa1-7818-dc25-8ad308816b30@web.de Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-06-02virtio: add VIRTIO_RING_NO_LEGACYMatej Genci
Add macro to disable legacy vring functions. Signed-off-by: Matej Genci <matej.genci@nutanix.com> Link: https://lore.kernel.org/r/20190911124942.243713-1-matej.genci@nutanix.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-17virtio-balloon: Avoid using the word 'report' when referring to free page ↵Alexander Duyck
hinting It can be confusing to have multiple features within the same driver that are using the same verbage. As such this patch is creating a union of free_page_report_cmd_id with free_page_hint_cmd_id so that we can clean-up the userspace code a bit in terms of readability while maintaining the functionality of legacy code. Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Link: https://lore.kernel.org/r/20200415174318.13597.99753.stgit@localhost.localdomain Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-17virtio-balloon: make virtballoon_free_page_report() staticJason Yan
Fix the following sparse warning: drivers/virtio/virtio_balloon.c:168:5: warning: symbol 'virtballoon_free_page_report' was not declared. Should it be static? Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Jason Yan <yanaijie@huawei.com> Link: https://lore.kernel.org/r/20200409085047.45483-1-yanaijie@huawei.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-17vdpa: make vhost, virtio depend on menuMichael S. Tsirkin
If user did not configure any vdpa drivers, neither vhost nor virtio vdpa are going to be useful. So there's no point in prompting for these and selecting vdpa core automatically. Simplify configuration by making virtio and vhost vdpa drivers depend on vdpa menu entry. Once done, we no longer need a separate menu entry, so also get rid of this. While at it, fix up the IFC entry: VDPA->vDPA for consistency with other places. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com>
2020-04-17virtio_input: pull in slab.hMichael S. Tsirkin
In preparation to virtio header changes, include slab.h directly as this module is using it. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-08Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhostLinus Torvalds
Pull virtio updates from Michael Tsirkin: - Some bug fixes - The new vdpa subsystem with two first drivers * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: virtio-balloon: Revert "virtio-balloon: Switch back to OOM handler for VIRTIO_BALLOON_F_DEFLATE_ON_OOM" vdpa: move to drivers/vdpa virtio: Intel IFC VF driver for VDPA vdpasim: vDPA device simulator vhost: introduce vDPA-based backend virtio: introduce a vDPA based transport vDPA: introduce vDPA bus vringh: IOTLB support vhost: factor out IOTLB vhost: allow per device message handler vhost: refine vhost and vringh kconfig virtio-balloon: Switch back to OOM handler for VIRTIO_BALLOON_F_DEFLATE_ON_OOM virtio-net: Introduce hash report feature virtio-net: Introduce RSS receive steering feature virtio-net: Introduce extended RSC feature tools/virtio: option to build an out of tree module
2020-04-07virtio-balloon: switch back to OOM handler for VIRTIO_BALLOON_F_DEFLATE_ON_OOMDavid Hildenbrand
Commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") changed the behavior when deflation happens automatically. Instead of deflating when called by the OOM handler, the shrinker is used. However, the balloon is not simply some other slab cache that should be shrunk when under memory pressure. The shrinker does not have a concept of priorities yet, so this behavior cannot be configured. Eventually once that is in place, we might want to switch back after doing proper testing. There was a report that this results in undesired side effects when inflating the balloon to shrink the page cache. [1] "When inflating the balloon against page cache (i.e. no free memory remains) vmscan.c will both shrink page cache, but also invoke the shrinkers -- including the balloon's shrinker. So the balloon driver allocates memory which requires reclaim, vmscan gets this memory by shrinking the balloon, and then the driver adds the memory back to the balloon. Basically a busy no-op." The name "deflate on OOM" makes it pretty clear when deflation should happen - after other approaches to reclaim memory failed, not while reclaiming. This allows to minimize the footprint of a guest - memory will only be taken out of the balloon when really needed. Keep using the shrinker for VIRTIO_BALLOON_F_FREE_PAGE_HINT, because this has no such side effects. Always register the shrinker with VIRTIO_BALLOON_F_FREE_PAGE_HINT now. We are always allowed to reuse free pages that are still to be processed by the guest. The hypervisor takes care of identifying and resolving possible races between processing a hinting request and the guest reusing a page. In contrast to pre commit 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker"), don't add a module parameter to configure the number of pages to deflate on OOM. Can be re-added if really needed. Also, pay attention that leak_balloon() returns the number of 4k pages - convert it properly in virtio_balloon_oom_notify(). Testing done by Tyler for future reference: Test setup: VM with 16 CPU, 64GB RAM. Running Debian 10. We have a 42 GB file full of random bytes that we continually cat to /dev/null. This fills the page cache as the file is read. Meanwhile, we trigger the balloon to inflate, with a target size of 53 GB. This setup causes the balloon inflation to pressure the page cache as the page cache is also trying to grow. Afterwards we shrink the balloon back to zero (so total deflate == total inflate). Without this patch (kernel 4.19.0-5): Inflation never reaches the target until we stop the "cat file > /dev/null" process. Total inflation time was 542 seconds. The longest period that made no net forward progress was 315 seconds. Result of "grep balloon /proc/vmstat" after the test: balloon_inflate 154828377 balloon_deflate 154828377 With this patch (kernel 5.6.0-rc4+): Total inflation duration was 63 seconds. No deflate-queue activity occurs when pressuring the page-cache. Result of "grep balloon /proc/vmstat" after the test: balloon_inflate 12968539 balloon_deflate 12968539 Conclusion: This patch fixes the issue. In the test it reduced inflate/deflate activity by 12x, and reduced inflation time by 8.6x. But more importantly, if we hadn't killed the "cat file > /dev/null" process then, without the patch, the inflation process would never reach the target. [1] https://www.spinics.net/lists/linux-virtualization/msg40863.html Link: http://lkml.kernel.org/r/20200311135523.18512-2-david@redhat.com Fixes: 71994620bb25 ("virtio_balloon: replace oom notifier with shrinker") Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: Tyler Sanderson <tysand@google.com> Tested-by: Tyler Sanderson <tysand@google.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Wei Wang <wei.w.wang@intel.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Nadav Amit <namit@vmware.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07virtio-balloon: add support for providing free page reports to hostAlexander Duyck
Add support for the page reporting feature provided by virtio-balloon. Reporting differs from the regular balloon functionality in that is is much less durable than a standard memory balloon. Instead of creating a list of pages that cannot be accessed the pages are only inaccessible while they are being indicated to the virtio interface. Once the interface has acknowledged them they are placed back into their respective free lists and are once again accessible by the guest system. Unlike a standard balloon we don't inflate and deflate the pages. Instead we perform the reporting, and once the reporting is completed it is assumed that the page has been dropped from the guest and will be faulted back in the next time the page is accessed. Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nitesh Narayan Lal <nitesh@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Gupta <pagupta@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Wang <wei.w.wang@intel.com> Cc: Yang Zhang <yang.zhang.wz@gmail.com> Cc: wei qi <weiqi4@huawei.com> Link: http://lkml.kernel.org/r/20200211224657.29318.68624.stgit@localhost.localdomain Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07virtio-balloon: pull page poisoning config out of free page hintingAlexander Duyck
Currently the page poisoning setting wasn't being enabled unless free page hinting was enabled. However we will need the page poisoning tracking logic as well for free page reporting. As such pull it out and make it a separate bit of config in the probe function. In addition we need to add support for the more recent init_on_free feature which expects a behavior similar to page poisoning in that we expect the page to be pre-zeroed. Signed-off-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: David Hildenbrand <david@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Nitesh Narayan Lal <nitesh@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pankaj Gupta <pagupta@redhat.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Wang <wei.w.wang@intel.com> Cc: Yang Zhang <yang.zhang.wz@gmail.com> Cc: wei qi <weiqi4@huawei.com> Link: http://lkml.kernel.org/r/20200211224646.29318.695.stgit@localhost.localdomain Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-07virtio-balloon: Revert "virtio-balloon: Switch back to OOM handler for ↵Michael S. Tsirkin
VIRTIO_BALLOON_F_DEFLATE_ON_OOM" This reverts commit 5a6b4cc5b7a1892a8d7f63d6cbac6e0ae2a9d031. It has been queued properly in the akpm tree, this version is just creating conflicts. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-02vdpa: move to drivers/vdpaMichael S. Tsirkin
We have both vhost and virtio drivers that depend on vdpa. It's easier to locate it at a top level directory otherwise we run into issues e.g. if vhost is built-in but virtio is modular. Let's just move it up a level. Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2020-04-02virtio: Intel IFC VF driver for VDPAZhu Lingshan
This commit introduced two layers to drive IFC VF: (1) ifcvf_base layer, which handles IFC VF NIC hardware operations and configurations. (2) ifcvf_main layer, which complies to VDPA bus framework, implemented device operations for VDPA bus, handles device probe, bus attaching, vring operations, etc. Signed-off-by: Zhu Lingshan <lingshan.zhu@intel.com> Signed-off-by: Bie Tiwei <tiwei.bie@intel.com> Signed-off-by: Wang Xiao <xiao.w.wang@intel.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20200326140125.19794-10-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>