Using a mask to represent bus DMA constraints has a set of limitations.
The biggest one being it can only hold a power of two (minus one). The
DMA mapping code is already aware of this and treats dev->bus_dma_mask
as a limit. This quirk is already used by some architectures although
still rare.

With the introduction of the Raspberry Pi 4 we've found a new contender
for the use of bus DMA limits, as its PCIe bus can only address the
lower 3GB of memory (of a total of 4GB). This is impossible to represent
with a mask. To make things worse the device-tree code rounds non power
of two bus DMA limits to the next power of two, which is unacceptable in
this case.

In the light of this, rename dev->bus_dma_mask to dev->bus_dma_limit all
over the tree and treat it as such. Note that dev->bus_dma_limit should
contain the higher accessible DMA address.
Signed-off-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Merge branch 'for-next/zone-dma' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into dma-mapping-for-next

Pull in a stable branch from the arm64 tree that adds the zone_dma_bits
variable to avoid creating hard to resolve conflicts with that addition.

The valid memory address check in dma_capable only makes sense when mapping
normal memory, not when using dma_map_resource to map a device resource.
Add a new boolean argument to dma_capable to exclude that check for the
dma_map_resource case.

Fixes: b12d6627 ("dma-direct: check for overflows on 32 bit DMA addresses")
Reported-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Tested-by: NMarek Szyprowski <m.szyprowski@samsung.com>

When mapping resources we can't just use swiotlb ram for bounce
buffering.  Switch to a direct dma_capable check instead.

Fixes: cfced786 ("dma-mapping: remove the default map_resource implementation")
Reported-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Tested-by: NMarek Szyprowski <m.szyprowski@samsung.com>

The put_hash_bucket() is a bit cleaner if it takes an unsigned long
directly instead of a pointer to unsigned long.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Support for calling the DMA API functions without a valid device pointer
was removed a while ago, so remove the stale support for that from the
powerpc __phys_to_dma / __dma_to_phys helpers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NMichael Ellerman <mpe@ellerman.id.au>
Reviewed-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>

Move dma_capable down a bit so that we don't need a forward declaration
for phys_to_dma.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>

Currently each architectures that wants to override dma_to_phys and
phys_to_dma also has to provide dma_capable.  But there isn't really
any good reason for that.  powerpc and mips just have copies of the
generic one minus the latests fix, and the arm one was the inspiration
for said fix, but misses the bus_dma_mask handling.
Make all architectures use the generic version instead.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>

These are pure cache maintainance routines, so drop the unused
struct device argument.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Suggested-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

The devices found behind this PCIe chip have unusual DMA mapping
constraints as there is an AMBA interconnect placed in between them and
the different PCI endpoints. The offset between physical memory
addresses and AMBA's view is provided by reading a PCI config register,
which is saved and used whenever DMA mapping is needed.

It turns out that this DMA setup can be represented by properly setting
'dma_pfn_offset', 'dma_bus_mask' and 'dma_mask' during the PCI device
enable fixup. And ultimately allows us to get rid of this device's
custom DMA functions.

Aside from the code deletion and DMA setup, sta2x11_pdev_to_mapping() is
moved to avoid warnings whenever CONFIG_PM is not enabled.
Signed-off-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

As seen on the new Raspberry Pi 4 and sta2x11's DMA implementation it is
possible for a device configured with 32 bit DMA addresses and a partial
DMA mapping located at the end of the address space to overflow. It
happens when a higher physical address, not DMAable, is translated to
it's DMA counterpart.

For example the Raspberry Pi 4, configurable up to 4 GB of memory, has
an interconnect capable of addressing the lower 1 GB of physical memory
with a DMA offset of 0xc0000000. It transpires that, any attempt to
translate physical addresses higher than the first GB will result in an
overflow which dma_capable() can't detect as it only checks for
addresses bigger then the maximum allowed DMA address.

Fix this by verifying in dma_capable() if the DMA address range provided
is at any point lower than the minimum possible DMA address on the bus.
Signed-off-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

With modern NIC, it is not unusual having about ~256,000 active dma
mappings and a hash size of 1024 buckets is too small.

Forcing full cache line per bucket does not seem useful, especially now
that we have contention on free_entries_lock for allocations and freeing
of entries.  Better use the space to fit more buckets.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Move all fields used during exact match lookups to the first cache line.
This makes debug_dma_mapping_error() and friends about 50% faster.

Since it removes two 32bit holes, force a cacheline alignment on struct
dma_debug_entry.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Switch xtensa over to use the generic uncached support, and thus the
generic implementations of dma_alloc_* and dma_alloc_*, which also
gains support for mmaping DMA memory.  The non-working nommu DMA
support has been disabled, but could be re-enabled easily if platforms
that actually have an uncached segment show up.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMax Filippov <jcmvbkbc@gmail.com>
Tested-by: NMax Filippov <jcmvbkbc@gmail.com>

Integrate the generic dma remapping implementation into the main flow.
This prepares for architectures like xtensa that use an uncached
segment for pages in the kernel mapping, but can also remap highmem
from CMA.  To simplify that implementation we now always deduct the
page from the physical address via the DMA address instead of the
virtual address.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMax Filippov <jcmvbkbc@gmail.com>

For dma-direct we know that the DMA address is an encoding of the
physical address that we can trivially decode.  Use that fact to
provide implementations that do not need the arch_dma_coherent_to_pfn
architecture hook.  Note that we still can only support mmap of
non-coherent memory only if the architecture provides a way to set an
uncached bit in the page tables.  This must be true for architectures
that use the generic remap helpers, but other architectures can also
manually select it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMax Filippov <jcmvbkbc@gmail.com>

The argument isn't used anywhere, so stop passing it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMax Filippov <jcmvbkbc@gmail.com>

We can just call dma_free_contiguous directly instead of wrapping it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NMax Filippov <jcmvbkbc@gmail.com>

With the introduction of ZONE_DMA in arm64 we moved the default CMA and
crashkernel reservation into that area. This caused a regression on big
machines that need big CMA and crashkernel reservations. Note that
ZONE_DMA is only 1GB big.

Restore the previous behavior as the wide majority of devices are OK
with reserving these in ZONE_DMA32. The ones that need them in ZONE_DMA
will configure it explicitly.

Fixes: 1a8e1cef ("arm64: use both ZONE_DMA and ZONE_DMA32")
Reported-by: NQian Cai <cai@lca.pw>
Signed-off-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Some architectures, notably ARM, are interested in tweaking this
depending on their runtime DMA addressing limitations.
Acked-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NNicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Now that the vmap area checks are being performed in the DMA
infrastructure directly, there is no need to repeat them in USB.
Signed-off-by: NKees Cook <keescook@chromium.org>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

These parameters are only referenced by __init routine calls during
early boot so they should be marked as __initdata and __initconst
accordingly.
Signed-off-by: NShyam Saini <mayhs11saini@gmail.com>
Reviewed-by: NRobin Murphy <robin.murphy@arm.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

debug_dma_dump_mappings() can take a lot of cpu cycles :

lpk43:/# time wc -l /sys/kernel/debug/dma-api/dump
163435 /sys/kernel/debug/dma-api/dump

real	0m0.463s
user	0m0.003s
sys	0m0.459s

Let's add a cond_resched() to avoid holding cpu for too long.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Corentin Labbe <clabbe@baylibre.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

As we've seen from USB and other areas[1], we need to always do runtime
checks for DMA operating on memory regions that might be remapped. This
adds vmap checks (similar to those already in USB but missing in other
places) into dma_map_single() so all callers benefit from the checking.

[1] https://git.kernel.org/linus/3840c5b78803b2b6cc1ff820100a74a092c40cbbSuggested-by: NLaura Abbott <labbott@redhat.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
[hch: fixed the printk message]
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Daniele reported that issue previously fixed in c41f9ea9
("drivers: dma-coherent: Account dma_pfn_offset when used with device
tree") reappear shortly after 43fc509c ("dma-coherent: introduce
interface for default DMA pool") where fix was accidentally dropped.

Lets put fix back in place and respect dma-ranges for reserved memory.

Fixes: 43fc509c ("dma-coherent: introduce interface for default DMA pool")
Reported-by: NDaniele Alessandrelli <daniele.alessandrelli@gmail.com>
Tested-by: NDaniele Alessandrelli <daniele.alessandrelli@gmail.com>
Tested-by: NAlexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Pull iommu fixes from Joerg Roedel:

 - Follow-on fix for Renesas IPMMU to get rid of a redundant error
   message.

 - Quirk for AMD IOMMU to make it work on another Acer Laptop model with
   a broken IVRS ACPI table.

 - Fix for a panic at kdump in the Intel IOMMU driver.

* tag 'iommu-fixes-v5.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu/vt-d: Fix panic after kexec -p for kdump
  iommu/amd: Apply the same IVRS IOAPIC workaround to Acer Aspire A315-41
  iommu/ipmmu-vmsa: Remove dev_err() on platform_get_irq() failure

Pull gfs2 fix from Andreas Gruenbacher:
 "Fix remounting (broken in -rc1)."

* tag 'gfs2-v5.4-rc5.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  gfs2: Fix initialisation of args for remount

When gfs2 was converted to use fs_context, the initialisation of the
mount args structure to the currently active args was lost with the
removal of gfs2_remount_fs(), so the checks of the new args on remount
became checks against the default values instead of the current ones.
This caused unexpected remount behaviour and test failures (xfstests
generic/294, generic/306 and generic/452).

Reinstate the args initialisation, this time in gfs2_init_fs_context()
and conditional upon fc->purpose, as that's the only time we get control
before the mount args are parsed in the remount process.

Fixes: 1f52aa08 ("gfs2: Convert gfs2 to fs_context")
Signed-off-by: NAndrew Price <anprice@redhat.com>
Signed-off-by: NAndreas Gruenbacher <agruenba@redhat.com>

This cures a panic on restart after a kexec operation on 5.3 and 5.4
kernels.

The underlying state of the iommu registers (iommu->flags &
VTD_FLAG_TRANS_PRE_ENABLED) on a restart results in a domain being marked as
"DEFER_DEVICE_DOMAIN_INFO" that produces an Oops in identity_mapping().

[   43.654737] BUG: kernel NULL pointer dereference, address:
0000000000000056
[   43.655720] #PF: supervisor read access in kernel mode
[   43.655720] #PF: error_code(0x0000) - not-present page
[   43.655720] PGD 0 P4D 0
[   43.655720] Oops: 0000 [#1] SMP PTI
[   43.655720] CPU: 0 PID: 1 Comm: swapper/0 Not tainted
5.3.2-1940.el8uek.x86_64 #1
[   43.655720] Hardware name: Oracle Corporation ORACLE SERVER
X5-2/ASM,MOTHERBOARD,1U, BIOS 30140300 09/20/2018
[   43.655720] RIP: 0010:iommu_need_mapping+0x29/0xd0
[   43.655720] Code: 00 0f 1f 44 00 00 48 8b 97 70 02 00 00 48 83 fa ff
74 53 48 8d 4a ff b8 01 00 00 00 48 83 f9 fd 76 01 c3 48 8b 35 7f 58 e0
01 <48> 39 72 58 75 f2 55 48 89 e5 41 54 53 48 8b 87 28 02 00 00 4c 8b
[   43.655720] RSP: 0018:ffffc9000001b9b0 EFLAGS: 00010246
[   43.655720] RAX: 0000000000000001 RBX: 0000000000001000 RCX:
fffffffffffffffd
[   43.655720] RDX: fffffffffffffffe RSI: ffff8880719b8000 RDI:
ffff8880477460b0
[   43.655720] RBP: ffffc9000001b9e8 R08: 0000000000000000 R09:
ffff888047c01700
[   43.655720] R10: 00002194036fc692 R11: 0000000000000000 R12:
0000000000000000
[   43.655720] R13: ffff8880477460b0 R14: 0000000000000cc0 R15:
ffff888072d2b558
[   43.655720] FS:  0000000000000000(0000) GS:ffff888071c00000(0000)
knlGS:0000000000000000
[   43.655720] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   43.655720] CR2: 0000000000000056 CR3: 000000007440a002 CR4:
00000000001606b0
[   43.655720] Call Trace:
[   43.655720]  ? intel_alloc_coherent+0x2a/0x180
[   43.655720]  ? __schedule+0x2c2/0x650
[   43.655720]  dma_alloc_attrs+0x8c/0xd0
[   43.655720]  dma_pool_alloc+0xdf/0x200
[   43.655720]  ehci_qh_alloc+0x58/0x130
[   43.655720]  ehci_setup+0x287/0x7ba
[   43.655720]  ? _dev_info+0x6c/0x83
[   43.655720]  ehci_pci_setup+0x91/0x436
[   43.655720]  usb_add_hcd.cold.48+0x1d4/0x754
[   43.655720]  usb_hcd_pci_probe+0x2bc/0x3f0
[   43.655720]  ehci_pci_probe+0x39/0x40
[   43.655720]  local_pci_probe+0x47/0x80
[   43.655720]  pci_device_probe+0xff/0x1b0
[   43.655720]  really_probe+0xf5/0x3a0
[   43.655720]  driver_probe_device+0xbb/0x100
[   43.655720]  device_driver_attach+0x58/0x60
[   43.655720]  __driver_attach+0x8f/0x150
[   43.655720]  ? device_driver_attach+0x60/0x60
[   43.655720]  bus_for_each_dev+0x74/0xb0
[   43.655720]  driver_attach+0x1e/0x20
[   43.655720]  bus_add_driver+0x151/0x1f0
[   43.655720]  ? ehci_hcd_init+0xb2/0xb2
[   43.655720]  ? do_early_param+0x95/0x95
[   43.655720]  driver_register+0x70/0xc0
[   43.655720]  ? ehci_hcd_init+0xb2/0xb2
[   43.655720]  __pci_register_driver+0x57/0x60
[   43.655720]  ehci_pci_init+0x6a/0x6c
[   43.655720]  do_one_initcall+0x4a/0x1fa
[   43.655720]  ? do_early_param+0x95/0x95
[   43.655720]  kernel_init_freeable+0x1bd/0x262
[   43.655720]  ? rest_init+0xb0/0xb0
[   43.655720]  kernel_init+0xe/0x110
[   43.655720]  ret_from_fork+0x24/0x50

Fixes: 8af46c78 ("iommu/vt-d: Implement is_attach_deferred iommu ops entry")
Cc: stable@vger.kernel.org # v5.3+
Signed-off-by: NJohn Donnelly <john.p.donnelly@oracle.com>
Reviewed-by: NLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Acer Aspire A315-41 requires the very same workaround as the existing
quirk for Dell Latitude 5495.  Add the new entry for that.

BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1137799Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

platform_get_irq() will call dev_err() itself on failure,
so there is no need for the driver to also do this.
This is detected by coccinelle.
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Reviewed-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NJoerg Roedel <jroedel@suse.de>

Pull fuse fixes from Miklos Szeredi:
 "Mostly virtiofs fixes, but also fixes a regression and couple of
  longstanding data/metadata writeback ordering issues"

* tag 'fuse-fixes-5.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: redundant get_fuse_inode() calls in fuse_writepages_fill()
  fuse: Add changelog entries for protocols 7.1 - 7.8
  fuse: truncate pending writes on O_TRUNC
  fuse: flush dirty data/metadata before non-truncate setattr
  virtiofs: Remove set but not used variable 'fc'
  virtiofs: Retry request submission from worker context
  virtiofs: Count pending forgets as in_flight forgets
  virtiofs: Set FR_SENT flag only after request has been sent
  virtiofs: No need to check fpq->connected state
  virtiofs: Do not end request in submission context
  fuse: don't advise readdirplus for negative lookup
  fuse: don't dereference req->args on finished request
  virtio-fs: don't show mount options
  virtio-fs: Change module name to virtiofs.ko

Pull ARC fixes from Vineet Gupta:
 "Small fixes for ARC:

   - perf fix for Big Endian build [Alexey]

   - hadk platform enable soem peripherals [Eugeniy]"

* tag 'arc-5.4-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: perf: Accommodate big-endian CPU
  ARC: [plat-hsdk]: Enable on-boardi SPI ADC IC
  ARC: [plat-hsdk]: Enable on-board SPI NOR flash IC

This variable is only used in the arch/arm64/mm/init.c file for
ZONE_DMA32 initialisation, no need to expose it.
Reported-by: NWill Deacon <will@kernel.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Pull HID fixes from Jiri Kosina:

 - HID++ device support regression fixes (race condition during cleanup,
   device detection fix, opps fix) from Andrey Smirnov

 - disable PM on i2c-hid, as it's causing problems with a lot of
   devices; other OSes apparently don't implement/enable it either; from
   Kai-Heng Feng

 - error handling fix in intel-ish driver, from Zhang Lixu

 - syzbot fuzzer fix for HID core code from Alan Stern

 - a few other tiny fixups (printk message cleanup, new device ID)

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid:
  HID: i2c-hid: add Trekstor Primebook C11B to descriptor override
  HID: logitech-hidpp: do all FF cleanup in hidpp_ff_destroy()
  HID: logitech-hidpp: rework device validation
  HID: logitech-hidpp: split g920_get_config()
  HID: i2c-hid: Remove runtime power management
  HID: intel-ish-hid: fix wrong error handling in ishtp_cl_alloc_tx_ring()
  HID: google: add magnemite/masterball USB ids
  HID: Fix assumption that devices have inputs
  HID: prodikeys: make array keys static const, makes object smaller
  HID: fix error message in hid_open_report()

Pull virtio fixes from Michael Tsirkin:
 "Some minor fixes"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vringh: fix copy direction of vringh_iov_push_kern()
  vsock/virtio: remove unused 'work' field from 'struct virtio_vsock_pkt'
  virtio_ring: fix stalls for packed rings

We want to copy from iov to buf, so the direction was wrong.

Note: no real user for the helper, but it will be used by future
features.
Signed-off-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

The 'work' field was introduced with commit 06a8fc78
("VSOCK: Introduce virtio_vsock_common.ko")
but it is never used in the code, so we can remove it to save
memory allocated in the per-packet 'struct virtio_vsock_pkt'
Suggested-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NStefano Garzarella <sgarzare@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

When VIRTIO_F_RING_EVENT_IDX is negotiated, virtio devices can
use virtqueue_enable_cb_delayed_packed to reduce the number of device
interrupts.  At the moment, this is the case for virtio-net when the
napi_tx module parameter is set to false.

In this case, the virtio driver selects an event offset and expects that
the device will send a notification when rolling over the event offset
in the ring.  However, if this roll-over happens before the event
suppression structure update, the notification won't be sent. To address
this race condition the driver needs to check wether the device rolled
over the offset after updating the event suppression structure.

With VIRTIO_F_RING_PACKED, the virtio driver did this by reading the
flags field of the descriptor at the specified offset.

Unfortunately, checking at the event offset isn't reliable: if
descriptors are chained (e.g. when INDIRECT is off) not all descriptors
are overwritten by the device, so it's possible that the device skipped
the specific descriptor driver is checking when writing out used
descriptors. If this happens, the driver won't detect the race condition
and will incorrectly expect the device to send a notification.

For virtio-net, the result will be a TX queue stall, with the
transmission getting blocked forever.

With the packed ring, it isn't easy to find a location which is
guaranteed to change upon the roll-over, except the next device
descriptor, as described in the spec:

        Writes of device and driver descriptors can generally be
        reordered, but each side (driver and device) are only required to
        poll (or test) a single location in memory: the next device descriptor after
        the one they processed previously, in circular order.

while this might be sub-optimal, let's do exactly this for now.

Cc: stable@vger.kernel.org
Cc: Jason Wang <jasowang@redhat.com>
Fixes: f51f9826 ("virtio_ring: leverage event idx in packed ring")
Signed-off-by: NMarvin Liu <yong.liu@intel.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>