Looks like a quiet cycle for vhost/virtio, just a couple of minor
tweaks. Most notable is automatic interrupt affinity for blk and scsi.
Hopefully other devices are not far behind.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull vhost updates from Michael Tsirkin:
"virtio, vhost: optimizations, fixes
Looks like a quiet cycle for vhost/virtio, just a couple of minor
tweaks. Most notable is automatic interrupt affinity for blk and scsi.
Hopefully other devices are not far behind"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
virtio-console: avoid DMA from stack
vhost: introduce O(1) vq metadata cache
virtio_scsi: use virtio IRQ affinity
virtio_blk: use virtio IRQ affinity
blk-mq: provide a default queue mapping for virtio device
virtio: provide a method to get the IRQ affinity mask for a virtqueue
virtio: allow drivers to request IRQ affinity when creating VQs
virtio_pci: simplify MSI-X setup
virtio_pci: don't duplicate the msix_enable flag in struct pci_dev
virtio_pci: use shared interrupts for virtqueues
virtio_pci: remove struct virtio_pci_vq_info
vhost: try avoiding avail index access when getting descriptor
virtio_mmio: expose header to userspace
This basically passed up the pci_irq_get_affinity information through
virtio through an optional get_vq_affinity method. It is only implemented
by the PCI backend for now, and only when we use per-virtqueue IRQs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Add a struct irq_affinity pointer to the find_vqs methods, which if set
is used to tell the PCI layer to create the MSI-X vectors for our I/O
virtqueues with the proper affinity from the start. Compared to after
the fact affinity hints this gives us an instantly working setup and
allows to allocate the irq descritors node-local and avoid interconnect
traffic. Last but not least this will allow blk-mq queues are created
based on the interrupt affinity for storage drivers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Try to grab the MSI-X vectors early and fall back to the shared one
before doing lots of allocations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This lets IRQ layer handle dispatching IRQs to separate handlers for the
case where we don't have per-VQ MSI-X vectors, and allows us to greatly
simplify the code based on the assumption that we always have interrupt
vector 0 (legacy INTx or config interrupt for MSI-X) available, and
any other interrupt is request/freed throught the VQ, even if the
actual interrupt line might be shared in some cases.
This allows removing a great deal of variables keeping track of the
interrupt state in struct virtio_pci_device, as we can now simply walk the
list of VQs and deal with per-VQ interrupt handlers there, and only treat
vector 0 special.
Additionally clean up the VQ allocation code to properly unwind on error
instead of having a single global cleanup label, which is error prone,
and in this case also leads to more code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We don't really need struct virtio_pci_vq_info, as most field in there
are redundant:
- the vq backpointer is not strictly neede to start with
- the entry in the vqs list is not needed - the generic virtqueue already
has list, we only need to check if it has a callback to get the same
semantics
- we can use a simple array to look up the MSI-X vec if needed.
- That simple array now also duoble serves to replace the per_vq_vectors
flag
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
With CONFIG_BALLOON_COMPACTION=y the kernel will mount balloon_mnt for
balloon page migration when we probe a virtio_balloon device. However
we do not unmount it when removing the device. Fix this.
Fixes: b1123ea6d3 ("mm: balloon: use general non-lru movable page feature")
Link: http://lkml.kernel.org/r/1486531318-35189-1-git-send-email-xieyisheng1@huawei.com
Signed-off-by: Yisheng Xie <xieyisheng1@huawei.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Gioh Kim <gi-oh.kim@profitbricks.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The conflict was an interaction between a bug fix in the
netvsc driver in 'net' and an optimization of the RX path
in 'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
For XDP we will need to reset the queues to allow for buffer headroom
to be configured. In order to do this we need to essentially run the
freeze()/restore() code path. Unfortunately the locking requirements
between the freeze/restore and reset paths are different however so
we can not simply reuse the code.
This patch refactors the code path and adds a reset helper routine.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit c7070619f3.
This has been shown to regress on some ARM systems:
by forcing on DMA API usage for ARM systems, we have inadvertently
kicked open a hornets' nest in terms of cache-coherency. Namely that
unless the virtio device is explicitly described as capable of coherent
DMA by firmware, the DMA APIs on ARM and other DT-based platforms will
assume it is non-coherent. This turns out to cause a big problem for the
likes of QEMU and kvmtool, which generate virtio-mmio devices in their
guest DTs but neglect to add the often-overlooked "dma-coherent"
property; as a result, we end up with the guest making non-cacheable
accesses to the vring, the host doing so cacheably, both talking past
each other and things going horribly wrong.
We are working on a safer work-around.
Fixes: c7070619f3 ("vring: Force use of DMA API for ARM-based systems with legacy devices")
Reported-by: Robin Murphy <robin.murphy@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Booting Linux on an ARM fastmodel containing an SMMU emulation results
in an unexpected I/O page fault from the legacy virtio-blk PCI device:
[ 1.211721] arm-smmu-v3 2b400000.smmu: event 0x10 received:
[ 1.211800] arm-smmu-v3 2b400000.smmu: 0x00000000fffff010
[ 1.211880] arm-smmu-v3 2b400000.smmu: 0x0000020800000000
[ 1.211959] arm-smmu-v3 2b400000.smmu: 0x00000008fa081002
[ 1.212075] arm-smmu-v3 2b400000.smmu: 0x0000000000000000
[ 1.212155] arm-smmu-v3 2b400000.smmu: event 0x10 received:
[ 1.212234] arm-smmu-v3 2b400000.smmu: 0x00000000fffff010
[ 1.212314] arm-smmu-v3 2b400000.smmu: 0x0000020800000000
[ 1.212394] arm-smmu-v3 2b400000.smmu: 0x00000008fa081000
[ 1.212471] arm-smmu-v3 2b400000.smmu: 0x0000000000000000
<system hangs failing to read partition table>
This is because the legacy virtio-blk device is behind an SMMU, so we
have consequently swizzled its DMA ops and configured the SMMU to
translate accesses. This then requires the vring code to use the DMA API
to establish translations, otherwise all transactions will result in
fatal faults and termination.
Given that ARM-based systems only see an SMMU if one is really present
(the topology is all described by firmware tables such as device-tree or
IORT), then we can safely use the DMA API for all legacy virtio devices.
Modern devices can advertise the prescense of an IOMMU using the
VIRTIO_F_IOMMU_PLATFORM feature flag.
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: <stable@vger.kernel.org>
Fixes: 876945dbf6 ("arm64: Hook up IOMMU dma_ops")
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Once DMA API usage is enabled, it becomes apparent that virtio-mmio is
inadvertently relying on the default 32-bit DMA mask, which leads to
problems like rapidly exhausting SWIOTLB bounce buffers.
Ensure that we set the appropriate 64-bit DMA mask whenever possible,
with the coherent mask suitably limited for the legacy vring as per
a0be1db430 ("virtio_pci: Limit DMA mask to 44 bits for legacy virtio
devices").
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Reported-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Fixes: b42111382f ("virtio_mmio: Use the DMA API if enabled")
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Fix a warning thrown from virtio_mmio_remove():
Device 'virtio0' does not have a release() function
The fix is according to virtio_pci_probe() of
drivers/virtio/virtio_pci_common.c
Signed-off-by: Yuan Liu <liuyuan@google.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The device (not the driver) populates the used ring and includes the len
of how much data was written.
Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
There is basically no shared logic between the INTx and MSI-X case in
vp_try_to_find_vqs, so split the function into two and clean them up
a little bit.
Also remove the fairly pointless vp_request_intx wrapper while we're at it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
vp_request_msix_vectors is only called by vp_try_to_find_vqs, which already
calls vp_free_vectors through vp_del_vqs in the failure case.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This avoids the separate allocation for the msix_entries structures, and
instead allows us to use pci_irq_vector to find a given IRQ vector.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
# make C=2 CF="-D__CHECK_ENDIAN__" ./drivers/virtio/
drivers/virtio/virtio_ring.c:423:19: warning: incorrect type in assignment (different base types)
drivers/virtio/virtio_ring.c:423:19: expected unsigned int [unsigned] [assigned] i
drivers/virtio/virtio_ring.c:423:19: got restricted __virtio16 [usertype] next
drivers/virtio/virtio_ring.c:423:19: warning: incorrect type in assignment (different base types)
drivers/virtio/virtio_ring.c:423:19: expected unsigned int [unsigned] [assigned] i
drivers/virtio/virtio_ring.c:423:19: got restricted __virtio16 [usertype] next
drivers/virtio/virtio_ring.c:423:19: warning: incorrect type in assignment (different base types)
drivers/virtio/virtio_ring.c:423:19: expected unsigned int [unsigned] [assigned] i
drivers/virtio/virtio_ring.c:423:19: got restricted __virtio16 [usertype] next
drivers/virtio/virtio_ring.c:604:39: warning: incorrect type in initializer (different base types)
drivers/virtio/virtio_ring.c:604:39: expected unsigned short [unsigned] [usertype] nextflag
drivers/virtio/virtio_ring.c:604:39: got restricted __virtio16
drivers/virtio/virtio_ring.c:612:33: warning: restricted __virtio16 degrades to integer
Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'v4.9-rc4' into sound
Bring in -rc4 patches so I can successfully merge the sound doc changes.
This inline function is unused on configurations
where dma_map/unmap are empty macros.
Make the function inline to avoid gcc errors because
of an unused static function.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The following commit 'fad7b7b27b6a (virtio_balloon: Use a workqueue
instead of "vballoon" kthread)' has added a regression. Original code with
kthread starts the thread inside probe and checks the necessity to update
balloon inside the thread immediately.
Nowadays the code behaves differently. Work is queued only on the first
command from the host after the negotiation. Thus there is a window
especially at the guest startup or the module reloading when the balloon
size is not updated until the notification from the host.
This patch adds balloon size check at the end of the probe to match
original behaviour.
Signed-off-by: Konstantin Neumoin <kneumoin@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
According to the spec, if the VIRTIO_RING_F_EVENT_IDX feature bit is
negotiated the driver MUST set flags to 0. Not dirtying the available
ring in virtqueue_disable_cb also has a minor positive performance
impact, improving L1 dcache load missed by ~0.5% in vring_bench.
Writes to the used event field (vring_used_event) are still unconditional.
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: <stable@vger.kernel.org> # f277ec4 virtio_ring: shadow available
Cc: <stable@vger.kernel.org>
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Legacy virtio defines the virtqueue base using a 32-bit PFN field, with
a read-only register indicating a fixed page size of 4k.
This can cause problems for DMA allocators that allocate top down from
the DMA mask, which is set to 64 bits. In this case, the addresses are
silently truncated to 44-bit, leading to IOMMU faults, failure to read
from the queue or data corruption.
This patch restricts the coherent DMA mask for legacy PCI virtio devices
to 44 bits, which matches the specification.
Cc: stable@vger.kernel.org
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Benjamin Serebrin <serebrin@google.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The previous patch renamed several files that are cross-referenced
along the Kernel documentation. Adjust the links to point to
the right places.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
We get 1 warning when building kernel with W=1:
drivers/virtio/virtio_ring.c:170:16: warning: no previous prototype for 'vring_dma_dev' [-Wmissing-prototypes]
In fact, this function is only used in the file in which it is
declared and don't need a declaration, but can be made static.
so this patch marks this function with 'static'.
Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
On error, virtqueue_add calls START_USE but not
END_USE. Thankfully that's normally empty anyway,
but might not be when debugging. Fix it up.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
When using the indirect buffers feature, 'desc' is allocated in
virtqueue_add() but isn't freed before leaving on a ring full error,
causing a memory leak.
For example, it seems rather clear that this can trigger
with virtio net if mergeable buffers are not used.
Cc: stable@vger.kernel.org
Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
- New vsock device support in host and guest
- Platform IOMMU support in host and guest,
including compatibility quirks for legacy systems.
- Misc fixes and cleanups.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio/vhost updates from Michael Tsirkin:
- new vsock device support in host and guest
- platform IOMMU support in host and guest, including compatibility
quirks for legacy systems.
- misc fixes and cleanups.
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
VSOCK: Use kvfree()
vhost: split out vringh Kconfig
vhost: detect 32 bit integer wrap around
vhost: new device IOTLB API
vhost: drop vringh dependency
vhost: convert pre sorted vhost memory array to interval tree
vhost: introduce vhost memory accessors
VSOCK: Add Makefile and Kconfig
VSOCK: Introduce vhost_vsock.ko
VSOCK: Introduce virtio_transport.ko
VSOCK: Introduce virtio_vsock_common.ko
VSOCK: defer sock removal to transports
VSOCK: transport-specific vsock_transport functions
vhost: drop vringh dependency
vop: pull in vhost Kconfig
virtio: new feature to detect IOMMU device quirk
balloon: check the number of available pages in leak balloon
vhost: lockless enqueuing
vhost: simplify work flushing
The interaction between virtio and IOMMUs is messy.
On most systems with virtio, physical addresses match bus addresses,
and it doesn't particularly matter which one we use to program
the device.
On some systems, including Xen and any system with a physical device
that speaks virtio behind a physical IOMMU, we must program the IOMMU
for virtio DMA to work at all.
On other systems, including SPARC and PPC64, virtio-pci devices are
enumerated as though they are behind an IOMMU, but the virtio host
ignores the IOMMU, so we must either pretend that the IOMMU isn't
there or somehow map everything as the identity.
Add a feature bit to detect that quirk: VIRTIO_F_IOMMU_PLATFORM.
Any device with this feature bit set to 0 needs a quirk and has to be
passed physical addresses (as opposed to bus addresses) even though
the device is behind an IOMMU.
Note: it has to be a per-device quirk because for example, there could
be a mix of passed-through and virtual virtio devices. As another
example, some devices could be implemented by an out of process
hypervisor backend (in case of qemu vhost, or vhost-user) and so support
for an IOMMU needs to be coded up separately.
It would be cleanest to handle this in IOMMU core code, but that needs
per-device DMA ops. While we are waiting for that to be implemented, use
a work-around in virtio core.
Note: a "noiommu" feature is a quirk - add a wrapper to make
that clear.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The balloon has a special mechanism that is subscribed to the oom
notification which leads to deflation for a fixed number of pages.
The number is always fixed even when the balloon is fully deflated.
But leak_balloon did not expect that the pages to deflate will be more
than taken, and raise a "BUG" in balloon_page_dequeue when page list
will be empty.
So, the simplest solution would be to check that the number of releases
pages is less or equal to the number taken pages.
Cc: stable@vger.kernel.org
Signed-off-by: Konstantin Neumoin <kneumoin@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Randy reported below build error.
> In file included from ../include/linux/balloon_compaction.h:48:0,
> from ../mm/balloon_compaction.c:11:
> ../include/linux/compaction.h:237:51: warning: 'struct node' declared inside parameter list [enabled by default]
> static inline int compaction_register_node(struct node *node)
> ../include/linux/compaction.h:237:51: warning: its scope is only this definition or declaration, which is probably not what you want [enabled by default]
> ../include/linux/compaction.h:242:54: warning: 'struct node' declared inside parameter list [enabled by default]
> static inline void compaction_unregister_node(struct node *node)
>
It was caused by non-lru page migration which needs compaction.h but
compaction.h doesn't include any header to be standalone.
I think proper header for non-lru page migration is migrate.h rather
than compaction.h because migrate.h has already headers needed to work
non-lru page migration indirectly like isolate_mode_t, migrate_mode
MIGRATEPAGE_SUCCESS.
[akpm@linux-foundation.org: revert mm-balloon-use-general-non-lru-movable-page-feature-fix.patch temp fix]
Link: http://lkml.kernel.org/r/20160610003304.GE29779@bbox
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Gioh Kim <gi-oh.kim@profitbricks.com>
Cc: Rafael Aquini <aquini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now, VM has a feature to migrate non-lru movable pages so balloon
doesn't need custom migration hooks in migrate.c and compaction.c.
Instead, this patch implements the page->mapping->a_ops->
{isolate|migrate|putback} functions.
With that, we could remove hooks for ballooning in general migration
functions and make balloon compaction simple.
[akpm@linux-foundation.org: compaction.h requires that the includer first include node.h]
Link: http://lkml.kernel.org/r/1464736881-24886-4-git-send-email-minchan@kernel.org
Signed-off-by: Gioh Kim <gi-oh.kim@profitbricks.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Everything should be LE when using virtio-1, but
the linux balloon driver does not seem to care about that.
Reported-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Smatch complains that we might not initialize "queue". The issue is
callers like setup_vq() from virtio_pci_modern.c where "num" could be
something like 2 and "vring_align" is 64. In that case, vring_size() is
less than PAGE_SIZE. It won't happen in real life, but we're getting
the value of "num" from a register so it's not really possible to tell
what value it holds with static analysis.
Let's just silence the warning.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The spec says: after writing 0 to device_status, the driver MUST wait
for a read of device_status to return 0 before reinitializing the
device.
Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
This adds basic polling support for vhost.
Reworks virtio to optionally use DMA API, fixing it on Xen.
Balloon stats gained a new entry.
Using the new napi_alloc_skb speeds up virtio net.
virtio blk stats can now be read while another VCPU
us busy inflating or deflating the balloon.
Plus misc cleanups in various places.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio/vhost updates from Michael Tsirkin:
"New features, performance improvements, cleanups:
- basic polling support for vhost
- rework virtio to optionally use DMA API, fixing it on Xen
- balloon stats gained a new entry
- using the new napi_alloc_skb speeds up virtio net
- virtio blk stats can now be read while another VCPU is busy
inflating or deflating the balloon
plus misc cleanups in various places"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
virtio_net: replace netdev_alloc_skb_ip_align() with napi_alloc_skb()
vhost_net: basic polling support
vhost: introduce vhost_vq_avail_empty()
vhost: introduce vhost_has_work()
virtio_balloon: Allow to resize and update the balloon stats in parallel
virtio_balloon: Use a workqueue instead of "vballoon" kthread
virtio/s390: size of SET_IND payload
virtio/s390: use dev_to_virtio
vhost: rename vhost_init_used()
vhost: rename cross-endian helpers
virtio_blk: VIRTIO_BLK_F_WCE->VIRTIO_BLK_F_FLUSH
vring: Use the DMA API on Xen
virtio_pci: Use the DMA API if enabled
virtio_mmio: Use the DMA API if enabled
virtio: Add improved queue allocation API
virtio_ring: Support DMA APIs
vring: Introduce vring_use_dma_api()
s390/dma: Allow per device dma ops
alpha/dma: use common noop dma ops
dma: Provide simple noop dma ops
Add a new field, VIRTIO_BALLOON_S_AVAIL, to virtio_balloon memory
statistics protocol, corresponding to 'Available' in /proc/meminfo.
It indicates to the hypervisor how big the balloon can be inflated
without pushing the guest system to swap.
Signed-off-by: Igor Redko <redkoi@virtuozzo.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The virtio balloon statistics are not updated when the balloon
is being resized. But it seems that both tasks could be done
in parallel.
stats_handle_request() updates the statistics in the balloon
structure and then communicates with the host.
update_balloon_stats() calls all_vm_events() that just reads
some per-CPU variables. The values might change during and
after the call but it is expected and happens even without
this patch.
update_balloon_stats() also calls si_meminfo(). It is a bit
more complex function. It too just reads some variables and
looks lock-less safe. In each case, it seems to be called
lock-less on several similar locations, e.g. from post_status()
in dm_thread_func(), or from vmballoon_send_get_target().
The communication with the host is done via a separate virtqueue,
see vb->stats_vq vs. vb->inflate_vq and vb->deflate_vq. Therefore
it could be used in parallel with fill_balloon() and leak_balloon().
This patch splits the existing work into two pieces. One is for
updating the balloon stats. The other is for resizing of the balloon.
It seems that they can be proceed in parallel without any
extra locking.
Signed-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This patch moves the deferred work from the "vballoon" kthread into a
system freezable workqueue.
We do not need to maintain and run a dedicated kthread. Also the event
driven workqueues API makes the logic much easier. Especially, we do
not longer need an own wait queue, wait function, and freeze point.
The conversion is pretty straightforward. One cycle of the main loop
is put into a work. The work is queued instead of waking the kthread.
fill_balloon() and leak_balloon() have a limit for the amount of modified
pages. The work re-queues itself when necessary. For this, we make
fill_balloon() to return the number of really modified pages.
Note that leak_balloon() already did this.
virtballoon_restore() queues the work only when really needed.
The only complication is that we need to prevent queuing the work
when the balloon is being removed. It was easier before because the
kthread simply removed itself from the wait queue. We need an
extra boolean and spin lock now.
My initial idea was to use a dedicated workqueue. Michael S. Tsirkin
suggested using a system one. Tejun Heo confirmed that the system
workqueue has a pretty high concurrency level (256) by default.
Therefore we need not be afraid of too long blocking.
Signed-off-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Introduce PCI_VENDOR/PCI_SUBVENDOR/PCI_SUBDEVICE defines to replace the
constants scattered in the kernel already used to detect QEMU.
They are defined in the QEMU codebase per docs/specs/pci-ids.txt.
Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
This switches to vring_create_virtqueue, simplifying the driver and
adding DMA API support.
This fixes virtio-pci on platforms and busses that have IOMMUs. This
will break the experimental QEMU Q35 IOMMU support until QEMU is
fixed. In exchange, it fixes physical virtio hardware as well as
virtio-pci running under Xen.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This switches to vring_create_virtqueue, simplifying the driver and
adding DMA API support.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
