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  1. 01 11月, 2016 26 次提交
  3. 31 10月, 2016 14 次提交
    • Y
      vfio: Add support for mmapping sub-page MMIO BARs · 95251725
      由 Yongji Xie 提交于 
      Now the kernel commit 05f0c03fbac1 ("vfio-pci: Allow to mmap
sub-page MMIO BARs if the mmio page is exclusive") allows VFIO
to mmap sub-page BARs. This is the corresponding QEMU patch.
With those patches applied, we could passthrough sub-page BARs
to guest, which can help to improve IO performance for some devices.

In this patch, we expand MemoryRegions of these sub-page
MMIO BARs to PAGE_SIZE in vfio_pci_write_config(), so that
the BARs could be passed to KVM ioctl KVM_SET_USER_MEMORY_REGION
with a valid size. The expanding size will be recovered when
the base address of sub-page BAR is changed and not page aligned
any more in guest. And we also set the priority of these BARs'
memory regions to zero in case of overlap with BARs which share
the same page with sub-page BARs in guest.
Signed-off-by: NYongji Xie <xyjxie@linux.vnet.ibm.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
      95251725
    • I
      vfio/pci: fix out-of-sync BAR information on reset · a52a4c47
      由 Ido Yariv 提交于 
      When a PCI device is reset, pci_do_device_reset resets all BAR addresses
in the relevant PCIDevice's config buffer.

The VFIO configuration space stays untouched, so the guest OS may choose
to skip restoring the BAR addresses as they would seem intact. The PCI
device may be left non-operational.
One example of such a scenario is when the guest exits S3.

Fix this by resetting the BAR addresses in the VFIO configuration space
as well.
Signed-off-by: NIdo Yariv <ido@wizery.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
      a52a4c47
    • A
      vfio: Handle zero-length sparse mmap ranges · 24acf72b
      由 Alex Williamson 提交于 
      As reported in the link below, user has a PCI device with a 4KB BAR
which contains the MSI-X table.  This seems to hit a corner case in
the kernel where the region reports being mmap capable, but the sparse
mmap information reports a zero sized range.  It's not entirely clear
that the kernel is incorrect in doing this, but regardless, we need
to handle it.  To do this, fill our mmap array only with non-zero
sized sparse mmap entries and add an error return from the function
so we can tell the difference between nr_mmaps being zero based on
sparse mmap info vs lack of sparse mmap info.

NB, this doesn't actually change the behavior of the device, it only
removes the scary "Failed to mmap ... Performance may be slow" error
message.  We cannot currently create an mmap over the MSI-X table.

Link: http://lists.nongnu.org/archive/html/qemu-discuss/2016-10/msg00009.htmlSigned-off-by: NAlex Williamson <alex.williamson@redhat.com>
      24acf72b
    • A
      memory: Don't use memcpy for ram_device regions · 4a2e242b
      由 Alex Williamson 提交于 
      With a vfio assigned device we lay down a base MemoryRegion registered
as an IO region, giving us read & write accessors.  If the region
supports mmap, we lay down a higher priority sub-region MemoryRegion
on top of the base layer initialized as a RAM device pointer to the
mmap.  Finally, if we have any quirks for the device (ie. address
ranges that need additional virtualization support), we put another IO
sub-region on top of the mmap MemoryRegion.  When this is flattened,
we now potentially have sub-page mmap MemoryRegions exposed which
cannot be directly mapped through KVM.

This is as expected, but a subtle detail of this is that we end up
with two different access mechanisms through QEMU.  If we disable the
mmap MemoryRegion, we make use of the IO MemoryRegion and service
accesses using pread and pwrite to the vfio device file descriptor.
If the mmap MemoryRegion is enabled and results in one of these
sub-page gaps, QEMU handles the access as RAM, using memcpy to the
mmap.  Using either pread/pwrite or the mmap directly should be
correct, but using memcpy causes us problems.  I expect that not only
does memcpy not necessarily honor the original width and alignment in
performing a copy, but it potentially also uses processor instructions
not intended for MMIO spaces.  It turns out that this has been a
problem for Realtek NIC assignment, which has such a quirk that
creates a sub-page mmap MemoryRegion access.

To resolve this, we disable memory_access_is_direct() for ram_device
regions since QEMU assumes that it can use memcpy for those regions.
Instead we access through MemoryRegionOps, which replaces the memcpy
with simple de-references of standard sizes to the host memory.

With this patch we attempt to provide unrestricted access to the RAM
device, allowing byte through qword access as well as unaligned
access.  The assumption here is that accesses initiated by the VM are
driven by a device specific driver, which knows the device
capabilities.  If unaligned accesses are not supported by the device,
we don't want them to work in a VM by performing multiple aligned
accesses to compose the unaligned access.  A down-side of this
philosophy is that the xp command from the monitor attempts to use
the largest available access weidth, unaware of the underlying
device.  Using memcpy had this same restriction, but at least now an
operator can dump individual registers, even if blocks of device
memory may result in access widths beyond the capabilities of a
given device (RTL NICs only support up to dword).
Reported-by: NThorsten Kohfeldt <thorsten.kohfeldt@gmx.de>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
      4a2e242b
    • A
      memory: Replace skip_dump flag with "ram_device" · 21e00fa5
      由 Alex Williamson 提交于 
      Setting skip_dump on a MemoryRegion allows us to modify one specific
code path, but the restriction we're trying to address encompasses
more than that.  If we have a RAM MemoryRegion backed by a physical
device, it not only restricts our ability to dump that region, but
also affects how we should manipulate it.  Here we recognize that
MemoryRegions do not change to sometimes allow dumps and other times
not, so we replace setting the skip_dump flag with a new initializer
so that we know exactly the type of region to which we're applying
this behavior.
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Acked-by: NPaolo Bonzini <pbonzini@redhat.com>
      21e00fa5
    • A
      qapi: allow blockdev-add for NFS · aa2623d8
      由 Ashijeet Acharya 提交于 
      Introduce new object 'BlockdevOptionsNFS' in qapi/block-core.json to
support blockdev-add for NFS network protocol driver. Also make a new
struct NFSServer to support tcp connection.
Signed-off-by: NAshijeet Acharya <ashijeetacharya@gmail.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      aa2623d8
    • A
      block/nfs: Introduce runtime_opts in NFS · 94d6a7a7
      由 Ashijeet Acharya 提交于 
      Make NFS block driver use various fine grained runtime_opts.
Set .bdrv_parse_filename() to nfs_parse_filename() and introduce two
new functions nfs_parse_filename() and nfs_parse_uri() to help parsing
the URI.
Add a new option "server" which then accepts a new struct NFSServer.
Signed-off-by: NAshijeet Acharya <ashijeetacharya@gmail.com>
[ kwolf: Fixed client->path ]
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      94d6a7a7
    • E
      block: Mention replication in BlockdevDriver enum docs · 68875e9f
      由 Eric Blake 提交于 
      Missed in commit 82ac5543.
Signed-off-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      68875e9f
    • T
      qemu-iotests: test 'offset' and 'size' options in raw driver · ccc47808
      由 Tomáš Golembiovský 提交于 
      Signed-off-by: NTomáš Golembiovský <tgolembi@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      ccc47808
    • T
      raw_bsd: add offset and size options · 2fdc7045
      由 Tomáš Golembiovský 提交于 
      Added two new options 'offset' and 'size'. This makes it possible to use
only part of the file as a device. This can be used e.g. to limit the
access only to single partition in a disk image or use a disk inside a
tar archive (like OVA).

When 'size' is specified we do our best to honour it.
Signed-off-by: NTomáš Golembiovský <tgolembi@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      2fdc7045
    • A
      qemu-iotests: Test the 'base-node' parameter of 'block-stream' · 7eb13c9d
      由 Alberto Garcia 提交于 
      The block-stream command has traditionally used the 'base' parameter
to indicate the image to copy the data from. This test checks that the
'base-node' parameter can also be used for the same purpose.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      7eb13c9d
    • A
      block: Add 'base-node' parameter to the 'block-stream' command · 312fe09c
      由 Alberto Garcia 提交于 
      The way to specify the node from which to copy data in the
block-stream operation is by using the 'base' parameter. This
parameter however takes a file name, not a node name.

Since we want to be able to perform this operation using only node
names, this patch adds a new 'base-node' parameter.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      312fe09c
    • A
      qemu-iotests: Test streaming to a Quorum child · 48361afb
      由 Alberto Garcia 提交于 
      Quorum children are special in the sense that they're not directly
attached to a block backend but they're not used as backing images
either. However the intermediate block streaming code supports
streaming to them. This is a test case for that scenario.
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      48361afb
    • A
      qemu-iotests: Add iotests.supports_quorum() · b0f90495
      由 Alberto Garcia 提交于 
      There's many tests that need Quorum support in order to run. At the
moment each test implements its own check to see if Quorum is
enabled. This patch centralizes all those checks in a new function
called iotests.supports_quorum().
Signed-off-by: NAlberto Garcia <berto@igalia.com>
Reviewed-by: NKevin Wolf <kwolf@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>
      b0f90495