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  1. 19 1月, 2018 1 次提交
    • H
      hostmem-file: add "align" option · 98376843
      由 Haozhong Zhang 提交于 
      When mmap(2) the backend files, QEMU uses the host page size
(getpagesize(2)) by default as the alignment of mapping address.
However, some backends may require alignments different than the page
size. For example, mmap a device DAX (e.g., /dev/dax0.0) on Linux
kernel 4.13 to an address, which is 4K-aligned but not 2M-aligned,
fails with a kernel message like

[617494.969768] dax dax0.0: qemu-system-x86: dax_mmap: fail, unaligned vma (0x7fa37c579000 - 0x7fa43c579000, 0x1fffff)

Because there is no common approach to get such alignment requirement,
we add the 'align' option to 'memory-backend-file', so that users or
management utils, which have enough knowledge about the backend, can
specify a proper alignment via this option.
Signed-off-by: NHaozhong Zhang <haozhong.zhang@intel.com>
Message-Id: <20171211072806.2812-2-haozhong.zhang@intel.com>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
[ehabkost: fixed typo, fixed error_setg() format string]
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
      98376843
  3. 18 12月, 2017 1 次提交
  5. 22 9月, 2017 6 次提交
  7. 04 9月, 2017 1 次提交
  9. 15 7月, 2017 4 次提交
  11. 14 7月, 2017 2 次提交
  13. 27 6月, 2017 1 次提交
  15. 15 6月, 2017 2 次提交
  17. 04 6月, 2017 1 次提交
  19. 26 5月, 2017 2 次提交
  21. 24 4月, 2017 1 次提交
    • G
      memory: add support getting and using a dirty bitmap copy. · 8deaf12c
      由 Gerd Hoffmann 提交于 
      This patch adds support for getting and using a local copy of the dirty
bitmap.

memory_region_snapshot_and_clear_dirty() will create a snapshot of the
dirty bitmap for the specified range, clear the dirty bitmap and return
the copy.  The returned bitmap can be a bit larger than requested, the
range is expanded so the code can copy unsigned longs from the bitmap
and avoid atomic bit update operations.

memory_region_snapshot_get_dirty() will return the dirty status of
pages, pretty much like memory_region_get_dirty(), but using the copy
returned by memory_region_copy_and_clear_dirty().
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Message-id: 20170421091632.30900-3-kraxel@redhat.com
Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
      8deaf12c
  23. 21 4月, 2017 6 次提交
  25. 03 4月, 2017 1 次提交
    • P
      exec: revert MemoryRegionCache · 90c4fe5f
      由 Paolo Bonzini 提交于 
      MemoryRegionCache did not know about virtio support for IOMMUs (because the
two features were developed at the same time).  Revert MemoryRegionCache
to "normal" address_space_* operations for 2.9, as it is simpler than
undoing the virtio patches.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      90c4fe5f
  27. 14 3月, 2017 1 次提交
  29. 18 2月, 2017 1 次提交
  31. 28 1月, 2017 1 次提交
  33. 17 1月, 2017 1 次提交
  35. 10 1月, 2017 2 次提交
  37. 22 12月, 2016 2 次提交
  39. 31 10月, 2016 2 次提交
    • 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
  41. 24 10月, 2016 1 次提交
    • P
      memory: add a per-AddressSpace list of listeners · 9a54635d
      由 Paolo Bonzini 提交于 
      This speeds up MEMORY_LISTENER_CALL noticeably.  Right now,
with many PCI devices you have N regions added to M AddressSpaces
(M = # PCI devices with bus-master enabled) and each call looks
up the whole listener list, with at least M listeners in it.
Because most of the regions in N are BARs, which are also roughly
proportional to M, the whole thing is O(M^3).  This changes it
to O(M^2), which is the best we can do without rewriting the
whole thing.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
      9a54635d