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  1. Feb 17, 2017
  3. Jan 31, 2017
  5. Jan 27, 2017
  7. Jan 10, 2017
  9. Oct 31, 2016
    • Alex Williamson's avatar
      memory: Don't use memcpy for ram_device regions · 4a2e242b
      Alex Williamson authored 
      
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: default avatarThorsten Kohfeldt <thorsten.kohfeldt@gmx.de>
Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
Acked-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      4a2e242b
    • Alex Williamson's avatar
      memory: Replace skip_dump flag with "ram_device" · 21e00fa5
      Alex Williamson authored 
      
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: default avatarAlex Williamson <alex.williamson@redhat.com>
Acked-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      21e00fa5
  11. Oct 24, 2016
  13. Sep 27, 2016
    • Paolo Bonzini's avatar
      migration: sync all address spaces · 9c1f8f44
      Paolo Bonzini authored 
      
Migrating a VM during reboot sometimes results in differences
between the source and destination in the SMRAM area.

This is because migration_bitmap_sync() only fetches from KVM
the dirty log of address_space_memory.  SMRAM memory slots
are ignored and the modifications to SMRAM are not sent to the
destination.

Reported-by: default avatarHe Rongguang <herongguang.he@huawei.com>
Reviewed-by: default avatarHe Rongguang <herongguang.he@huawei.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      9c1f8f44
    • Peter Xu's avatar
      memory: introduce IOMMUOps.notify_flag_changed · 5bf3d319
      Peter Xu authored 
      
The new interface can be used to replace the old notify_started() and
notify_stopped(). Meanwhile it provides explicit flags so that IOMMUs
can know what kind of notifications it is requested for.

Acked-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Message-Id: <1474606948-14391-3-git-send-email-peterx@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      5bf3d319
    • Peter Xu's avatar
      memory: introduce IOMMUNotifier and its caps · cdb30812
      Peter Xu authored 
      
IOMMU Notifier list is used for notifying IO address mapping changes.
Currently VFIO is the only user.

However it is possible that future consumer like vhost would like to
only listen to part of its notifications (e.g., cache invalidations).

This patch introduced IOMMUNotifier and IOMMUNotfierFlag bits for a
finer grained control of it.

IOMMUNotifier contains a bitfield for the notify consumer describing
what kind of notification it is interested in. Currently two kinds of
notifications are defined:

- IOMMU_NOTIFIER_MAP:    for newly mapped entries (additions)
- IOMMU_NOTIFIER_UNMAP:  for entries to be removed (cache invalidates)

When registering the IOMMU notifier, we need to specify one or multiple
types of messages to listen to.

When notifications are triggered, its type will be checked against the
notifier's type bits, and only notifiers with registered bits will be
notified.

(For any IOMMU implementation, an in-place mapping change should be
 notified with an UNMAP followed by a MAP.)

Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Message-Id: <1474606948-14391-2-git-send-email-peterx@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      cdb30812
  15. Sep 14, 2016
  17. Jul 04, 2016
    • Peter Maydell's avatar
      memory: Assert that memory_region_init_rom_device() ops aren't NULL · 39e0b03d
      Peter Maydell authored 
      
It doesn't make sense to pass a NULL ops argument to
memory_region_init_rom_device(), because the effect will
be that if the guest tries to write to the memory region
then QEMU will segfault. Catch the bug earlier by sanity
checking the arguments to this function, and remove the
misleading documentation that suggests that passing NULL
might be sensible.

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Message-id: 1467122287-24974-4-git-send-email-peter.maydell@linaro.org
      39e0b03d
    • Peter Maydell's avatar
      memory: Provide memory_region_init_rom() · a1777f7f
      Peter Maydell authored 
      
Provide a new helper function memory_region_init_rom() for memory
regions which are read-only (and unlike those created by
memory_region_init_rom_device() don't have special behaviour
for writes). This has the same behaviour as calling
memory_region_init_ram() and then memory_region_set_readonly()
(which is what we do today in boards with pure ROMs) but is a
more easily discoverable API for the purpose.

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Message-id: 1467122287-24974-2-git-send-email-peter.maydell@linaro.org
      a1777f7f
  19. Jun 30, 2016
  21. Jun 22, 2016
  23. May 29, 2016
  25. May 23, 2016
  27. May 19, 2016
  29. Mar 22, 2016
    • Markus Armbruster's avatar
      include/qemu/osdep.h: Don't include qapi/error.h · da34e65c
      Markus Armbruster authored 
      
Commit 57cb38b3 included qapi/error.h into qemu/osdep.h to get the
Error typedef.  Since then, we've moved to include qemu/osdep.h
everywhere.  Its file comment explains: "To avoid getting into
possible circular include dependencies, this file should not include
any other QEMU headers, with the exceptions of config-host.h,
compiler.h, os-posix.h and os-win32.h, all of which are doing a
similar job to this file and are under similar constraints."
qapi/error.h doesn't do a similar job, and it doesn't adhere to
similar constraints: it includes qapi-types.h.  That's in excess of
100KiB of crap most .c files don't actually need.

Add the typedef to qemu/typedefs.h, and include that instead of
qapi/error.h.  Include qapi/error.h in .c files that need it and don't
get it now.  Include qapi-types.h in qom/object.h for uint16List.

Update scripts/clean-includes accordingly.  Update it further to match
reality: replace config.h by config-target.h, add sysemu/os-posix.h,
sysemu/os-win32.h.  Update the list of includes in the qemu/osdep.h
comment quoted above similarly.

This reduces the number of objects depending on qapi/error.h from "all
of them" to less than a third.  Unfortunately, the number depending on
qapi-types.h shrinks only a little.  More work is needed for that one.

Signed-off-by: default avatarMarkus Armbruster <armbru@redhat.com>
[Fix compilation without the spice devel packages. - Paolo]
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
      da34e65c
  31. Mar 14, 2016
  33. Mar 07, 2016
  35. Mar 01, 2016
  37. Feb 25, 2016