Commit Graph

18 Commits

Author SHA1 Message Date
Stefan Weil
0546b8c2f0 Spelling fixes in comments and documentation
These wrong spellings were detected by codespell:

* successully -> successfully

* alot -> a lot

* wanna -> want to

* infomation -> information

* occured -> occurred

["also is" -> "is also" and "ressources" -> "resources" suggested by
Peter Maydell <peter.maydell@linaro.org>]

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-09-14 08:21:28 +01:00
Stefan Hajnoczi
dae8796d00 docs: add lazy refcounts bit to qcow2 specification
The lazy refcounts bit indicates that this image can take advantage of
the dirty bit and that refcount updates can be postponed.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-08-06 22:39:14 +02:00
Stefan Hajnoczi
0f6d767aa8 docs: add dirty bit to qcow2 specification
The dirty bit will make it possible to perform lazy refcount updates,
where the image file is not kept consistent all the time.  Upon opening
a dirty image file, it is necessary to perform a consistency check and
repair any incorrect refcounts.

Therefore the dirty bit must be an incompatible feature bit.  We don't
want old programs accessing a file with stale refcounts.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-08-06 22:39:14 +02:00
Benjamin Herrenschmidt
c73e3771ea spapr: Add "memop" hypercall
This adds a qemu-specific hypervisor call to the pseries machine
which allows to do what amounts to memmove, memcpy and xor over
regions of physical memory such as the framebuffer.

This is the simplest way to get usable framebuffer speed from
SLOF since the framebuffer isn't mapped in the VRMA and so would
otherwise require an hcall per 8 bytes access.

The performance is still not great but usable, and can be improved
with a more complex implementation of the hcall itself if needed.

This also adds some documentation for the qemu-specific hypercalls
that we add to PAPR along with a new qemu,hypertas-functions property
that mirrors ibm,hypertas-functions and provides some discoverability
for the new calls.

Note: I chose note to advertise H_RTAS to the guest via that mechanism.
This is done on purpose, the guest uses the normal RTAS interfaces
provided by qemu (including SLOF) which internally calls H_RTAS.

We might in the future implement part (or even all) of RTAS inside the
guest like IBM's firmware does and replace H_RTAS with some finer grained
set of private hypercalls.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2012-06-24 01:04:45 +02:00
Zhi Yong Wu
bf3f363a5b docs: fix one issue in qcow2 specs
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-05-02 18:39:39 +02:00
Kevin Wolf
4fabffc112 Specification for qcow2 version 3
This updates the qcow2 specification to cover version 3. It contains the
following changes:

- Added compatible/incompatible/auto-clear feature bits plus an optional
  feature name table to allow useful error messages even if an older
  version doesn't know some feature at all.

- Configurable refcount width. If you don't want to use internal
  snapshots, make refcounts one bit and save cache space and I/O.

- Zero cluster flags. This allows discard even with a backing file that
  doesn't contain zeros. It is also useful for copy-on-read/image
  streaming, as you'll want to keep sparseness without accessing the
  remote image for an unallocated cluster all the time.

- Fixed internal snapshot metadata to use 64 bit VM state size. You
  can't save a snapshot of a VM with >= 4 GB RAM today.

- Extended internal snapshot metadata to contain the disk size, so that
  resizing images that have snapshots can be allowed in the future.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2012-04-20 15:57:27 +02:00
Alex Williamson
9290f364c1 acpi_piix4: Re-define PCI hotplug eject register read
The PCI hotplug eject register has always returned 0, so let's redefine
it as a hotplug feature register.  The existing model of using separate
up & down read-only registers and an eject via write to this register
becomes the base implementation.  As we make use of new interfaces we'll
set bits here to allow the BIOS and AML implementation to optimize for
the platform implementation.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-04-15 12:17:23 +03:00
Alex Williamson
31745aabcd acpi_piix4: Remove PCI_RMV_BASE write code
Clarify this register as read-only and remove write code.  No
change in existing behavior.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-04-15 12:17:23 +03:00
Alex Williamson
ba737541ed acpi_piix4: Disallow write to up/down PCI hotplug registers
The write side of these registers is never used and actually can't be
used as defined because any read/modify/write sequence from the guest
potentially races with qemu.  Drop the write support and define these
as read-only registers.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2012-04-15 12:17:22 +03:00
Stefan Weil
6576b74b0b Replace Qemu by QEMU in internal documentation
The official spelling is QEMU.

Signed-off-by: Stefan Weil <sw@weilnetz.de>
Reviewed-by: Andreas Färber <afaerber@suse.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2012-04-07 13:58:25 +00:00
Kevin Wolf
c2c9a46609 qcow2: Allow >4 GB VM state
This is a compatible extension to the snapshot header format that allows
saving a 64 bit VM state size.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-12-15 12:40:33 +01:00
Zhi Yong Wu
3789985f40 qcow2: fix some errors and typo in qcow2.txt
Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-10-28 19:25:49 +02:00
Stefan Hajnoczi
d54f10bba7 docs: Describe zero data clusters in QED specification
Zero data clusters are a space-efficient way of storing zeroed regions
of the image.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2011-04-13 12:06:40 +02:00
Kevin Wolf
03feae7305 Add qcow2 documentation
This adds a description of the qcow2 file format to the docs/ directory.
Besides documenting what's there, which is never wrong, the document should
provide a good basis for the discussion of format extensions (called "qcow3"
in previous discussions)

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2011-03-16 09:56:18 +01:00
Marcelo Tosatti
9c046d96d4 document QEMU<->ACPIBIOS PCI hotplug interface
Document how QEMU communicates with ACPI BIOS for PCI hotplug.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-01-17 17:29:42 +02:00
Stefan Hajnoczi
e59d688ad1 docs: Fix missing carets in QED specification
For some reason the carets ('^') in the QED specification disappeared.
This patch puts them back.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-12-17 17:05:06 +01:00
Stefan Hajnoczi
71af014f14 docs: Add QED image format specification
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-12-17 16:11:04 +01:00
Cam Macdonell
b6828931eb Device specification for shared memory PCI device
Signed-off-by: Cam Macdonell <cam@cs.ualberta.ca>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2010-08-10 16:25:15 -05:00