Paolo Bonzini [Thu, 28 Nov 2013 10:18:56 +0000 (11:18 +0100)]
scsi-disk: fix VERIFY emulation
VERIFY emulation was completely botched (and remained botched through
all the refactorings). The command must be emulated both in check-medium
mode (BYTCHK=00, which we implement by doing nothing) and in check-bytes
mode (which we do not implement yet). Unlike WRITE AND VERIFY (which we
treat simply as WRITE with FUA bit set), VERIFY cannot be handled like
READ. In fact the device is _receiving_ data for VERIFY, not _sending_
it like READ.
Cc: qemu-stable@nongnu.org Tested-by: Hervé Poussineau <hpoussin@reactos.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Stefan Hajnoczi [Thu, 14 Nov 2013 14:24:58 +0000 (15:24 +0100)]
qemu-iotests: filter QEMU monitor \r\n
SMTP does not preserve newlines. This is normally not a problem if the
email body uses DOS or UNIX newlines consistently. In 051.out we mix
UNIX newlines with DOS newlines (since QEMU monitor output uses \r\n).
This patch filters the QEMU monitor output so the golden master file
uses UNIX newlines exclusively.
The result is that patches touching 051.out will apply cleanly without
mangling newlines after this commit.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Stefan Hajnoczi [Tue, 26 Nov 2013 15:18:01 +0000 (16:18 +0100)]
aio: make aio_poll(ctx, true) block with no fds
This patch drops a special case where aio_poll(ctx, true) returns false
instead of blocking if no file descriptors are waiting on I/O. Now it
is possible to block in aio_poll() to wait for aio_notify().
This change eliminates busy waiting. bdrv_drain_all() used to rely on
busy waiting to completed throttled I/O requests but this is no longer
required so we can simplify aio_poll().
Note that aio_poll() still returns false when aio_notify() was used. In
other words, stopping a blocking aio_poll() wait is not considered
making progress.
Adjust test-aio /aio/bh/callback-delete/one which assumed aio_poll(ctx,
true) would immediately return false instead of blocking.
Reviewed-by: Alex Bligh <alex@alex.org.uk> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Stefan Hajnoczi [Tue, 26 Nov 2013 15:18:00 +0000 (16:18 +0100)]
block: clean up bdrv_drain_all() throttling comments
Since cc0681c45430a1f1a4c2d06e9499b7775afc9a18 ("block: Enable the new
throttling code in the block layer.") bdrv_drain_all() no longer spins.
The code used to look as follows:
do {
busy = qemu_aio_wait();
/* FIXME: We do not have timer support here, so this is effectively
* a busy wait.
*/
QTAILQ_FOREACH(bs, &bdrv_states, list) {
while (qemu_co_enter_next(&bs->throttled_reqs)) {
busy = true;
}
}
} while (busy);
Note that throttle requests are kicked but I/O throttling limits are
still in effect. The loop spins until the vm_clock time allows the
request to make progress and complete.
The new throttling code introduced bdrv_start_throttled_reqs(). This
function not only kicks throttled requests but also temporarily disables
throttling so requests can run.
The outdated FIXME comment can be removed. Also drop the busy = true
assignment since we overwrite it immediately afterwards.
Reviewed-by: Alex Bligh <alex@alex.org.uk> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Peter Lieven [Wed, 27 Nov 2013 10:07:06 +0000 (11:07 +0100)]
qemu-img: dynamically adjust iobuffer size during convert
since the convert process is basically a sync operation it might
be benificial in some case to change the hardcoded I/O buffer
size to a greater value.
This patch increases the I/O buffer size if the output
driver advertises an optimal transfer length or discard alignment
that is greater than the default buffer size of 2M.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Peter Lieven [Wed, 27 Nov 2013 10:07:02 +0000 (11:07 +0100)]
qemu-img: fix usage instruction for qemu-img convert
Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Peter Lieven [Wed, 27 Nov 2013 10:07:01 +0000 (11:07 +0100)]
qemu-img: add support for skipping zeroes in input during convert
we currently do not check if a sector is allocated during convert.
This means if a sector is unallocated that we allocate a bounce
buffer of zeroes, find out its zero later and do not write it
in the best case. In the worst case this can lead to reading
blocks from a raw device (like iSCSI) altough we could easily
know via get_block_status that they are zero and simply skip them.
This patch also fixes the progress output not being at 100% after
a successful conversion.
Signed-off-by: Peter Lieven <pl@kamp.de> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Wenchao Xia [Wed, 4 Dec 2013 09:10:56 +0000 (17:10 +0800)]
qemu-iotests: add 058 internal snapshot export with qemu-nbd case
This case can't run when IMGPROTO=nbd, since it needs to create some
internal snapshot which would fail for EOF write request, even when
TEST_IMG is exported with "-f raw" in common.rc, so set _supported_proto
to file.
_require_command() is changed to tip what util is missing, instead
of printing a blank.
Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Wenchao Xia [Wed, 4 Dec 2013 09:10:54 +0000 (17:10 +0800)]
snapshot: distinguish id and name in load_tmp
Since later this function will be used so improve it. The only caller of it
now is qemu-img, and it is not impacted by introduce function
bdrv_snapshot_load_tmp_by_id_or_name() that call bdrv_snapshot_load_tmp()
twice to keep old search logic. bdrv_snapshot_load_tmp_by_id_or_name() return
int to let caller know the errno, and errno will be used later.
Also fix a typo in comments of bdrv_snapshot_delete().
Signed-off-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Kevin Wolf [Wed, 4 Dec 2013 10:06:36 +0000 (11:06 +0100)]
qcow2: Zero-initialise first cluster for new images
Strictly speaking, this is only required for has_zero_init() == false,
but it's easy enough to just do a cluster-aligned write that is padded
with zeros after the header.
This fixes that after 'qemu-img create' header extensions are attempted
to be parsed that are really just random leftover data.
Cc: qemu-stable@nongnu.org Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Max Reitz [Tue, 3 Dec 2013 13:57:52 +0000 (14:57 +0100)]
block: Close backing file early in bdrv_img_create
Leaving the backing file open although it is not needed anymore can
cause problems if it is opened through a block driver which allows
exclusive access only and if the create function of the block driver
used for the top image (the one being created) tries to close and reopen
the image file (which will include opening the backing file a second
time).
In particular, this will happen with a backing file opened through
qemu-nbd and using qcow2 as the top image file format (which reopens the
image to flush it to disk).
In addition, the BlockDriverState in bdrv_img_create() is used for the
backing file only; it should therefore be made local to the respective
block.
Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Paolo Bonzini [Fri, 22 Nov 2013 12:40:01 +0000 (13:40 +0100)]
scsi-disk: correctly implement WRITE SAME
Fetch the data to be written from the input buffer. If it is all zeroes,
we can use the write_zeroes call (possibly with the new MAY_UNMAP flag).
Otherwise, do as many write cycles as needed, writing 512k at a time.
Strictly speaking, this is still incorrect because a zero cluster should
only be written if the MAY_UNMAP flag is set. But this is a bug in qcow2
and the other formats, not in the SCSI code.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Paolo Bonzini [Fri, 22 Nov 2013 12:40:00 +0000 (13:40 +0100)]
scsi-disk: reject ANCHOR=1 for UNMAP and WRITE SAME commands
Since we report ANC_SUP==0 in VPD page B2h, we need to return
an error (ILLEGAL REQUEST/INVALID FIELD IN CDB) for all WRITE SAME
requests with ANCHOR==1.
Inspired by a similar patch to the LIO in-kernel target.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Paolo Bonzini [Fri, 22 Nov 2013 12:39:57 +0000 (13:39 +0100)]
raw-posix: add support for write_zeroes on XFS and block devices
The code is similar to the implementation of discard and write_zeroes
with UNMAP. However, failure must be propagated up to block.c.
The stale page cache problem can be reproduced as follows:
# modprobe scsi-debug lbpws=1 lbprz=1
# ./qemu-io /dev/sdXX
qemu-io> write -P 0xcc 0 2M
qemu-io> write -z 0 1M
qemu-io> read -P 0x00 0 512
Pattern verification failed at offset 0, 512 bytes
qemu-io> read -v 0 512 00000000: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc ................
...
Paolo Bonzini [Fri, 22 Nov 2013 12:39:48 +0000 (13:39 +0100)]
block: make bdrv_co_do_write_zeroes stricter in producing aligned requests
Right now, bdrv_co_do_write_zeroes will only try to align the
beginning of the request. However, it is simpler for many
formats to expect the block layer to separate both the head *and*
the tail. This makes sure that the format's bdrv_co_write_zeroes
function will be called with aligned sector_num and nb_sectors for
the bulk of the request.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Peter Lieven <pl@kamp.de> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Paolo Bonzini [Fri, 22 Nov 2013 12:39:47 +0000 (13:39 +0100)]
block: handle ENOTSUP from discard in generic code
Similar to write_zeroes, let the generic code receive a ENOTSUP for
discard operations. Since bdrv_discard has advisory semantics,
we can just swallow the error.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Peter Lieven <pl@kamp.de> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Paolo Bonzini [Fri, 22 Nov 2013 12:39:43 +0000 (13:39 +0100)]
block: generalize BlockLimits handling to cover bdrv_aio_discard too
bdrv_co_discard is only covering drivers which have a .bdrv_co_discard()
implementation, but not those with .bdrv_aio_discard(). Not very nice,
and easy to avoid.
Suggested-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Peter Lieven <pl@kamp.de> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Fam Zheng [Tue, 3 Dec 2013 02:41:05 +0000 (10:41 +0800)]
vmdk: Fix creating big description file
The buffer for description file was 4096 which only covers a few
hundred of extents. This changes the buffer to dynamic allocated with
g_strdup_printf in order to support bigger cases.
Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Kevin Wolf [Thu, 28 Nov 2013 10:58:02 +0000 (11:58 +0100)]
block: Use BDRV_O_NO_BACKING where appropriate
If you open an image temporarily just because you want to check its size
or get it flushed, there's no real reason to open the whole backing file
chain.
Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Fam Zheng <famz@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net>
Kevin Wolf [Thu, 14 Nov 2013 14:37:12 +0000 (15:37 +0100)]
block: Enable BDRV_O_SNAPSHOT with driver-specific options
In the case of snapshot=on, don't rely on the backing file path in the
temporary image any more, but override the backing file with the given
set of options. This way, block drivers that don't use a file name can
be accessed with snapshot=on, for example:
Fam Zheng [Wed, 20 Nov 2013 02:01:54 +0000 (10:01 +0800)]
blkdebug: add "remove_break" command
This adds "remove_break" command which is the reverse of blkdebug
command "break": it removes all breakpoints with given tag and resumes
all the requests.
Signed-off-by: Fam Zheng <famz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Liu Yuan <namei.unix@gmail.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Liu Yuan [Thu, 7 Nov 2013 14:56:37 +0000 (22:56 +0800)]
sheepdog: refactor do_sd_create()
We can actually use BDRVSheepdogState *s to pass most of the parameters.
Cc: Kevin Wolf <kwolf@redhat.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Liu Yuan <namei.unix@gmail.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Kevin Wolf [Wed, 20 Nov 2013 12:09:21 +0000 (13:09 +0100)]
qdict: Optimise qdict_do_flatten()
Nested QDicts used to be both entered recursively in order to move their
entries to the target QDict and also be moved themselves to the target
QDict like all other objects. This is harmless because for the top
level, qdict_do_flatten() will encounter the (now empty) QDict for a
second time and then delete it, but at the same time it's obviously
unnecessary overhead. Just delete nested QDicts directly after moving
all of their entries.
Reported-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Liu Yuan [Wed, 20 Nov 2013 07:51:59 +0000 (15:51 +0800)]
MAINTAINERS: add sheepdog development mailing list
This will help people find mailing list relevant to sheepdog.
Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: Kevin Wolf <kwolf@redhat.com> Signed-off-by: Liu Yuan <namei.unix@gmail.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Charlie Shepherd [Fri, 15 Nov 2013 18:47:02 +0000 (19:47 +0100)]
COW: Extend checking allocated bits to beyond one sector
cow_co_is_allocated() only checks one sector's worth of allocated bits
before returning. This is allowed but (slightly) inefficient, so extend
it to check all of the file's metadata sectors.
Signed-off-by: Charlie Shepherd <charlie@ctshepherd.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
[kwolf: silenced compiler warning (-Wmaybe-uninitialized for changed)] Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Charlie Shepherd [Fri, 15 Nov 2013 18:47:01 +0000 (19:47 +0100)]
COW: Speed up writes
Process a whole sector's worth of COW bits by reading a sector, setting
the bits after skipping any already set bits, then writing it out again.
Make sure we only flush once before writing metadata, and only if we
need to write metadata.
Signed-off-by: Charlie Shepherd <charlie@ctshepherd.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Fam Zheng [Wed, 13 Nov 2013 10:29:43 +0000 (18:29 +0800)]
block: per caller dirty bitmap
Previously a BlockDriverState has only one dirty bitmap, so only one
caller (e.g. a block job) can keep track of writing. This changes the
dirty bitmap to a list and creates a BdrvDirtyBitmap for each caller, the
lifecycle is managed with these new functions:
Max Reitz [Wed, 13 Nov 2013 19:37:58 +0000 (20:37 +0100)]
block/stream: Don't stream unbacked devices
If a block device is unbacked, a streaming blockjob should immediately
finish instead of beginning to try to stream, then noticing the backing
file does not contain even the first sector (since it does not exist)
and then finishing normally.
Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Liu Yuan [Wed, 7 Aug 2013 08:59:53 +0000 (16:59 +0800)]
sheepdog: implement .bdrv_get_allocated_file_size
With this patch, qemu-img info sheepdog:image will show disk size for sheepdog
images.
Cc: Kevin Wolf <kwolf@redhat.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Cc: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp> Signed-off-by: Liu Yuan <namei.unix@gmail.com> Reviewed-by: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Max Reitz [Thu, 7 Nov 2013 19:10:29 +0000 (20:10 +0100)]
util/error: Save errno from clobbering
There may be calls to error_setg() and especially error_setg_errno()
which blindly (and until now wrongly) assume these functions not to
clobber errno (e.g., they pass errno to error_setg_errno() and return
-errno afterwards). Instead of trying to find and fix all of these
constructs, just make sure error_setg() and error_setg_errno() indeed do
not clobber errno.
Suggested-by: Eric Blake <eblake@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Benoit Canet <benoit@irqsave.net Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Peter Lieven [Thu, 24 Oct 2013 10:07:06 +0000 (12:07 +0200)]
qemu-img: conditionally zero out target on convert
If the target has_zero_init = 0, but supports efficiently
writing zeroes by unmapping we call bdrv_make_zero to
avoid fully allocating the target. This currently works
only for iscsi. It can be extended to raw with
BLKDISCARDZEROES for example.
Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Peter Lieven [Thu, 24 Oct 2013 10:07:04 +0000 (12:07 +0200)]
block/get_block_status: fix BDRV_BLOCK_ZERO for unallocated blocks
this patch does 2 things:
a) only do additional call outs if BDRV_BLOCK_ZERO is not already set.
b) use the newly introduced bdrv_unallocated_blocks_are_zero()
to return the zero state of an unallocated block. the used callout
to bdrv_has_zero_init() is only valid right after bdrv_create.
Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Peter Lieven [Thu, 24 Oct 2013 10:07:03 +0000 (12:07 +0200)]
block: introduce bdrv_make_zero
this patch adds a call to completely zero out a block device.
the operation is sped up by checking the block status and
only writing zeroes to the device if they currently do not
return zeroes. optionally the zero writing can be sped up
by setting the flag BDRV_REQ_MAY_UNMAP to emulate the zero
write by unmapping if the driver supports it.
Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Peter Lieven [Thu, 24 Oct 2013 10:06:54 +0000 (12:06 +0200)]
block: add wrappers for logical block provisioning information
This adds 2 wrappers to read the unallocated_blocks_are_zero and
can_write_zeroes_with_unmap info from the BDI. The wrappers are
required to check for the existence of a backing_hd and
if the devices are opened with the correct flags.
Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Max Reitz [Mon, 25 Nov 2013 19:28:56 +0000 (20:28 +0100)]
qemu-iotests: Fix test 041
Performing multiple drive-mirror blockjobs on the same qemu instance
results in the image file used for the block device being replaced by
the newly mirrored file, which is not what we want.
Fix this by performing one dedicated test per sync mode.
Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1385407736-13941-3-git-send-email-mreitz@redhat.com Signed-off-by: Anthony Liguori <aliguori@amazon.com>
Max Reitz [Mon, 25 Nov 2013 19:28:55 +0000 (20:28 +0100)]
block/drive-mirror: Reuse backing HD for sync=none
For "none" sync mode in "absolute-paths" mode, the current image should
be used as the backing file for the newly created image.
The current behavior is:
a) If the image to be mirrored has a backing file, use that (which is
wrong, since the operations recorded by "none" are applied to the
image itself, not to its backing file).
b) If the image to be mirrored lacks a backing file, the target doesn't
have one either (which is not really wrong, but not really right,
either; "none" records a set of operations executed on the image
file, therefore having no backing file to apply these operations on
seems rather pointless).
For a, this is clearly a bugfix. For b, it is still a bugfix, although
it might break existing API - but since that case crashed qemu just
three weeks ago (before 1452686495922b81d6cf43edf025c1aef15965c0), we
can safely assume there is no such API relying on that case yet.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Max Reitz <mreitz@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 1385407736-13941-2-git-send-email-mreitz@redhat.com Signed-off-by: Anthony Liguori <aliguori@amazon.com>
Stefan Weil [Mon, 25 Nov 2013 19:54:17 +0000 (20:54 +0100)]
qga: Fix two format strings for MinGW
Both code locations cause a compiler warning. Using "%s" instead of "%lu"
would result in a program crash if the wrong code were executed.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Message-id: 1385409257-2522-1-git-send-email-sw@weilnetz.de Signed-off-by: Anthony Liguori <aliguori@amazon.com>
Alexander Graf [Mon, 25 Nov 2013 21:46:55 +0000 (22:46 +0100)]
PPC: BookE: Make FIT/WDT timers at best millisecond grained
The default granularity for the FIT timer on 440 is on every 0x1000th
transition of TB from 0 to 1. Translated that means 48828 times a second.
Since interrupts are quite expensive for 440 and we don't really care
about the accuracy of the FIT to that significance, let's force FIT and
WDT to at best millisecond granularity.
This basically restores behavior as it was in QEMU 1.6, where timers
could only deal with millisecond granularities at all.
This patch greatly improves performance with the 440 target and restores
roughly the same performance level that QEMU 1.6 had for me.
Signed-off-by: Alexander Graf <agraf@suse.de>
Message-id: 1385416015-22775-3-git-send-email-agraf@suse.de Signed-off-by: Anthony Liguori <aliguori@amazon.com>
Alexander Graf [Mon, 25 Nov 2013 21:46:54 +0000 (22:46 +0100)]
PPC: Make BookE FIT/WDT timers more lazy
Today we fire FIT and WDT timer events every time the respective bit
position in TB flips from 0 -> 1.
However, there is no need to do this if the end result would be that
we're changing a TSR bit that is set to 1 to 1 again. No guest visible
change would have occured.
So whenever we see that the TSR bit to our timer is already set, don't
even bother to update the timer that would potentially fire it off.
However, we do need to make sure that we update our timer that notifies
us of the TB flip when the respective TSR bit gets unset. In that case
we do care about the flip and need to notify the guest again. So add
a callback into our timer handlers when TSR bits get unset.
This improves performance for me when the guest is busy processing things.
Signed-off-by: Alexander Graf <agraf@suse.de>
Message-id: 1385416015-22775-2-git-send-email-agraf@suse.de Signed-off-by: Anthony Liguori <aliguori@amazon.com>
projects / thirdparty / qemu.git / log
