This function returns ${prefix}/var/RELATIVE_PATHNAME on POSIX-y systems,
and <CSIDL_COMMON_APPDATA>/RELATIVE_PATHNAME on Win32.
http://msdn.microsoft.com/en-us/library/bb762494.aspx
[...] This folder is used for application data that is not user
specific. For example, an application can store a spell-check
dictionary, a database of clip art, or a log file in the
CSIDL_COMMON_APPDATA folder. [...]
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
On FreeBSD libutil is used for openpty(), but it also provides a hexdump()
which conflicts with QEMU's.
Signed-off-by: Ed Maste <emaste@freebsd.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1368718348-15199-1-git-send-email-emaste@freebsd.org
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
We switched from qemu_memalign to mmap() but then we don't modify
qemu_vfree() to do a munmap() over free(). Which we cannot do
because qemu_vfree() frees memory allocated by qemu_{mem,block}align.
Introduce a new function that does the munmap(), luckily the size is
available in the RAMBlock.
Reported-by: Amos Kong <akong@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Amos Kong <akong@redhat.com>
Message-id: 1368454796-14989-3-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This is preparatory to the introduction of a separate freeing API.
Reported-by: Amos Kong <akong@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Amos Kong <akong@redhat.com>
Message-id: 1368454796-14989-2-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
This adds the Castagnoli CRC32C algorithm, using the 0x11EDC6F41
polynomial.
This is extracted from the linux kernel cryptographic crc32.c module.
The algorithm is based on:
Castagnoli93: Guy Castagnoli and Stefan Braeuer and Martin Herrman
"Optimization of Cyclic Redundancy-Check Codes with 24
and 32 Parity Bits", IEEE Transactions on Communication,
Volume 41, Number 6, June 1993
Signed-off-by: Jeff Cody <jcody@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Commit e9d8fbf (qemu-file: do not use stdio for qemu_fdopen, 2013-03-27)
introduced a usage of writev, which mingw32 does not have. Even though
qemu_fdopen itself is not used on mingw32, the future-proof solution is
to add an implementation of it. This is simple and similar to how we
emulate sendmsg/recvmsg in util/iov.c.
Some files include osdep.h without qemu-common.h, so move the definition
of iovec to osdep.h too, and include osdep.h from qemu-common.h
unconditionally (protection against including files when NEED_CPU_H is
defined is not needed since the removal of AREG0).
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Libvirt has no way to probe if an option or property is supported,
This patch introduces a new qmp command to query command line
option information. hmp command isn't added because it's not needed.
Signed-off-by: Amos Kong <akong@redhat.com>
CC: Luiz Capitulino <lcapitulino@redhat.com>
CC: Osier Yang <jyang@redhat.com>
CC: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Introduces a new utility function: parse_debug_env to avoid code
duplication.
This overrides whatever debug value is set on the corresponding devices
from the command line, and is meant to ease the usage with any
management stack. For libvirt you can set environment variables by
extending the dom namespace, i.e:
<domain type='kvm' id='3' xmlns:qemu='http://libvirt.org/schemas/domain/qemu/1.0'>
<qemu:commandline>
<qemu:env name='QEMU_CCID_PASSTHRU_DEBUG' value='4'/>
<qemu:env name='QEMU_CCID_DEBUG' value='4'/>
</qemu:commandline>
</domain>
Signed-off-by: Alon Levy <alevy@redhat.com>
Reviewed-by: Marc-André Lureau <mlureau@redhat.com>
vscclient needs to call socket_init() for portability.
Moving to osdep.c since it has no internal dependency.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Alon Levy <alevy@redhat.com>
Partial writes can still happen in sendmsg and recvmsg, if a
signal is received in the middle of a write. To handle this,
retry the operation with a new offset/bytes pair.
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Orit Wassermann <owasserm@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
"si" and "ei" are merged in a single variable.
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Orit Wassermann <owasserm@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Do not touch the "bytes" argument anymore. Instead, remember the
original length of the last iovec if we touch it, and restore it
afterwards.
This requires undoing the changes in opposite order. The previous
algorithm didn't care.
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Orit Wassermann <owasserm@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Once the initial part of the iov is dropped, it is not used anymore.
Modify iov/iovcnt directly instead of adjusting them with the "si"
variable.
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Orit Wassermann <owasserm@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Using qemu_memalign only leaves the RAM zero by chance, because libc
will usually use mmap to satisfy our huge requests. But memory will
not be zero when using MALLOC_PERTURB_ with a nonzero value. In the
case of incoming migration, this breaks a recently-introduced
invariant (commit f1c7279, migration: do not sent zero pages in
bulk stage, 2013-03-26).
To fix this, use mmap ourselves to get a well-aligned, always zero
block for the RAM. Mmap-ed memory is easy to "trim" at the sides.
This also removes the need to do something special on valgrind
(see commit c2a8238a, Support running QEMU on Valgrind, 2011-10-31),
thus effectively reverts that patch.
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1365522223-20153-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Remove static attribute to Td[0-5] and Te[0-5] tables so that they
can be used outside of aes.c. Change their type from u32 to uint32_t,
to keep the u32 udef local to aes.c. Prefix them with AES_ so that they
do not conflict with other symbols.
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Move aes.h from include/block to include/qemu to show it can be reused
by other subsystems.
Cc: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Allow the clock_gettime() code using monotonic clock to be utilized on
more POSIX compliannt OS's. This started as a fix for OpenBSD which was
listed in one function as part of the previous hard coded list of OS's
for the functions to support but not in the other.
Signed-off-by: Brad Smith <brad@comstyle.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20130405003748.GH884@rox.home.comstyle.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
socket_connect() sets non-blocking on TCP or UNIX domain sockets if a
callback function is passed. Do the same for file descriptor passing,
otherwise we could unexpectedly be using a blocking file descriptor.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
The fcntl(fd, F_SETFL, O_NONBLOCK) flag is not specific to sockets.
Rename to qemu_set_nonblock() just like qemu_set_cloexec().
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
this patch adopts the loop unrolling idea of bitmap_is_zero() to
speed up the skipping of large areas with zeros in find_next_bit().
this routine is extensively used to find dirty pages in
live migration.
testing only the find_next_bit performance on a zeroed bitfield
the loop onrolling decreased executing time by approx. 50% on x86_64.
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
performance gain on SSE2 is approx. 20-25%. altivec
is not tested. performance for unsigned long arithmetic
is unchanged.
Signed-off-by: Peter Lieven <pl@kamp.de>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Orit Wasserman <owasserm@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
this adds buffer_find_nonzero_offset() which is a SSE2/Altivec
optimized function that searches for non-zero content in a
buffer.
the function starts full unrolling only after the first few chunks have
been checked one by one. analyzing real memory page data has revealed
that non-zero pages are non-zero within the first 256-512 bits in
most cases. as this function is also heavily used to check for zero memory
pages this tweak has been made to avoid the high setup costs of the fully
unrolled check for non-zero pages.
due to the optimizations used in the function there are restrictions
on buffer address and search length. the function
can_use_buffer_find_nonzero_content() can be used to check if
the function can be used safely.
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Juan Quintela <quintela@redhat.com>
# By Kevin Wolf (12) and Peter Lieven (2)
# Via Kevin Wolf
* kwolf/for-anthony:
nbd: Check against invalid option combinations
nbd: Use default port if only host is specified
block: Allow omitting the file name when using driver-specific options
block: Make find_image_format safe with NULL filename
block: Rename variable to avoid shadowing
block: Introduce .bdrv_parse_filename callback
nbd: Accept -drive options for the network connection
nbd: Remove unused functions
nbd: Keep hostname and port separate
qemu-socket: Make socket_optslist public
block: Pass bdrv_file_open() options to block drivers
block: Add options QDict to bdrv_file_open() prototypes
block: complete all IOs before resizing a device
Revert "block: complete all IOs before .bdrv_truncate"
The NBD block supports an URL syntax, for which a URL parser returns
separate hostname and port fields. It also supports the traditional qemu
syntax encoded in a filename. Until now, after parsing the URL to get
each piece of information, a new string is built to be fed to socket
functions.
Instead of building a string in the URL case that is immediately parsed
again, parse the string in both cases and use the QemuOpts interface to
qemu-sockets.c.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Allow other users to create the QemuOpts needed for inet_connect_opts().
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Instead of adding missing type casts which are needed by MinGW for the
4th argument, the patch uses qemu_setsockopt which was invented for this
purpose.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Factor out the hexdumper functionality from iov for all to use. Useful for
creating verbose debug printfery that dumps packet data.
Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Message-id: faaac219c55ea586d3f748befaf5a2788fd271b8.1361853677.git.peter.crosthwaite@xilinx.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This adds a function that adds all entries of a QDict to a QemuOpts if
the keys are known, and leaves only the rest in the QDict.
This way a single QDict of -drive options can be processed in multiple
places (generic block layer, block driver, backing file block driver,
etc.), where each part picks the options it knows. If at the end of the
process the QDict isn't empty, the user specified an invalid option.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
* bonzini/hw-dirs:
sh: move files referencing CPU to hw/sh4/
ppc: move more files to hw/ppc
ppc: move files referencing CPU to hw/ppc/
m68k: move files referencing CPU to hw/m68k/
i386: move files referencing CPU to hw/i386/
arm: move files referencing CPU to hw/arm/
hw: move boards and other isolated files to hw/ARCH
ppc: express FDT dependency of pSeries and e500 boards via default-configs/
build: always link device_tree.o into emulators if libfdt available
hw: include hw header files with full paths
ppc: do not use ../ in include files
vt82c686: vt82c686 is not a PCI host bridge
virtio-9p: remove PCI dependencies from hw/9pfs/
virtio-9p: use CONFIG_VIRTFS, not CONFIG_LINUX
hw: move device-hotplug.o to toplevel, compile it once
hw: move qdev-monitor.o to toplevel directory
hw: move fifo.[ch] to libqemuutil
hw: move char backends to backends/
Conflicts:
backends/baum.c
backends/msmouse.c
hw/a15mpcore.c
hw/arm/Makefile.objs
hw/arm/pic_cpu.c
hw/dataplane/event-poll.c
hw/dataplane/virtio-blk.c
include/char/baum.h
include/char/msmouse.h
qemu-char.c
vl.c
Resolve conflicts caused by header movements.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
# By Lei Li (2) and others
# Via Stefan Hajnoczi
* stefanha/trivial-patches:
Fix the wrong description in qemu manual
pci_host: Drop write-only address_space field
rng-random: Use qemu_open / qemu_close
configure: Require at least spice-protocol-0.12.3
osdep: replace setsockopt by qemu_setsockopt
lm32: remove unused function
rtc-test: Fix test failures with recent glib
configure: Create link to icon bitmap for out-of-tree builds
Right now the inet connect code tries all available addresses but until one
doesn't fail. It passes local_err each time without clearing it from the
previous failure. This can trigger an assert since the inet connect code
tries to set an error on an object != NULL.
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Message-id: 16c806d60aa5e9660ed7751bb4e37dcd278f97f0.1362505276.git.amit.shah@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Fix the compiler warning when cross build qemu-ga
for windows by using qemu_setsockopt() instead of
setsockopt().
util/osdep.c: In function 'socket_set_nodelay':
util/osdep.c:69:5: warning: passing argument 4 of 'setsockopt' from
incompatible pointer type [enabled by default]
In file included from /home/lei/qemu_b/include/sysemu/os-win32.h:30:0,
from /home/lei/qemu_b/include/qemu-common.h:46,
from util/osdep.c:48:
/usr/i686-w64-mingw32/sys-root/mingw/include/winsock2.h:990:63: note:
expected 'const char *' but argument is of type 'int *'
Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
ARM Linux (like x86-64 Linux) can use transparent hugepages for
KVM if memory blocks are 2MiB aligned; set QEMU_VMALLOC_ALIGN
accordingly.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
qdev-monitor.c is the only "core qdev" file that is not used in
user-mode emulation, and it does not define anything that is used
by hardware models. Remove it from the hw/ directory and
remove hw/qdev-monitor.h from hw/qdev.h too; this requires
some files to have some new explicitly includes.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The new formulation makes better use of add-with-carry type insns
that the host may have. Use gcc's sign adjustment trick to avoid
having to perform a 128-bit negation.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Replace some x86_64 specific inline assembly with something that
all 64-bit hosts ought to optimize well. At worst this becomes
a call to the gcc __multi3 routine, which is no worse than our
implementation in util/host-utils.c.
With gcc 4.7, we get identical code generation for x86_64. We
now get native multiplication on ia64 and s390x hosts. With minor
improvements to gcc we can get it for ppc64 as well.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
The is the only remaining user.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
This is the only remaining user.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
The use of ctz has already eliminated zero, and thus the difference
in edge conditions between the two routines is irrelevant.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Both uses of ctz have already eliminated zero, and thus the difference
in edge conditions between the two routines is irrelevant.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
commit 8be7e7e4 and commit ec7b2ccb messed up the ordering of error
message and the helpful explanation that should follow it, like this:
$ qemu-system-x86_64 --nodefaults -S --vnc :0 --chardev null,id=,
Identifiers consist of letters, digits, '-', '.', '_', starting with a letter.
qemu-system-x86_64: -chardev null,id=,: Parameter 'id' expects an identifier
$ qemu-system-x86_64 --nodefaults -S --vnc :0 --machine kvm_shadow_mem=dunno
You may use k, M, G or T suffixes for kilobytes, megabytes, gigabytes and terabytes.
qemu-system-x86_64: -machine kvm_shadow_mem=dunno: Parameter 'kvm_shadow_mem' expects a size
Pity. Disable them for now.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1360354939-10994-5-git-send-email-armbru@redhat.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Since these values can possibly be sent from guest (for hw/9pfs), do a sanity check
on them. A 9p write request with 0 bytes caused qemu to abort without this patch
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
There are lots of duplicate parsing code using strto*() in QEMU, and
most of that code is broken in one way or another. Even the visitors
code have duplicate integer parsing code[1]. This introduces functions
to help parsing unsigned int values: parse_uint() and parse_uint_full().
Parsing functions for signed ints and floats will be submitted later.
parse_uint_full() has all the checks made by opts_type_uint64() at
opts-visitor.c:
- Check for NULL (returns -EINVAL)
- Check for negative numbers (returns -EINVAL)
- Check for empty string (returns -EINVAL)
- Check for overflow or other errno values set by strtoll() (returns
-errno)
- Check for end of string (reject invalid characters after number)
(returns -EINVAL)
parse_uint() does everything above except checking for the end of the
string, so callers can continue parsing the remainder of string after
the number.
Unit tests included.
[1] string-input-visitor.c:parse_int() could use the same parsing code
used by opts-visitor.c:opts_type_int(), instead of duplicating that
logic.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
We had two copies of a ffs function for longs with subtly different
semantics and, for the one in bitops.h, a confusing name: the result
was off-by-one compared to the library function ffsl.
Unify the functions into one, and solve the name problem by calling
the 0-based functions "bitops_ctzl" and "bitops_ctol" respectively.
This also fixes the build on platforms with ffsl, including Mac OS X
and Windows.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Tested-by: Andreas Färber <afaerber@suse.de>
Tested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
MinGW has no strtok_r, so we need a declaration in sysemu/os-win32.h.
We must also fix the include statements in util/envlist.c to include
that file.
We currently don't need an implementation of strtok_r because the
code is compiled but not linked for MinGW.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
# By Paolo Bonzini (14) and others
# Via Kevin Wolf
* kwolf/for-anthony: (24 commits)
ide: Add fall through annotations
block: Create proper size file for disk mirror
ahci: Add migration support
ahci: Change data types in preparation for migration
ahci: Remove unused AHCIDevice fields
hbitmap: add assertion on hbitmap_iter_init
mirror: do nothing on zero-sized disk
block/vdi: Check for bad signature
block/vdi: Improved return values from vdi_open
block/vdi: Improve debug output for signature
block: Use error code EMEDIUMTYPE for wrong format in some block drivers
block: Add special error code for wrong format
mirror: support arbitrarily-sized iterations
mirror: support more than one in-flight AIO operation
mirror: add buf-size argument to drive-mirror
mirror: switch mirror_iteration to AIO
mirror: allow customizing the granularity
block: allow customizing the granularity of the dirty bitmap
block: return count of dirty sectors, not chunks
mirror: perform COW if the cluster size is bigger than the granularity
...
Rename qemu_vmalloc() to bsd_vmalloc(), adjust the only user.
Remove #ifdeffery in oslib-posix.c.
Tested-by: Andreas Färber <andreas.faerber@web.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
hbitmap_iter_init causes an out-of-bounds access when the "first"
argument is or greater than or equal to the size of the bitmap.
Forbid this with an assertion, and remove the failing testcase.
Reported-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
HBitmaps provides an array of bits. The bits are stored as usual in an
array of unsigned longs, but HBitmap is also optimized to provide fast
iteration over set bits; going from one bit to the next is O(logB n)
worst case, with B = sizeof(long) * CHAR_BIT: the result is low enough
that the number of levels is in fact fixed.
In order to do this, it stacks multiple bitmaps with progressively coarser
granularity; in all levels except the last, bit N is set iff the N-th
unsigned long is nonzero in the immediately next level. When iteration
completes on the last level it can examine the 2nd-last level to quickly
skip entire words, and even do so recursively to skip blocks of 64 words or
powers thereof (32 on 32-bit machines).
Given an index in the bitmap, it can be split in group of bits like
this (for the 64-bit case):
bits 0-57 => word in the last bitmap | bits 58-63 => bit in the word
bits 0-51 => word in the 2nd-last bitmap | bits 52-57 => bit in the word
bits 0-45 => word in the 3rd-last bitmap | bits 46-51 => bit in the word
So it is easy to move up simply by shifting the index right by
log2(BITS_PER_LONG) bits. To move down, you shift the index left
similarly, and add the word index within the group. Iteration uses
ffs (find first set bit) to find the next word to examine; this
operation can be done in constant time in most current architectures.
Setting or clearing a range of m bits on all levels, the work to perform
is O(m + m/W + m/W^2 + ...), which is O(m) like on a regular bitmap.
When iterating on a bitmap, each bit (on any level) is only visited
once. Hence, The total cost of visiting a bitmap with m bits in it is
the number of bits that are set in all bitmaps. Unless the bitmap is
extremely sparse, this is also O(m + m/W + m/W^2 + ...), so the amortized
cost of advancing from one bit to the next is usually constant.
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
g_strdup_printf already handles OOM errors, so some error handling in
QEMU code can be removed.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
It leaks memory and fails to adjust qemu_acl member nentries. Future
acl_add become confused: can misreport the position, and can silently
fail to add.
Cc: qemu-stable@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
On POSIX, qemu_vfree() accepts NULL, because it's merely wrapper
around free(). As far as I can tell, the Windows implementation
doesn't. Breeds bugs that bite only under Windows.
Make the Windows implementation behave like the POSIX implementation.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
