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>
