bdrv_pad_request() was the main user of qemu_iovec_init_extended().
HEAD^ has removed that use, so we can remove qemu_iovec_init_extended()
now.
The only remaining user is qemu_iovec_init_slice(), which can easily
inline the small part it really needs.
Note that qemu_iovec_init_extended() offered a memcpy() optimization to
initialize the new I/O vector. qemu_iovec_concat_iov(), which is used
to replace its functionality, does not, but calls qemu_iovec_add() for
every single element. If we decide this optimization was important, we
will need to re-implement it in qemu_iovec_concat_iov(), which might
also benefit its pre-existing users.
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Message-Id: <20230411173418.19549-4-hreitz@redhat.com>
We want to inline qemu_iovec_init_extended() in block/io.c for padding
requests, and having access to qiov_slice() is useful for this. As a
public function, it is renamed to qemu_iovec_slice().
(We will need to count the number of I/O vector elements of a slice
there, and then later process this slice. Without qiov_slice(), we
would need to call qemu_iovec_subvec_niov(), and all further
IOV-processing functions may need to skip prefixing elements to
accomodate for a qiov_offset. Because qemu_iovec_subvec_niov()
internally calls qiov_slice(), we can just have the block/io.c code call
qiov_slice() itself, thus get the number of elements, and also create an
iovec array with the superfluous prefixing elements stripped, so the
following processing functions no longer need to skip them.)
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Message-Id: <20230411173418.19549-2-hreitz@redhat.com>
Actually, we can't extend the io vector in all cases. Handle possible
MAX_IOV and size_t overflows.
For now add assertion to callers (actually they rely on success anyway)
and fix them in the following patch.
Add also some additional good assertions to qemu_iovec_init_slice()
while being here.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20201211183934.169161-3-vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
The iov_discard_front/back() operations are useful for parsing iovecs
but they modify the array elements. If the original array is needed
after parsing finishes there is currently no way to restore it.
Although g_memdup() can be used before performing destructive
iov_discard_front/back() operations, this is inefficient.
Introduce iov_discard_undo() to restore the array to the state prior to
an iov_discard_front/back() operation.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Message-Id: <20200917094455.822379-2-stefanha@redhat.com>
Implement and use new interface to get rid of hd_qiov.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-13-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-13-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
We'll need to check a part of qiov soon, so implement it now.
Optimization with align down to 4 * sizeof(long) is dropped due to:
1. It is strange: it aligns length of the buffer, but where is a
guarantee that buffer pointer is aligned itself?
2. buffer_is_zero() is a better place for optimizations and it has
them.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-3-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-3-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Introduce new initialization API, to create requests with padding. Will
be used in the following patch. New API uses qemu_iovec_init_buf if
resulting io vector has only one element, to avoid extra allocations.
So, we need to update qemu_iovec_destroy to support destroying such
QIOVs.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20190604161514.262241-2-vsementsov@virtuozzo.com
Message-Id: <20190604161514.262241-2-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Add a possibility of embedded iovec, for cases when we need only one
local iov.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-id: 20190218140926.333779-2-vsementsov@virtuozzo.com
Message-Id: <20190218140926.333779-2-vsementsov@virtuozzo.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Most files that have TABs only contain a handful of them. Change
them to spaces so that we don't confuse people.
disas, standard-headers, linux-headers and libdecnumber are imported
from other projects and probably should be exempted from the check.
Outside those, after this patch the following files still contain both
8-space and TAB sequences at the beginning of the line. Many of them
have a majority of TABs, or were initially committed with all tabs.
bsd-user/i386/target_syscall.h
bsd-user/x86_64/target_syscall.h
crypto/aes.c
hw/audio/fmopl.c
hw/audio/fmopl.h
hw/block/tc58128.c
hw/display/cirrus_vga.c
hw/display/xenfb.c
hw/dma/etraxfs_dma.c
hw/intc/sh_intc.c
hw/misc/mst_fpga.c
hw/net/pcnet.c
hw/sh4/sh7750.c
hw/timer/m48t59.c
hw/timer/sh_timer.c
include/crypto/aes.h
include/disas/bfd.h
include/hw/sh4/sh.h
libdecnumber/decNumber.c
linux-headers/asm-generic/unistd.h
linux-headers/linux/kvm.h
linux-user/alpha/target_syscall.h
linux-user/arm/nwfpe/double_cpdo.c
linux-user/arm/nwfpe/fpa11_cpdt.c
linux-user/arm/nwfpe/fpa11_cprt.c
linux-user/arm/nwfpe/fpa11.h
linux-user/flat.h
linux-user/flatload.c
linux-user/i386/target_syscall.h
linux-user/ppc/target_syscall.h
linux-user/sparc/target_syscall.h
linux-user/syscall.c
linux-user/syscall_defs.h
linux-user/x86_64/target_syscall.h
slirp/cksum.c
slirp/if.c
slirp/ip.h
slirp/ip_icmp.c
slirp/ip_icmp.h
slirp/ip_input.c
slirp/ip_output.c
slirp/mbuf.c
slirp/misc.c
slirp/sbuf.c
slirp/socket.c
slirp/socket.h
slirp/tcp_input.c
slirp/tcpip.h
slirp/tcp_output.c
slirp/tcp_subr.c
slirp/tcp_timer.c
slirp/tftp.c
slirp/udp.c
slirp/udp.h
target/cris/cpu.h
target/cris/mmu.c
target/cris/op_helper.c
target/sh4/helper.c
target/sh4/op_helper.c
target/sh4/translate.c
tcg/sparc/tcg-target.inc.c
tests/tcg/cris/check_addo.c
tests/tcg/cris/check_moveq.c
tests/tcg/cris/check_swap.c
tests/tcg/multiarch/test-mmap.c
ui/vnc-enc-hextile-template.h
ui/vnc-enc-zywrle.h
util/envlist.c
util/readline.c
The following have only TABs:
bsd-user/i386/target_signal.h
bsd-user/sparc64/target_signal.h
bsd-user/sparc64/target_syscall.h
bsd-user/sparc/target_signal.h
bsd-user/sparc/target_syscall.h
bsd-user/x86_64/target_signal.h
crypto/desrfb.c
hw/audio/intel-hda-defs.h
hw/core/uboot_image.h
hw/sh4/sh7750_regnames.c
hw/sh4/sh7750_regs.h
include/hw/cris/etraxfs_dma.h
linux-user/alpha/termbits.h
linux-user/arm/nwfpe/fpopcode.h
linux-user/arm/nwfpe/fpsr.h
linux-user/arm/syscall_nr.h
linux-user/arm/target_signal.h
linux-user/cris/target_signal.h
linux-user/i386/target_signal.h
linux-user/linux_loop.h
linux-user/m68k/target_signal.h
linux-user/microblaze/target_signal.h
linux-user/mips64/target_signal.h
linux-user/mips/target_signal.h
linux-user/mips/target_syscall.h
linux-user/mips/termbits.h
linux-user/ppc/target_signal.h
linux-user/sh4/target_signal.h
linux-user/sh4/termbits.h
linux-user/sparc64/target_syscall.h
linux-user/sparc/target_signal.h
linux-user/x86_64/target_signal.h
linux-user/x86_64/termbits.h
pc-bios/optionrom/optionrom.h
slirp/mbuf.h
slirp/misc.h
slirp/sbuf.h
slirp/tcp.h
slirp/tcp_timer.h
slirp/tcp_var.h
target/i386/svm.h
target/sparc/asi.h
target/xtensa/core-dc232b/xtensa-modules.inc.c
target/xtensa/core-dc233c/xtensa-modules.inc.c
target/xtensa/core-de212/core-isa.h
target/xtensa/core-de212/xtensa-modules.inc.c
target/xtensa/core-fsf/xtensa-modules.inc.c
target/xtensa/core-sample_controller/core-isa.h
target/xtensa/core-sample_controller/xtensa-modules.inc.c
target/xtensa/core-test_kc705_be/core-isa.h
target/xtensa/core-test_kc705_be/xtensa-modules.inc.c
tests/tcg/cris/check_abs.c
tests/tcg/cris/check_addc.c
tests/tcg/cris/check_addcm.c
tests/tcg/cris/check_addoq.c
tests/tcg/cris/check_bound.c
tests/tcg/cris/check_ftag.c
tests/tcg/cris/check_int64.c
tests/tcg/cris/check_lz.c
tests/tcg/cris/check_openpf5.c
tests/tcg/cris/check_sigalrm.c
tests/tcg/cris/crisutils.h
tests/tcg/cris/sys.c
tests/tcg/i386/test-i386-ssse3.c
ui/vgafont.h
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20181213223737.11793-3-pbonzini@redhat.com>
Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Eric Blake <eblake@redhat.com>
Acked-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Stefan Markovic <smarkovic@wavecomp.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
We were using -1 instead of the real size because the functions check
what is bigger, size in bytes or the size of the iov. Recent gcc's
barf at this.
Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Cleber Rosa <crosa@redhat.com>
--
Remove comments about this feature.
Fix missing -1.
qemu-common.h should only be included by .c files. Its file comment
explains why: "No header file should depend on qemu-common.h, as this
would easily lead to circular header dependencies."
qemu/iov.h includes qemu-common.h for QEMUIOVector stuff. Move all
that to qemu/iov.h and drop the ill-advised include. Include
qemu/iov.h where the QEMUIOVector stuff is now missing.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
memcpy can take a large amount of time for small reads and writes.
For virtio it is a common case that the first iovec can satisfy the
whole read or write. In that case, and if bytes is a constant to
avoid excessive growth of code, inline the first iteration
into the caller.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 1450782213-14227-1-git-send-email-pbonzini@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
The iov_discard_front/back() functions remove data from the front or
back of the vector. This is useful when peeling off header/footer
structs.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
