With this microbenchmark we can measure the overhead of emulating atomic
instructions with a configurable degree of contention.
The benchmark spawns $n threads, each performing $o atomic ops (additions)
in a loop. Each atomic operation is performed on a different cache line
(assuming lines are 64b long) that is randomly selected from a range [0, $r).
[ Note: each $foo corresponds to a -foo flag ]
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1467054136-10430-20-git-send-email-cota@braap.org>
[rth: Move load of reg value to common location.]
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1467054136-10430-17-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
[rth: Move redundant qemu_load out of cmpxchg loop.]
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1467054136-10430-16-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
[rth: Avoid qemu_load that's redundant with the atomic op.]
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1467054136-10430-15-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
[rth: Merge gen_inc_locked back into gen_inc to share cc update.]
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1467054136-10430-14-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
The diff here is uglier than necessary. All this does is to turn
FOO
into:
if (s->prefix & PREFIX_LOCK) {
BAR
} else {
FOO
}
where FOO is the original implementation of an unlocked cmpxchg.
[rth: Adjust unlocked cmpxchg to use movcond instead of branches.
Adjust helpers to use atomic helpers.]
Signed-off-by: Emilio G. Cota <cota@braap.org>
Message-Id: <1467054136-10430-6-git-send-email-cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Allow qemu to build on 32-bit hosts without 64-bit atomic ops.
Even if we only allow 32-bit hosts to multi-thread emulate 32-bit
guests, we still need some way to handle the 32-bit guest using a
64-bit atomic operation. Do so by dropping back to single-step.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Force the use of cmpxchg16b on x86_64.
Wikipedia suggests that only very old AMD64 (circa 2004) did not have
this instruction. Further, it's required by Windows 8 so no new cpus
will ever omit it.
If we truely care about these, then we could check this at startup time
and then avoid executing paths that use it.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Add all of cmpxchg, op_fetch, fetch_op, and xchg.
Handle both endian-ness, and sizes up to 8.
Handle expanding non-atomically, when emulating in serial.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
TGT_LE and TGT_BE are not size dependent and do not need to be
redefined. The others are no longer used at all.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Saves 2k code size off of a cold path.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
We already include exec/address-spaces.h and exec/memory.h in
cputlb.c; the include of qemu/timer.h appears to be a fossil.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
The variable parallel_cpus controls the generation of thread aware
atomic code. We only need to set it once we clone our first thread.
At this point any existing translations need to be thrown away.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
When we cannot emulate an atomic operation within a parallel
context, this exception allows us to stop the world and try
again in a serial context.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Allows Int128 to be used more generally, rather than having to
begin with 64-bit inputs and accumulate.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
While the check against sizeof(void *) is appropriate for
normal usage within qemu, there are places in which we want
wider operaions and have checked for their existance.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
This paves the way for upcoming work.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1467054136-10430-9-git-send-email-cota@braap.org>
This paves the way for upcoming work.
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Message-Id: <1467054136-10430-8-git-send-email-cota@braap.org>
Making these functional rather than object macros will
prevent later problems with complex macro expansion.
Reviewed-by: Emilio G. Cota <cota@braap.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
In virtio gpu resource create dispatch, if the pixman format is zero
it doesn't free the resource object allocated previously. Thus leading
a host memory leak issue. This patch avoid this.
Signed-off-by: Li Qiang <liqiang6-s@360.cn>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 57df486e.8379240a.c3620.ff81@mx.google.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Intel HDA emulator uses stream of buffers during DMA data
transfers. Each entry has buffer length and buffer pointer
position, which are used to derive bytes to 'copy'. If this
length and buffer pointer were to be same, 'copy' could be
set to zero(0), leading to an infinite loop. Add check to
avoid it.
Reported-by: Huawei PSIRT <psirt@huawei.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1476949224-6865-1-git-send-email-ppandit@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Fix memory leak in colo-compare.c and filter-rewriter.c
Report by Coverity and add some comments.
Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
Reviewed-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
RTL8139 ethernet controller in C+ mode supports multiple
descriptor rings, each with maximum of 64 descriptors. While
processing transmit descriptor ring in 'rtl8139_cplus_transmit',
it does not limit the descriptor count and runs forever. Add
check to avoid it.
Reported-by: Andrew Henderson <hendersa@icculus.org>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
In Vmxnet3 device emulator while processing transmit(tx) queue,
when it reaches end of packet, it calls vmxnet3_complete_packet.
In that local 'txcq_descr' object is not initialised, which could
leak host memory bytes a guest.
Reported-by: Li Qiang <liqiang6-s@360.cn>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Reviewed-by: Dmitry Fleytman <dmitry@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
The e1000e emulation zeroes out any used rx descriptor and then writes a
completely newly constructed value there. By doing this, it doesn't only
update the write-back area of the descriptors (as it's supposed to do),
but it also clears the buffer address, which real hardware doesn't do.
The spec explicitly mentions in chapter 7.1.8 that it is valid for a
driver to reuse a descriptor and only update the status field while
doing so, i.e. reusing the old buffer address:
If software statically allocates buffers, and uses memory read to
check for completed descriptors, it simply has to zero the status
byte in the descriptor to make it ready for reuse by hardware.
This patch fixes the behaviour to leave the buffer address in
descriptors unchanged even after the descriptor has been used.
Signed-off-by: Kevin Wolf <mail@kevin-wolf.de>
Reviewed-by: Dmitry Fleytman <dmitry@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Rocker network switch emulator has test registers to help debug
DMA operations. While testing host DMA access, a buffer address
is written to register 'TEST_DMA_ADDR' and its size is written to
register 'TEST_DMA_SIZE'. When performing TEST_DMA_CTRL_INVERT
test, if DMA buffer size was greater than 'INT_MAX', it leads to
an invalid buffer access. Limit the DMA buffer size to avoid it.
Reported-by: Huawei PSIRT <psirt@huawei.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
The exit dispatch of eepro100 network card device doesn't free
the 's->vmstate' field which was allocated in device realize thus
leading a host memory leak. This patch avoid this.
Signed-off-by: Li Qiang <liqiang6-s@360.cn>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Fix indentations and source format at few places. Add braces
around 'if' and 'while' statements.
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
The AMD PC-Net II emulator has set of control and status(CSR)
registers. Of these, CSR76 and CSR78 hold receive and transmit
descriptor ring length respectively. This ring length could range
from 1 to 65535. Setting ring length to zero leads to an infinite
loop in pcnet_rdra_addr() or pcnet_transmit(). Add check to avoid it.
Reported-by: Li Qiang <liqiang6-s@360.cn>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Separate all ccr bits. Continue to batch updates via cc_op.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Fix gen_logic_cc() to really extend the size of the result.
Fix gen_get_ccr(): update cc_op as it is used by the helper.
Factorize flags computing and src/ccr cleanup
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
target-m68k: sr/ccr cleanup
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
The CF docs certainly doesnt suggest this is true.
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
