We won't use the SSE GFNI instructions, so delay
detection until we know AVX is present.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Currently the tracing 'log' back emits special code to add timestamps
to trace points sent via qemu_log(). This current impl is a bad design
for a number of reasons.
* It changes the QEMU headers, such that 'error-report.h' content
is visible to all files using tracing, but only when the 'log'
backend is enabled. This has led to build failure bugs as devs
rarely test without the (default) 'log' backend enabled, and
CI can't cover every scenario for every trace backend.
* It bloats the trace points definitions which are inlined into
every probe location due to repeated inlining of timestamp
formatting code, adding MBs of overhead to QEMU.
* The tracing subsystem should not be treated any differently
from other users of qemu_log. They all would benefit from
having timestamps present.
* The timestamp emitted with the tracepoints is in a needlessly
different format to that used by error_report() in response
to '-msg timestamp=on'.
This fixes all these issues simply by moving timestamp formatting
into qemu_log, using the same approach as for error_report.
The code before:
static inline void _nocheck__trace_qcrypto_tls_creds_get_path(void * creds, const char * filename, const char * path)
{
if (trace_event_get_state(TRACE_QCRYPTO_TLS_CREDS_GET_PATH) && qemu_loglevel_mask(LOG_TRACE)) {
if (message_with_timestamp) {
struct timeval _now;
gettimeofday(&_now, NULL);
qemu_log("%d@%zu.%06zu:qcrypto_tls_creds_get_path " "TLS creds path creds=%p filename=%s path=%s" "\n",
qemu_get_thread_id(),
(size_t)_now.tv_sec, (size_t)_now.tv_usec
, creds, filename, path);
} else {
qemu_log("qcrypto_tls_creds_get_path " "TLS creds path creds=%p filename=%s path=%s" "\n", creds, filename, path);
}
}
}
and after:
static inline void _nocheck__trace_qcrypto_tls_creds_get_path(void * creds, const char * filename, const char * path)
{
if (trace_event_get_state(TRACE_QCRYPTO_TLS_CREDS_GET_PATH) && qemu_loglevel_mask(LOG_TRACE)) {
qemu_log("qcrypto_tls_creds_get_path " "TLS creds path creds=%p filename=%s path=%s" "\n", creds, filename, path);
}
}
The log and error messages before:
$ qemu-system-x86_64 -trace qcrypto* -object tls-creds-x509,id=tls0,dir=$HOME/tls -msg timestamp=on
2986097@1753122905.917608:qcrypto_tls_creds_x509_load TLS creds x509 load creds=0x55d925bd9490 dir=/var/home/berrange/tls
2986097@1753122905.917621:qcrypto_tls_creds_get_path TLS creds path creds=0x55d925bd9490 filename=ca-cert.pem path=<none>
2025-07-21T18:35:05.917626Z qemu-system-x86_64: Unable to access credentials /var/home/berrange/tls/ca-cert.pem: No such file or directory
and after:
$ qemu-system-x86_64 -trace qcrypto* -object tls-creds-x509,id=tls0,dir=$HOME/tls -msg timestamp=on
2025-07-21T18:43:28.089797Z qcrypto_tls_creds_x509_load TLS creds x509 load creds=0x55bf5bf12380 dir=/var/home/berrange/tls
2025-07-21T18:43:28.089815Z qcrypto_tls_creds_get_path TLS creds path creds=0x55bf5bf12380 filename=ca-cert.pem path=<none>
2025-07-21T18:43:28.089819Z qemu-system-x86_64: Unable to access credentials /var/home/berrange/tls/ca-cert.pem: No such file or directory
The binary size before:
$ ls -alh qemu-system-x86_64
-rwxr-xr-x. 1 berrange berrange 87M Jul 21 19:39 qemu-system-x86_64
$ strip qemu-system-x86_64
$ ls -alh qemu-system-x86_64
-rwxr-xr-x. 1 berrange berrange 30M Jul 21 19:39 qemu-system-x86_64
and after:
$ ls -alh qemu-system-x86_64
-rwxr-xr-x. 1 berrange berrange 85M Jul 21 19:41 qemu-system-x86_64
$ strip qemu-system-x86_64
$ ls -alh qemu-system-x86_64
-rwxr-xr-x. 1 berrange berrange 29M Jul 21 19:41 qemu-system-x86_64
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-id: 20250721185452.3016488-1-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This makes it possible to lock the log file; it also makes log_mask_ln!
not allocate memory when logging a constant string.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
qemu-thread used to abstract pthread primitives into futex for the
QemuEvent implementation of POSIX systems other than Linux. However,
this abstraction has one key difference: unlike futex, pthread
primitives require an explicit destruction, and it must be ordered after
wait and wake operations.
It would be easier to perform destruction if a wait operation ensures
the corresponding wake operation finishes as POSIX semaphore does, but
that requires to protect state accesses in qemu_event_set() and
qemu_event_wait() with a mutex. On the other hand, real futex does not
need such a protection but needs complex barrier and atomic operations
to ensure ordering between the two functions.
Add special implementations of qemu_event_set() and qemu_event_wait()
using pthread primitives. qemu_event_wait() will ensure qemu_event_set()
finishes, and these functions will avoid complex barrier and atomic
operations to ensure ordering between them.
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Tested-by: Phil Dennis-Jordan <phil@philjordan.eu>
Reviewed-by: Phil Dennis-Jordan <phil@philjordan.eu>
Link: https://lore.kernel.org/r/20250526-event-v4-5-5b784cc8e1de@daynix.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
futex(2) - Linux manual page
https://man7.org/linux/man-pages/man2/futex.2.html
> Note that a wake-up can also be caused by common futex usage patterns
> in unrelated code that happened to have previously used the futex
> word's memory location (e.g., typical futex-based implementations of
> Pthreads mutexes can cause this under some conditions). Therefore,
> callers should always conservatively assume that a return value of 0
> can mean a spurious wake-up, and use the futex word's value (i.e.,
> the user-space synchronization scheme) to decide whether to continue
> to block or not.
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Link: https://lore.kernel.org/r/20250529-event-v5-1-53b285203794@daynix.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The function name is not available in Rust, so make it optional.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Rust makes the current file available as a statically-allocated string,
but without a NUL terminator. Allow this by storing an optional maximum
length in the Error.
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
With the default TCP stack configuration, it could be even 2 hours
before the connection times out due to the other side not being
reachable. However, in some cases, the application needs to be aware of
a connection issue much sooner.
This is the case, for example, for postcopy live migration. If there is
no traffic from the migration destination guest (server-side) to the
migration source guest (client-side), the destination keeps waiting for
pages indefinitely and does not switch to the postcopy-paused state.
This can happen, for example, if the destination QEMU instance is
started with the '-S' command line option and the machine is not started
yet, or if the machine is idle and produces no new page faults for
not-yet-migrated pages.
This patch introduces new inet socket parameters that control count,
idle period, and interval of TCP keep-alive packets before the
connection is considered broken. These parameters are available on
systems where the respective TCP socket options are defined, that
includes Linux, Windows, macOS, but not OpenBSD. Additionally, macOS
defines TCP_KEEPIDLE as TCP_KEEPALIVE instead, so the patch supplies its
own definition.
The default value for all is 0, which means the system configuration is
used.
Signed-off-by: Juraj Marcin <jmarcin@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Currently, the inet address parser cannot handle multiple options where
one is prefixed with the name of the other. For example, with the
'keep-alive-idle' option added, the current parser cannot parse
'127.0.0.1:5000,keep-alive-idle=60,keep-alive' correctly. Instead, it
fails with "error parsing 'keep-alive' flag '-idle=60,keep-alive'".
To resolve these issues, this patch rewrites the inet address parsing
using the QemuOpts parser, which the inet_parse_flag() function tries to
mimic. This new parser supports all previously supported options and on
top of that the 'numeric' flag is now also supported. The only
difference is, the new parser produces an error if an unknown option is
passed, instead of silently ignoring it.
Signed-off-by: Juraj Marcin <jmarcin@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Commit aec21d3175 (qapi: Add InetSocketAddress member keep-alive)
introduces the keep-alive flag, which enables the SO_KEEPALIVE socket
option, but only on client-side sockets. However, this option is also
useful for server-side sockets, so they can check if a client is still
reachable or drop the connection otherwise.
This patch enables the SO_KEEPALIVE socket option on passive server-side
sockets if the keep-alive flag is enabled. This socket option is then
inherited by active server-side sockets communicating with connected
clients.
Signed-off-by: Juraj Marcin <jmarcin@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
To get a listening socket, we need to first create a socket, try binding
it to a certain port, and lastly starting listening to it. Each of these
operations can fail due to various reasons, one of them being that the
requested address/port is already in use. In such case, the function
tries the same process with a new port number.
This patch refactors the port number loop, so the success path is no
longer buried inside the 'if' statements in the middle of the loop. Now,
the success path is not nested and ends at the end of the iteration
after successful socket creation, binding, and listening. In case any of
the operations fails, it either continues to the next iteration (and the
next port) or jumps out of the loop to handle the error and exits the
function.
Signed-off-by: Juraj Marcin <jmarcin@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
This is done in preparation for enabling the SO_KEEPALIVE support for
server sockets and adding settings for more TCP keep-alive socket
options.
Signed-off-by: Juraj Marcin <jmarcin@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Starting with z15 (or newer) we can execute mmio
instructions from userspace. On older platforms
where we don't have these instructions available
we can fallback to using system calls to access
the PCI mapped resources.
This patch adds helper functions for mmio reads
and writes for s390x.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Acked-by: Thomas Huth <thuth@redhat.com>
Message-id: 20250430185012.2303-2-alifm@linux.ibm.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Although __builtin___clear_cache is used to flush the instruction cache for
a specified memory region, this operation doesn't apply to wasm, as its
memory isn't executable. Moreover, Emscripten does not support this builtin
and fails to compile it with the following error.
> fatal error: error in backend: llvm.clear_cache is not supported on wasm
To resolve this, this commit removes the call to __builtin___clear_cache for
Emscripten build.
Signed-off-by: Kohei Tokunaga <ktokunaga.mail@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/2926a798fa52a3a5b11c3df4edd1643d2b7cdcb9.1745820062.git.ktokunaga.mail@gmail.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
