qemu/include/sysemu/os-posix.h
Fiona Ebner 03e471c41d qemu_init: increase NOFILE soft limit on POSIX
In many configurations, e.g. multiple vNICs with multiple queues or
with many Ceph OSDs, the default soft limit of 1024 is not enough.
QEMU is supposed to work fine with file descriptors >= 1024 and does
not use select() on POSIX. Bump the soft limit to the allowed hard
limit to avoid issues with the aforementioned configurations.

Of course the limit could be raised from the outside, but the man page
of systemd.exec states about 'LimitNOFILE=':

> Don't use.
> [...]
> Typically applications should increase their soft limit to the hard
> limit on their own, if they are OK with working with file
> descriptors above 1023,

If the soft limit is already the same as the hard limit, avoid the
superfluous setrlimit call. This can avoid a warning with a strict
seccomp filter blocking setrlimit if NOFILE was already raised before
executing QEMU.

Buglink: https://bugzilla.proxmox.com/show_bug.cgi?id=4507
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
2024-02-09 12:47:58 +00:00

102 lines
3.0 KiB
C

/*
* posix specific declarations
*
* Copyright (c) 2003-2008 Fabrice Bellard
* Copyright (c) 2010 Jes Sorensen <Jes.Sorensen@redhat.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#ifndef QEMU_OS_POSIX_H
#define QEMU_OS_POSIX_H
#include <sys/mman.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <sys/un.h>
#ifdef CONFIG_SYSMACROS
#include <sys/sysmacros.h>
#endif
#ifdef __cplusplus
extern "C" {
#endif
void os_set_line_buffering(void);
void os_setup_early_signal_handling(void);
void os_set_proc_name(const char *s);
void os_setup_signal_handling(void);
int os_set_daemonize(bool d);
bool is_daemonized(void);
void os_daemonize(void);
bool os_set_runas(const char *user_id);
void os_set_chroot(const char *path);
void os_setup_limits(void);
void os_setup_post(void);
int os_mlock(void);
/**
* qemu_alloc_stack:
* @sz: pointer to a size_t holding the requested usable stack size
*
* Allocate memory that can be used as a stack, for instance for
* coroutines. If the memory cannot be allocated, this function
* will abort (like g_malloc()). This function also inserts an
* additional guard page to catch a potential stack overflow.
* Note that the memory required for the guard page and alignment
* and minimal stack size restrictions will increase the value of sz.
*
* The allocated stack must be freed with qemu_free_stack().
*
* Returns: pointer to (the lowest address of) the stack memory.
*/
void *qemu_alloc_stack(size_t *sz);
/**
* qemu_free_stack:
* @stack: stack to free
* @sz: size of stack in bytes
*
* Free a stack allocated via qemu_alloc_stack(). Note that sz must
* be exactly the adjusted stack size returned by qemu_alloc_stack.
*/
void qemu_free_stack(void *stack, size_t sz);
/* POSIX and Mingw32 differ in the name of the stdio lock functions. */
static inline void qemu_flockfile(FILE *f)
{
flockfile(f);
}
static inline void qemu_funlockfile(FILE *f)
{
funlockfile(f);
}
#ifdef __cplusplus
}
#endif
#endif