From: Daniil Tatianin <d-tatia...@yandex-team.ru> This will be used in the following commits to make it possible to only lock memory on fault instead of right away.
Signed-off-by: Daniil Tatianin <d-tatia...@yandex-team.ru> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@yandex-team.ru> Link: https://lore.kernel.org/r/20250212143920.1269754-2-d-tatia...@yandex-team.ru [peterx: fail os_mlock(on_fault=1) when not supported] [peterx: use G_GNUC_UNUSED instead of "(void)on_fault", per Dan] Signed-off-by: Peter Xu <pet...@redhat.com> --- meson.build | 6 ++++++ include/system/os-posix.h | 2 +- include/system/os-win32.h | 2 +- migration/postcopy-ram.c | 2 +- os-posix.c | 15 +++++++++++++-- system/vl.c | 2 +- 6 files changed, 23 insertions(+), 6 deletions(-) diff --git a/meson.build b/meson.build index 18cf9e2913..59953cbe6b 100644 --- a/meson.build +++ b/meson.build @@ -2885,6 +2885,12 @@ config_host_data.set('HAVE_MLOCKALL', cc.links(gnu_source_prefix + ''' return mlockall(MCL_FUTURE); }''')) +config_host_data.set('HAVE_MLOCK_ONFAULT', cc.links(gnu_source_prefix + ''' + #include <sys/mman.h> + int main(void) { + return mlockall(MCL_FUTURE | MCL_ONFAULT); + }''')) + have_l2tpv3 = false if get_option('l2tpv3').allowed() and have_system have_l2tpv3 = cc.has_type('struct mmsghdr', diff --git a/include/system/os-posix.h b/include/system/os-posix.h index b881ac6c6f..ce5b3bccf8 100644 --- a/include/system/os-posix.h +++ b/include/system/os-posix.h @@ -53,7 +53,7 @@ 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); +int os_mlock(bool on_fault); /** * qemu_alloc_stack: diff --git a/include/system/os-win32.h b/include/system/os-win32.h index b82a5d3ad9..bc623061d8 100644 --- a/include/system/os-win32.h +++ b/include/system/os-win32.h @@ -123,7 +123,7 @@ static inline bool is_daemonized(void) return false; } -static inline int os_mlock(void) +static inline int os_mlock(bool on_fault G_GNUC_UNUSED) { return -ENOSYS; } diff --git a/migration/postcopy-ram.c b/migration/postcopy-ram.c index 6a6da6ba7f..fc4d8a10df 100644 --- a/migration/postcopy-ram.c +++ b/migration/postcopy-ram.c @@ -652,7 +652,7 @@ int postcopy_ram_incoming_cleanup(MigrationIncomingState *mis) } if (enable_mlock) { - if (os_mlock() < 0) { + if (os_mlock(false) < 0) { error_report("mlock: %s", strerror(errno)); /* * It doesn't feel right to fail at this point, we have a valid diff --git a/os-posix.c b/os-posix.c index 9cce55ff2f..52925c23d3 100644 --- a/os-posix.c +++ b/os-posix.c @@ -327,18 +327,29 @@ void os_set_line_buffering(void) setvbuf(stdout, NULL, _IOLBF, 0); } -int os_mlock(void) +int os_mlock(bool on_fault) { #ifdef HAVE_MLOCKALL int ret = 0; + int flags = MCL_CURRENT | MCL_FUTURE; - ret = mlockall(MCL_CURRENT | MCL_FUTURE); + if (on_fault) { +#ifdef HAVE_MLOCK_ONFAULT + flags |= MCL_ONFAULT; +#else + error_report("mlockall: on_fault not supported"); + return -EINVAL; +#endif + } + + ret = mlockall(flags); if (ret < 0) { error_report("mlockall: %s", strerror(errno)); } return ret; #else + (void)on_fault; return -ENOSYS; #endif } diff --git a/system/vl.c b/system/vl.c index 9c6942c6cf..e94fc7ea35 100644 --- a/system/vl.c +++ b/system/vl.c @@ -797,7 +797,7 @@ static QemuOptsList qemu_run_with_opts = { static void realtime_init(void) { if (enable_mlock) { - if (os_mlock() < 0) { + if (os_mlock(false) < 0) { error_report("locking memory failed"); exit(1); } -- 2.47.0
