From 3b7a93880a88fb2e3c0e71378a7d39d25103d734 Mon Sep 17 00:00:00 2001 From: Alex Bennée Date: Thu, 29 Sep 2022 12:42:23 +0100 Subject: gdbstub: move sstep flags probing into AccelClass MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The support of single-stepping is very much dependent on support from the accelerator we are using. To avoid special casing in gdbstub move the probing out to an AccelClass function so future accelerators can put their code there. Reviewed-by: Richard Henderson Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Alex Bennée Reviewed-by: Mads Ynddal Message-Id: <20220929114231.583801-44-alex.bennee@linaro.org> --- include/qemu/accel.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'include/qemu') diff --git a/include/qemu/accel.h b/include/qemu/accel.h index be56da1b99..ce4747634a 100644 --- a/include/qemu/accel.h +++ b/include/qemu/accel.h @@ -43,6 +43,10 @@ typedef struct AccelClass { bool (*has_memory)(MachineState *ms, AddressSpace *as, hwaddr start_addr, hwaddr size); #endif + + /* gdbstub related hooks */ + int (*gdbstub_supported_sstep_flags)(void); + bool *allowed; /* * Array of global properties that would be applied when specific @@ -92,4 +96,12 @@ void accel_cpu_instance_init(CPUState *cpu); */ bool accel_cpu_realizefn(CPUState *cpu, Error **errp); +/** + * accel_supported_gdbstub_sstep_flags: + * + * Returns the supported single step modes for the configured + * accelerator. + */ +int accel_supported_gdbstub_sstep_flags(void); + #endif /* QEMU_ACCEL_H */ -- cgit 1.4.1 From f7e15affa8e574a800180de3bde1a6462aec7241 Mon Sep 17 00:00:00 2001 From: Alex Bennée Date: Tue, 4 Oct 2022 12:52:21 +0100 Subject: plugins: add [pre|post]fork helpers to linux-user MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Special care needs to be taken in ensuring locks are in a consistent state across fork events. Add helpers so the plugin system can ensure that. Signed-off-by: Alex Bennée Fixes: https://gitlab.com/qemu-project/qemu/-/issues/358 Reviewed-by: Daniel P. Berrangé Tested-by: Daniel P. Berrangé Message-Id: <20221004115221.2174499-1-alex.bennee@linaro.org> --- include/qemu/plugin.h | 24 ++++++++++++++++++++++++ linux-user/main.c | 2 ++ plugins/core.c | 20 ++++++++++++++++++++ 3 files changed, 46 insertions(+) (limited to 'include/qemu') diff --git a/include/qemu/plugin.h b/include/qemu/plugin.h index 145f8a221a..a772e14193 100644 --- a/include/qemu/plugin.h +++ b/include/qemu/plugin.h @@ -224,6 +224,23 @@ void qemu_plugin_disable_mem_helpers(CPUState *cpu); */ void qemu_plugin_user_exit(void); +/** + * qemu_plugin_user_prefork_lock(): take plugin lock before forking + * + * This is a user-mode only helper to take the internal plugin lock + * before a fork event. This is ensure a consistent lock state + */ +void qemu_plugin_user_prefork_lock(void); + +/** + * qemu_plugin_user_postfork(): reset the plugin lock + * @is_child: is this thread the child + * + * This user-mode only helper resets the lock state after a fork so we + * can continue using the plugin interface. + */ +void qemu_plugin_user_postfork(bool is_child); + #else /* !CONFIG_PLUGIN */ static inline void qemu_plugin_add_opts(void) @@ -287,6 +304,13 @@ static inline void qemu_plugin_disable_mem_helpers(CPUState *cpu) static inline void qemu_plugin_user_exit(void) { } + +static inline void qemu_plugin_user_prefork_lock(void) +{ } + +static inline void qemu_plugin_user_postfork(bool is_child) +{ } + #endif /* !CONFIG_PLUGIN */ #endif /* QEMU_PLUGIN_H */ diff --git a/linux-user/main.c b/linux-user/main.c index 88fccfe261..a17fed045b 100644 --- a/linux-user/main.c +++ b/linux-user/main.c @@ -142,10 +142,12 @@ void fork_start(void) start_exclusive(); mmap_fork_start(); cpu_list_lock(); + qemu_plugin_user_prefork_lock(); } void fork_end(int child) { + qemu_plugin_user_postfork(child); mmap_fork_end(child); if (child) { CPUState *cpu, *next_cpu; diff --git a/plugins/core.c b/plugins/core.c index c3ae284994..ccb770a485 100644 --- a/plugins/core.c +++ b/plugins/core.c @@ -526,6 +526,26 @@ void qemu_plugin_user_exit(void) qemu_plugin_atexit_cb(); } +/* + * Helpers for *-user to ensure locks are sane across fork() events. + */ + +void qemu_plugin_user_prefork_lock(void) +{ + qemu_rec_mutex_lock(&plugin.lock); +} + +void qemu_plugin_user_postfork(bool is_child) +{ + if (is_child) { + /* should we just reset via plugin_init? */ + qemu_rec_mutex_init(&plugin.lock); + } else { + qemu_rec_mutex_unlock(&plugin.lock); + } +} + + /* * Call this function after longjmp'ing to the main loop. It's possible that the * last instruction of a TB might have used helpers, and therefore the -- cgit 1.4.1