| Message ID | 20240620152220.2192768-9-alex.bennee@linaro.org |
|---|---|
| State | New |
| Headers | show |
| Series | maintainer updates pre-PR (gdbstub, plugins, time control) | expand |
Reviewed-by: Alwalid Salama <quic_asalama@qualcomm.com> On 6/20/2024 5:22 PM, Alex Bennée wrote: > Expose the ability to control time through the plugin API. Only one > plugin can control time so it has to request control when loaded. > There are probably more corner cases to catch here. > > Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org> > [AJB: tweaked user-mode handling, merged QEMU_PLUGIN_API fix] > Signed-off-by: Alex Bennée <alex.bennee@linaro.org> > Message-Id: <20240530220610.1245424-6-pierrick.bouvier@linaro.org> > > --- > plugins/next > - make qemu_plugin_update_ns a NOP in user-mode > v2 > - remove From: header > - merged in plugins: missing QEMU_PLUGIN_API for time control > --- > include/qemu/qemu-plugin.h | 27 +++++++++++++++++++++++++++ > plugins/api.c | 35 +++++++++++++++++++++++++++++++++++ > plugins/qemu-plugins.symbols | 2 ++ > 3 files changed, 64 insertions(+) > > diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h > index 95703d8fec..c71c705b69 100644 > --- a/include/qemu/qemu-plugin.h > +++ b/include/qemu/qemu-plugin.h > @@ -661,6 +661,33 @@ void qemu_plugin_register_vcpu_mem_inline_per_vcpu( > qemu_plugin_u64 entry, > uint64_t imm); > > +/** > + * qemu_plugin_request_time_control() - request the ability to control time > + * > + * This grants the plugin the ability to control system time. Only one > + * plugin can control time so if multiple plugins request the ability > + * all but the first will fail. > + * > + * Returns an opaque handle or NULL if fails > + */ > +QEMU_PLUGIN_API > +const void *qemu_plugin_request_time_control(void); > + > +/** > + * qemu_plugin_update_ns() - update system emulation time > + * @handle: opaque handle returned by qemu_plugin_request_time_control() > + * @time: time in nanoseconds > + * > + * This allows an appropriately authorised plugin (i.e. holding the > + * time control handle) to move system time forward to @time. For > + * user-mode emulation the time is not changed by this as all reported > + * time comes from the host kernel. > + * > + * Start time is 0. > + */ > +QEMU_PLUGIN_API > +void qemu_plugin_update_ns(const void *handle, int64_t time); > + > typedef void > (*qemu_plugin_vcpu_syscall_cb_t)(qemu_plugin_id_t id, unsigned int vcpu_index, > int64_t num, uint64_t a1, uint64_t a2, > diff --git a/plugins/api.c b/plugins/api.c > index 6bdb26bbe3..4431a0ea7e 100644 > --- a/plugins/api.c > +++ b/plugins/api.c > @@ -39,6 +39,7 @@ > #include "qemu/main-loop.h" > #include "qemu/plugin.h" > #include "qemu/log.h" > +#include "qemu/timer.h" > #include "tcg/tcg.h" > #include "exec/exec-all.h" > #include "exec/gdbstub.h" > @@ -583,3 +584,37 @@ uint64_t qemu_plugin_u64_sum(qemu_plugin_u64 entry) > } > return total; > } > + > +/* > + * Time control > + */ > +static bool has_control; > + > +const void *qemu_plugin_request_time_control(void) > +{ > + if (!has_control) { > + has_control = true; > + return &has_control; > + } > + return NULL; > +} > + > +#ifdef CONFIG_SOFTMMU > +static void advance_virtual_time__async(CPUState *cpu, run_on_cpu_data data) > +{ > + int64_t new_time = data.host_ulong; > + qemu_clock_advance_virtual_time(new_time); > +} > +#endif > + > +void qemu_plugin_update_ns(const void *handle, int64_t new_time) > +{ > +#ifdef CONFIG_SOFTMMU > + if (handle == &has_control) { > + /* Need to execute out of cpu_exec, so bql can be locked. */ > + async_run_on_cpu(current_cpu, > + advance_virtual_time__async, > + RUN_ON_CPU_HOST_ULONG(new_time)); > + } > +#endif > +} > diff --git a/plugins/qemu-plugins.symbols b/plugins/qemu-plugins.symbols > index aa0a77a319..ca773d8d9f 100644 > --- a/plugins/qemu-plugins.symbols > +++ b/plugins/qemu-plugins.symbols > @@ -38,6 +38,7 @@ > qemu_plugin_register_vcpu_tb_exec_cond_cb; > qemu_plugin_register_vcpu_tb_exec_inline_per_vcpu; > qemu_plugin_register_vcpu_tb_trans_cb; > + qemu_plugin_request_time_control; > qemu_plugin_reset; > qemu_plugin_scoreboard_free; > qemu_plugin_scoreboard_find; > @@ -51,5 +52,6 @@ > qemu_plugin_u64_set; > qemu_plugin_u64_sum; > qemu_plugin_uninstall; > + qemu_plugin_update_ns; > qemu_plugin_vcpu_for_each; > };
diff --git a/include/qemu/qemu-plugin.h b/include/qemu/qemu-plugin.h index 95703d8fec..c71c705b69 100644 --- a/include/qemu/qemu-plugin.h +++ b/include/qemu/qemu-plugin.h @@ -661,6 +661,33 @@ void qemu_plugin_register_vcpu_mem_inline_per_vcpu( qemu_plugin_u64 entry, uint64_t imm); +/** + * qemu_plugin_request_time_control() - request the ability to control time + * + * This grants the plugin the ability to control system time. Only one + * plugin can control time so if multiple plugins request the ability + * all but the first will fail. + * + * Returns an opaque handle or NULL if fails + */ +QEMU_PLUGIN_API +const void *qemu_plugin_request_time_control(void); + +/** + * qemu_plugin_update_ns() - update system emulation time + * @handle: opaque handle returned by qemu_plugin_request_time_control() + * @time: time in nanoseconds + * + * This allows an appropriately authorised plugin (i.e. holding the + * time control handle) to move system time forward to @time. For + * user-mode emulation the time is not changed by this as all reported + * time comes from the host kernel. + * + * Start time is 0. + */ +QEMU_PLUGIN_API +void qemu_plugin_update_ns(const void *handle, int64_t time); + typedef void (*qemu_plugin_vcpu_syscall_cb_t)(qemu_plugin_id_t id, unsigned int vcpu_index, int64_t num, uint64_t a1, uint64_t a2, diff --git a/plugins/api.c b/plugins/api.c index 6bdb26bbe3..4431a0ea7e 100644 --- a/plugins/api.c +++ b/plugins/api.c @@ -39,6 +39,7 @@ #include "qemu/main-loop.h" #include "qemu/plugin.h" #include "qemu/log.h" +#include "qemu/timer.h" #include "tcg/tcg.h" #include "exec/exec-all.h" #include "exec/gdbstub.h" @@ -583,3 +584,37 @@ uint64_t qemu_plugin_u64_sum(qemu_plugin_u64 entry) } return total; } + +/* + * Time control + */ +static bool has_control; + +const void *qemu_plugin_request_time_control(void) +{ + if (!has_control) { + has_control = true; + return &has_control; + } + return NULL; +} + +#ifdef CONFIG_SOFTMMU +static void advance_virtual_time__async(CPUState *cpu, run_on_cpu_data data) +{ + int64_t new_time = data.host_ulong; + qemu_clock_advance_virtual_time(new_time); +} +#endif + +void qemu_plugin_update_ns(const void *handle, int64_t new_time) +{ +#ifdef CONFIG_SOFTMMU + if (handle == &has_control) { + /* Need to execute out of cpu_exec, so bql can be locked. */ + async_run_on_cpu(current_cpu, + advance_virtual_time__async, + RUN_ON_CPU_HOST_ULONG(new_time)); + } +#endif +} diff --git a/plugins/qemu-plugins.symbols b/plugins/qemu-plugins.symbols index aa0a77a319..ca773d8d9f 100644 --- a/plugins/qemu-plugins.symbols +++ b/plugins/qemu-plugins.symbols @@ -38,6 +38,7 @@ qemu_plugin_register_vcpu_tb_exec_cond_cb; qemu_plugin_register_vcpu_tb_exec_inline_per_vcpu; qemu_plugin_register_vcpu_tb_trans_cb; + qemu_plugin_request_time_control; qemu_plugin_reset; qemu_plugin_scoreboard_free; qemu_plugin_scoreboard_find; @@ -51,5 +52,6 @@ qemu_plugin_u64_set; qemu_plugin_u64_sum; qemu_plugin_uninstall; + qemu_plugin_update_ns; qemu_plugin_vcpu_for_each; };