| Message ID | 20181025172057.20414-48-cota@braap.org |
|---|---|
| State | New |
| Headers | show |
| Series | Plugin support | expand |
Emilio G. Cota <cota@braap.org> writes: > These "hooks" are callbacks from the guest to plugins. This is > useful when we need guest-host communication, for instance to > signal the beginning/end of a certain "region of interest" in > the guest program. Simulators typically would use "magic" > instructions for this, but that is painful to maintain across > ISAs. Instead, we use plugin-chan PCI device through which we can > relay guest messages to the host. I suspect the solution for this is either a virtio socket that may (or may not) be located on a PCI bus. However definitely out of scope for a first cut of the plugin API, especially without an example usage. Android has a similar guest-aware channel although the host side was outside of QEMU and QEMU's part was just to expose a socket on the host side that adb could talk to. > > Signed-off-by: Emilio G. Cota <cota@braap.org> > --- > include/qemu/plugin-api.h | 6 ++++++ > include/qemu/plugin.h | 2 ++ > plugin.c | 13 +++++++++++++ > qemu-plugins.symbols | 1 + > 4 files changed, 22 insertions(+) > > diff --git a/include/qemu/plugin-api.h b/include/qemu/plugin-api.h > index 5062e20e08..a5faff6a2a 100644 > --- a/include/qemu/plugin-api.h > +++ b/include/qemu/plugin-api.h > @@ -234,6 +234,12 @@ void qemu_plugin_register_lockstep_cb(qemu_plugin_id_t id, > > void qemu_plugin_end_time_slice(void); > > +typedef void (*qemu_plugin_hook_cb_t)(uint32_t cmd, const void *data, > + size_t size); > + > +void qemu_plugin_register_hook_cb(qemu_plugin_id_t id, > + qemu_plugin_hook_cb_t cb); > + > /* returns -1 in user-mode */ > int qemu_plugin_n_vcpus(void); > > diff --git a/include/qemu/plugin.h b/include/qemu/plugin.h > index f3c18d1032..ced265a127 100644 > --- a/include/qemu/plugin.h > +++ b/include/qemu/plugin.h > @@ -61,12 +61,14 @@ enum qemu_plugin_event { > QEMU_PLUGIN_EV_LOCKSTEP, > QEMU_PLUGIN_EV_FLUSH, > QEMU_PLUGIN_EV_ATEXIT, > + QEMU_PLUGIN_EV_HOOK, > QEMU_PLUGIN_EV_MAX, > }; > > union qemu_plugin_cb_sig { > qemu_plugin_simple_cb_t simple; > qemu_plugin_udata_cb_t udata; > + qemu_plugin_hook_cb_t hook; > qemu_plugin_vcpu_simple_cb_t vcpu_simple; > qemu_plugin_vcpu_udata_cb_t vcpu_udata; > qemu_plugin_vcpu_tb_trans_cb_t vcpu_tb_trans; > diff --git a/plugin.c b/plugin.c > index 2bbc14e2f3..4004451bdb 100644 > --- a/plugin.c > +++ b/plugin.c > @@ -1078,8 +1078,21 @@ void plugin_lockstep_cb(void) > plugin_cb__simple(QEMU_PLUGIN_EV_LOCKSTEP); > } > > +void qemu_plugin_register_hook_cb(qemu_plugin_id_t id, qemu_plugin_hook_cb_t cb) > +{ > + plugin_register_cb(id, QEMU_PLUGIN_EV_HOOK, cb); > +} > + > void plugin_chan_xmit(uint32_t cmd, const void *data, size_t size) > { > + struct qemu_plugin_cb *cb, *next; > + enum qemu_plugin_event ev = QEMU_PLUGIN_EV_HOOK; > + > + QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) { > + qemu_plugin_hook_cb_t func = cb->f.hook; > + > + func(cmd, data, size); > + } > } > > static void __attribute__((__constructor__)) plugin_init(void) > diff --git a/qemu-plugins.symbols b/qemu-plugins.symbols > index a3268a40c7..2e17693da8 100644 > --- a/qemu-plugins.symbols > +++ b/qemu-plugins.symbols > @@ -31,6 +31,7 @@ > qemu_plugin_mem_is_big_endian; > qemu_plugin_mem_is_store; > qemu_plugin_vcpu_for_each; > + qemu_plugin_register_hook_cb; > qemu_plugin_n_vcpus; > qemu_plugin_n_max_vcpus; > }; -- Alex Bennée
diff --git a/include/qemu/plugin-api.h b/include/qemu/plugin-api.h index 5062e20e08..a5faff6a2a 100644 --- a/include/qemu/plugin-api.h +++ b/include/qemu/plugin-api.h @@ -234,6 +234,12 @@ void qemu_plugin_register_lockstep_cb(qemu_plugin_id_t id, void qemu_plugin_end_time_slice(void); +typedef void (*qemu_plugin_hook_cb_t)(uint32_t cmd, const void *data, + size_t size); + +void qemu_plugin_register_hook_cb(qemu_plugin_id_t id, + qemu_plugin_hook_cb_t cb); + /* returns -1 in user-mode */ int qemu_plugin_n_vcpus(void); diff --git a/include/qemu/plugin.h b/include/qemu/plugin.h index f3c18d1032..ced265a127 100644 --- a/include/qemu/plugin.h +++ b/include/qemu/plugin.h @@ -61,12 +61,14 @@ enum qemu_plugin_event { QEMU_PLUGIN_EV_LOCKSTEP, QEMU_PLUGIN_EV_FLUSH, QEMU_PLUGIN_EV_ATEXIT, + QEMU_PLUGIN_EV_HOOK, QEMU_PLUGIN_EV_MAX, }; union qemu_plugin_cb_sig { qemu_plugin_simple_cb_t simple; qemu_plugin_udata_cb_t udata; + qemu_plugin_hook_cb_t hook; qemu_plugin_vcpu_simple_cb_t vcpu_simple; qemu_plugin_vcpu_udata_cb_t vcpu_udata; qemu_plugin_vcpu_tb_trans_cb_t vcpu_tb_trans; diff --git a/plugin.c b/plugin.c index 2bbc14e2f3..4004451bdb 100644 --- a/plugin.c +++ b/plugin.c @@ -1078,8 +1078,21 @@ void plugin_lockstep_cb(void) plugin_cb__simple(QEMU_PLUGIN_EV_LOCKSTEP); } +void qemu_plugin_register_hook_cb(qemu_plugin_id_t id, qemu_plugin_hook_cb_t cb) +{ + plugin_register_cb(id, QEMU_PLUGIN_EV_HOOK, cb); +} + void plugin_chan_xmit(uint32_t cmd, const void *data, size_t size) { + struct qemu_plugin_cb *cb, *next; + enum qemu_plugin_event ev = QEMU_PLUGIN_EV_HOOK; + + QLIST_FOREACH_SAFE_RCU(cb, &plugin.cb_lists[ev], entry, next) { + qemu_plugin_hook_cb_t func = cb->f.hook; + + func(cmd, data, size); + } } static void __attribute__((__constructor__)) plugin_init(void) diff --git a/qemu-plugins.symbols b/qemu-plugins.symbols index a3268a40c7..2e17693da8 100644 --- a/qemu-plugins.symbols +++ b/qemu-plugins.symbols @@ -31,6 +31,7 @@ qemu_plugin_mem_is_big_endian; qemu_plugin_mem_is_store; qemu_plugin_vcpu_for_each; + qemu_plugin_register_hook_cb; qemu_plugin_n_vcpus; qemu_plugin_n_max_vcpus; };
These "hooks" are callbacks from the guest to plugins. This is useful when we need guest-host communication, for instance to signal the beginning/end of a certain "region of interest" in the guest program. Simulators typically would use "magic" instructions for this, but that is painful to maintain across ISAs. Instead, we use plugin-chan PCI device through which we can relay guest messages to the host. Signed-off-by: Emilio G. Cota <cota@braap.org> --- include/qemu/plugin-api.h | 6 ++++++ include/qemu/plugin.h | 2 ++ plugin.c | 13 +++++++++++++ qemu-plugins.symbols | 1 + 4 files changed, 22 insertions(+)