Re: [PATCH 18/25] plugins: add userdata to qemu_plugin_register_vcpu_syscall_cb

[Manos Pitsidianakis <manos.pitsidianakis@linaro.org>]

On Wed, 03 Jun 2026 23:51, Pierrick Bouvier <pierrick.bouvier@oss.qualcomm.com> wrote:
>Signed-off-by: Pierrick Bouvier <pierrick.bouvier@oss.qualcomm.com>
>---
> include/plugins/qemu-plugin.h | 8 ++++++--
> plugins/api.c                 | 5 +++--
> plugins/core.c                | 2 +-
> tests/tcg/plugins/syscall.c   | 5 +++--
> 4 files changed, 13 insertions(+), 7 deletions(-)
>
>diff --git a/include/plugins/qemu-plugin.h b/include/plugins/qemu-plugin.h
>index d82d996bce6..909f19b7128 100644
>--- a/include/plugins/qemu-plugin.h
>+++ b/include/plugins/qemu-plugin.h
>@@ -840,12 +840,14 @@ void qemu_plugin_update_ns(const void *handle, int64_t time);
>  * @a6: the 6th syscall argument
>  * @a7: the 7th syscall argument
>  * @a8: the 8th syscall argument
>+ * @userdata: user data for callback
>  */
> typedef void
> (*qemu_plugin_vcpu_syscall_cb_t)(unsigned int vcpu_index,
>                                  int64_t num, uint64_t a1, uint64_t a2,
>                                  uint64_t a3, uint64_t a4, uint64_t a5,
>-                                 uint64_t a6, uint64_t a7, uint64_t a8);
>+                                 uint64_t a6, uint64_t a7, uint64_t a8,
>+                                 void *userdata);
> 
> /**
>  * typedef qemu_plugin_vcpu_syscall_filter_cb_t - vCPU syscall filter callback
>@@ -891,13 +893,15 @@ typedef void
>  * qemu_plugin_register_vcpu_syscall_cb() - register a syscall entry callback
>  * @id: plugin id
>  * @cb: callback of type qemu_plugin_vcpu_syscall_cb_t
>+ * @userdata: user data for callback

Suggestion: I noticed in some patches you say "for @cb" and sometimes 
"for callback", if you re-spin this series you could make them 
consistent if you wish.

Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>

>  *
>  * This registers a callback for every syscall executed by the guest. The @cb
>  * function is executed before a syscall is handled by the host.
>  */
> QEMU_PLUGIN_API
> void qemu_plugin_register_vcpu_syscall_cb(qemu_plugin_id_t id,
>-                                          qemu_plugin_vcpu_syscall_cb_t cb);
>+                                          qemu_plugin_vcpu_syscall_cb_t cb,
>+                                          void *userdata);
> 
> /**
>  * qemu_plugin_register_vcpu_syscall_filter_cb() - register a syscall filter
>diff --git a/plugins/api.c b/plugins/api.c
>index 774b1b80214..a72cec541dc 100644
>--- a/plugins/api.c
>+++ b/plugins/api.c
>@@ -202,9 +202,10 @@ void qemu_plugin_register_vcpu_tb_trans_cb(qemu_plugin_id_t id,
> }
> 
> void qemu_plugin_register_vcpu_syscall_cb(qemu_plugin_id_t id,
>-                                          qemu_plugin_vcpu_syscall_cb_t cb)
>+                                          qemu_plugin_vcpu_syscall_cb_t cb,
>+                                          void *userdata)
> {
>-    plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_SYSCALL, cb);
>+    plugin_register_cb_udata(id, QEMU_PLUGIN_EV_VCPU_SYSCALL, cb, userdata);
> }
> 
> void
>diff --git a/plugins/core.c b/plugins/core.c
>index 878fc47cbe1..45136bf950a 100644
>--- a/plugins/core.c
>+++ b/plugins/core.c
>@@ -533,7 +533,7 @@ qemu_plugin_vcpu_syscall(CPUState *cpu, int64_t num, uint64_t a1, uint64_t a2,
>         qemu_plugin_vcpu_syscall_cb_t func = cb->f.vcpu_syscall;
> 
>         qemu_plugin_set_cb_flags(cpu, QEMU_PLUGIN_CB_RW_REGS_PC);
>-        func(cpu->cpu_index, num, a1, a2, a3, a4, a5, a6, a7, a8);
>+        func(cpu->cpu_index, num, a1, a2, a3, a4, a5, a6, a7, a8, cb->udata);
>         qemu_plugin_set_cb_flags(cpu, QEMU_PLUGIN_CB_NO_REGS);
>     }
> }
>diff --git a/tests/tcg/plugins/syscall.c b/tests/tcg/plugins/syscall.c
>index bfe12ad5558..8a823acfca7 100644
>--- a/tests/tcg/plugins/syscall.c
>+++ b/tests/tcg/plugins/syscall.c
>@@ -128,7 +128,8 @@ static void hexdump(const GByteArray *data)
> static void vcpu_syscall(unsigned int vcpu_index,
>                          int64_t num, uint64_t a1, uint64_t a2,
>                          uint64_t a3, uint64_t a4, uint64_t a5,
>-                         uint64_t a6, uint64_t a7, uint64_t a8)
>+                         uint64_t a6, uint64_t a7, uint64_t a8,
>+                         void *userdata)
> {
>     if (statistics) {
>         SyscallStats *entry;
>@@ -271,7 +272,7 @@ QEMU_PLUGIN_EXPORT int qemu_plugin_install(qemu_plugin_id_t id,
>         memory_buffer = g_byte_array_new();
>     }
> 
>-    qemu_plugin_register_vcpu_syscall_cb(id, vcpu_syscall);
>+    qemu_plugin_register_vcpu_syscall_cb(id, vcpu_syscall, NULL);
>     qemu_plugin_register_vcpu_syscall_ret_cb(id, vcpu_syscall_ret);
>     qemu_plugin_register_vcpu_syscall_filter_cb(id, vcpu_syscall_filter);
>     qemu_plugin_register_atexit_cb(id, plugin_exit, NULL);
>-- 
>2.43.0
>
>