[v2] Add architecture agnostic code to support vCPU Hotplug

[PATCH V2 09/10] gdbstub: Add helper function to unregister GDB register space

Posted by Salil Mehta via 2 years, 4 months ago

Add common function to help unregister the GDB Register Space. This shall be
done in context to the CPU unrealization.

Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
---
 gdbstub/gdbstub.c      | 14 ++++++++++++++
 include/exec/gdbstub.h |  5 +++++
 2 files changed, 19 insertions(+)

diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
index 349d348c7b..89ac0edfea 100644
--- a/gdbstub/gdbstub.c
+++ b/gdbstub/gdbstub.c
@@ -491,6 +491,20 @@ void gdb_register_coprocessor(CPUState *cpu,
     }
 }
 
+void gdb_unregister_coprocessor_all(CPUState *cpu)
+{
+    GDBRegisterState *s, *p;
+
+    p = cpu->gdb_regs;
+    while (p) {
+        s = p;
+        p = p->next;
+        /* s->xml is static const char so isn't freed */
+        g_free(s);
+    }
+    cpu->gdb_regs = NULL;
+}
+
 static void gdb_process_breakpoint_remove_all(GDBProcess *p)
 {
     CPUState *cpu = gdb_get_first_cpu_in_process(p);
diff --git a/include/exec/gdbstub.h b/include/exec/gdbstub.h
index 16a139043f..7d1368d377 100644
--- a/include/exec/gdbstub.h
+++ b/include/exec/gdbstub.h
@@ -27,6 +27,11 @@ typedef int (*gdb_set_reg_cb)(CPUArchState *env, uint8_t *buf, int reg);
 void gdb_register_coprocessor(CPUState *cpu,
                               gdb_get_reg_cb get_reg, gdb_set_reg_cb set_reg,
                               int num_regs, const char *xml, int g_pos);
+/**
+ * gdb_unregister_coprocessor_all() - unregisters supplemental set of registers
+ * @cpu - the CPU associated with registers
+ */
+void gdb_unregister_coprocessor_all(CPUState *cpu);
 
 /**
  * gdbserver_start: start the gdb server
-- 
2.34.1

Re: [PATCH V2 09/10] gdbstub: Add helper function to unregister GDB register space

Posted by Gavin Shan 2 years, 4 months ago

On 9/30/23 10:19, Salil Mehta wrote:
> Add common function to help unregister the GDB Register Space. This shall be
> done in context to the CPU unrealization.
> 
> Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
> ---
>   gdbstub/gdbstub.c      | 14 ++++++++++++++
>   include/exec/gdbstub.h |  5 +++++
>   2 files changed, 19 insertions(+)
> 

With the following nits addressed:

Reviewed-by: Gavin Shan <gshan@redhat.com>

> diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
> index 349d348c7b..89ac0edfea 100644
> --- a/gdbstub/gdbstub.c
> +++ b/gdbstub/gdbstub.c
> @@ -491,6 +491,20 @@ void gdb_register_coprocessor(CPUState *cpu,
>       }
>   }
>   
> +void gdb_unregister_coprocessor_all(CPUState *cpu)
> +{
> +    GDBRegisterState *s, *p;
> +
> +    p = cpu->gdb_regs;
> +    while (p) {
> +        s = p;
> +        p = p->next;
> +        /* s->xml is static const char so isn't freed */
                                      ^^^
                                      string so that it needn't be freed
> +        g_free(s);
> +    }
> +    cpu->gdb_regs = NULL;
> +}
> +

For consistency, CPUState::gdb_num_regs and CPUState::gdb_num_g_regs
need to be updated accordingly, even the CPU instance will be destroyed
shortly.

>   static void gdb_process_breakpoint_remove_all(GDBProcess *p)
>   {
>       CPUState *cpu = gdb_get_first_cpu_in_process(p);
> diff --git a/include/exec/gdbstub.h b/include/exec/gdbstub.h
> index 16a139043f..7d1368d377 100644
> --- a/include/exec/gdbstub.h
> +++ b/include/exec/gdbstub.h
> @@ -27,6 +27,11 @@ typedef int (*gdb_set_reg_cb)(CPUArchState *env, uint8_t *buf, int reg);
>   void gdb_register_coprocessor(CPUState *cpu,
>                                 gdb_get_reg_cb get_reg, gdb_set_reg_cb set_reg,
>                                 int num_regs, const char *xml, int g_pos);
> +/**
> + * gdb_unregister_coprocessor_all() - unregisters supplemental set of registers
> + * @cpu - the CPU associated with registers
> + */
> +void gdb_unregister_coprocessor_all(CPUState *cpu);
>   
>   /**
>    * gdbserver_start: start the gdb server

Thanks,
Gavin

RE: [PATCH V2 09/10] gdbstub: Add helper function to unregister GDB register space

Posted by Salil Mehta via 2 years, 4 months ago

> From: Gavin Shan <gshan@redhat.com>
> Sent: Tuesday, October 3, 2023 4:17 AM
> To: Salil Mehta <salil.mehta@huawei.com>; qemu-devel@nongnu.org; qemu-
> arm@nongnu.org
> Cc: maz@kernel.org; jean-philippe@linaro.org; Jonathan Cameron
> <jonathan.cameron@huawei.com>; lpieralisi@kernel.org;
> peter.maydell@linaro.org; richard.henderson@linaro.org;
> imammedo@redhat.com; andrew.jones@linux.dev; david@redhat.com;
> philmd@linaro.org; eric.auger@redhat.com; oliver.upton@linux.dev;
> pbonzini@redhat.com; mst@redhat.com; will@kernel.org; rafael@kernel.org;
> alex.bennee@linaro.org; linux@armlinux.org.uk;
> darren@os.amperecomputing.com; ilkka@os.amperecomputing.com;
> vishnu@os.amperecomputing.com; karl.heubaum@oracle.com;
> miguel.luis@oracle.com; salil.mehta@opnsrc.net; zhukeqian
> <zhukeqian1@huawei.com>; wangxiongfeng (C) <wangxiongfeng2@huawei.com>;
> wangyanan (Y) <wangyanan55@huawei.com>; jiakernel2@gmail.com;
> maobibo@loongson.cn; lixianglai@loongson.cn; Linuxarm <linuxarm@huawei.com>
> Subject: Re: [PATCH V2 09/10] gdbstub: Add helper function to unregister
> GDB register space
> 
> 
> On 9/30/23 10:19, Salil Mehta wrote:
> > Add common function to help unregister the GDB Register Space. This shall
> be
> > done in context to the CPU unrealization.
> >
> > Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
> > ---
> >   gdbstub/gdbstub.c      | 14 ++++++++++++++
> >   include/exec/gdbstub.h |  5 +++++
> >   2 files changed, 19 insertions(+)
> >
> 
> With the following nits addressed:
> 
> Reviewed-by: Gavin Shan <gshan@redhat.com>
> 
> > diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
> > index 349d348c7b..89ac0edfea 100644
> > --- a/gdbstub/gdbstub.c
> > +++ b/gdbstub/gdbstub.c
> > @@ -491,6 +491,20 @@ void gdb_register_coprocessor(CPUState *cpu,
> >       }
> >   }
> >
> > +void gdb_unregister_coprocessor_all(CPUState *cpu)
> > +{
> > +    GDBRegisterState *s, *p;
> > +
> > +    p = cpu->gdb_regs;
> > +    while (p) {
> > +        s = p;
> > +        p = p->next;
> > +        /* s->xml is static const char so isn't freed */
>                                       ^^^
>                                       string so that it needn't be freed
> > +        g_free(s);
> > +    }
> > +    cpu->gdb_regs = NULL;
> > +}
> > +
> 
> For consistency, CPUState::gdb_num_regs and CPUState::gdb_num_g_regs
> need to be updated accordingly, even the CPU instance will be destroyed
> shortly.

Good point.

Thanks
Salil.