Re: [PATCH] gdbstub: move update guest debug to accel ops

["Philippe Mathieu-Daudé" <philmd@linaro.org>]

Hi,

On 23/11/22 13:17, Mads Ynddal wrote:
> From: Mads Ynddal <m.ynddal@samsung.com>
> 
> Continuing the refactor of a48e7d9e52 (gdbstub: move guest debug support
> check to ops) by removing hardcoded kvm_enabled() from generic cpu.c
> code, and replace it with a property of AccelOpsClass.
> 
> Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
> ---
>   accel/kvm/kvm-accel-ops.c  |  1 +
>   cpu.c                      | 10 +++++++---
>   include/sysemu/accel-ops.h |  1 +
>   3 files changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/accel/kvm/kvm-accel-ops.c b/accel/kvm/kvm-accel-ops.c
> index fbf4fe3497..6ebf9a644f 100644
> --- a/accel/kvm/kvm-accel-ops.c
> +++ b/accel/kvm/kvm-accel-ops.c
> @@ -99,6 +99,7 @@ static void kvm_accel_ops_class_init(ObjectClass *oc, void *data)
>       ops->synchronize_pre_loadvm = kvm_cpu_synchronize_pre_loadvm;
>   
>   #ifdef KVM_CAP_SET_GUEST_DEBUG
> +    ops->update_guest_debug = kvm_update_guest_debug;
>       ops->supports_guest_debug = kvm_supports_guest_debug;
>       ops->insert_breakpoint = kvm_insert_breakpoint;
>       ops->remove_breakpoint = kvm_remove_breakpoint;
> diff --git a/cpu.c b/cpu.c
> index 2a09b05205..ef433a79e3 100644
> --- a/cpu.c
> +++ b/cpu.c
> @@ -31,8 +31,8 @@
>   #include "hw/core/sysemu-cpu-ops.h"
>   #include "exec/address-spaces.h"
>   #endif
> +#include "sysemu/cpus.h"
>   #include "sysemu/tcg.h"
> -#include "sysemu/kvm.h"
>   #include "sysemu/replay.h"
>   #include "exec/cpu-common.h"
>   #include "exec/exec-all.h"
> @@ -378,10 +378,14 @@ void cpu_breakpoint_remove_all(CPUState *cpu, int mask)
>   void cpu_single_step(CPUState *cpu, int enabled)
>   {
>       if (cpu->singlestep_enabled != enabled) {
> +        const AccelOpsClass *ops = cpus_get_accel();
> +
>           cpu->singlestep_enabled = enabled;
> -        if (kvm_enabled()) {
> -            kvm_update_guest_debug(cpu, 0);
> +
> +        if (ops->update_guest_debug) {
> +            ops->update_guest_debug(cpu, 0);

Isn't this '0' flag here accelerator-specific? ...

>           }
> +
>           trace_breakpoint_singlestep(cpu->cpu_index, enabled);
>       }
>   }
> diff --git a/include/sysemu/accel-ops.h b/include/sysemu/accel-ops.h
> index 8cc7996def..0a47a2f00c 100644
> --- a/include/sysemu/accel-ops.h
> +++ b/include/sysemu/accel-ops.h
> @@ -48,6 +48,7 @@ struct AccelOpsClass {
>   
>       /* gdbstub hooks */
>       bool (*supports_guest_debug)(void);
> +    int (*update_guest_debug)(CPUState *cpu, unsigned long flags);

... if so the prototype should be:

        int (*update_guest_debug)(CPUState *cpu);

and the '0' value set within kvm-accel-ops.c handler implementation.

>       int (*insert_breakpoint)(CPUState *cpu, int type, hwaddr addr, hwaddr len);
>       int (*remove_breakpoint)(CPUState *cpu, int type, hwaddr addr, hwaddr len);
>       void (*remove_all_breakpoints)(CPUState *cpu);

Regards,

Phil.