Re: [PATCH v3 2/3] dump: add crash_occurred flag to QEMUCPUState

On 2026/08/06 17:47, Zhengrong Li wrote:
> Add is_crash_occurred_cpu field to the local QEMUCPUState in
> arch_dump.c so that dump-guest-memory can record which CPU
> triggered the guest panic.
> 
> The new field is appended after kernel_gs_base, so existing
> tools that check the 'size' field can safely ignore it when
> reading older dumps.

Message nit: appending the field lets older tools ignore it in newer 
dumps; checking size lets newer tools detect its absence in older dumps. 
The current compatibility sentence conflates those directions.

Regards,
Akihiko Odaki

> 
> Signed-off-by: Zhengrong Li <[email protected]>
> ---
>   target/i386/arch_dump.c | 6 ++++++
>   1 file changed, 6 insertions(+)
> 
> diff --git a/target/i386/arch_dump.c b/target/i386/arch_dump.c
> index 16e47c4747..8ce2c7e9bb 100644
> --- a/target/i386/arch_dump.c
> +++ b/target/i386/arch_dump.c
> @@ -264,6 +264,8 @@ struct QEMUCPUState {
>        * by checking 'size' field.
>        */
>       uint64_t kernel_gs_base;
> +    uint8_t  is_crash_occurred_cpu;
> +    uint8_t  pad[7];
>   };
>   
>   typedef struct QEMUCPUState QEMUCPUState;
> @@ -279,6 +281,7 @@ static void copy_segment(QEMUCPUSegment *d, SegmentCache *s)
>   
>   static void qemu_get_cpustate(QEMUCPUState *s, CPUX86State *env)
>   {
> +    CPUState *cs = env_cpu(env);
>       memset(s, 0, sizeof(QEMUCPUState));
>   
>       s->version = QEMUCPUSTATE_VERSION;
> @@ -325,6 +328,9 @@ static void qemu_get_cpustate(QEMUCPUState *s, CPUX86State *env)
>   #ifdef TARGET_X86_64
>       s->kernel_gs_base = env->kernelgsbase;
>   #endif
> +    if (cs->crash_occurred) {
> +        s->is_crash_occurred_cpu = 1;
> +    }
>   }
>   
>   static inline int cpu_write_qemu_note(WriteCoreDumpFunction f,