Re: [Xen-devel] [PATCH RFC] hvm: Allow triple fault to imply crash rather than reboot

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Mon, 2013-02-04 at 14:25 +0000, Andrew Cooper wrote:
> While the triple fault action on native hardware will result in a system
> reset, any modern operating system can and will make use of less violent
> reboot methods.  As a result, the most likely cause of a triple fault is a
> fatal software bug.
> 
> This patch allows the toolstack to indicate that a triple fault should mean a
> crash rather than a reboot.  The default of reboot still remains the same.

Just a random thought -- what about adding SHUTDOWN_triple_fault as an
explicit thing, then the toolstack can decide what to do?

> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> 
> diff -r 5af4f2ab06f3 -r 6f8c532df545 xen/arch/x86/hvm/hvm.c
> --- a/xen/arch/x86/hvm/hvm.c
> +++ b/xen/arch/x86/hvm/hvm.c
> @@ -1233,9 +1233,14 @@ void hvm_hlt(unsigned long rflags)
>  void hvm_triple_fault(void)
>  {
>      struct vcpu *v = current;
> +    struct domain * d = v->domain;
> +    u8 reason = d->arch.hvm_domain.params[HVM_PARAM_TRIPLE_FAULT_CRASH]
> +        ? SHUTDOWN_crash : SHUTDOWN_reboot;
> +
>      gdprintk(XENLOG_INFO, "Triple fault on VCPU%d - "
> -             "invoking HVM system reset.\n", v->vcpu_id);
> -    domain_shutdown(v->domain, SHUTDOWN_reboot);
> +             "invoking HVM system %s.\n", v->vcpu_id,
> +             reason == SHUTDOWN_crash ? "crash" : "reboot");
> +    domain_shutdown(v->domain, reason);
>  }
>  
>  void hvm_inject_trap(struct hvm_trap *trap)
> diff -r 5af4f2ab06f3 -r 6f8c532df545 xen/include/public/hvm/params.h
> --- a/xen/include/public/hvm/params.h
> +++ b/xen/include/public/hvm/params.h
> @@ -142,6 +142,9 @@
>  #define HVM_PARAM_ACCESS_RING_PFN   28
>  #define HVM_PARAM_SHARING_RING_PFN  29
>  
> -#define HVM_NR_PARAMS          31
> +/* Boolean: Should a triple fault imply crash rather than reboot? */
> +#define HVM_PARAM_TRIPLE_FAULT_CRASH 31
> +
> +#define HVM_NR_PARAMS          32
>  
>  #endif /* __XEN_PUBLIC_HVM_PARAMS_H__ */
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel