Mahesh J Salgaonkar <mahesh@xxxxxxxxxxxxxxxxxx> writes:
> From: Mahesh Salgaonkar <mahesh@xxxxxxxxxxxxxxxxxx>
>
> This patch introduces a mce hook which is invoked at the time of guest
> exit to facilitate the host-side handling of machine check exception
> before the exception is passed on to the guest. This hook will be invoked
> from host virtual mode from KVM (before exiting the guest with
> KVM_EXIT_NMI reason) for machine check exception that occurs in the guest.
Hi Mahesh,
This patch doesn't meaningfully abstract anything.
opal_machine_check_guest() doesn't call opal, or do anything opal
specific. It just passes the evt struct back to code in mce.c, which is
where the struct came from in the first place.
> --- a/arch/powerpc/platforms/powernv/opal.c
> +++ b/arch/powerpc/platforms/powernv/opal.c
> @@ -479,6 +479,32 @@ int opal_machine_check(struct pt_regs *regs)
> return 0;
> }
>
> +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
> +/*
> + * opal_machine_check_guest() is a hook which is invoked at the time
> + * of guest exit to facilitate the host-side handling of machine check
> + * exception before the exception is passed on to the guest. This hook
> + * is invoked from host virtual mode from KVM (before exiting the guest
> + * with KVM_EXIT_NMI reason) for machine check exception that occurs in
> + * the guest.
> + *
> + * Currently no action is performed in the host other than printing the
> + * event information. The machine check exception is passed on to the
> + * guest kernel and the guest kernel will attempt for recovery.
> + */
> +int opal_machine_check_guest(struct machine_check_event *evt)
> +{
> + /* Print things out */
> + if (evt->version != MCE_V1) {
> + pr_err("Machine Check Exception, Unknown event version %d !\n",
> + evt->version);
> + return 0;
> + }
> + machine_check_print_event_info(evt);
> + return 0;
> +}
> +#endif
Called from kvmppc_handle_exit_hv():
+ if (ppc_md.machine_check_exception_guest)
+ ppc_md.machine_check_exception_guest(
+ &vcpu->arch.mce_evt);
break;
Just call machine_check_print_event_info() directly from
kvmppc_handle_exit_hv().
You'll need to export symbol it, but that's all AFAICS, I don't think it
even needs any #ifdefs.
If we ever want to do anything different we can change the code then.
cheers
