Re: [PATCH 3/3] xen/vm_event: Add safe to disable vm_event

[Jan Beulich <jbeulich@suse.com>]

On 15.05.2020 18:53, Tamas K Lengyel wrote:
> --- a/xen/arch/x86/hvm/hvm.c
> +++ b/xen/arch/x86/hvm/hvm.c
> @@ -563,15 +563,41 @@ void hvm_do_resume(struct vcpu *v)
>          v->arch.hvm.inject_event.vector = HVM_EVENT_VECTOR_UNSET;
>      }
>  
> -    if ( unlikely(v->arch.vm_event) && v->arch.monitor.next_interrupt_enabled )
> +    if ( unlikely(v->arch.vm_event) )
>      {
> -        struct x86_event info;
> +        struct domain *d = v->domain;

const

> +        if ( v->arch.monitor.next_interrupt_enabled )
> +        {
> +            struct x86_event info;
> +
> +            if ( hvm_get_pending_event(v, &info) )
> +            {
> +                hvm_monitor_interrupt(info.vector, info.type, info.error_code,
> +                                      info.cr2);
> +                v->arch.monitor.next_interrupt_enabled = false;
> +            }
> +        }
>  
> -        if ( hvm_get_pending_event(v, &info) )
> +        if ( d->arch.monitor.safe_to_disable )
>          {
> -            hvm_monitor_interrupt(info.vector, info.type, info.error_code,
> -                                  info.cr2);
> -            v->arch.monitor.next_interrupt_enabled = false;
> +            struct vcpu *check_vcpu;

const again, requiring a respective adjustment to patch 2.

> +            bool pending_op = false;
> +
> +            for_each_vcpu ( d, check_vcpu )
> +            {
> +                if ( vm_event_check_pending_op(check_vcpu) )
> +                {
> +                    pending_op = true;
> +                    break;
> +                }
> +            }
> +
> +            if ( !pending_op )
> +            {
> +                hvm_monitor_safe_to_disable();

This new function returns bool without the caller caring about the
return value.

Jan