Re: [Xen-devel] [PATCH v5 1/6] x86: allow IRQ to be disabled for resource access

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 21.01.15 at 12:19, <chao.p.peng@xxxxxxxxxxxxxxx> wrote:
> --- a/xen/arch/x86/platform_hypercall.c
> +++ b/xen/arch/x86/platform_hypercall.c
> @@ -90,7 +90,9 @@ static void check_resource_access(struct 
> xen_resource_access *ra)
>          int ret = 0;
>          xenpf_resource_entry_t *entry = ra->entries + i;
>  
> -        if ( entry->rsvd )
> +        /* DISABLE_IRQ flag should never be set for the last entry */
> +        if ( entry->flags & XEN_RESOURCE_ENTRY_FLAGS_DISABLE_IRQ &&

This needs checking that all the other 31 bits are clear as well as
parenthesizing.

> @@ -124,11 +126,19 @@ static void resource_access(void *info)
>  {
>      struct xen_resource_access *ra = info;
>      unsigned int i;
> +    unsigned long irqflags = 0;
> +    bool_t irq_disabled = 0;

I don't think you need two variables for this - this is x86-only code
and EFLAGS bit 1 is always set.

Jan


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