Re: [PATCH v5 1/6] x86/sev: Fix calculation of end address based on number of pages

[Tom Lendacky]

On 9/27/22 12:10, Dave Hansen wrote:
> On 9/27/22 10:04, Tom Lendacky wrote:
> > --- a/arch/x86/kernel/sev.c
> > +++ b/arch/x86/kernel/sev.c
> > @@ -649,7 +649,7 @@ static void pvalidate_pages(unsigned long vaddr, unsigned int npages, bool valid
> >   	int rc;
> >   
> >   	vaddr = vaddr & PAGE_MASK;
> > -	vaddr_end = vaddr + (npages << PAGE_SHIFT);
> > +	vaddr_end = vaddr + ((unsigned long)npages << PAGE_SHIFT);
>
> Could we please just fix the fragile typing that cascaded down to this
> point?
>
> Shouldn't 'npages' in this interface be a long?

I'll take a look at that.

Thanks,
Tom

> > struct x86_guest {
> >          void (*enc_status_change_prepare)(unsigned long vaddr, int npages, bool enc);
> >          bool (*enc_status_change_finish)(unsigned long vaddr, int npages, bool enc);
> >          bool (*enc_tlb_flush_required)(bool enc);
> >          bool (*enc_cache_flush_required)(void);
> > };