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

[Dave Hansen]

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?

> 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);
> };