Re: [PATCH] kvm: selftests: Fix cut-off of addr_gva2gpa lookup

[Paolo Bonzini]

On 4/14/22 15:56, Sean Christopherson wrote:
> > -	return (pte[index[0]].pfn * vm->page_size) + (gva & 0xfffu);
> > +	return ((vm_paddr_t)pte[index[0]].pfn * vm->page_size) + (gva & 0xfffu);
> This is but one of many paths that can get burned by pfn being 40 bits.  The
> most backport friendly fix is probably to add a pfn=>gpa helper and use that to
> place the myriad "pfn * vm->page_size" instances.
>
> For a true long term solution, my vote is to do away with the bit field struct
> and use #define'd masks and whatnot.

Yes, bitfields larger than 32 bits are a mess.

Paolo