Re: [PATCH v6 02/76] KVM: SVM: Add GHCB definitions

Joerg Roedel
2020-08-25T09:22:35Z

On Mon, Aug 24, 2020 at 12:44:51PM +0200, Borislav Petkov wrote:
> On Mon, Aug 24, 2020 at 10:53:57AM +0200, Joerg Roedel wrote:
> > static inline void __unused_size_checks(void)
> > {
> > - BUILD_BUG_ON(sizeof(struct vmcb_save_area) != 0x298);
> > + BUILD_BUG_ON(sizeof(struct vmcb_save_area) != 1032);
> > BUILD_BUG_ON(sizeof(struct vmcb_control_area) != 256);
> > + BUILD_BUG_ON(sizeof(struct ghcb) != 4096);
>
> Could those naked numbers be proper, meaningfully named defines?

I don't think so, if I look at the history of these checks their whole
purpose seems to be to alert the developer/maintainer when their size
changes and that they might not fit on the stack anymore. But that is
taken care of in patch 1.

Regards,

Joerg