Re: [PATCH v5 07/14] x86/sev: Move and reorganize sev guest request api

[Tom Lendacky]

On 11/1/23 23:28, Nikunj A. Dadhania wrote:
> On 10/31/2023 12:46 AM, Tom Lendacky wrote:
> > On 10/30/23 01:36, Nikunj A Dadhania wrote:
> > > For enabling Secure TSC, SEV-SNP guests need to communicate with the
> > > AMD Security Processor early during boot. Many of the required
> > > functions are implemented in the sev-guest driver and therefore not
> > > available at early boot. Move the required functions and provide an
> > > API to the driver to assign key and send guest request.
> > >
> > > Signed-off-by: Nikunj A Dadhania <nikunj@xxxxxxx>
> > > ---

> > > +static void snp_inc_msg_seqno(struct snp_guest_dev *snp_dev)
> > > +{
> > > +    u32 *os_area_msg_seqno = snp_get_os_area_msg_seqno(snp_dev->vmpck_id);
> > > +
> > > +    if (!os_area_msg_seqno) {
> > > +        pr_err("SNP unable to get message sequence counter\n");
> > > +        return;
> > > +    }
> >
> > I probably missed this in the other patch or even when the driver was first created, but shouldn't we have a lockdep_assert_held() here, too, before updating the count?
>
> As per the current code flow, snp_get_msg_seqno() is always called before snp_inc_msg_seqno(), maybe because of that the check wasnt there. It still makes sense to have a lockdep_assert_held() in snp_inc_msg_seqno().
>
> Should I add this change as a separate fix ?

It can be sent as a separate patch (I don't think it is a fix) either 
before or after this series.

Thanks,
Tom

> >