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From:   Peter Gonda <pgonda@google.com>
Date:   Tue, 15 Nov 2022 14:48:28 -0700
Message-ID: <CAMkAt6qUpthB893PWXcNvdZbVmwDs1Ca-5BYwEsxnHEOM_TEsA@mail.gmail.com>
Subject: Re: [PATCH V4] virt: sev: Prevent IV reuse in SNP guest driver
To:     Borislav Petkov <bp@suse.de>
Cc:     thomas.lendacky@amd.com, Dionna Glaze <dionnaglaze@google.com>,
        Michael Roth <michael.roth@amd.com>,
        Haowen Bai <baihaowen@meizu.com>,
        Yang Yingliang <yangyingliang@huawei.com>,
        Marc Orr <marcorr@google.com>,
        David Rientjes <rientjes@google.com>,
        Ashish Kalra <Ashish.Kalra@amd.com>,
        linux-kernel@vger.kernel.org, kvm@vger.kernel.org
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On Tue, Nov 15, 2022 at 2:36 PM Borislav Petkov <bp@suse.de> wrote:
>
> On Mon, Nov 14, 2022 at 02:11:48PM -0700, Peter Gonda wrote:
> > Thanks for detailed review. Working on cleaning up the text for a V5.
>
> Yeah, and I have some questions in my reply which you haven't
> addressed...

Ah I was just applying answers to those in the comments/commit description.

I have replied back to your first post.

>
> > > > @@ -676,7 +712,7 @@ static int __init sev_guest_probe(struct platform_device *pdev)
> > > >       if (!snp_dev->response)
> > > >               goto e_free_request;
> > > >
> > > > -     snp_dev->certs_data = alloc_shared_pages(dev, SEV_FW_BLOB_MAX_SIZE);
> > > > +     snp_dev->certs_data = alloc_shared_pages(dev, sizeof(*snp_dev->certs_data));
> > >
> > > What's that change for?
> > >
> > > I went searching for that ->certs_data only ot realize that it is an
> > > array of size of SEV_FW_BLOB_MAX_SIZE elems.
> >
> > Do you want this change reverted? I liked the extra readability of the
> > sizeof(*snp_dev->certs_data) but its unnecessary for this change.
>
> Really?
>
> I think using a define which is a SIZE define is better. Especially if
> you look at
>
>         sizeof(*snp_dev->certs_data)
>
> and wonder what type ->certs_data is.
>
> And it's not like it'll go out of sync since it is an array of size,
> well, SEV_FW_BLOB_MAX_SIZE.
>

OK! I'll revert this part of the change.