linux-kernel - Re: [Part2 PATCH v6 13/38] crypto: ccp: Add Secure Encrypted Virtualization (SEV) command support

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Message-ID: <20171027201554.GH12039@nazgul.tnic>
Date:   Fri, 27 Oct 2017 22:15:54 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Brijesh Singh <brijesh.singh@....com>
Cc:     kvm@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        Gary Hook <gary.hook@....com>,
        Tom Lendacky <thomas.lendacky@....com>,
        linux-crypto@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [Part2 PATCH v6 13/38] crypto: ccp: Add Secure Encrypted
 Virtualization (SEV) command support

On Fri, Oct 27, 2017 at 06:28:38AM -0500, Brijesh Singh wrote:
> ... User can retry the command sometime later when nobody else is
> using the PSP.

That still doesn't prevent you from doing two things:

* make that fw_init_count a proper kref instead of your homegrown thing

* do not preemptively execute commands on the PSP if you can't possibly
know what the next command is going to be - instead, just put it in the
required state only when you really have to. I.e., don't do all that
unnecessary INIT -> CMD -> SHUTDOWN game for no reason.

Thx.

-- 
Regards/Gruss,
    Boris.

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