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Message-ID: <80a69f94-23ca-3ca9-4c77-14e09683dc7d@redhat.com>
Date:   Thu, 21 Oct 2021 17:39:34 +0200
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Subject: Re: [RFC 06/16] KVM: selftests: add library for creating/interacting
 with SEV guests
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To:     Michael Roth <michael.roth@amd.com>,
        linux-kselftest@vger.kernel.org
Cc:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org, x86@kernel.org,
        Nathan Tempelman <natet@google.com>,
        Marc Orr <marcorr@google.com>,
        Steve Rutherford <srutherford@google.com>,
        Sean Christopherson <seanjc@google.com>,
        Mingwei Zhang <mizhang@google.com>,
        Brijesh Singh <brijesh.singh@amd.com>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        Varad Gautam <varad.gautam@suse.com>,
        Shuah Khan <shuah@kernel.org>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        David Woodhouse <dwmw@amazon.co.uk>,
        Ricardo Koller <ricarkol@google.com>,
        Jim Mattson <jmattson@google.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Joerg Roedel <joro@8bytes.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "H . Peter Anvin" <hpa@zytor.com>
References: <20211005234459.430873-1-michael.roth@amd.com>
 <20211006203710.13326-1-michael.roth@amd.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
In-Reply-To: <20211006203710.13326-1-michael.roth@amd.com>
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On 06/10/21 22:37, Michael Roth wrote:
> +struct sev_sync_data {
> +	uint32_t token;
> +	bool pending;
> +	bool done;
> +	bool aborted;
> +	uint64_t info;
> +};
> +

Please add a comment explaining roughly the design and what the fields 
are for.  Maybe the bools can be replaced by an enum { DONE, ABORT, 
SYNC, RUNNING } (running is for pending==false)?

Also, for the part that you can feel free to ignore: this seems to be 
similar to the ucall mechanism.  Is it possible to implement the ucall 
interface in terms of this one (or vice versa)?

One idea could be to:

- move ucall to the main lib/ directory

- make it use a struct of function pointers, whose default 
implementation would be in the existing lib/ARCH/ucall.c files

- add a function to register the struct for the desired implementation

- make sev.c register its own implementation

Thanks,

Paolo