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From:   Peter Gonda <pgonda@google.com>
Date:   Fri, 26 Aug 2022 15:32:30 -0600
Message-ID: <CAMkAt6ryLh-gQYvmUYfxS3+CRwCLfK3Fby1W5NxxFLSK7M_v0w@mail.gmail.com>
Subject: Re: [PATCH v5 0/7] KVM: selftests: Implement ucall "pool" (for SEV)
To:     Sean Christopherson <seanjc@google.com>
Cc:     Paolo Bonzini <pbonzini@redhat.com>, Marc Zyngier <maz@kernel.org>,
        Anup Patel <anup@brainfault.org>,
        Paul Walmsley <paul.walmsley@sifive.com>,
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        Janosch Frank <frankja@linux.ibm.com>,
        Claudio Imbrenda <imbrenda@linux.ibm.com>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        James Morse <james.morse@arm.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Oliver Upton <oliver.upton@linux.dev>,
        Atish Patra <atishp@atishpatra.org>,
        David Hildenbrand <david@redhat.com>,
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On Thu, Aug 25, 2022 at 5:25 PM Sean Christopherson <seanjc@google.com> wrote:
>
> Non-KVM folks, y'all got pulled in because of the atomic_test_and_set_bit()
> patch.
>
> Rework the ucall infrastructure to use a pool of ucall structs to pass
> memory instead of using the guest's stack.  For confidential VMs with
> encrypted memory, e.g. SEV, the guest's stack "needs" to be private memory
> and so can't be used to communicate with the host.
>
> Convert all implementations to the pool as all of the complexity is hidden
> in common code, and supporting multiple interfaces adds its own kind of
> complexity.
>
> Tested on x86 and ARM, compile tested on s390 and RISC-V.
>

Thanks for the help on the ucall-pool Sean!

I rebased the SEV selftests on these and everything works as before

TESTED-BY: Peter Gonda <pgonda@google.com>