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Date:   Tue, 20 Oct 2020 09:06:58 +0100
From:   Christoph Hellwig <hch@infradead.org>
To:     "Kirill A. Shutemov" <kirill@shutemov.name>
Cc:     Dave Hansen <dave.hansen@linux.intel.com>,
        Andy Lutomirski <luto@kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Sean Christopherson <sean.j.christopherson@intel.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
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        Andrea Arcangeli <aarcange@redhat.com>,
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        "Edgecombe, Rick P" <rick.p.edgecombe@intel.com>,
        "Kleen, Andi" <andi.kleen@intel.com>,
        Liran Alon <liran.alon@oracle.com>,
        Mike Rapoport <rppt@kernel.org>, x86@kernel.org,
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        linux-kernel@vger.kernel.org,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Subject: Re: [RFCv2 05/16] x86/kvm: Make VirtIO use DMA API in KVM guest
Message-ID: <20201020080658.GA21238@infradead.org>
References: <20201020061859.18385-1-kirill.shutemov@linux.intel.com>
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NAK.  Any virtio implementation that needs special DMA OPS treatment
needs to set the VIRTIO_F_ACCESS_PLATFORM bit.  The only reason the
Xen hack existst is because it slipped in a long time ago and we can't
fix that any more.