Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Message-ID: <4aa51c58-63f5-c7de-f8e5-f4184fd1c822@linux.intel.com>
Date:   Tue, 12 Oct 2021 14:24:07 -0700
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101
 Thunderbird/91.2.0
Subject: Re: [PATCH v5 12/16] PCI: Add pci_iomap_host_shared(),
 pci_iomap_host_shared_range()
Content-Language: en-US
To:     "Michael S. Tsirkin" <mst@redhat.com>,
        Dan Williams <dan.j.williams@intel.com>
Cc:     Kuppuswamy Sathyanarayanan 
        <sathyanarayanan.kuppuswamy@linux.intel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Peter Zijlstra <peterz@infradead.org>,
        Andy Lutomirski <luto@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>,
        Richard Henderson <rth@twiddle.net>,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        James E J Bottomley <James.Bottomley@hansenpartnership.com>,
        Helge Deller <deller@gmx.de>,
        "David S . Miller" <davem@davemloft.net>,
        Arnd Bergmann <arnd@arndb.de>,
        Jonathan Corbet <corbet@lwn.net>,
        Paolo Bonzini <pbonzini@redhat.com>,
        David Hildenbrand <david@redhat.com>,
        Andrea Arcangeli <aarcange@redhat.com>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Peter H Anvin <hpa@zytor.com>,
        Dave Hansen <dave.hansen@intel.com>,
        Tony Luck <tony.luck@intel.com>,
        Kirill Shutemov <kirill.shutemov@linux.intel.com>,
        Sean Christopherson <seanjc@google.com>,
        Kuppuswamy Sathyanarayanan <knsathya@kernel.org>,
        X86 ML <x86@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux PCI <linux-pci@vger.kernel.org>,
        linux-alpha@vger.kernel.org, linux-mips@vger.kernel.org,
        linux-parisc@vger.kernel.org, sparclinux@vger.kernel.org,
        linux-arch <linux-arch@vger.kernel.org>,
        Linux Doc Mailing List <linux-doc@vger.kernel.org>,
        virtualization@lists.linux-foundation.org,
        "Reshetova, Elena" <elena.reshetova@intel.com>
References: <20211009003711.1390019-1-sathyanarayanan.kuppuswamy@linux.intel.com>
 <20211009003711.1390019-13-sathyanarayanan.kuppuswamy@linux.intel.com>
 <20211009053103-mutt-send-email-mst@kernel.org>
 <CAPcyv4hDhjRXYCX_aiOboLF0eaTo6VySbZDa5NQu2ed9Ty2Ekw@mail.gmail.com>
 <0e6664ac-cbb2-96ff-0106-9301735c0836@linux.intel.com>
 <CAPcyv4g0v0YHZ-okxf4wwVCYxHotxdKwsJpZGkoT+fhvvAJEFg@mail.gmail.com>
 <9302f1c2-b3f8-2c9e-52c5-d5a4a2987409@linux.intel.com>
 <CAPcyv4hG0HcbUO8Mb=ccDp5Bz3RJNkAJwKwNzRkQ1gCMpp_OMQ@mail.gmail.com>
 <20211012171628-mutt-send-email-mst@kernel.org>
From:   Andi Kleen <ak@linux.intel.com>
In-Reply-To: <20211012171628-mutt-send-email-mst@kernel.org>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk


On 10/12/2021 2:18 PM, Michael S. Tsirkin wrote:
> On Tue, Oct 12, 2021 at 02:14:44PM -0700, Dan Williams wrote:
>> Especially in this case where the virtio use case being
>> opted-in is *already* in a path that has been authorized by the
>> device-filter policy engine.
> That's a good point. Andi, how about setting a per-device flag
> if its ID has been allowed and then making pci_iomap create
> a shared mapping transparently?

Yes for pci_iomap we could do that.

If someone uses raw ioremap without a device it won't work, but I don't 
think that's the case for virtio at least.

I suppose we could solve that problem if it actually happens.

-Andi