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[95.120.215.139]) by smtp.gmail.com with ESMTPSA id z9sm5560762wrp.26.2019.09.25.00.33.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Sep 2019 00:33:26 -0700 (PDT) References: <20190924124433.96810-1-slp@redhat.com> <20190924124433.96810-8-slp@redhat.com> <20190925050629.lg5w6vvikxtgddy6@sirius.home.kraxel.org> User-agent: mu4e 1.2.0; emacs 26.2 From: Sergio Lopez To: Gerd Hoffmann Cc: qemu-devel@nongnu.org, mst@redhat.com, imammedo@redhat.com, marcel.apfelbaum@gmail.com, pbonzini@redhat.com, rth@twiddle.net, ehabkost@redhat.com, philmd@redhat.com, lersek@redhat.com, mtosatti@redhat.com, kvm@vger.kernel.org Subject: Re: [PATCH v4 7/8] docs/microvm.txt: document the new microvm machine type In-reply-to: <20190925050629.lg5w6vvikxtgddy6@sirius.home.kraxel.org> Date: Wed, 25 Sep 2019 09:33:12 +0200 Message-ID: <87impgsudj.fsf@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org --=-=-= Content-Type: text/plain Gerd Hoffmann writes: > Hi, > >> +microvm.kernel-cmdline=bool (Set off to disable adding virtio-mmio devices to the kernel cmdline) > > Hmm, is that the long-term plan? IMO the virtio-mmio devices should be > discoverable somehow. ACPI, or device-tree, or fw_cfg, or ... I'd say that depends on the machine type. ARM's virt and vexpress do support virtio-mmio devices, adding them to a generated DTB. For microvm that's simply not worth it. Fiddling with the command line achieves the same result without any significant drawbacks, with less code and less consumed cycles on both sides. >> +As no current FW is able to boot from a block device using virtio-mmio >> +as its transport, > > To fix that the firmware must be able to find the virtio-mmio devices. No FW supports modern virtio-mmio transports anyway. And, from microvm's perspective, there's little incentive to change this situation, given that it's main use cases (serverless computing and VM-isolated containers) will run with an external kernel. Thanks, Sergio. --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEvtX891EthoCRQuii9GknjS8MAjUFAl2LGDgACgkQ9GknjS8M AjUGFA/9En3xpwaRRlk8noOWngoaHWQN83Ugk1tJ6/lQackkpCwakxv+Bhupj9C4 bdw0Fa7nwIKDfEWx5j/iQH8ig1pyw7qWAlJaZuo09XAW2qkBdIvacyTuIK9z/Xxz C2IXRdIY1X90ovNqrZPCX48TtUlGBgCBB8CTMBMktKmA1aqcGahzzHYJE7B24iRo onXEy5w3Hss6ln+voTgOvLHtrJ+qBAE92h+UjdICIa748gGWqGI8HjqEIDjMUZfb VjxlzR+0U92kOGH6bQmc+inVENltSAlyEC5PuzKUZ8X24VGFae1EHY3nAB9wKtPI uxGsqNYJIxliWSwMOEWJzde81b3H30l9dYhxbQKfZri4oOIfr/EG4pAARSKjsZBI pZMe9C5eNeCWcfaHA59SHR7Sw4XBdgU+xekL8RR5lCgYz4DYPlVd+1ny6IKcUICV aZdY0SYC0eOWVHaAsphjEHf6c+WTQ9CZkC/Wzha8UgGMsL3s0oU6nRcUhIe1LVL/ Gv75N19Ji+XW2fSRYLi7WMXL7hpgQxWzJ4H8G4ijb88tBtHlGttHlnxtj7g/PIvp 9w90y+xdK6JXzRYOTwGzN8TSMBmUeEkgUT2EiWCPZNCAZrze0WliEktUBN1g+rsQ c74pQhEfC8cAPWMHpGgn1/vsz7K8YOi6KDuoPNpcVOEAkBNcjhs= =McNV -----END PGP SIGNATURE----- --=-=-=--