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[82.30.61.225]) by smtp.gmail.com with ESMTPSA id n5sm19420819wrm.3.2022.02.16.09.40.46 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Feb 2022 09:40:46 -0800 (PST) Date: Wed, 16 Feb 2022 17:40:44 +0000 From: "Dr. David Alan Gilbert" To: Thomas Huth Subject: Re: [PATCH 3/3] x86: Switch to q35 as the default machine type Message-ID: References: <20220215162537.605030-1-dgilbert@redhat.com> <20220215162537.605030-4-dgilbert@redhat.com> <20220216105808.77kqhmsagz3ej74h@sirius.home.kraxel.org> MIME-Version: 1.0 In-Reply-To: User-Agent: Mutt/2.1.5 (2021-12-30) Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dgilbert@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Received-SPF: pass client-ip=170.10.129.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.083, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: eduardo@habkost.net, Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= , mst@redhat.com, quintela@redhat.com, qemu-devel@nongnu.org, Gerd Hoffmann , pbonzini@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Thomas Huth (thuth@redhat.com) wrote: > On 16/02/2022 12.01, Dr. David Alan Gilbert wrote: > > * Gerd Hoffmann (kraxel@redhat.com) wrote: > > > Hi, > > > > Given the semantic differences from 'i440fx', changing the default > > > > machine type has effects that are equivalent to breaking command > > > > line syntax compatibility, which is something we've always tried > > > > to avoid. > > > > > > And if we are fine breaking backward compatibility I'd rather *not* pick > > > a default, effectively making -M $something mandatory, similar to arm. > > > > Oh, that's probably easy to do; what are other peoples thoughts on > > that? > > I agree with Gerd. Getting rid of a default machine on x86 is likely better > than silently changing it to q35. But I'd maybe say that this should go > through the deprecation process first? So just adding something like the following under 'System emulator machines': x86 default machine type ------------------------ x86 currently defaults to the very old ```pc``` machine type which is based on the very old ```i440f``` chipset. This default will be removed and the user will be required to specify a machine type explicitly using -M; users are encouraged to switch to the not quite as old ```q35``` machine types. (This option is going to take a lot more work switching all the test cases over; in my world here I'd only changed the tests that broke on q35, now everything is going to need to specify a type). Dave > Thomas > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK