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David Alan Gilbert" , mopsfelder@gmail.com, qemu-ppc@nongnu.org, =?UTF-8?Q?C=C3=A9dric_Le_Goater?= , qemu-RISC-V Content-Type: text/plain; charset="UTF-8" Received-SPF: pass client-ip=2607:f8b0:4864:20::b34; envelope-from=peter.maydell@linaro.org; helo=mail-yb1-xb34.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Tue, 10 May 2022 at 10:01, Thomas Huth wrote: > > On 10/05/2022 10.54, Markus Armbruster wrote: > > Thomas Huth writes: > > > > [...] > > > >> I once suggested in the past already that we should maybe get rid of > >> the 32-bit variants in case the 64-bit variant is a full superset, so > >> we can save compile- and test times (which is quite a bit for QEMU), > >> but I've been told that the 32-bit variants are mostly still required > >> for supporting KVM on 32-bit host machines. > > > > Do we still care for 32-bit host machines? > > As long as the Linux kernel still supports 32-bit KVM virtualization, I > think we have to keep the userspace around for that, too. > > But I wonder why we're keeping qemu-system-arm around? 32-bit KVM support > for ARM has been removed with Linux kernel 5.7 as far as I know, so I think > we could likely drop the qemu-system-arm nowadays, too? Peter, Richard, > what's your opinion on this? Two main reasons, I think: * command-line compatibility (ie there are lots of command lines out there using that binary name) * nobody has yet cared enough to come up with a plan for what we want to do differently for these 32-bit architectures, so the default is "keep doing what we always have" In particular, I don't want to get rid of qemu-system-arm as the *only* 32-bit target binary we drop. Either we stick with what we have or we have a larger plan for sorting this out consistently across target architectures. -- PMM