From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id EF371C282EC for ; Tue, 18 Mar 2025 12:35:37 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tuW9y-0000Ou-9o; Tue, 18 Mar 2025 08:35:06 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tuW9v-0000Mc-L3 for qemu-devel@nongnu.org; Tue, 18 Mar 2025 08:35:03 -0400 Received: from smtp-out1.suse.de ([195.135.223.130]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1tuW9s-0005z0-Qx for qemu-devel@nongnu.org; Tue, 18 Mar 2025 08:35:02 -0400 Received: from hawking.nue2.suse.org (unknown [IPv6:2a07:de40:a101:3:92b1:1cff:fe69:ddc]) by smtp-out1.suse.de (Postfix) with ESMTP id EDE3F21C6B; Tue, 18 Mar 2025 12:34:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1742301298; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3gX5tV2h9AeeYUMvUvHUuJnAAol65fuiWYm/RGUYWE8=; b=vAPrZDdc1HkbCyYcJh4WYXoiNUUpavkfFl5cRh5yejiHMIGvFClWimhzgGm9UO8Hc8sUzo lNls6gCeXEpShSDW14ehOyu4InjQDHps58G7ZLIXjuFy/A/r/KbtyqoqQncoq8BfW5DvuA cgvhm9qdMgFZfs8kmJHJ5AR0GjBIF8I= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1742301298; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3gX5tV2h9AeeYUMvUvHUuJnAAol65fuiWYm/RGUYWE8=; b=xmpD9D7sM8hFPuWQ+j2e82oRvVsD+DIcofMXTnYrHgxa3BuI/GBW4kMBysTY3kmKfqYbtY tV0xvhB5MLEF9EDw== Authentication-Results: smtp-out1.suse.de; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=SzQejDmO; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=egLyXCCi DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1742301297; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3gX5tV2h9AeeYUMvUvHUuJnAAol65fuiWYm/RGUYWE8=; b=SzQejDmOMj3lET8X5RY+W+YkU0OD+t1ZzcdDWR/h9pV6Yi41SkfJj1xGK8Fo6GO6OUv7tX a0/ro9moWJ3PibXn9CpVzMSkDjHp80kROCV2WaZ2f4QfVNvVxMJJu6b5yJcBvH5VnjcruM twK6zw38uSm3xkgPiML3Nf4AuHdrNes= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1742301297; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=3gX5tV2h9AeeYUMvUvHUuJnAAol65fuiWYm/RGUYWE8=; b=egLyXCCiMiwjT8z6InQATTpaDlFSy/SBoTuLnVMa9XtCJDbK0ocimGHBIm7GRyMhMHGBJu K0I24yXdj0dOvABQ== Received: by hawking.nue2.suse.org (Postfix, from userid 17005) id CDE104A0561; Tue, 18 Mar 2025 13:34:57 +0100 (CET) From: Andreas Schwab To: Daniel P. =?utf-8?Q?Berrang=C3=A9?= Cc: Peter Maydell , Helge Deller , qemu-devel@nongnu.org Subject: Re: Generic way to detect qemu linux-user emulation In-Reply-To: ("Daniel P. =?utf-8?Q?Berrang?= =?utf-8?Q?=C3=A9=22's?= message of "Tue, 18 Mar 2025 11:58:38 +0000") References: Date: Tue, 18 Mar 2025 13:34:57 +0100 Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Spamd-Result: default: False [2.60 / 50.00]; BAYES_HAM(-2.99)[99.97%]; HFILTER_HOSTNAME_UNKNOWN(2.50)[]; RDNS_NONE(2.00)[]; ONCE_RECEIVED(1.20)[]; HFILTER_HELO_IP_A(1.00)[hawking.nue2.suse.org]; NEURAL_HAM_LONG(-1.00)[-1.000]; HFILTER_HELO_NORES_A_OR_MX(0.30)[hawking.nue2.suse.org]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-0.988]; RCVD_NO_TLS_LAST(0.10)[]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; DIRECT_TO_MX(0.00)[Gnus/5.13 (Gnus v5.13)]; ARC_NA(0.00)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; MIME_TRACE(0.00)[0:+]; FREEMAIL_ENVRCPT(0.00)[gmx.de]; FREEMAIL_CC(0.00)[linaro.org,gmx.de,nongnu.org]; TO_DN_SOME(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; RCPT_COUNT_THREE(0.00)[4]; RCVD_COUNT_ONE(0.00)[1]; DKIM_TRACE(0.00)[suse.de:+]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:email,suse.de:dkim,suse.de:mid] X-Spamd-Bar: ++ X-Rspamd-Queue-Id: EDE3F21C6B X-Rspamd-Action: no action X-Rspamd-Server: rspamd2.dmz-prg2.suse.org Received-SPF: pass client-ip=195.135.223.130; envelope-from=schwab@suse.de; helo=smtp-out1.suse.de X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 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_MED=-2.3, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 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: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Mär 18 2025, Daniel P. Berrangé wrote: > Whereever practical, it is preferrable to check a discrete feature > or behaviour in a functional way, rather than matching on "is it QEMU" Do you know a way to detect support for CLONE_VFORK that isn't too expensive? -- Andreas Schwab, SUSE Labs, schwab@suse.de GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7 "And now for something completely different."