{"id":2197502,"url":"http://patchwork.ozlabs.org/api/1.0/patches/2197502/?format=json","project":{"id":14,"url":"http://patchwork.ozlabs.org/api/1.0/projects/14/?format=json","name":"QEMU Development","link_name":"qemu-devel","list_id":"qemu-devel.nongnu.org","list_email":"qemu-devel@nongnu.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20260218015151.4052-7-graf@amazon.com>","date":"2026-02-18T01:51:46","name":"[06/10] target/arm/cpu64: Allow -host for nitro","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"4f84a4520ca0e4b6b9525b4728d97b4ccfce1ef3","submitter":{"id":76572,"url":"http://patchwork.ozlabs.org/api/1.0/people/76572/?format=json","name":"Alexander Graf","email":"graf@amazon.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/qemu-devel/patch/20260218015151.4052-7-graf@amazon.com/mbox/","series":[{"id":492503,"url":"http://patchwork.ozlabs.org/api/1.0/series/492503/?format=json","date":"2026-02-18T01:51:40","name":"Native Nitro Enclaves support","version":1,"mbox":"http://patchwork.ozlabs.org/series/492503/mbox/"}],"check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2197502/checks/","tags":{},"headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=amazon.com header.i=@amazon.com header.a=rsa-sha256\n header.s=amazoncorp2 header.b=UXRY5C0G;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; 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a=rsa-sha256; c=relaxed/relaxed;\n d=amazon.com; i=@amazon.com; q=dns/txt; s=amazoncorp2;\n t=1771379581; x=1802915581;\n h=from:to:cc:subject:date:message-id:in-reply-to:\n references:mime-version:content-transfer-encoding;\n bh=uVNVDznm7NxQ+bwTqP9jZD0VXeg2067NIquqLqqPp8k=;\n b=UXRY5C0G990DBgrw/dvKvQujZca4G5QBODoCfh1ikdtEG9cTAbVUlRZ9\n SZnv1lYQn3U/RuD1Lw7nmAiZUW3iTt8xd5WLMB2m8vhX/32zil0GfdpPS\n iU67TWv6lRkG1leUY8k+U5vr1PIfxn4ZG6oHe84Tu6TvECqnoKhbp9pAa\n GZkJsSFqlUSRFlFrhqdzepIi/qC1T0D2tEqKJUb0VGuP2NgzzxMQmRdaD\n Zqb1dbRi1Sh0zOMg+Er9bF3CvUvjy77tALU5Y+uFaXObSvZ3Y8zUH8mAi\n 3fP0k0ed0Raw0u29596c5q587ee6HWLdaA1Ztc9LRr17rJ01zIbzrHHeN g==;","X-CSE-ConnectionGUID":"ec2gWyq0ToGqRTSbtgy7Gw==","X-CSE-MsgGUID":"CyXLfvGWR6OfJac8E+6vEQ==","X-IronPort-AV":"E=Sophos;i=\"6.21,297,1763424000\"; d=\"scan'208\";a=\"13037355\"","X-Farcaster-Flow-ID":"37763521-d57a-4bf4-8565-5edb81b6cdf3","From":"Alexander Graf ","To":"","CC":", Peter Maydell , \"Thomas\n Huth\" , , ,\n , , Cornelia Huck\n , , Dorjoy Chowdhury\n , Pierrick Bouvier ,\n Paolo Bonzini , Tyler Fanelli ,\n , ","Subject":"[PATCH 06/10] target/arm/cpu64: Allow -host for nitro","Date":"Wed, 18 Feb 2026 01:51:46 +0000","Message-ID":"<20260218015151.4052-7-graf@amazon.com>","X-Mailer":"git-send-email 2.47.1","In-Reply-To":"<20260218015151.4052-1-graf@amazon.com>","References":"<20260218015151.4052-1-graf@amazon.com>","MIME-Version":"1.0","X-Originating-IP":"[172.19.99.218]","X-ClientProxiedBy":"EX19D032UWA001.ant.amazon.com (10.13.139.62) To\n EX19D020UWC004.ant.amazon.com (10.13.138.149)","Content-Type":"text/plain; charset=\"us-ascii\"","Content-Transfer-Encoding":"7bit","Received-SPF":"pass client-ip=52.35.192.45;\n envelope-from=prvs=502105d20=graf@amazon.de;\n helo=pdx-out-011.esa.us-west-2.outbound.mail-perimeter.amazon.com","X-Spam_score_int":"-19","X-Spam_score":"-2.0","X-Spam_bar":"--","X-Spam_report":"(-2.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.043,\n DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1,\n HEADER_FROM_DIFFERENT_DOMAINS=0.001, RCVD_IN_DNSWL_NONE=-0.0001,\n RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=0.001,\n SPF_HELO_NONE=0.001, T_SPF_PERMERROR=0.01,\n UNPARSEABLE_RELAY=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":"qemu development ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org"},"content":"The nitro accel does not actually make use of CPU emulation or details:\nIt always uses the host CPU regardless of configuration. Machines for\nthe nitro accel select the host CPU type as default to have a clear\nstatement of the above and to have a unified cpu type across all\nsupported architectures.\n\nThe arm64 logic on Linux currently only allows -cpu host for KVM based\nvirtual machines. Add a special case for nitro so that when the nitro\naccel is active, it allows use of the host cpu type.\n\nSigned-off-by: Alexander Graf \n---\n target/arm/cpu64.c | 8 ++++++++\n 1 file changed, 8 insertions(+)","diff":"diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c\nindex 5d7c6b7fbb..c01051f038 100644\n--- a/target/arm/cpu64.c\n+++ b/target/arm/cpu64.c\n@@ -765,6 +765,14 @@ static void aarch64_a53_initfn(Object *obj)\n static void aarch64_host_initfn(Object *obj)\n {\n ARMCPU *cpu = ARM_CPU(obj);\n+\n+#if defined(CONFIG_NITRO)\n+ if (nitro_enabled()) {\n+ /* The nitro accel uses -cpu host, but does not actually consume it */\n+ return;\n+ }\n+#endif\n+\n #if defined(CONFIG_KVM)\n kvm_arm_set_cpu_features_from_host(cpu);\n if (arm_feature(&cpu->env, ARM_FEATURE_AARCH64)) {\n","prefixes":["06/10"]}