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GET /api/1.1/patches/2225174/?format=api
{ "id": 2225174, "url": "http://patchwork.ozlabs.org/api/1.1/patches/2225174/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20260420140552.104369-5-eric.auger@redhat.com/", "project": { "id": 14, "url": "http://patchwork.ozlabs.org/api/1.1/projects/14/?format=api", "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": "<20260420140552.104369-5-eric.auger@redhat.com>", "date": "2026-04-20T14:03:54", "name": "[v10,4/7] target/arm/cpu64: Mitigate migration failures due to spurious TCR_EL1, PIRE0_EL1 and PIR_EL1", "commit_ref": null, "pull_url": null, "state": "new", "archived": false, "hash": "a78464ae25a22deb3a1f95e2d25c578eb59a069c", "submitter": { "id": 69187, "url": "http://patchwork.ozlabs.org/api/1.1/people/69187/?format=api", "name": "Eric Auger", "email": "eric.auger@redhat.com" }, "delegate": null, "mbox": "http://patchwork.ozlabs.org/project/qemu-devel/patch/20260420140552.104369-5-eric.auger@redhat.com/mbox/", "series": [ { "id": 500612, "url": "http://patchwork.ozlabs.org/api/1.1/series/500612/?format=api", "web_url": "http://patchwork.ozlabs.org/project/qemu-devel/list/?series=500612", "date": "2026-04-20T14:03:52", "name": "[v10,1/7] target/arm/cpu: Introduce the infrastructure for cpreg migration tolerances", "version": 10, "mbox": "http://patchwork.ozlabs.org/series/500612/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/patches/2225174/comments/", "check": "pending", "checks": "http://patchwork.ozlabs.org/api/patches/2225174/checks/", "tags": {}, "headers": { "Return-Path": "<qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org>", "X-Original-To": "incoming@patchwork.ozlabs.org", "Delivered-To": "patchwork-incoming@legolas.ozlabs.org", "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256\n header.s=mimecast20190719 header.b=HES7Agvu;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; helo=lists1p.gnu.org;\n envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n receiver=patchwork.ozlabs.org)" ], "Received": [ "from lists1p.gnu.org (lists1p.gnu.org [209.51.188.17])\n\t(using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fznQ72PxCz1yGs\n\tfor <incoming@patchwork.ozlabs.org>; Tue, 21 Apr 2026 00:08:15 +1000 (AEST)", "from localhost ([::1] helo=lists1p.gnu.org)\n\tby lists1p.gnu.org with esmtp (Exim 4.90_1)\n\t(envelope-from <qemu-devel-bounces@nongnu.org>)\n\tid 1wEpH6-00035X-QY; Mon, 20 Apr 2026 10:07:00 -0400", "from eggs.gnu.org ([2001:470:142:3::10])\n by lists1p.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from <eric.auger@redhat.com>)\n id 1wEpGn-00031E-4V\n for qemu-devel@nongnu.org; Mon, 20 Apr 2026 10:06:38 -0400", "from us-smtp-delivery-124.mimecast.com ([170.10.133.124])\n by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256)\n (Exim 4.90_1) (envelope-from <eric.auger@redhat.com>)\n id 1wEpGb-0001Ov-Hp\n for qemu-devel@nongnu.org; Mon, 20 Apr 2026 10:06:28 -0400", "from mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com\n (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by\n relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3,\n cipher=TLS_AES_256_GCM_SHA384) id us-mta-292-vfXhS75uNo2weegzwuybVQ-1; Mon,\n 20 Apr 2026 10:06:20 -0400", "from mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com\n (mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.93])\n (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest\n SHA256)\n (No client certificate requested)\n by mx-prod-mc-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS\n id 7AB991800366; Mon, 20 Apr 2026 14:06:18 +0000 (UTC)", "from laptop.redhat.com (unknown [10.44.32.74])\n by mx-prod-int-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTP\n id 5A23D180047F; Mon, 20 Apr 2026 14:06:14 +0000 (UTC)" ], "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com;\n s=mimecast20190719; t=1776693983;\n h=from:from:reply-to:subject:subject:date:date:message-id:message-id:\n to:to:cc:mime-version:mime-version:content-type:content-type:\n content-transfer-encoding:content-transfer-encoding:\n in-reply-to:in-reply-to:references:references;\n bh=+l+uWChkkozwf5QeJqHEsWEwd/BGRJHJ7CnI9tN5Jjo=;\n b=HES7Agvu5AUhbjDzupOfopnS97DaPuMxdIVc2kqEen+znBg0HpX5JU2gYlWX8DaseKcmkH\n UFUOvBZv89yi8HbanjQPhMqZJ0RkWQUlICY/sPloyyoBAsI/nb//Qi4eJCukKJRfHu/xji\n v1r6iFRZiqZS3+Y9fWm18n4fEwCfB/A=", "X-MC-Unique": "vfXhS75uNo2weegzwuybVQ-1", "X-Mimecast-MFC-AGG-ID": "vfXhS75uNo2weegzwuybVQ_1776693978", "From": "Eric Auger <eric.auger@redhat.com>", "To": "eric.auger.pro@gmail.com, eric.auger@redhat.com, qemu-devel@nongnu.org,\n qemu-arm@nongnu.org, peter.maydell@linaro.org, cohuck@redhat.com,\n sebott@redhat.com, peterx@redhat.com, philmd@linaro.org,\n alex.bennee@linaro.org", "Subject": "[PATCH v10 4/7] target/arm/cpu64: Mitigate migration failures due to\n spurious TCR_EL1, PIRE0_EL1 and PIR_EL1", "Date": "Mon, 20 Apr 2026 16:03:54 +0200", "Message-ID": "<20260420140552.104369-5-eric.auger@redhat.com>", "In-Reply-To": "<20260420140552.104369-1-eric.auger@redhat.com>", "References": "<20260420140552.104369-1-eric.auger@redhat.com>", "MIME-Version": "1.0", "Content-Type": "text/plain; charset=UTF-8", "Content-Transfer-Encoding": "8bit", "X-Scanned-By": "MIMEDefang 3.4.1 on 10.30.177.93", "Received-SPF": "pass client-ip=170.10.133.124;\n envelope-from=eric.auger@redhat.com; helo=us-smtp-delivery-124.mimecast.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, DKIMWL_WL_HIGH=-0.001,\n DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,\n RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_PASS=-0.001,\n 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": "qemu development <qemu-devel.nongnu.org>", "List-Unsubscribe": "<https://lists.nongnu.org/mailman/options/qemu-devel>,\n <mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>", "List-Archive": "<https://lists.nongnu.org/archive/html/qemu-devel>", "List-Post": "<mailto:qemu-devel@nongnu.org>", "List-Help": "<mailto:qemu-devel-request@nongnu.org?subject=help>", "List-Subscribe": "<https://lists.nongnu.org/mailman/listinfo/qemu-devel>,\n <mailto:qemu-devel-request@nongnu.org?subject=subscribe>", "Errors-To": "qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org", "Sender": "qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org" }, "content": "Before linux v6.13 those registers were erroneously unconditionally\nexposed and this was fixed by commits:\n- 0fcb4eea5345 (\"KVM: arm64: Hide TCR2_EL1 from userspace when\n disabled for guests\")\n- a68cddbe47ef (\"KVM: arm64: Hide S1PIE registers from userspace\n when disabled for guests\")\nin v6.13.\n\nThis means if we migrate from an old kernel host to a >= 6.13 kernel\nhost, migration currently fails.\n\nDeclare cpreg migration tolerance for those registers.\n\nSigned-off-by: Eric Auger <eric.auger@redhat.com>\nReviewed-by: Sebastian Ott <sebott@redhat.com>\nReviewed-by: Peter Maydell <peter.maydell@linaro.org>\n\n---\n\nv9 -> v10\n- Put kvm_arm_set_cpreg_mig_tolerances definition in\n #if defined(CONFIG_KVM).\n- Added Peter's R-b\n---\n target/arm/cpu64.c | 28 ++++++++++++++++++++++++++++\n 1 file changed, 28 insertions(+)", "diff": "diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c\nindex d6feba220e8..e7014022df4 100644\n--- a/target/arm/cpu64.c\n+++ b/target/arm/cpu64.c\n@@ -810,6 +810,33 @@ static void aarch64_a53_initfn(Object *obj)\n define_cortex_a72_a57_a53_cp_reginfo(cpu);\n }\n \n+#if defined(CONFIG_KVM)\n+static void kvm_arm_set_cpreg_mig_tolerances(ARMCPU *cpu)\n+{\n+ /*\n+ * Registers that may be in the incoming stream and not exposed\n+ * on the destination\n+ */\n+\n+ /*\n+ * TCR_EL1 was erroneously unconditionnally exposed before linux v6.13.\n+ * See commit 0fcb4eea5345 (\"KVM: arm64: Hide TCR2_EL1 from userspace\n+ * when disabled for guests\")\n+ */\n+ arm_register_cpreg_mig_tolerance(cpu, ARM64_SYS_REG(3, 0, 2, 0, 3),\n+ 0, 0, ToleranceNotOnBothEnds);\n+ /*\n+ * PIRE0_EL1 and PIR_EL1 were erroneously unconditionnally exposed\n+ * before linux v6.13. See commit a68cddbe47ef (\"KVM: arm64: Hide\n+ * S1PIE registers from userspace when disabled for guests\")\n+ */\n+ arm_register_cpreg_mig_tolerance(cpu, ARM64_SYS_REG(3, 0, 10, 2, 2),\n+ 0, 0, ToleranceNotOnBothEnds);\n+ arm_register_cpreg_mig_tolerance(cpu, ARM64_SYS_REG(3, 0, 10, 2, 3),\n+ 0, 0, ToleranceNotOnBothEnds);\n+}\n+#endif\n+\n static void aarch64_host_initfn(Object *obj)\n {\n ARMCPU *cpu = ARM_CPU(obj);\n@@ -822,6 +849,7 @@ static void aarch64_host_initfn(Object *obj)\n #endif\n \n #if defined(CONFIG_KVM)\n+ kvm_arm_set_cpreg_mig_tolerances(cpu);\n kvm_arm_set_cpu_features_from_host(cpu);\n aarch64_add_sve_properties(obj);\n #elif defined(CONFIG_HVF)\n", "prefixes": [ "v10", "4/7" ] }