From nobody Wed Oct 23 00:41:01 2024 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1728987516; cv=none; d=zohomail.com; s=zohoarc; b=Jd1hxsdbKK9KL6d0zyJmLseD2KUei1sxRYmFc5LO/6RfGSpvVuiWQJcRHV//Uc89dKsrjFvT7+l7QJnUuR7ONPa/jkMI+AXs+ugIJJ7Ebi9Eb5A9S7l6JNVxjP53WQeOr3A6Li54x969KlC2jFbBIwsDc2HdZ8Fw6xTQtx0DcPE= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1728987516; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:Reply-To:Reply-To:References:Sender:Subject:Subject:To:To:Message-Id; bh=ydkYIUVvxKvJ/KF8zq28V6bhiE02qiIOCQCjIztTqEM=; b=ECWhm2kt0U+CHdN7gRkTNq6cEGZi5B/D/6g4CNJkN0DLcqZv05urk8CnxV4/4o7hlSFu5v8a5JsCQ/uP+bM3Fv/7D2tVW1jYw6/BxCDuaSiAtNnfvPmNchn41CVOBlrQHu02T0r1hILKGgElF4EXIqlkEAiH0USZD7MsXPC11iM= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1728987515952270.9909932917069; Tue, 15 Oct 2024 03:18:35 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t0eci-0003lR-Ht; Tue, 15 Oct 2024 06:17:52 -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 1t0ecf-0003ki-St; Tue, 15 Oct 2024 06:17:49 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1t0ece-0003VN-2G; Tue, 15 Oct 2024 06:17:49 -0400 Received: from mail.maildlp.com (unknown [172.18.186.216]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4XSVQB2VjXz6K985; Tue, 15 Oct 2024 18:17:06 +0800 (CST) Received: from frapeml500007.china.huawei.com (unknown [7.182.85.172]) by mail.maildlp.com (Postfix) with ESMTPS id 7FB101400D9; Tue, 15 Oct 2024 18:17:40 +0800 (CST) Received: from 00293818-MRGF.huawei.com (10.48.146.149) by frapeml500007.china.huawei.com (7.182.85.172) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Tue, 15 Oct 2024 12:17:21 +0200 To: , , CC: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , Subject: [PATCH RFC V5 29/30] hw/intc/arm_gicv3_kvm: Pause all vCPU to ensure locking in KVM of resetting vCPU Date: Tue, 15 Oct 2024 11:16:56 +0100 Message-ID: <20241015101656.254330-1-salil.mehta@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241015100012.254223-1-salil.mehta@huawei.com> References: <20241015100012.254223-1-salil.mehta@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.48.146.149] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To frapeml500007.china.huawei.com (7.182.85.172) Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=185.176.79.56; envelope-from=salil.mehta@huawei.com; helo=frasgout.his.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, 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: , Reply-to: Salil Mehta From: Salil Mehta via Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1728987520359116600 Content-Type: text/plain; charset="utf-8" vCPU reset can result in device access to VGIC CPU system registers using t= he `IOCTL KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS` interface. When accessing these registers in the KVM host, it is necessary to acquire a lock on all vCPUs d= uring the `vgic_v3_attr_regs_access()` operation. This operation may fail if KVM is unable to acquire the necessary locks on = all vCPUs. Therefore, to ensure proper locking of the vCPU being reset and prev= ent failures, we need to *pause all vCPUs* during this operation to facilitate successful locking within the host. Signed-off-by: Salil Mehta --- hw/intc/arm_gicv3_kvm.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/hw/intc/arm_gicv3_kvm.c b/hw/intc/arm_gicv3_kvm.c index 3e1e97d830..bcdbf83897 100644 --- a/hw/intc/arm_gicv3_kvm.c +++ b/hw/intc/arm_gicv3_kvm.c @@ -714,10 +714,19 @@ static void arm_gicv3_icc_reset(CPUARMState *env, con= st ARMCPRegInfo *ri) return; } =20 + /* + * This shall be called even when vcpu is being hotplugged or onlined = and + * other vcpus might be running. Host kernel KVM code to handle device + * access of IOCTLs KVM_{GET|SET}_DEVICE_ATTR might fail due to inabil= ity to + * grab vcpu locks for all the vcpus. Hence, we need to pause all vcpu= s to + * facilitate locking within host. + */ + pause_all_vcpus(); /* Initialize to actual HW supported configuration */ kvm_device_access(s->dev_fd, KVM_DEV_ARM_VGIC_GRP_CPU_SYSREGS, KVM_VGIC_ATTR(ICC_CTLR_EL1, c->gicr_typer), &c->icc_ctlr_el1[GICV3_NS], false, &error_abort); + resume_all_vcpus(); =20 c->icc_ctlr_el1[GICV3_S] =3D c->icc_ctlr_el1[GICV3_NS]; } --=20 2.34.1