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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 C6746CD6E5D for ; Tue, 2 Jun 2026 21:26:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Q67DNBKcuffmWspv6LvVXCmA21SteXLC22ebhEgdn1U=; b=I+YOegSj0aMAJUrNF7d+KrOiyz ooX8Ov92sT0956ozEB1pxCoXkzbT0xC6s5ZCoqAjvj7zFlDu0QZhc3BSi6QgvZKRUK0VYJlIjqoRV izKwOEQetSI4erX1eHW508Muyp+ti3rWWc229KcI7koq78s5ZYUd5ecpU3NdYsvikPynSRyS4eCtY 71Z1V4M+rtu0Fc72ubTDf17ud46Cr9i7Em86agvh8EnZQ3CRTjMLiTfkIopglPSnq79A59NMJqQAZ 6Wk2aBZvsQXZbm69jm+gh1Yj1WExMNjRbmniDBBJyUPmHqJ7CH4Er9njEIKRNwMm4sB8eOnJp8naa vfqGlxgQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wUWcu-0000000Doqz-2fE9; Tue, 02 Jun 2026 21:26:20 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wUWcs-0000000DoqZ-3PDt for linux-arm-kernel@lists.infradead.org; Tue, 02 Jun 2026 21:26:18 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id CED9A6012B; Tue, 2 Jun 2026 21:26:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5BBC41F00893; Tue, 2 Jun 2026 21:26:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1780435577; bh=Q67DNBKcuffmWspv6LvVXCmA21SteXLC22ebhEgdn1U=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=mdbJmsmkEsdF6WXBnuWjh113rOwL2Pkj8cahrG8MIion6Mz4kplBkEhwPrDD33eDD znJSL3Bibb+P0LWtHqZVhkaYTTlsjFLBbn+TB7WYFekuQYnB6/BA0xquWaFJL5DHPn TuwV9LJLjB8JHgjfzUrsFuUHGOQpbKFa+5fp+uG1pxjBjrnB9SODF/YTjNxUg7ymZt HQ8g4hoCHHaBwCoFvYsf8ubM69aIgs9gl+gLeVh5B6quLPTQTFmjCV6bU2eGkCAFn7 PDwfb2rpskRTXn+L5A43fU6kavrSI3fkI7tESb84CJ7qEImG5/D25t8R64BdT3qupN Hb7Xbj58pX/sw== Date: Tue, 2 Jun 2026 14:26:16 -0700 From: Oliver Upton To: Hyunwoo Kim Cc: maz@kernel.org, joey.gouly@arm.com, seiden@linux.ibm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, kees@kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v2] KVM: arm64: vgic-its: Serialize translation cache invalidation under its_lock Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Hyunwoo, Thanks for respinning. On Tue, Jun 02, 2026 at 04:52:18PM +0900, Hyunwoo Kim wrote: > @@ -607,17 +609,16 @@ void vgic_its_invalidate_all_caches(struct kvm *kvm) > struct kvm_device *dev; > struct vgic_its *its; > > - rcu_read_lock(); > + guard(mutex)(&kvm->lock); Urgh, entirely my mistake but we can get here holding the vcpu->mutex which is an ordering bug. We can defer the locking cleanup as a long term fix (which I still want) and take what you had before in v1. Sorry for the noise. Thanks, Oliver > - list_for_each_entry_rcu(dev, &kvm->devices, vm_node) { > + list_for_each_entry(dev, &kvm->devices, vm_node) { > if (dev->ops != &kvm_arm_vgic_its_ops) > continue; > > its = dev->private; > + guard(mutex)(&its->its_lock); > vgic_its_invalidate_cache(its); > } > - > - rcu_read_unlock(); > } > > int vgic_its_resolve_lpi(struct kvm *kvm, struct vgic_its *its, > @@ -1725,8 +1726,10 @@ static void vgic_mmio_write_its_ctlr(struct kvm *kvm, struct vgic_its *its, > goto out; > > its->enabled = !!(val & GITS_CTLR_ENABLE); > - if (!its->enabled) > + if (!its->enabled) { > + guard(mutex)(&its->its_lock); > vgic_its_invalidate_cache(its); > + } > > /* > * Try to process any pending commands. This function bails out early > -- > 2.43.0 >