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 4D80C10ED64A for ; Fri, 27 Mar 2026 11:36:57 +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:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ZzRs9uQkPgiHfbZEpsdu0nSfteqrXKxz9ECItSznHeM=; b=LYxljlLiGp1jMr89JI++jYqW1H N7OlXeNfbfiyi8XNEfpo5iHgzKRzi3KiGbsOXFEm2dat8S0NgH+MGyJjjqZ6sNZbAHs2bTD7xN7SU 5lCHXCXy4Gb3NlaihK95Ou4ur9/XEJDB0yls/ymWV3PYhBSDSv+IutA0iERA4D9tgO/7lsS5sL6NP J5WHKJ7y+Dx3ZQKfTkzSeJTOl9D95b1xmsCTVR/BzpljsIfC0Ohuo7qDSgJWvoMmVi9zJv49MvZ4Y vHuk3isc/A9R9Zf6v284P0asOLRPi8PKw0H+CkSMtoDIA4iOMtq/wYNHXhD2c40LKYzwDRAeUA1Qm KccsirNQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1w65Ug-00000007FN6-1qMY; Fri, 27 Mar 2026 11:36:50 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1w65UJ-00000007F2L-1Izo for linux-arm-kernel@lists.infradead.org; Fri, 27 Mar 2026 11:36:29 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id F184D4475B; Fri, 27 Mar 2026 11:36:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D42BBC19423; Fri, 27 Mar 2026 11:36:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1774611386; bh=N9bhiVx5Vh1CUIB4IHblaqgBEI4KzyxLhqGgwc8mT8U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZXcZJB+fmHnNctN4JagniqSKrNn0NZ+FF4d2/PMUsVXHYe5ozVi1Vs6wDCbhkMWVl kbtsBMwriXE8+iqnod94kKQkkDBVidwwEVKZcZ4hI4MrVEg4e+awoETdz8J3zNhWZ4 jUCKaCTeno52ao89BJn2QEn75PidrxH8ZDQtZyO/KVhspUdROjDEry0V3FvSHUaM// DR6stROoc8egaC8wuX45Sxu8jE+suyLZlCYKjg/jxRWbnyr/LVNDORgcwGNy4vktIs MOOMECQw3PCmkSSSDiTQlcf3OcNMrRBR0GR08ZosciOpZgKGGTX2eYWtihYX+zpLG7 M+5v6BFhqS9Xg== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1w65UG-00000006K4a-4Adm; Fri, 27 Mar 2026 11:36:25 +0000 From: Marc Zyngier To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org Cc: Joey Gouly , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Fuad Tabba , Will Deacon , Quentin Perret Subject: [PATCH v2 12/30] KVM: arm64: Hoist MTE validation check out of MMU lock path Date: Fri, 27 Mar 2026 11:36:00 +0000 Message-ID: <20260327113618.4051534-13-maz@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260327113618.4051534-1-maz@kernel.org> References: <20260327113618.4051534-1-maz@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, oupton@kernel.org, yuzenghui@huawei.com, tabba@google.com, will@kernel.org, qperret@google.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260327_043627_411839_37BF96A2 X-CRM114-Status: GOOD ( 15.11 ) 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 From: Fuad Tabba Simplify the non-cacheable attributes assignment by using a ternary operator. Additionally, hoist the MTE validation check (mte_allowed) out of kvm_s2_fault_map() and into kvm_s2_fault_compute_prot(). This allows us to fail faster and avoid acquiring the KVM MMU lock unnecessarily when the VMM introduces a disallowed VMA for an MTE-enabled guest. Signed-off-by: Fuad Tabba Signed-off-by: Marc Zyngier --- arch/arm64/kvm/mmu.c | 28 ++++++++++++---------------- 1 file changed, 12 insertions(+), 16 deletions(-) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index 0c71e3a9af8b0..ee2a548999b1b 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1870,18 +1870,21 @@ static int kvm_s2_fault_compute_prot(struct kvm_s2_fault *fault) if (fault->exec_fault) fault->prot |= KVM_PGTABLE_PROT_X; - if (fault->s2_force_noncacheable) { - if (fault->vm_flags & VM_ALLOW_ANY_UNCACHED) - fault->prot |= KVM_PGTABLE_PROT_NORMAL_NC; - else - fault->prot |= KVM_PGTABLE_PROT_DEVICE; - } else if (cpus_have_final_cap(ARM64_HAS_CACHE_DIC)) { + if (fault->s2_force_noncacheable) + fault->prot |= (fault->vm_flags & VM_ALLOW_ANY_UNCACHED) ? + KVM_PGTABLE_PROT_NORMAL_NC : KVM_PGTABLE_PROT_DEVICE; + else if (cpus_have_final_cap(ARM64_HAS_CACHE_DIC)) fault->prot |= KVM_PGTABLE_PROT_X; - } if (fault->nested) adjust_nested_exec_perms(kvm, fault->nested, &fault->prot); + if (!fault->fault_is_perm && !fault->s2_force_noncacheable && kvm_has_mte(kvm)) { + /* Check the VMM hasn't introduced a new disallowed VMA */ + if (!fault->mte_allowed) + return -EFAULT; + } + return 0; } @@ -1918,15 +1921,8 @@ static int kvm_s2_fault_map(struct kvm_s2_fault *fault, void *memcache) } } - if (!fault->fault_is_perm && !fault->s2_force_noncacheable && kvm_has_mte(kvm)) { - /* Check the VMM hasn't introduced a new disallowed VMA */ - if (fault->mte_allowed) { - sanitise_mte_tags(kvm, fault->pfn, fault->vma_pagesize); - } else { - ret = -EFAULT; - goto out_unlock; - } - } + if (!fault->fault_is_perm && !fault->s2_force_noncacheable && kvm_has_mte(kvm)) + sanitise_mte_tags(kvm, fault->pfn, fault->vma_pagesize); /* * Under the premise of getting a FSC_PERM fault, we just need to relax -- 2.47.3