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 21811F0183C for ; Fri, 6 Mar 2026 14:03:13 +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-Type:Cc:To:From: Subject:Message-ID:References:Mime-Version:In-Reply-To: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=CtHGmGW+kuNXfpqkwV8R0QzbahP6BhHBAQuRE9dnG2k=; b=pAUrASf010Zju0wFN3iSQtI7q3 OlUALIHa/657/S0eW932wpbQh478rjcvB6sWWCvyHEaHEDKpZAhxgaGM1KMTVa6pEGsC3xE6SfkH0 2bGpKWgoaVGmvtVoXU7dcIMf2wYXGJSKVgR84L4gh7UvJ0pcBU2q27BSLMigtka0wmrSkpW7s/9n6 5XbGSrD1B3LnjdqQ9aBqwoGmtxeWK3u78h42N54RE3TXl30w23X/svjI5+wxus8LK4GVp7ac5wDvI jxml/JsrO0eW0nKTeh4OpQRSnQBnIodn1q4sYF2Mq7ztUildElwVqTM/JiqxPzpUooWQ5ccLaB/rO lXC1v1Kg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vyVlf-00000003qSO-0L7B; Fri, 06 Mar 2026 14:03:03 +0000 Received: from mail-ed1-x54a.google.com ([2a00:1450:4864:20::54a]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vyVlV-00000003qE7-0Fc2 for linux-arm-kernel@lists.infradead.org; Fri, 06 Mar 2026 14:02:54 +0000 Received: by mail-ed1-x54a.google.com with SMTP id 4fb4d7f45d1cf-6613679e8cbso2915580a12.3 for ; Fri, 06 Mar 2026 06:02:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1772805769; x=1773410569; darn=lists.infradead.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=CtHGmGW+kuNXfpqkwV8R0QzbahP6BhHBAQuRE9dnG2k=; b=FSZHszg6nhGufkYiXe069KP3AruMsgEYci3ZrzmMj6B+w3oqXnHxrDZYRjgiSvxO8n Pwy77oVxvc+BlWSL0MaYj1fJ/i/WozvO/390qkK6DkFVs4tu0ANbSdmaHUyIG6emQC51 CdE++Zjz0uO3tA790E6ywZHDZSDIE/kr2yjiA07Wp4a73UWpSo8r+JHzdHifdeJaMPVJ vryflQY8bIA1xBnrerdMo/jZ+08lbTZUYjeUfnPAa/A11HgI2Fb/SxtgFuFUmlSoo/Nj ejZXNJsQqDnyzZwKRMYj082ejWuVKpnWFbyM1rUNOKzTAKqYncSZe8z+b3IoElStPbFk Cn2A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772805769; x=1773410569; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=CtHGmGW+kuNXfpqkwV8R0QzbahP6BhHBAQuRE9dnG2k=; b=VE+hrUcfdqGKyPfxXo1vVEpTx2DYOm41dZNRLpoB1i7Dh4loTZ8C1eSEwWhdnyC5z5 6a4J8RcD/xBUUUd6oBvRhzLo1Qe695ikHPbe6vltCJ/OYiKWBEaoVd2sWyTOJOKr2Ui7 1GfewsMY9SdvnpsJvg1QwHa4WFG0iokjuhwAJDsm5FUxSDoSIYcl5oPVR7Fi4HpFbnnP mXZmmlZ/Rz4Psw5Dpkgsioc5iKL8H/mox6SgYGlxd2N/iXOZ9/jHD1mu9bV9oPB3dD6Q rqoJW7xXCDvV+37ejSsiMcme6eikno4qTomtl02krUI4+rj1o11DqK6piLaaCdi46dsD J0Iw== X-Forwarded-Encrypted: i=1; AJvYcCXkl+QkCuKoJ49WiIiszqYDhqM1QMLTK7eL+w9VgphULiJKFaeeQl9HnyhurJR2j5CbRldJAdTyfL+h0RrQpAST@lists.infradead.org X-Gm-Message-State: AOJu0YwHa8P33dhOlOoBbFnjR6tT3bRWvTfAangyMoO9vbd+mUNggVl6 nWG8nf3ktWSClhdq73vsUzQXssAP9HffaQeTrp+m8darqmApoNrNCsgDq/dMNguv1jJx3JnPBgc gew== X-Received: from edoy18.prod.google.com ([2002:aa7:c252:0:b0:660:e9bd:31af]) (user=tabba job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6402:2807:b0:658:1304:b699 with SMTP id 4fb4d7f45d1cf-6619d50626dmr1271444a12.31.1772805768583; Fri, 06 Mar 2026 06:02:48 -0800 (PST) Date: Fri, 6 Mar 2026 14:02:31 +0000 In-Reply-To: <20260306140232.2193802-1-tabba@google.com> Mime-Version: 1.0 References: <20260306140232.2193802-1-tabba@google.com> X-Mailer: git-send-email 2.53.0.473.g4a7958ca14-goog Message-ID: <20260306140232.2193802-13-tabba@google.com> Subject: [PATCH v1 12/13] KVM: arm64: Hoist MTE validation check out of MMU lock path From: Fuad Tabba To: kvm@vger.kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org, qperret@google.com, vdonnefort@google.com, tabba@google.com Content-Type: text/plain; charset="UTF-8" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260306_060253_238908_5CFAE184 X-CRM114-Status: GOOD ( 14.65 ) 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 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 --- 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 9265a7fc43f7..cc6b35efcee5 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 -- 2.53.0.473.g4a7958ca14-goog