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 E80F9CDB46F for ; Tue, 23 Jun 2026 16:03:58 +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: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:In-Reply-To:References:List-Owner; bh=qp76MOZfkgfbvVC3NAMXAD7D03E4T9rNo0rJqkiEJiI=; b=MR/c9+DXi0H9ml3BMxy7EyOyO6 h0T0+1IAKEFAXguWSg+KFKorhXAFESIiMezkugvXivhv41hmiSdPC5vVYi4aV1ZJg8XL6qmbMEYX1 hC+UsCumcMotzArl7fuZHJUnR6le3YKE8+om2T4ozRSEUAd6wtv/sP9ahNDMkvijpTzkeAlpyVtPa Jm5mgO9II4RoBti6Tka3qZ1bCrZAfOrrCEKUsasUlTAEC/7nulrzHnNLNHGS0vCxBEvAI+4agVQ1Y rTpPkbOvDQZQw/Mf2KmZNslrgBObGo7jt6LYV4LxyO1VE7wK/8YnxsiW8qmQT9nsDnBDzNetCEXe1 zgiwDbYA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wc3bL-00000006bAR-246L; Tue, 23 Jun 2026 16:03:51 +0000 Received: from confino.investici.org ([2a11:7980:1::2:0]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wc3bI-00000006b9D-3Q3a for linux-arm-kernel@lists.infradead.org; Tue, 23 Jun 2026 16:03:50 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=grrlz.net; s=stigmate; t=1782230623; bh=qp76MOZfkgfbvVC3NAMXAD7D03E4T9rNo0rJqkiEJiI=; h=From:To:Cc:Subject:Date:From; b=roH4qtC/vCJAmrGeyJBBp+EBB3owg2oMpGfPEaMRjNOAHg+SZF+HbaoH7bG+8ARfx yJC1StVlOmpPO41qaaT090JQeNsMxzxy3dj2t3pZ2vozAHaQ8/gG/z4iiTiGQXj1aj JaiMqrPOchzCEWycjntF7H8RSOUdN6qXqfCDOtw4= Received: from mx1.investici.org (unknown [127.0.0.1]) by confino.investici.org (Postfix) with ESMTP id 4gl8xq50DFz110W; Tue, 23 Jun 2026 16:03:43 +0000 (UTC) Received: by mx1.investici.org (Postfix) id 4gl8xp6CCYz10hk; Tue, 23 Jun 2026 16:03:42 +0000 (UTC) From: Bradley Morgan To: Marc Zyngier , Oliver Upton , kvmarm@lists.linux.dev Cc: Fuad Tabba , Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon , Quentin Perret , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Bradley Morgan , stable@vger.kernel.org Subject: [PATCH] KVM: arm64: skip pKVM cache flushes for non cacheable mappings Date: Tue, 23 Jun 2026 16:03:39 +0000 Message-ID: <20260623160339.15143-1-include@grrlz.net> X-Mailer: git-send-email 2.53.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260623_090349_289326_A8D6C0B6 X-CRM114-Status: GOOD ( 12.12 ) 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 pKVM keeps its own mapping list for stage 2 operations. Its flush path uses that list directly, so it lost the PTE attribute check done by the generic stage 2 walker. Record whether a mapping is cacheable and skip cache maintenance for mappings that are not cacheable. Fixes: e912efed485a ("KVM: arm64: Introduce the EL1 pKVM MMU") Cc: stable@vger.kernel.org Signed-off-by: Bradley Morgan --- arch/arm64/include/asm/kvm_pkvm.h | 1 + arch/arm64/kvm/pkvm.c | 8 +++++++- 2 files changed, 8 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kvm_pkvm.h b/arch/arm64/include/asm/kvm_pkvm.h index 74fedd9c5ff0..d9dd8239910d 100644 --- a/arch/arm64/include/asm/kvm_pkvm.h +++ b/arch/arm64/include/asm/kvm_pkvm.h @@ -196,6 +196,7 @@ struct pkvm_mapping { u64 gfn; u64 pfn; u64 nr_pages; + bool cacheable; u64 __subtree_last; /* Internal member for interval tree */ }; diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c index 428723b1b0f5..105ab1258066 100644 --- a/arch/arm64/kvm/pkvm.c +++ b/arch/arm64/kvm/pkvm.c @@ -473,6 +473,8 @@ int pkvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, mapping->gfn = gfn; mapping->pfn = pfn; mapping->nr_pages = size / PAGE_SIZE; + mapping->cacheable = !(prot & (KVM_PGTABLE_PROT_DEVICE | + KVM_PGTABLE_PROT_NORMAL_NC)); pkvm_mapping_insert(mapping, &pgt->pkvm_mappings); return ret; @@ -517,9 +519,13 @@ int pkvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size) struct pkvm_mapping *mapping; lockdep_assert_held(&kvm->mmu_lock); - for_each_mapping_in_range_safe(pgt, addr, addr + size, mapping) + for_each_mapping_in_range_safe(pgt, addr, addr + size, mapping) { + if (!mapping->cacheable) + continue; + __clean_dcache_guest_page(pfn_to_kaddr(mapping->pfn), PAGE_SIZE * mapping->nr_pages); + } return 0; } -- 2.53.0