From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D1FB21EE00A for ; Mon, 19 Jan 2026 10:56:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768820217; cv=none; b=fgapX9Os/ZCWZLuINYpPoLKcbkODVHftKUlYLVUOQiks/FedW93R/Vbkdii8SYwLlJj1JRE17IfmGB1Ht+pqRqV0W+bHEMHWuMoXOjkjj3xuKwA3tpN0Bwfnf/5b4y1LL0qS0g45FGCJbccV7kk01VZtSj0+ExS6BLLph+J5e6E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768820217; c=relaxed/simple; bh=uTXpYO5WtXclYdggoann9HiinQtNq2ANggCc1hfRfek=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jaUGb6LNapaR60UQp62QmcbzvcQY6ytJAoiqdzCJimDIQZYoKRjqHo1SnU0qUNWQ90Mtw1VqtTm+MPxSZXrTlGkCVaMExc5gZ2eiDKvgrHNus13RNmBG3D7uSO+VeqGwWD98dlqCjyl9Eiu0UVQblCfsh93sfYK9sm+9h0y02NQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=IwsATEUp; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IwsATEUp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A8C23C19424; Mon, 19 Jan 2026 10:56:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768820217; bh=uTXpYO5WtXclYdggoann9HiinQtNq2ANggCc1hfRfek=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IwsATEUp/4Lvgj/M1nAevcyTnGN18Kcx878AvV6kkj8rKrRmCTfiJqizx21mVFM8A zQVR5QGIZSVrwpYNUKpE82eCdzFDxLvWl8YCIs+ukHArSxCfJ1YG/YjMyWXBGJvNYg DsaKVFunRHdvkghInB8lp9iZdAigCJe8yI/oxaNtby5MNItaNdP6161qy/iXE55S05 EaWVI/SjlguW12PLgnlM1kJIHuC2dz1nrvoAE9XUKLOfcrKSD0AQdaES07uWQJmV/7 otUDVgAyREspLQvu1yqjOCq45M3BWwMy3PtvRj8ONaJ2tx1hedeDnodWGDJ67chd0S B76A+j/b5m5rQ== 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 1vhmwJ-00000003YVK-1gB3; Mon, 19 Jan 2026 10:56:55 +0000 From: Marc Zyngier To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: Joey Gouly , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Will Deacon , Quentin Perret , Fuad Tabba Subject: [PATCH 3/6] KVM: arm64: Make stage2_pte_cacheable() return false when S2_AS_S1 is set Date: Mon, 19 Jan 2026 10:56:48 +0000 Message-ID: <20260119105651.255693-4-maz@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260119105651.255693-1-maz@kernel.org> References: <20260119105651.255693-1-maz@kernel.org> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: 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, joey.gouly@arm.com, suzuki.poulose@arm.com, oupton@kernel.org, yuzenghui@huawei.com, will@kernel.org, qperret@google.com, tabba@google.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false We cannot tell from the S2 attributes whether what we map is memory or not when S2_AS_S1 is set, and issuing a CMO on device memory may not be the best idea. In this particular case, pretend that the mapping isn't cacheable. Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp/pgtable.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index 3c5f399b1b986..07561a227f75e 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -911,6 +911,14 @@ static void stage2_unmap_put_pte(const struct kvm_pgtable_visit_ctx *ctx, static bool stage2_pte_cacheable(struct kvm_pgtable *pgt, kvm_pte_t pte) { u64 memattr = pte & KVM_PTE_LEAF_ATTR_LO_S2_MEMATTR; + + /* + * With S2_AS_S1, we have no idea whether the OA is actual memory or + * a device. Don't even try a CMO on that. + */ + if (pgt->flags & KVM_PGTABLE_S2_AS_S1) + return false; + return kvm_pte_valid(pte) && memattr == KVM_S2_MEMATTR(pgt, NORMAL); } -- 2.47.3