From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-189.mta0.migadu.com (out-189.mta0.migadu.com [91.218.175.189]) (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 D968A3BFE2D for ; Wed, 25 Feb 2026 17:35:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772040942; cv=none; b=SktbJZ4JWQWo/ZV82tJSAvKLed4KVw7lAU3fxYWMPyZ1joPIpAwl8sMHv1YppyTcVeHOuaeVHma/xl0rVNmAU3PLVmiXo/tzj4XvE00FS2hc83a10soI9xTt43AjvwpB7ohRrCE8kv872oVQnTSLQ1thMN5NPrMnyhEMQqFikpU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772040942; c=relaxed/simple; bh=MUGRfB4oYWG7DyZuMYskkLphXSNYgZFTg2+9PYuk/K0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=k8MFrCGXpSyXlbduDwLEO+J7U+E1PcYVs9pWRfU/LcXac4NP62N+gtqSaiywBL+S6TiuA45z8M1n+2rqaII5CNABkol04Opaiwha2tuYJl1/nMjM93PjhNC4MQkktV40zc8iJtn0PvUuBk/Z8dBZnRdsZhTM9VSyTGySp0gl2NE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=T6tTNy3J; arc=none smtp.client-ip=91.218.175.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="T6tTNy3J" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1772040939; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=VY0eOcbP10xypHAaHBqk13P+uVcLzRh1cwtoBu1zlLg=; b=T6tTNy3J0NKZ3vVtfsZaNmJ3RWluFB+MVGvDgb63KduKHnw56dW5iFn4tJuihx1rmd6/OV hBRZrSxFr4yjZJGd4AofiyEpHb6vQkp82KPkGqCDKJI4NB8Al+7IVpCEEjPVQSkxQpzrKV 5ayRPePmoODkK4hJ5K9IeRqfpza+8mQ= From: Zenghui Yu To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: maz@kernel.org, oupton@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, "Zenghui Yu (Huawei)" Subject: [PATCH 1/3] KVM: arm64: nv: Check S2 limits based on implemented PA size Date: Thu, 26 Feb 2026 01:35:13 +0800 Message-ID: <20260225173515.20490-2-zenghui.yu@linux.dev> In-Reply-To: <20260225173515.20490-1-zenghui.yu@linux.dev> References: <20260225173515.20490-1-zenghui.yu@linux.dev> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT From: "Zenghui Yu (Huawei)" check_base_s2_limits() checks the validity of SL0 and inputsize against ia_size (inputsize again!) but the pseudocode from DDI0487 G.a AArch64.TranslationTableWalk() says that we should check against the implemented PA size. We would otherwise fail to walk S2 with a valid configuration. E.g., granule size = 4KB, inputsize = 40 bits, initial lookup level = 0 (no concatenation) on a system with 48 bits PA range supported is allowed by architecture. Fix it by obtaining PA size by kvm_get_pa_bits(). Note that kvm_get_pa_bits() returns the fixed limit now and should eventually reflect the per VM PARange (one day!). Given that the configured PARange should not be greater that kvm_ipa_limit, it at least fixes the problem described above. While at it, inject a level 0 translation fault to guest if check_base_s2_limits() fails, as per the pseudocode. Fixes: 61e30b9eef7f ("KVM: arm64: nv: Implement nested Stage-2 page table walk logic") Signed-off-by: Zenghui Yu (Huawei) --- arch/arm64/kvm/nested.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index 620126d1f0dc..44ed3915b961 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -152,31 +152,31 @@ static int get_ia_size(struct s2_walk_info *wi) return 64 - wi->t0sz; } -static int check_base_s2_limits(struct s2_walk_info *wi, +static int check_base_s2_limits(struct kvm_vcpu *vcpu, struct s2_walk_info *wi, int level, int input_size, int stride) { - int start_size, ia_size; + int start_size, pa_max; - ia_size = get_ia_size(wi); + pa_max = kvm_get_pa_bits(vcpu->kvm); /* Check translation limits */ switch (BIT(wi->pgshift)) { case SZ_64K: - if (level == 0 || (level == 1 && ia_size <= 42)) + if (level == 0 || (level == 1 && pa_max <= 42)) return -EFAULT; break; case SZ_16K: - if (level == 0 || (level == 1 && ia_size <= 40)) + if (level == 0 || (level == 1 && pa_max <= 40)) return -EFAULT; break; case SZ_4K: - if (level < 0 || (level == 0 && ia_size <= 42)) + if (level < 0 || (level == 0 && pa_max <= 42)) return -EFAULT; break; } /* Check input size limits */ - if (input_size > ia_size) + if (input_size > pa_max) return -EFAULT; /* Check number of entries in starting level table */ @@ -269,9 +269,11 @@ static int walk_nested_s2_pgd(struct kvm_vcpu *vcpu, phys_addr_t ipa, if (input_size > 48 || input_size < 25) return -EFAULT; - ret = check_base_s2_limits(wi, level, input_size, stride); - if (WARN_ON(ret)) + ret = check_base_s2_limits(vcpu, wi, level, input_size, stride); + if (WARN_ON(ret)) { + out->esr = compute_fsc(0, ESR_ELx_FSC_FAULT); return ret; + } base_lower_bound = 3 + input_size - ((3 - level) * stride + wi->pgshift); -- 2.53.0