From patchwork Mon Mar 6 19:54:35 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryan Roberts X-Patchwork-Id: 13162277 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 AFBD5C64EC4 for ; Mon, 6 Mar 2023 19:58:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=rDQoHUZI6yyDkLLyEXuLcapx1Zn/LeOF1xYl1dxoNVY=; b=22aeiA8X7xwtY1 cT0ia0yucigv8oACNGNNRCTdXjWpP3Lve5hfQcIWANo44MMrVCXGeUBUvVJMzW2txaEeGzLBv/Yrp g4noX0xX3hKTpjUS7XJiW5SaAWUT9kxKvGggCjQEpNl8SWN1ivwxDXuXxy4iVngJP0GicrV8kTHe1 Vfo2EDcwnoQmsFEorCWyWOT+GmcJ2WEPgODBGcl1OVk/ng9C38uSwCtu6IDaWtpEcbLJgrwcNstQo 5nZNOu/iS2UduyzKJFDU01OibL/8n/MWUkivOUy90TtSFYEd/pAq+Zt1GhskCxoltrXynFtAfq/Tv kzF1VEg9r8F10auoVGmQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pZGxM-00EhmN-W6; Mon, 06 Mar 2023 19:57:13 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pZGvU-00Eggd-7J for linux-arm-kernel@lists.infradead.org; Mon, 06 Mar 2023 19:55:19 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 49F1B11FB; Mon, 6 Mar 2023 11:55:56 -0800 (PST) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.26]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 917DF3F71A; Mon, 6 Mar 2023 11:55:11 -0800 (PST) From: Ryan Roberts To: Catalin Marinas , Will Deacon , Marc Zyngier , Oliver Upton , Suzuki K Poulose , Ard Biesheuvel , Anshuman Khandual Cc: Ryan Roberts , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev Subject: [PATCH v2 09/12] KVM: arm64: Support up to 5 levels of translation in kvm_pgtable Date: Mon, 6 Mar 2023 19:54:35 +0000 Message-Id: <20230306195438.1557851-10-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230306195438.1557851-1-ryan.roberts@arm.com> References: <20230306195438.1557851-1-ryan.roberts@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230306_115516_409675_39F4B1F4 X-CRM114-Status: GOOD ( 20.47 ) 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 FEAT_LPA2 increases the maximum levels of translation from 4 to 5 for the 4KB page case, when IA is >48 bits. While we can still use 4 levels for stage2 translation in this case (due to stage2 allowing concatenated page tables for first level lookup), the same kvm_pgtable library is used for the hyp stage1 page tables and stage1 does not support concatenation. Therefore, modify the library to support up to 5 levels. Previous patches already laid the groundwork for this by refactoring code to work in terms of KVM_PGTABLE_FIRST_LEVEL and KVM_PGTABLE_LAST_LEVEL. So we just need to change these macros. The hardware sometimes encodes the new level differently from the others: One such place is when reading the level from the FSC field in the ESR_EL2 register. We never expect to see the lowest level (-1) here since the stage 2 page tables always use concatenated tables for first level lookup and therefore only use 4 levels of lookup. So we get away with just adding a comment to explain why we are not being careful about decoding level -1. For stage2 VTCR_EL2.SL2 is introduced to encode the new start level. However, since we always use concatenated page tables for first level look up at stage2 (and therefore we will never need the new extra level) we never touch this new field. Signed-off-by: Ryan Roberts --- arch/arm64/include/asm/kvm_emulate.h | 10 ++++++++++ arch/arm64/include/asm/kvm_pgtable.h | 2 +- arch/arm64/kvm/hyp/pgtable.c | 10 ++++++++++ 3 files changed, 21 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index 26666a623fa8..542575aad159 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -405,6 +405,16 @@ static __always_inline u8 kvm_vcpu_trap_get_fault_type(const struct kvm_vcpu *vc static __always_inline s8 kvm_vcpu_trap_get_fault_level(const struct kvm_vcpu *vcpu) { + /* + * Note: With the introduction of FEAT_LPA2 an extra level of + * translation (level -1) is added. This level (obviously) doesn't + * follow the previous convention of encoding the 4 levels in the 2 LSBs + * of the FSC so this function breaks if the fault is for level -1. + * + * However, stage2 tables always use concatenated tables for first level + * lookup and therefore it is guaranteed that the level will be between + * 0 and 3, and this function continues to work. + */ return kvm_vcpu_get_esr(vcpu) & ESR_ELx_FSC_LEVEL; } diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index 8c7e65147777..a5d96592c658 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h @@ -11,7 +11,7 @@ #include #include -#define KVM_PGTABLE_FIRST_LEVEL 0 +#define KVM_PGTABLE_FIRST_LEVEL -1 #define KVM_PGTABLE_LAST_LEVEL 3 /* diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index 939eab245205..a09c17242da7 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -612,6 +612,15 @@ u64 kvm_get_vtcr(u64 mmfr0, u64 mmfr1, u32 phys_shift) lvls = stage2_pgtable_levels(phys_shift); if (lvls < 2) lvls = 2; + + /* + * When LPA2 is enabled, the HW supports an extra level of translation + * (for 5 in total) when using 4K pages. It also introduces VTCR_EL2.SL2 + * to as an addition to SL0 to enable encoding this extra start level. + * However, since we always use concatenated pages for the first level + * lookup, we will never need this extra level and therefore do not need + * to touch SL2. + */ vtcr |= VTCR_EL2_LVLS_TO_SL0(lvls); #ifdef CONFIG_ARM64_HW_AFDBM @@ -1053,6 +1062,7 @@ struct stage2_attr_data { kvm_pte_t attr_clr; kvm_pte_t pte; s8 level; + struct kvm_pgtable_mm_ops *mm_ops; }; static int stage2_attr_walker(const struct kvm_pgtable_visit_ctx *ctx,