From patchwork Mon Nov 27 11:17:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ryan Roberts X-Patchwork-Id: 13469388 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 3AAD7C0755A for ; Mon, 27 Nov 2023 11:18:43 +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=JPv/l5L4llR1gnlfXOD9Nkzb6cMtHO3mb13Mjr3wtkE=; b=IUc5+3o1BzouJf COKr0WgVHKO16iBi5OhDUnPFBlcYZkHDcqJWRLs3Bdm6Tqwd27pQvAWWjOG/Ia/gU6YqTGPYACkhQ 9EVk4fQNqwV6nECo2plY9YWB8koLSA1m8+W4WIeG/JAvat6gVNj7hgVmGRjfyBMWekh0Qcz27Mh+E OyYbIr/fFr01UB6Lm/TKWwRDzoJYfCe3BW2lgLzhb+OpJL4F2d4uEFeG6hQe0kVbSYVi4z67gMzk9 92E62G3iAYn6jBr0/xUK0nKEdwbiZzUDTtOrV6d8LHzyOqBt76pqCCxdSsZu3OoUQpcCC8dbstBK+ 8biV9mHGR0yNLgWedrHA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r7Zd4-002Brb-0b; Mon, 27 Nov 2023 11:18:18 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r7Zcw-002Bjm-0i for linux-arm-kernel@lists.infradead.org; Mon, 27 Nov 2023 11:18:11 +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 4C891165C; Mon, 27 Nov 2023 03:18:56 -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 332653F73F; Mon, 27 Nov 2023 03:18:07 -0800 (PST) From: Ryan Roberts To: Catalin Marinas , Will Deacon , Marc Zyngier , Oliver Upton , Suzuki K Poulose , James Morse , Zenghui Yu , Ard Biesheuvel , Anshuman Khandual Cc: Ryan Roberts , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev Subject: [PATCH v6 09/12] KVM: arm64: Support up to 5 levels of translation in kvm_pgtable Date: Mon, 27 Nov 2023 11:17:34 +0000 Message-Id: <20231127111737.1897081-10-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20231127111737.1897081-1-ryan.roberts@arm.com> References: <20231127111737.1897081-1-ryan.roberts@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231127_031810_350927_FF361233 X-CRM114-Status: GOOD ( 19.11 ) 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. Reviewed-by: Oliver Upton 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 | 9 +++++++++ 3 files changed, 20 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h index 13fd9dbf2d1d..d4f1e9cdd554 100644 --- a/arch/arm64/include/asm/kvm_emulate.h +++ b/arch/arm64/include/asm/kvm_emulate.h @@ -411,6 +411,16 @@ 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 3253828e453d..cfdf40f734b1 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 744bded18e99..c651df904fe3 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -645,6 +645,15 @@ 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