From patchwork Fri Oct 19 12:58:46 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 10649515 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id DF97514E2 for ; Fri, 19 Oct 2018 13:41:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CBD1B28B93 for ; Fri, 19 Oct 2018 13:41:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BFAA728BEC; Fri, 19 Oct 2018 13:41:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 32E9628B93 for ; Fri, 19 Oct 2018 13:41:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=OthidM9hv1R53EVHg0L3fSfPuz0UhO8SVIHZonI1bq0=; b=qWQWbYJTkhpmjZ ER/DpcrmIMvS+sWWbzlcD2QJ1XLMsgF2SlOBRNwdteACy9xkMt3GDRfWZ0aVZ8I0UMXhHjGaKOM7I AKjr8i4wAY1tipS6TjTnphyfPy++eglLRlqtASVtmo+TG4Ccog7Fs1v+zlgwPUNA2RJ88lLLkUGWp LANVmcBV9IllTuzJcnEFfT+8L22fj+WXsTwkb4Z+LGY++5A73g8vZ2C6zWWJcLB9jLZoDuL+sy56I Nf5Jhf4CFrkXmBq0ubXb4sWyIfF1JGriCeFmlVEQbsLChyf65cIGPP7NVB5HXmWecnMytEEo1/O7v hixsHiUvkEeFWxq1+aeg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gDV2I-0002D6-9T; Fri, 19 Oct 2018 13:41:54 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gDUc2-0008Vq-5i for linux-arm-kernel@bombadil.infradead.org; Fri, 19 Oct 2018 13:14:46 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=Z+6NPAafZbsW6ktV0S+7YRfY7qay/Uph9eEb1bTmt4A=; b=kQAGinHaH1j7PD9UMHhT5kaI/3 Ik1wDFNCUIWn/N2Nt9ysbb6TI3H9mZRptpP6OoXizF1ae1lBKAjJyVs0jmFO7pwHwH08J/Z8OhjRq E23xXsIrMRRcpqwTnDhCGQFLAHSZt9obSEX7xanhaYr95+uAImsFewxDV7Cgq0WbKk0fmgxAvea+q va05hkZstEYhsCeLxDlTb+G9QyPucOHpWV+6UWNqRfc0w7GIcUtjU0+yiD1LqBO8Un1qXthPKpeF+ RhwrLnjiYPTcP039K1Vqr5trWWukCa1JuGW9DksnMdj/O9iN1o8sQqJXezuvTXqCv9v2J0uwwdr94 T/R51+6w==; Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by casper.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gDUNb-0000Iu-7O for linux-arm-kernel@lists.infradead.org; Fri, 19 Oct 2018 12:59:53 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id CCC41EBD; Fri, 19 Oct 2018 05:59:50 -0700 (PDT) Received: from filthy-habits.cambridge.arm.com (filthy-habits.cambridge.arm.com [10.1.196.62]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 2EBE43F71D; Fri, 19 Oct 2018 05:59:48 -0700 (PDT) From: Marc Zyngier To: Paolo Bonzini , =?utf-8?b?UmFkaW0gS3LEjW3DocWZ?= Subject: [PATCH 11/26] kvm: arm64: Dynamic configuration of VTTBR mask Date: Fri, 19 Oct 2018 13:58:46 +0100 Message-Id: <20181019125901.185478-12-marc.zyngier@arm.com> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181019125901.185478-1-marc.zyngier@arm.com> References: <20181019125901.185478-1-marc.zyngier@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181019_135951_563406_CA3FD97B X-CRM114-Status: GOOD ( 22.81 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , zhong jiang , kvm@vger.kernel.org, Suzuki K Poulose , Catalin Marinas , Punit Agrawal , Christoffer Dall , Kristina Martsenko , Dongjiu Geng , Eric Auger , James Morse , Robin Murphy , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP From: Suzuki K Poulose On arm64 VTTBR_EL2:BADDR holds the base address for the stage2 translation table. The Arm ARM mandates that the bits BADDR[x-1:0] should be 0, where 'x' is defined for a given IPA Size and the number of levels for a translation granule size. It is defined using some magical constants. This patch is a reverse engineered implementation to calculate the 'x' at runtime for a given ipa and number of page table levels. See patch for more details. Cc: Marc Zyngier Cc: Christoffer Dall Signed-off-by: Suzuki K Poulose Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_arm.h | 73 ++++++++++++++++++++++++++++---- arch/arm64/include/asm/kvm_mmu.h | 25 ++++++++++- 2 files changed, 88 insertions(+), 10 deletions(-) diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index 14317b3a1820..b236d90ca056 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -123,7 +123,6 @@ #define VTCR_EL2_SL0_MASK (3 << VTCR_EL2_SL0_SHIFT) #define VTCR_EL2_SL0_LVL1 (1 << VTCR_EL2_SL0_SHIFT) #define VTCR_EL2_T0SZ_MASK 0x3f -#define VTCR_EL2_T0SZ_40B 24 #define VTCR_EL2_VS_SHIFT 19 #define VTCR_EL2_VS_8BIT (0 << VTCR_EL2_VS_SHIFT) #define VTCR_EL2_VS_16BIT (1 << VTCR_EL2_VS_SHIFT) @@ -140,11 +139,8 @@ * Note that when using 4K pages, we concatenate two first level page tables * together. With 16K pages, we concatenate 16 first level page tables. * - * The magic numbers used for VTTBR_X in this patch can be found in Tables - * D4-23 and D4-25 in ARM DDI 0487A.b. */ -#define VTCR_EL2_T0SZ_IPA VTCR_EL2_T0SZ_40B #define VTCR_EL2_COMMON_BITS (VTCR_EL2_SH0_INNER | VTCR_EL2_ORGN0_WBWA | \ VTCR_EL2_IRGN0_WBWA | VTCR_EL2_RES1) @@ -155,7 +151,6 @@ * 2 level page tables (SL = 1) */ #define VTCR_EL2_TGRAN_FLAGS (VTCR_EL2_TG0_64K | VTCR_EL2_SL0_LVL1) -#define VTTBR_X_TGRAN_MAGIC 38 #elif defined(CONFIG_ARM64_16K_PAGES) /* * Stage2 translation configuration: @@ -163,7 +158,6 @@ * 2 level page tables (SL = 1) */ #define VTCR_EL2_TGRAN_FLAGS (VTCR_EL2_TG0_16K | VTCR_EL2_SL0_LVL1) -#define VTTBR_X_TGRAN_MAGIC 42 #else /* 4K */ /* * Stage2 translation configuration: @@ -171,13 +165,74 @@ * 3 level page tables (SL = 1) */ #define VTCR_EL2_TGRAN_FLAGS (VTCR_EL2_TG0_4K | VTCR_EL2_SL0_LVL1) -#define VTTBR_X_TGRAN_MAGIC 37 #endif #define VTCR_EL2_FLAGS (VTCR_EL2_COMMON_BITS | VTCR_EL2_TGRAN_FLAGS) -#define VTTBR_X (VTTBR_X_TGRAN_MAGIC - VTCR_EL2_T0SZ_IPA) +/* + * ARM VMSAv8-64 defines an algorithm for finding the translation table + * descriptors in section D4.2.8 in ARM DDI 0487C.a. + * + * The algorithm defines the expectations on the translation table + * addresses for each level, based on PAGE_SIZE, entry level + * and the translation table size (T0SZ). The variable "x" in the + * algorithm determines the alignment of a table base address at a given + * level and thus determines the alignment of VTTBR:BADDR for stage2 + * page table entry level. + * Since the number of bits resolved at the entry level could vary + * depending on the T0SZ, the value of "x" is defined based on a + * Magic constant for a given PAGE_SIZE and Entry Level. The + * intermediate levels must be always aligned to the PAGE_SIZE (i.e, + * x = PAGE_SHIFT). + * + * The value of "x" for entry level is calculated as : + * x = Magic_N - T0SZ + * + * where Magic_N is an integer depending on the page size and the entry + * level of the page table as below: + * + * -------------------------------------------- + * | Entry level | 4K 16K 64K | + * -------------------------------------------- + * | Level: 0 (4 levels) | 28 | - | - | + * -------------------------------------------- + * | Level: 1 (3 levels) | 37 | 31 | 25 | + * -------------------------------------------- + * | Level: 2 (2 levels) | 46 | 42 | 38 | + * -------------------------------------------- + * | Level: 3 (1 level) | - | 53 | 51 | + * -------------------------------------------- + * + * We have a magic formula for the Magic_N below: + * + * Magic_N(PAGE_SIZE, Level) = 64 - ((PAGE_SHIFT - 3) * Number_of_levels) + * + * where Number_of_levels = (4 - Level). We are only interested in the + * value for Entry_Level for the stage2 page table. + * + * So, given that T0SZ = (64 - IPA_SHIFT), we can compute 'x' as follows: + * + * x = (64 - ((PAGE_SHIFT - 3) * Number_of_levels)) - (64 - IPA_SHIFT) + * = IPA_SHIFT - ((PAGE_SHIFT - 3) * Number of levels) + * + * Here is one way to explain the Magic Formula: + * + * x = log2(Size_of_Entry_Level_Table) + * + * Since, we can resolve (PAGE_SHIFT - 3) bits at each level, and another + * PAGE_SHIFT bits in the PTE, we have : + * + * Bits_Entry_level = IPA_SHIFT - ((PAGE_SHIFT - 3) * (n - 1) + PAGE_SHIFT) + * = IPA_SHIFT - (PAGE_SHIFT - 3) * n - 3 + * where n = number of levels, and since each pointer is 8bytes, we have: + * + * x = Bits_Entry_Level + 3 + * = IPA_SHIFT - (PAGE_SHIFT - 3) * n + * + * The only constraint here is that, we have to find the number of page table + * levels for a given IPA size (which we do, see stage2_pt_levels()) + */ +#define ARM64_VTTBR_X(ipa, levels) ((ipa) - ((levels) * (PAGE_SHIFT - 3))) -#define VTTBR_BADDR_MASK (((UL(1) << (PHYS_MASK_SHIFT - VTTBR_X)) - 1) << VTTBR_X) #define VTTBR_VMID_SHIFT (UL(48)) #define VTTBR_VMID_MASK(size) (_AT(u64, (1 << size) - 1) << VTTBR_VMID_SHIFT) diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index 7342d2c51773..ac3ca9690bad 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -145,7 +145,6 @@ static inline unsigned long __kern_hyp_va(unsigned long v) #define kvm_phys_shift(kvm) KVM_PHYS_SHIFT #define kvm_phys_size(kvm) (_AC(1, ULL) << kvm_phys_shift(kvm)) #define kvm_phys_mask(kvm) (kvm_phys_size(kvm) - _AC(1, ULL)) -#define kvm_vttbr_baddr_mask(kvm) VTTBR_BADDR_MASK static inline bool kvm_page_empty(void *ptr) { @@ -520,5 +519,29 @@ static inline int hyp_map_aux_data(void) #define kvm_phys_to_vttbr(addr) phys_to_ttbr(addr) +/* + * Get the magic number 'x' for VTTBR:BADDR of this KVM instance. + * With v8.2 LVA extensions, 'x' should be a minimum of 6 with + * 52bit IPS. + */ +static inline int arm64_vttbr_x(u32 ipa_shift, u32 levels) +{ + int x = ARM64_VTTBR_X(ipa_shift, levels); + + return (IS_ENABLED(CONFIG_ARM64_PA_BITS_52) && x < 6) ? 6 : x; +} + +static inline u64 vttbr_baddr_mask(u32 ipa_shift, u32 levels) +{ + unsigned int x = arm64_vttbr_x(ipa_shift, levels); + + return GENMASK_ULL(PHYS_MASK_SHIFT - 1, x); +} + +static inline u64 kvm_vttbr_baddr_mask(struct kvm *kvm) +{ + return vttbr_baddr_mask(kvm_phys_shift(kvm), kvm_stage2_levels(kvm)); +} + #endif /* __ASSEMBLY__ */ #endif /* __ARM64_KVM_MMU_H__ */