From patchwork Tue Mar 7 14:05:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 13163864 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 D6F25C678D4 for ; Tue, 7 Mar 2023 14:50:07 +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=0iylB2iuspXbl5mhwXtd7dq8MoXLB4vB+GWDEtgXJ5o=; b=aSA6fHpwdb80fa /HyUYRDHTlL4GBh56AHISTQxZU+DPg4gOG7HOcFWepIk+S6f9bLA9y64yTMFJGK+d45UuWh0HzDso UX/0qKd8isgo3qUOoQ9pKU1JDwMi2JFnEZibmrW9bpcCKfpHQpkb0tJY9tCPbDlw7FMHbNzRcHWCG r7Im9kz3KWgUDMxGszdqVFJcSBRSkprFayz9rvfj+6F2HWFpIZgKVRK6TFT+fBv9kRNUp8AdJN1X9 BLUCpvp0HSXVvs4qBmXxJg5dAgvpwsdNSh90C/9PmI9zOVwFSPxugLSPiBTIVsoO2M8LXT+F/teVg jhLCjAFa4gLDOcbhRTmA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pZYce-000x3N-0Y; Tue, 07 Mar 2023 14:49:00 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1pZXzX-000eqP-18 for linux-arm-kernel@lists.infradead.org; Tue, 07 Mar 2023 14:08:37 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7C37F61457; Tue, 7 Mar 2023 14:08:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E972AC4339C; Tue, 7 Mar 2023 14:08:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1678198113; bh=8hH3Uc2UhkT3/0ty5o1TlACCwFDCvfgL5+D5fFfUrRw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SgjjhnR4pTHZpaj/6ZDOwtohlCgzHpgWtCMrmDY487+DK61hEpB0pKS9D6MrpiI2x /FBOCQF9lVgZno6QOJ5wK9dEpT9v7eQW3Z+eNATCmvGkL616zfS6Kfc8nR8mnSPTpM +Gf1v9yTp3b3nzm7775uBCgxI2YHDK2BGYJdCMU0rtt7NekHAQJvjWk4Um0Lzc7XgE JuSYku7jBB5t/EsH4yrwtMFBSDWqUFDaD5uV8iJLTzbXnkDQMzHElLP3hu2s3VXEhS UQSGdMZV1Dm7ZNRb6s+/HwttDRbNXh1tdGqbU4y2RZ/Kockdolw80TdlvhY77A6Apf eCbH4a2sjs+Ow== From: Ard Biesheuvel To: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, Ard Biesheuvel , Catalin Marinas , Will Deacon , Marc Zyngier , Mark Rutland , Ryan Roberts , Anshuman Khandual , Kees Cook Subject: [PATCH v3 48/60] arm64: mm: add LPA2 and 5 level paging support to G-to-nG conversion Date: Tue, 7 Mar 2023 15:05:10 +0100 Message-Id: <20230307140522.2311461-49-ardb@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307140522.2311461-1-ardb@kernel.org> References: <20230307140522.2311461-1-ardb@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=6585; i=ardb@kernel.org; h=from:subject; bh=8hH3Uc2UhkT3/0ty5o1TlACCwFDCvfgL5+D5fFfUrRw=; b=owGbwMvMwCFmkMcZplerG8N4Wi2JIYXdpfZPfbnckdXbp75p25549WuFMbs7w6XrG4NXGQSlS C9U6GLqKGVhEONgkBVTZBGY/ffdztMTpWqdZ8nCzGFlAhnCwMUpABP5IMPwh2vHfYXND/ckrzpt pa0x5VK6m7vCKaULv5Ou8O/gucx2s4CRYe3u2luObIs+Hg1KXRVnxnieS3Wi495rNzM4p/18N72 bmRcA X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230307_060835_219352_D6D64951 X-CRM114-Status: GOOD ( 21.90 ) 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 Add support for 5 level paging in the G-to-nG routine that creates its own temporary page tables to traverse the swapper page tables. Also add support for running the 5 level configuration with the top level folded at runtime, to support CPUs that do not implement the LPA2 extension. While at it, wire up the level skipping logic so it will also trigger on 4 level configurations with LPA2 enabled at build time but not active at runtime, as we'll fall back to 3 level paging in that case. Signed-off-by: Ard Biesheuvel --- arch/arm64/kernel/cpufeature.c | 9 ++- arch/arm64/mm/proc.S | 70 +++++++++++++++++--- 2 files changed, 66 insertions(+), 13 deletions(-) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index f8e3f37accdddc86..b0fee11886e54ca2 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1729,6 +1729,9 @@ kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused) pgd_t *kpti_ng_temp_pgd; u64 alloc = 0; + if (levels == 5 && !pgtable_l5_enabled()) + levels = 4; + if (__this_cpu_read(this_cpu_vector) == vectors) { const char *v = arm64_get_bp_hardening_vector(EL1_VECTOR_KPTI); @@ -1756,9 +1759,9 @@ kpti_install_ng_mappings(const struct arm64_cpu_capabilities *__unused) // // The physical pages are laid out as follows: // - // +--------+-/-------+-/------ +-\\--------+ - // : PTE[] : | PMD[] : | PUD[] : || PGD[] : - // +--------+-\-------+-\------ +-//--------+ + // +--------+-/-------+-/------ +-/------ +-\\\--------+ + // : PTE[] : | PMD[] : | PUD[] : | P4D[] : ||| PGD[] : + // +--------+-\-------+-\------ +-\------ +-///--------+ // ^ // The first page is mapped into this hierarchy at a PMD_SHIFT // aligned virtual address, so that we can manipulate the PTE diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 74b846d77b88e843..f425cfc3e4dad188 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -215,16 +215,15 @@ SYM_FUNC_ALIAS(__pi_idmap_cpu_replace_ttbr1, idmap_cpu_replace_ttbr1) .macro kpti_mk_tbl_ng, type, num_entries add end_\type\()p, cur_\type\()p, #\num_entries * 8 .Ldo_\type: - ldr \type, [cur_\type\()p] // Load the entry + ldr \type, [cur_\type\()p], #8 // Load the entry and advance tbz \type, #0, .Lnext_\type // Skip invalid and tbnz \type, #11, .Lnext_\type // non-global entries orr \type, \type, #PTE_NG // Same bit for blocks and pages - str \type, [cur_\type\()p] // Update the entry + str \type, [cur_\type\()p, #-8] // Update the entry .ifnc \type, pte tbnz \type, #1, .Lderef_\type .endif .Lnext_\type: - add cur_\type\()p, cur_\type\()p, #8 cmp cur_\type\()p, end_\type\()p b.ne .Ldo_\type .endm @@ -234,18 +233,18 @@ SYM_FUNC_ALIAS(__pi_idmap_cpu_replace_ttbr1, idmap_cpu_replace_ttbr1) * fixmap slot associated with the current level. */ .macro kpti_map_pgtbl, type, level - str xzr, [temp_pte, #8 * (\level + 1)] // break before make + str xzr, [temp_pte, #8 * (\level + 2)] // break before make dsb nshst - add pte, temp_pte, #PAGE_SIZE * (\level + 1) + add pte, temp_pte, #PAGE_SIZE * (\level + 2) lsr pte, pte, #12 tlbi vaae1, pte dsb nsh isb phys_to_pte pte, cur_\type\()p - add cur_\type\()p, temp_pte, #PAGE_SIZE * (\level + 1) + add cur_\type\()p, temp_pte, #PAGE_SIZE * (\level + 2) orr pte, pte, pte_flags - str pte, [temp_pte, #8 * (\level + 1)] + str pte, [temp_pte, #8 * (\level + 2)] dsb nshst .endm @@ -278,6 +277,8 @@ SYM_TYPED_FUNC_START(idmap_kpti_install_ng_mappings) end_ptep .req x15 pte .req x16 valid .req x17 + cur_p4dp .req x19 + end_p4dp .req x20 mov x5, x3 // preserve temp_pte arg mrs swapper_ttb, ttbr1_el1 @@ -285,6 +286,12 @@ SYM_TYPED_FUNC_START(idmap_kpti_install_ng_mappings) cbnz cpu, __idmap_kpti_secondary +#if CONFIG_PGTABLE_LEVELS > 4 + stp x29, x30, [sp, #-32]! + mov x29, sp + stp x19, x20, [sp, #16] +#endif + /* We're the boot CPU. Wait for the others to catch up */ sevl 1: wfe @@ -302,9 +309,32 @@ SYM_TYPED_FUNC_START(idmap_kpti_install_ng_mappings) mov pte_flags, #KPTI_NG_PTE_FLAGS /* Everybody is enjoying the idmap, so we can rewrite swapper. */ + +#ifdef CONFIG_ARM64_LPA2 + /* + * If LPA2 support is configured, but 52-bit virtual addressing is not + * enabled at runtime, we will fall back to one level of paging less, + * and so we have to walk swapper_pg_dir as if we dereferenced its + * address from a PGD level entry, and terminate the PGD level loop + * right after. + */ + adrp pgd, swapper_pg_dir // walk &swapper_pg_dir at the next level + mov cur_pgdp, end_pgdp // must be equal to terminate the PGD loop +alternative_if_not ARM64_HAS_VA52 + b .Lderef_pgd // skip to the next level +alternative_else_nop_endif + /* + * LPA2 based 52-bit virtual addressing requires 52-bit physical + * addressing to be enabled as well. In this case, the shareability + * bits are repurposed as physical address bits, and should not be + * set in pte_flags. + */ + bic pte_flags, pte_flags, #PTE_SHARED +#endif + /* PGD */ adrp cur_pgdp, swapper_pg_dir - kpti_map_pgtbl pgd, 0 + kpti_map_pgtbl pgd, -1 kpti_mk_tbl_ng pgd, PTRS_PER_PGD /* Ensure all the updated entries are visible to secondary CPUs */ @@ -317,16 +347,33 @@ SYM_TYPED_FUNC_START(idmap_kpti_install_ng_mappings) /* Set the flag to zero to indicate that we're all done */ str wzr, [flag_ptr] +#if CONFIG_PGTABLE_LEVELS > 4 + ldp x19, x20, [sp, #16] + ldp x29, x30, [sp], #32 +#endif ret .Lderef_pgd: + /* P4D */ + .if CONFIG_PGTABLE_LEVELS > 4 + p4d .req x30 + pte_to_phys cur_p4dp, pgd + kpti_map_pgtbl p4d, 0 + kpti_mk_tbl_ng p4d, PTRS_PER_P4D + b .Lnext_pgd + .else /* CONFIG_PGTABLE_LEVELS <= 4 */ + p4d .req pgd + .set .Lnext_p4d, .Lnext_pgd + .endif + +.Lderef_p4d: /* PUD */ .if CONFIG_PGTABLE_LEVELS > 3 pud .req x10 - pte_to_phys cur_pudp, pgd + pte_to_phys cur_pudp, p4d kpti_map_pgtbl pud, 1 kpti_mk_tbl_ng pud, PTRS_PER_PUD - b .Lnext_pgd + b .Lnext_p4d .else /* CONFIG_PGTABLE_LEVELS <= 3 */ pud .req pgd .set .Lnext_pud, .Lnext_pgd @@ -370,6 +417,9 @@ SYM_TYPED_FUNC_START(idmap_kpti_install_ng_mappings) .unreq end_ptep .unreq pte .unreq valid + .unreq cur_p4dp + .unreq end_p4dp + .unreq p4d /* Secondary CPUs end up here */ __idmap_kpti_secondary: