From patchwork Wed Feb 5 01:39:50 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rik van Riel X-Patchwork-Id: 13960409 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38B5BC02193 for ; Wed, 5 Feb 2025 01:42:10 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9A94628002C; Tue, 4 Feb 2025 20:42:00 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 959F3280029; Tue, 4 Feb 2025 20:42:00 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7D1ED28002C; Tue, 4 Feb 2025 20:42:00 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 5A9E4280029 for ; Tue, 4 Feb 2025 20:42:00 -0500 (EST) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 017AA47CD6 for ; Wed, 5 Feb 2025 01:42:00 +0000 (UTC) X-FDA: 83084190000.24.D2BF021 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) by imf07.hostedemail.com (Postfix) with ESMTP id 7A3C740007 for ; Wed, 5 Feb 2025 01:41:58 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=none; spf=pass (imf07.hostedemail.com: domain of riel@shelob.surriel.com designates 96.67.55.147 as permitted sender) smtp.mailfrom=riel@shelob.surriel.com; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1738719718; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=POY3K8VJw3a1uUU3SOCTreZCz+W5UIji1O9L3bkG7jk=; b=ip6IZe3oo5uqxg8ZjhyfYmkwoxfDeIFpv/FoRZTLf+sjr2xD9Ir/ou1aJVc6UtFLZQWHX5 iH5rbGKghBoAbJZyflorOT5iTtj+varYMsohmUO0BaT75ggnjdrjBwvHV4a1Q8xZKLxVuj Z6oR9mniygvEYrahgzOqXo1ldBWnTJE= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=none; spf=pass (imf07.hostedemail.com: domain of riel@shelob.surriel.com designates 96.67.55.147 as permitted sender) smtp.mailfrom=riel@shelob.surriel.com; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1738719718; a=rsa-sha256; cv=none; b=x8unks3ILedGpvXWO2hkgTzRP4Nww0obUi/2cx3JwR3r5D/ClYM4IVmbkfxa7e+0W0IOTU nqEOk4KooKtw5pzgFvLAVjlH8V84y1ETyBiQkV0JyocjAYHXnmcfcSgVLia0DUK+D45zzL cYQcmtqqrQ1U6gvLfTWZG+2/v8Avit4= Received: from fangorn.home.surriel.com ([10.0.13.7]) by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.97.1) (envelope-from ) id 1tfUP4-000000004Cs-2T4Y; Tue, 04 Feb 2025 20:40:34 -0500 From: Rik van Riel To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, bp@alien8.de, peterz@infradead.org, dave.hansen@linux.intel.com, zhengqi.arch@bytedance.com, nadav.amit@gmail.com, thomas.lendacky@amd.com, kernel-team@meta.com, linux-mm@kvack.org, akpm@linux-foundation.org, jannh@google.com, mhklinux@outlook.com, andrew.cooper3@citrix.com, Rik van Riel , Manali Shukla Subject: [PATCH v8 01/12] x86/mm: make MMU_GATHER_RCU_TABLE_FREE unconditional Date: Tue, 4 Feb 2025 20:39:50 -0500 Message-ID: <20250205014033.3626204-2-riel@surriel.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250205014033.3626204-1-riel@surriel.com> References: <20250205014033.3626204-1-riel@surriel.com> MIME-Version: 1.0 X-Rspamd-Queue-Id: 7A3C740007 X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: 5drrzqgg9yp9xtti5mq6f19c14x5uo4h X-HE-Tag: 1738719718-45288 X-HE-Meta: U2FsdGVkX1+7u6SWX/B0uTqy2FZs0gQ+Ioc5B7giO4v4nsQyhCn8tSzGg5vdISfJhpBLLWJ9J7X2pPcIXJrkrjNiDl+Rbto3fD8Z1cmrPEI25YNSTZdalCr15gEJPW9D6c3k5qhj6/jfy7PQbKN0+N+TtwlsfVriy5ci9nlfHfnZITQDUixvba/47qRxztTV48quLgbHd/PFEe8Ouu/+1tCi8NVXwYCv8wRIlB0L/ZjQIg1KItdY1z7if6K/c4C0USNau8cYv3QKVXAQD0Wvb3gPzFtS3La3S/RxFjqN6qxZAXxHg13PSVJeVcth3mMzSqRMAdhefLek2CxMoPL8NHXSygeYE9YRECck9Ljr8s+0cIcvGoJ0JEkJMMvP8T9O4AKboYmTTIZlrfYS2LxuCfacChGT3XUTD2hJYAMqFWQqBAGBeQh1I6qY4cfX88L8G9aq6PktOy+qXNQ1d1FyHLgVH8kNZy9aDsss9/nON2vjcAiBp2+HN+qvv+2kY0aqBj0cXcTe5e0FnCXluGJU+9x5ctu2HMXBXmERh98BDLX0eKSAXVwIf/JY9X4jxu+VAmz3rNLbjwDby5XJES/mZP6FDDC2zBgbDCpwSZ//x6sNvijXMTCSot846QJu2KgV3H7Vfu+LaTJkrGN8cScBJNIv2J6r5B2vJ9S3nMAfaMD6tOVZ1nlkropCUex3uQIxhXI3tXKfsEqxLwLBD38KRFvIStXvH37zv1r9V02sdT1xufTWfT0f3sPAQlWTCYe7fhRA1Z9vUpOovBaX7zJpUBCx0FujyhJquHjOaIyiSelmIGas7T0HKxlixWbgns4UfjZYCDFA8gQj8Quh8H8gsDilqQV07nKS+K6ZpLorDW9cPU6bDY8k/+r01U5JN7vUfvZ2DLNy7oCvLQjZiqoT6XWHWw2WRJU/hyckU0WawvyRn8ub9ytAuJKwI0l3wKKaERKJUuBNK2FTIK4aBJq v6/Uf0S+ 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Currently x86 uses CONFIG_MMU_GATHER_TABLE_FREE when using paravirt, and not when running on bare metal. There is no real good reason to do things differently for each setup. Make them all the same. Currently get_user_pages_fast synchronizes against page table freeing in two different ways: - on bare metal, by blocking IRQs, which block TLB flush IPIs - on paravirt, with MMU_GATHER_RCU_TABLE_FREE This is done because some paravirt TLB flush implementations handle the TLB flush in the hypervisor, and will do the flush even when the target CPU has interrupts disabled. Always handle page table freeing with MMU_GATHER_RCU_TABLE_FREE. Using RCU synchronization between page table freeing and get_user_pages_fast() allows bare metal to also do TLB flushing while interrupts are disabled. Various places in the mm do still block IRQs or disable preemption as an implicit way to block RCU frees. That makes it safe to use INVLPGB on AMD CPUs. Signed-off-by: Rik van Riel Suggested-by: Peter Zijlstra Tested-by: Manali Shukla --- arch/x86/Kconfig | 2 +- arch/x86/kernel/paravirt.c | 7 +------ arch/x86/mm/pgtable.c | 16 ++++------------ 3 files changed, 6 insertions(+), 19 deletions(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 9d7bd0ae48c4..e8743f8c9fd0 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -274,7 +274,7 @@ config X86 select HAVE_PCI select HAVE_PERF_REGS select HAVE_PERF_USER_STACK_DUMP - select MMU_GATHER_RCU_TABLE_FREE if PARAVIRT + select MMU_GATHER_RCU_TABLE_FREE select MMU_GATHER_MERGE_VMAS select HAVE_POSIX_CPU_TIMERS_TASK_WORK select HAVE_REGS_AND_STACK_ACCESS_API diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index fec381533555..2b78a6b466ed 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -59,11 +59,6 @@ void __init native_pv_lock_init(void) static_branch_enable(&virt_spin_lock_key); } -static void native_tlb_remove_table(struct mmu_gather *tlb, void *table) -{ - tlb_remove_page(tlb, table); -} - struct static_key paravirt_steal_enabled; struct static_key paravirt_steal_rq_enabled; @@ -191,7 +186,7 @@ struct paravirt_patch_template pv_ops = { .mmu.flush_tlb_kernel = native_flush_tlb_global, .mmu.flush_tlb_one_user = native_flush_tlb_one_user, .mmu.flush_tlb_multi = native_flush_tlb_multi, - .mmu.tlb_remove_table = native_tlb_remove_table, + .mmu.tlb_remove_table = tlb_remove_table, .mmu.exit_mmap = paravirt_nop, .mmu.notify_page_enc_status_changed = paravirt_nop, diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index 5745a354a241..3dc4af1f7868 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -18,14 +18,6 @@ EXPORT_SYMBOL(physical_mask); #define PGTABLE_HIGHMEM 0 #endif -#ifndef CONFIG_PARAVIRT -static inline -void paravirt_tlb_remove_table(struct mmu_gather *tlb, void *table) -{ - tlb_remove_page(tlb, table); -} -#endif - gfp_t __userpte_alloc_gfp = GFP_PGTABLE_USER | PGTABLE_HIGHMEM; pgtable_t pte_alloc_one(struct mm_struct *mm) @@ -54,7 +46,7 @@ void ___pte_free_tlb(struct mmu_gather *tlb, struct page *pte) { pagetable_pte_dtor(page_ptdesc(pte)); paravirt_release_pte(page_to_pfn(pte)); - paravirt_tlb_remove_table(tlb, pte); + tlb_remove_table(tlb, pte); } #if CONFIG_PGTABLE_LEVELS > 2 @@ -70,7 +62,7 @@ void ___pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd) tlb->need_flush_all = 1; #endif pagetable_pmd_dtor(ptdesc); - paravirt_tlb_remove_table(tlb, ptdesc_page(ptdesc)); + tlb_remove_table(tlb, ptdesc_page(ptdesc)); } #if CONFIG_PGTABLE_LEVELS > 3 @@ -80,14 +72,14 @@ void ___pud_free_tlb(struct mmu_gather *tlb, pud_t *pud) pagetable_pud_dtor(ptdesc); paravirt_release_pud(__pa(pud) >> PAGE_SHIFT); - paravirt_tlb_remove_table(tlb, virt_to_page(pud)); + tlb_remove_table(tlb, virt_to_page(pud)); } #if CONFIG_PGTABLE_LEVELS > 4 void ___p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d) { paravirt_release_p4d(__pa(p4d) >> PAGE_SHIFT); - paravirt_tlb_remove_table(tlb, virt_to_page(p4d)); + tlb_remove_table(tlb, virt_to_page(p4d)); } #endif /* CONFIG_PGTABLE_LEVELS > 4 */ #endif /* CONFIG_PGTABLE_LEVELS > 3 */