From mboxrd@z Thu Jan 1 00:00:00 1970 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 76775C02183 for ; Fri, 17 Jan 2025 10:05:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=7k0WJN9VHYrWroEqAlCojPU8Gu3aynTgjEPQVaU2xJg=; b=P0SRse4b4HDsoW40oHcMO3hOon AuU8/GOAtMHprZJqk8EuitOjnOpizosGTiO69Al5t2fB4JSoXyd7lwpuuVXZfDPlrc3AyYT0I5cdi VZ9MzobQby1VwNJsJH8mVoOzqCmF9XsV9WkKIwFZRddTnl3Uyr1wiv1cTtUFjJ13vrOyujf84bxwf /EyFpQT2FJYVcxhYzXhR+u+iNzlepTe1z8SzqE0L/0ZdGdZi1+zn1ANw2MGY7BsSzvfOeagyjbrJI AzF+pxpJoyXjOcwKFkRLfmLodEDI1fVRXvRFZ98qob6GKordp1b2ZYhNhAaU1Gi7cOlKSIFa7U61v gO1sZEmg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tYjDu-0000000HXVa-3hJC; Fri, 17 Jan 2025 10:05:06 +0000 Received: from desiato.infradead.org ([2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tYjDs-0000000HXTU-3ofL for linux-nvme@bombadil.infradead.org; Fri, 17 Jan 2025 10:05:05 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; 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; bh=7k0WJN9VHYrWroEqAlCojPU8Gu3aynTgjEPQVaU2xJg=; b=rA158kvzpG+oPsbpgPRHW7cnoz OgRSfYQGMf9b91v8Y3ycEfGcSODhYwuj5qd9yBh/Nx+gAFKVlyhbaqQzlHUYxKo4iMeRmVOTx+Ps/ +XwTXNqp2Lp09u3MRSgSBRZcRuXoUeSLyhTlxUeuw5zQfmdPnVXuqwoOqjWPFNG2V3mD0FdzGYof8 w0A+pLu5mM5SrJj0fRqHYnIOW4Gv54wBgyLa4oxO6s1sfALCH+Uul5CaflJF98rf0XN07K5oHnz0y 6VIhT8jj4Slr1aqD4GKVBIPvju2T3czUezQ+lNMuOMByYyYpNw2TBJD99blUupPdkx76u1dJyJqLJ RVstCObA==; Received: from nyc.source.kernel.org ([147.75.193.91]) by desiato.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tYjDR-0000000BOox-2h2D for linux-nvme@lists.infradead.org; Fri, 17 Jan 2025 10:05:03 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id AD4A0A42B2D; Fri, 17 Jan 2025 10:02:44 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8AC4EC4CEDD; Fri, 17 Jan 2025 10:04:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737108272; bh=In+edwZaKe3io90YLtv4jjZtq6muAkpbvftk2SGeHaY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cxib5n7OJ4awdwP9n9ns3nBcyKLJpElFKANRoB+QeGzY2n8K+dzz9u4siNPoi/ZnW Kf2WnGEWbgoEw9iGxK03Z4nR7BFjomVC4rzGpC6Vrfs+xVBgJXjtijNOXpqddYAckb PCWupB6fuyFakIhYaGkH/Gz9iDn9q8MwXlPbPdAUoTEX8G9wNd59qIGSPJqDk6oRM3 BKJl1Pieag1pVLLq8efeLNN7WKuLpAofCUz54s6lVSkTdKz4tp92eiZbwNL4vmEg5A wyXUt4T215wqVCJBt9DlaTkJ3mdqoZRm/yKP0XJzJFb0eWhGiwB/yi3S7nmrxG8cTN 9a3+9jsvMWZZQ== From: Leon Romanovsky To: Cc: Leon Romanovsky , Jens Axboe , Joerg Roedel , Will Deacon , Sagi Grimberg , "Keith Busch" , "Bjorn Helgaas" , "Logan Gunthorpe" , "Yishai Hadas" , "Shameer Kolothum" , "Kevin Tian" , "Alex Williamson" , "Marek Szyprowski" , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , "Andrew Morton" , "Jonathan Corbet" , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-rdma@vger.kernel.org, iommu@lists.linux.dev, linux-nvme@lists.infradead.org, linux-pci@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, "Randy Dunlap" Subject: [PATCH v6 10/17] mm/hmm: let users to tag specific PFN with DMA mapped bit Date: Fri, 17 Jan 2025 12:03:41 +0200 Message-ID: <0f89921b4197830f410330ae7a5e89ecbe7739d5.1737106761.git.leon@kernel.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250117_100447_745710_8EAF22FB X-CRM114-Status: GOOD ( 18.69 ) X-BeenThere: linux-nvme@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-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org From: Leon Romanovsky Introduce new sticky flag (HMM_PFN_DMA_MAPPED), which isn't overwritten by HMM range fault. Such flag allows users to tag specific PFNs with information if this specific PFN was already DMA mapped. Signed-off-by: Leon Romanovsky --- include/linux/hmm.h | 17 +++++++++++++++ mm/hmm.c | 51 ++++++++++++++++++++++++++++----------------- 2 files changed, 49 insertions(+), 19 deletions(-) diff --git a/include/linux/hmm.h b/include/linux/hmm.h index 126a36571667..a1ddbedc19c0 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -23,6 +23,8 @@ struct mmu_interval_notifier; * HMM_PFN_WRITE - if the page memory can be written to (requires HMM_PFN_VALID) * HMM_PFN_ERROR - accessing the pfn is impossible and the device should * fail. ie poisoned memory, special pages, no vma, etc + * HMM_PFN_DMA_MAPPED - Flag preserved on input-to-output transformation + * to mark that page is already DMA mapped * * On input: * 0 - Return the current state of the page, do not fault it. @@ -36,6 +38,13 @@ enum hmm_pfn_flags { HMM_PFN_VALID = 1UL << (BITS_PER_LONG - 1), HMM_PFN_WRITE = 1UL << (BITS_PER_LONG - 2), HMM_PFN_ERROR = 1UL << (BITS_PER_LONG - 3), + + /* + * Sticky flags, carried from input to output, + * don't forget to update HMM_PFN_INOUT_FLAGS + */ + HMM_PFN_DMA_MAPPED = 1UL << (BITS_PER_LONG - 7), + HMM_PFN_ORDER_SHIFT = (BITS_PER_LONG - 8), /* Input flags */ @@ -57,6 +66,14 @@ static inline struct page *hmm_pfn_to_page(unsigned long hmm_pfn) return pfn_to_page(hmm_pfn & ~HMM_PFN_FLAGS); } +/* + * hmm_pfn_to_phys() - return physical address pointed to by a device entry + */ +static inline phys_addr_t hmm_pfn_to_phys(unsigned long hmm_pfn) +{ + return __pfn_to_phys(hmm_pfn & ~HMM_PFN_FLAGS); +} + /* * hmm_pfn_to_map_order() - return the CPU mapping size order * diff --git a/mm/hmm.c b/mm/hmm.c index 7e0229ae4a5a..da5743f6d854 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -39,13 +39,20 @@ enum { HMM_NEED_ALL_BITS = HMM_NEED_FAULT | HMM_NEED_WRITE_FAULT, }; +enum { + /* These flags are carried from input-to-output */ + HMM_PFN_INOUT_FLAGS = HMM_PFN_DMA_MAPPED, +}; + static int hmm_pfns_fill(unsigned long addr, unsigned long end, struct hmm_range *range, unsigned long cpu_flags) { unsigned long i = (addr - range->start) >> PAGE_SHIFT; - for (; addr < end; addr += PAGE_SIZE, i++) - range->hmm_pfns[i] = cpu_flags; + for (; addr < end; addr += PAGE_SIZE, i++) { + range->hmm_pfns[i] &= HMM_PFN_INOUT_FLAGS; + range->hmm_pfns[i] |= cpu_flags; + } return 0; } @@ -202,8 +209,10 @@ static int hmm_vma_handle_pmd(struct mm_walk *walk, unsigned long addr, return hmm_vma_fault(addr, end, required_fault, walk); pfn = pmd_pfn(pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); - for (i = 0; addr < end; addr += PAGE_SIZE, i++, pfn++) - hmm_pfns[i] = pfn | cpu_flags; + for (i = 0; addr < end; addr += PAGE_SIZE, i++, pfn++) { + hmm_pfns[i] &= HMM_PFN_INOUT_FLAGS; + hmm_pfns[i] |= pfn | cpu_flags; + } return 0; } #else /* CONFIG_TRANSPARENT_HUGEPAGE */ @@ -230,14 +239,14 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, unsigned long cpu_flags; pte_t pte = ptep_get(ptep); uint64_t pfn_req_flags = *hmm_pfn; + uint64_t new_pfn_flags = 0; if (pte_none_mostly(pte)) { required_fault = hmm_pte_need_fault(hmm_vma_walk, pfn_req_flags, 0); if (required_fault) goto fault; - *hmm_pfn = 0; - return 0; + goto out; } if (!pte_present(pte)) { @@ -253,16 +262,14 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, cpu_flags = HMM_PFN_VALID; if (is_writable_device_private_entry(entry)) cpu_flags |= HMM_PFN_WRITE; - *hmm_pfn = swp_offset_pfn(entry) | cpu_flags; - return 0; + new_pfn_flags = swp_offset_pfn(entry) | cpu_flags; + goto out; } required_fault = hmm_pte_need_fault(hmm_vma_walk, pfn_req_flags, 0); - if (!required_fault) { - *hmm_pfn = 0; - return 0; - } + if (!required_fault) + goto out; if (!non_swap_entry(entry)) goto fault; @@ -304,11 +311,13 @@ static int hmm_vma_handle_pte(struct mm_walk *walk, unsigned long addr, pte_unmap(ptep); return -EFAULT; } - *hmm_pfn = HMM_PFN_ERROR; - return 0; + new_pfn_flags = HMM_PFN_ERROR; + goto out; } - *hmm_pfn = pte_pfn(pte) | cpu_flags; + new_pfn_flags = pte_pfn(pte) | cpu_flags; +out: + *hmm_pfn = (*hmm_pfn & HMM_PFN_INOUT_FLAGS) | new_pfn_flags; return 0; fault: @@ -448,8 +457,10 @@ static int hmm_vma_walk_pud(pud_t *pudp, unsigned long start, unsigned long end, } pfn = pud_pfn(pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT); - for (i = 0; i < npages; ++i, ++pfn) - hmm_pfns[i] = pfn | cpu_flags; + for (i = 0; i < npages; ++i, ++pfn) { + hmm_pfns[i] &= HMM_PFN_INOUT_FLAGS; + hmm_pfns[i] |= pfn | cpu_flags; + } goto out_unlock; } @@ -507,8 +518,10 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask, } pfn = pte_pfn(entry) + ((start & ~hmask) >> PAGE_SHIFT); - for (; addr < end; addr += PAGE_SIZE, i++, pfn++) - range->hmm_pfns[i] = pfn | cpu_flags; + for (; addr < end; addr += PAGE_SIZE, i++, pfn++) { + range->hmm_pfns[i] &= HMM_PFN_INOUT_FLAGS; + range->hmm_pfns[i] |= pfn | cpu_flags; + } spin_unlock(ptl); return 0; -- 2.47.1