From patchwork Tue Mar 5 03:05:16 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexei Starovoitov X-Patchwork-Id: 13581570 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 F3E9CC5478C for ; Tue, 5 Mar 2024 03:05:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 85CC16B0089; Mon, 4 Mar 2024 22:05:31 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 80C386B008A; Mon, 4 Mar 2024 22:05:31 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 685FA6B008C; Mon, 4 Mar 2024 22:05:31 -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 55ADB6B0089 for ; Mon, 4 Mar 2024 22:05:31 -0500 (EST) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 25AFD14011C for ; Tue, 5 Mar 2024 03:05:31 +0000 (UTC) X-FDA: 81861494862.23.C42D600 Received: from mail-pg1-f179.google.com (mail-pg1-f179.google.com [209.85.215.179]) by imf19.hostedemail.com (Postfix) with ESMTP id 6F9661A000B for ; Tue, 5 Mar 2024 03:05:29 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=BB5zTcQb; spf=pass (imf19.hostedemail.com: domain of alexei.starovoitov@gmail.com designates 209.85.215.179 as permitted sender) smtp.mailfrom=alexei.starovoitov@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1709607929; a=rsa-sha256; cv=none; b=QXcSB7iWaeiqP++bi5nDvmwoP5+9MQzgspR3oGUMpJPplWLSTxCD2dFkXXSZzjL0D2U+xr y5g5mu5mY1I2asknVSSrdqtAG6s0M1QEe5tpRc42rrd2DwzPN8Tt9ylNopmFZzhB6GzixE 61HA6gqDR48FmhZIJ722uWD59avWx6Q= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=gmail.com header.s=20230601 header.b=BB5zTcQb; spf=pass (imf19.hostedemail.com: domain of alexei.starovoitov@gmail.com designates 209.85.215.179 as permitted sender) smtp.mailfrom=alexei.starovoitov@gmail.com; dmarc=pass (policy=none) header.from=gmail.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1709607929; h=from:from: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:dkim-signature; bh=o3Uab1G5GTmyRpRg7HZiDcHzBw+gqXSTLydz3NAXDjw=; b=WRMNFkgWSUHOXVtYCNmknEaHoOrFuif9OR1tDXGfOymwOEGLtE8y5jNsBWWnpGl2frHFzG sj8EnU2NAUdYkJywPjVRT4z4ONZh6sgeYEmY0qDQC4h6oVjO5WFMf/0cUN3PrXy4Qy/9F4 vMYXVwfr+ZRbkazjLMduIesDdj5HXTc= Received: by mail-pg1-f179.google.com with SMTP id 41be03b00d2f7-5c229dabbb6so173334a12.0 for ; Mon, 04 Mar 2024 19:05:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1709607928; x=1710212728; darn=kvack.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=o3Uab1G5GTmyRpRg7HZiDcHzBw+gqXSTLydz3NAXDjw=; b=BB5zTcQb45JdtKLQDWz2AS/iH01/3+nvqkXk34FgK6g7Xlnze8Dfg7Z9YjqT14j+vR QgjYgZqiRla/4NAuhJsnt7+nFlt5xsr0csK0htLjFaT7qsnpVusTYuNZjbaS1FhZw3Wn RA68j14Efr3dOvqxQqVP7+J3Ymlp/5kls6lszDJWRda9TpYrJqqNN3EYprLnY+th55Ws V0hPumHS2M57r6SUGT2HokhN5cCsWgqpS8Ry2ocuDImVxJdLmrJu8E7IRo5pMpuFz/N5 wBlCvyGc/ff1cmkvZJbAKV1lfk9THw6IQxTCsHQs4sztLn1exnZD06RKVty3Fv/S9ET2 52eQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709607928; x=1710212728; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=o3Uab1G5GTmyRpRg7HZiDcHzBw+gqXSTLydz3NAXDjw=; b=VhSBC6ijAK8L2GAYEk5u1NcBES793d3MAt2IX22ZTpV1cZ6XRVyd6aVPdW39qvnSXO Xhn+v9Rzc9l7j7vJ7sAFoUjt6pAnL0gxFSS5pGQXjfv5Mr1PBwBR6CDHlN7S/veoMYcr 7/V4K+ctIjTzVNVxZhPqBOJpd8XBcMx85y6RxVRjFHpcgsrETRlyB5shj27lP2ECn9Eq 5DU8irh5bEOgj2vbzC3X09aQv2dhtQZO2zY5W6Ri9q9cJ7bWgllYTma8/GYAVpyRciGW aE6r62rAQw/pE11JeirGRyYJbmED54Owq8EfE44jaCJhelY3onxrDaRyS1DHaD0kUZ7t ULqQ== X-Forwarded-Encrypted: i=1; AJvYcCXqaW7rl5zxC4IVW1w8Gmw87jZgPO7r3KSe0RANvEdGr1ChRHXcqUodf/7uO3RWBJt2IYemrT8l7NOf/ZET6J50Aus= X-Gm-Message-State: AOJu0Yx/UMyIAuDZk9tffOiILrnKHCpq++rugUenESmprUaQEqr3FEZd UlHiUKB8T5O486nV0C6fd/Gdt+f9IdodNbH6LC5an1AW5bxMIs++8sGKMbNs X-Google-Smtp-Source: AGHT+IHbzyFXZDmwTFXKOBQzhI/J5ZF4BBhSMJWYsXowuh6pvkssrM9sK35Jd24futLM3qVbKmDLRw== X-Received: by 2002:a05:6a20:1da:b0:1a1:4d41:3570 with SMTP id 26-20020a056a2001da00b001a14d413570mr470241pzz.59.1709607927721; Mon, 04 Mar 2024 19:05:27 -0800 (PST) Received: from localhost.localdomain ([2620:10d:c090:400::5:9426]) by smtp.gmail.com with ESMTPSA id ep2-20020a17090ae64200b0029932d175c3sm62083pjb.0.2024.03.04.19.05.25 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Mon, 04 Mar 2024 19:05:27 -0800 (PST) From: Alexei Starovoitov To: bpf@vger.kernel.org Cc: daniel@iogearbox.net, andrii@kernel.org, torvalds@linux-foundation.org, brho@google.com, hannes@cmpxchg.org, lstoakes@gmail.com, akpm@linux-foundation.org, urezki@gmail.com, hch@infradead.org, rppt@kernel.org, boris.ostrovsky@oracle.com, sstabellini@kernel.org, jgross@suse.com, linux-mm@kvack.org, xen-devel@lists.xenproject.org, kernel-team@fb.com Subject: [PATCH v4 bpf-next 2/2] mm: Introduce VM_SPARSE kind and vm_area_[un]map_pages(). Date: Mon, 4 Mar 2024 19:05:16 -0800 Message-Id: <20240305030516.41519-3-alexei.starovoitov@gmail.com> X-Mailer: git-send-email 2.39.3 (Apple Git-145) In-Reply-To: <20240305030516.41519-1-alexei.starovoitov@gmail.com> References: <20240305030516.41519-1-alexei.starovoitov@gmail.com> MIME-Version: 1.0 X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 6F9661A000B X-Stat-Signature: 6ppdke4en16hu3hqz8agyddq6fee74ui X-Rspam-User: X-HE-Tag: 1709607929-439744 X-HE-Meta: U2FsdGVkX18yVySsbyevS+FOMAe38ioioFgQpqbFX8CnDsyAIo1Is6eJ+VToaFQnpNNQAQdM3IInHtvdaCpeCCyRoT7LWWI2zwgHXRfKVF08iHfWyqD2TJ3DVyseOoU5anYHND4fbmVETTWT9r3btxLmquQU3nussvajNeGcYrm4BMnrJRkdAEgtFkJNoxJhfVSyCJM8SyYztTw+ibPlakmQ4atB79OlyzyiiM+hb5wPo4dGDJ5/j04dzjLm/uuoXTECSTEmh5vpP78+/qCZwS/YWA0/iFSvVW8s4x5hbMHcMFnzAnhHV8B7GpzKTK++OhCgx38A8BBE/LdVt7Ltuv0b5Nbj1iwroKwQ/q9VDPyF/GhUe0qwJSHb46xm90VrFeP9emiR+TdLGI7iDi8/JNvrodDw2HMyP5B1bkeU/JOCc5MKvv2OYeniBoVwfZD/2yxhDBQxvkm/XOhIzahSyqYp4ujNTnoL5p82M6VKC88HFmSBuFVpr6Es4hF96KVUr1ABy5CXogY6JwjHxT+XpSPNXYhSwC6dnUocfFv7P1Uy7e4mMgK4c6+9NWytYTXA0x+jrWdS5763RVgWtDuLzAg4rR4gVpbc+H54JxqbSHTWMtVQzbw1MEy+kEgn9s7Q31GdrDQjeuqCbCKOlYqmUwJIn9klPcwgho9T34wvfneEtMTUmon7IVP2EbeQDbZi58cQHz9SpKTy0pSfVc4Bmf9GsJAjOGDMNc7DdkchbRDhaVA7hnoLHOQyYrDh9C1wh3azClJpSgzzhj1D8nzudnOv2NJBucmWp2kyN/iJwQLivW2qIM7a9lR7YN2kkD9NRSUes0pTZCdMxEOHCpVxzSQbXtSJhWJNMcqT2TupDs9hCVjWpkHK4fEQrEqq6SZFBo9CZF/7bu17O/qShff5hdSfKqPpiG9x/2r9csaQnvAzv0caLr9KQ+65j1l264B59PJW49vh8hmgoicGRvr xjoQdN7K WgPlytb9oyHPVA4lzEZkb5hPOy1c71E5MLahRRlvoro39Kl4KI3IkFi6UeQcIr51EVHURDPQnHpHFblc/UYASOl8RgK6G50Ehg/fRuY9p5OrLq5GCmAdk0rMsds1ZNRIOCT1cYIQpRoFBNPjTeG6gqkNJ2NzMX+cO5FdjFqASRcQVN0XXN1Rlspk3XVdekA/DSxvg 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: From: Alexei Starovoitov vmap/vmalloc APIs are used to map a set of pages into contiguous kernel virtual space. get_vm_area() with appropriate flag is used to request an area of kernel address range. It's used for vmalloc, vmap, ioremap, xen use cases. - vmalloc use case dominates the usage. Such vm areas have VM_ALLOC flag. - the areas created by vmap() function should be tagged with VM_MAP. - ioremap areas are tagged with VM_IOREMAP. BPF would like to extend the vmap API to implement a lazily-populated sparse, yet contiguous kernel virtual space. Introduce VM_SPARSE flag and vm_area_map_pages(area, start_addr, count, pages) API to map a set of pages within a given area. It has the same sanity checks as vmap() does. It also checks that get_vm_area() was created with VM_SPARSE flag which identifies such areas in /proc/vmallocinfo and returns zero pages on read through /proc/kcore. The next commits will introduce bpf_arena which is a sparsely populated shared memory region between bpf program and user space process. It will map privately-managed pages into a sparse vm area with the following steps: // request virtual memory region during bpf prog verification area = get_vm_area(area_size, VM_SPARSE); // on demand vm_area_map_pages(area, kaddr, kend, pages); vm_area_unmap_pages(area, kaddr, kend); // after bpf program is detached and unloaded free_vm_area(area); Signed-off-by: Alexei Starovoitov Reviewed-by: Christoph Hellwig Reviewed-by: Pasha Tatashin --- include/linux/vmalloc.h | 5 ++++ mm/vmalloc.c | 59 +++++++++++++++++++++++++++++++++++++++-- 2 files changed, 62 insertions(+), 2 deletions(-) diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index c720be70c8dd..0f72c85a377b 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -35,6 +35,7 @@ struct iov_iter; /* in uio.h */ #else #define VM_DEFER_KMEMLEAK 0 #endif +#define VM_SPARSE 0x00001000 /* sparse vm_area. not all pages are present. */ /* bits [20..32] reserved for arch specific ioremap internals */ @@ -232,6 +233,10 @@ static inline bool is_vm_area_hugepages(const void *addr) } #ifdef CONFIG_MMU +int vm_area_map_pages(struct vm_struct *area, unsigned long start, + unsigned long end, struct page **pages); +void vm_area_unmap_pages(struct vm_struct *area, unsigned long start, + unsigned long end); void vunmap_range(unsigned long addr, unsigned long end); static inline void set_vm_flush_reset_perms(void *addr) { diff --git a/mm/vmalloc.c b/mm/vmalloc.c index f42f98a127d5..e5b8c70950bc 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -648,6 +648,58 @@ static int vmap_pages_range(unsigned long addr, unsigned long end, return err; } +static int check_sparse_vm_area(struct vm_struct *area, unsigned long start, + unsigned long end) +{ + might_sleep(); + if (WARN_ON_ONCE(area->flags & VM_FLUSH_RESET_PERMS)) + return -EINVAL; + if (WARN_ON_ONCE(area->flags & VM_NO_GUARD)) + return -EINVAL; + if (WARN_ON_ONCE(!(area->flags & VM_SPARSE))) + return -EINVAL; + if ((end - start) >> PAGE_SHIFT > totalram_pages()) + return -E2BIG; + if (start < (unsigned long)area->addr || + (void *)end > area->addr + get_vm_area_size(area)) + return -ERANGE; + return 0; +} + +/** + * vm_area_map_pages - map pages inside given sparse vm_area + * @area: vm_area + * @start: start address inside vm_area + * @end: end address inside vm_area + * @pages: pages to map (always PAGE_SIZE pages) + */ +int vm_area_map_pages(struct vm_struct *area, unsigned long start, + unsigned long end, struct page **pages) +{ + int err; + + err = check_sparse_vm_area(area, start, end); + if (err) + return err; + + return vmap_pages_range(start, end, PAGE_KERNEL, pages, PAGE_SHIFT); +} + +/** + * vm_area_unmap_pages - unmap pages inside given sparse vm_area + * @area: vm_area + * @start: start address inside vm_area + * @end: end address inside vm_area + */ +void vm_area_unmap_pages(struct vm_struct *area, unsigned long start, + unsigned long end) +{ + if (check_sparse_vm_area(area, start, end)) + return; + + vunmap_range(start, end); +} + int is_vmalloc_or_module_addr(const void *x) { /* @@ -3822,9 +3874,9 @@ long vread_iter(struct iov_iter *iter, const char *addr, size_t count) if (flags & VMAP_RAM) copied = vmap_ram_vread_iter(iter, addr, n, flags); - else if (!(vm && (vm->flags & VM_IOREMAP))) + else if (!(vm && (vm->flags & (VM_IOREMAP | VM_SPARSE)))) copied = aligned_vread_iter(iter, addr, n); - else /* IOREMAP area is treated as memory hole */ + else /* IOREMAP | SPARSE area is treated as memory hole */ copied = zero_iter(iter, n); addr += copied; @@ -4415,6 +4467,9 @@ static int s_show(struct seq_file *m, void *p) if (v->flags & VM_IOREMAP) seq_puts(m, " ioremap"); + if (v->flags & VM_SPARSE) + seq_puts(m, " sparse"); + if (v->flags & VM_ALLOC) seq_puts(m, " vmalloc");