From patchwork Wed Aug 23 15:34:02 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13362775 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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 EF8D9C3DA66 for ; Wed, 23 Aug 2023 15:35:23 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qYpsO-0001v1-ER; Wed, 23 Aug 2023 11:34:32 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qYpsK-0001tM-RO for qemu-devel@nongnu.org; Wed, 23 Aug 2023 11:34:30 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qYpsI-0007vd-6x for qemu-devel@nongnu.org; Wed, 23 Aug 2023 11:34:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1692804865; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9CzMKg1HAEzal46X3K+Yyo/0UZfnJlj1bng/MWpcxIs=; b=fThOW+QMRGqRRc9dz69rApV5jXlwRg1qq96EhzZLG2tiTrCjUeD7jVjAPkntgNd9p6yBuu SH5eMUukvA78+XY4AlyzonbdlBIiHl/GZ7hzEqlYBGA9Y14LkDClczJyKdjAfbX1QWKhZg s+86V/f306hCxBv5gPuqiuEPlxbUE+0= Received: from mimecast-mx02.redhat.com (66.187.233.73 [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-55-LN1_r5KpOyaGVlRmyRKaAQ-1; Wed, 23 Aug 2023 11:34:22 -0400 X-MC-Unique: LN1_r5KpOyaGVlRmyRKaAQ-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id B65783C0FC9C; Wed, 23 Aug 2023 15:34:21 +0000 (UTC) Received: from t14s.fritz.box (unknown [10.39.193.128]) by smtp.corp.redhat.com (Postfix) with ESMTP id F2AF71121314; Wed, 23 Aug 2023 15:34:18 +0000 (UTC) From: David Hildenbrand To: qemu-devel@nongnu.org Cc: qemu-ppc@nongnu.org, David Hildenbrand , Paolo Bonzini , Peter Xu , Igor Mammedov , Thiner Logoer , =?utf-8?q?Philippe_Mathieu-Daud=C3=A9?= , =?utf-8?q?Dani?= =?utf-8?q?el_P_=2E_Berrang=C3=A9?= , Stefan Hajnoczi , Elena Ufimtseva , Jagannathan Raman , "Michael S. Tsirkin" , Ani Sinha , Xiao Guangrong , Daniel Henrique Barboza , Greg Kurz , Eric Blake , Markus Armbruster , Eduardo Habkost Subject: [PATCH v3 02/11] softmmu/physmem: Distinguish between file access mode and mmap protection Date: Wed, 23 Aug 2023 17:34:02 +0200 Message-ID: <20230823153412.832081-3-david@redhat.com> In-Reply-To: <20230823153412.832081-1-david@redhat.com> References: <20230823153412.832081-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 Received-SPF: pass client-ip=170.10.129.124; envelope-from=david@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org There is a difference between how we open a file and how we mmap it, and we want to support writable private mappings of readonly files. Let's define RAM_READONLY and RAM_READONLY_FD flags, to replace the single "readonly" parameter for file-related functions. In memory_region_init_ram_from_fd() and memory_region_init_ram_from_file(), initialize mr->readonly based on the new RAM_READONLY flag. While at it, add some RAM_* flags we missed to add to the list of accepted flags in the documentation of some functions. No change in functionality intended. We'll make use of both flags next and start setting them independently for memory-backend-file. Signed-off-by: David Hildenbrand Acked-by: Peter Xu --- backends/hostmem-file.c | 4 ++-- include/exec/memory.h | 14 ++++++++++---- include/exec/ram_addr.h | 8 ++++---- softmmu/memory.c | 8 ++++---- softmmu/physmem.c | 21 ++++++++++----------- 5 files changed, 30 insertions(+), 25 deletions(-) diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c index b4335a80e6..ef2d5533af 100644 --- a/backends/hostmem-file.c +++ b/backends/hostmem-file.c @@ -55,13 +55,13 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) name = host_memory_backend_get_name(backend); ram_flags = backend->share ? RAM_SHARED : 0; + ram_flags |= fb->readonly ? RAM_READONLY | RAM_READONLY_FD : 0; ram_flags |= backend->reserve ? 0 : RAM_NORESERVE; ram_flags |= fb->is_pmem ? RAM_PMEM : 0; ram_flags |= RAM_NAMED_FILE; memory_region_init_ram_from_file(&backend->mr, OBJECT(backend), name, backend->size, fb->align, ram_flags, - fb->mem_path, fb->offset, fb->readonly, - errp); + fb->mem_path, fb->offset, errp); g_free(name); #endif } diff --git a/include/exec/memory.h b/include/exec/memory.h index 68284428f8..cc68249eda 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -235,6 +235,12 @@ typedef struct IOMMUTLBEvent { /* RAM is an mmap-ed named file */ #define RAM_NAMED_FILE (1 << 9) +/* RAM is mmap-ed read-only */ +#define RAM_READONLY (1 << 10) + +/* RAM FD is opened read-only */ +#define RAM_READONLY_FD (1 << 11) + static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn, IOMMUNotifierFlag flags, hwaddr start, hwaddr end, @@ -1331,10 +1337,10 @@ void memory_region_init_resizeable_ram(MemoryRegion *mr, * @align: alignment of the region base address; if 0, the default alignment * (getpagesize()) will be used. * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM, - * RAM_NORESERVE, + * RAM_NORESERVE, RAM_PROTECTED, RAM_NAMED_FILE, RAM_READONLY, + * RAM_READONLY_FD * @path: the path in which to allocate the RAM. * @offset: offset within the file referenced by path - * @readonly: true to open @path for reading, false for read/write. * @errp: pointer to Error*, to store an error if it happens. * * Note that this function does not do anything to cause the data in the @@ -1348,7 +1354,6 @@ void memory_region_init_ram_from_file(MemoryRegion *mr, uint32_t ram_flags, const char *path, ram_addr_t offset, - bool readonly, Error **errp); /** @@ -1360,7 +1365,8 @@ void memory_region_init_ram_from_file(MemoryRegion *mr, * @name: the name of the region. * @size: size of the region. * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM, - * RAM_NORESERVE, RAM_PROTECTED. + * RAM_NORESERVE, RAM_PROTECTED, RAM_NAMED_FILE, RAM_READONLY, + * RAM_READONLY_FD * @fd: the fd to mmap. * @offset: offset within the file referenced by fd * @errp: pointer to Error*, to store an error if it happens. diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h index 9f2e3893f5..90676093f5 100644 --- a/include/exec/ram_addr.h +++ b/include/exec/ram_addr.h @@ -108,10 +108,10 @@ long qemu_maxrampagesize(void); * @size: the size in bytes of the ram block * @mr: the memory region where the ram block is * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM, - * RAM_NORESERVE. + * RAM_NORESERVE, RAM_PROTECTED, RAM_NAMED_FILE, RAM_READONLY, + * RAM_READONLY_FD * @mem_path or @fd: specify the backing file or device * @offset: Offset into target file - * @readonly: true to open @path for reading, false for read/write. * @errp: pointer to Error*, to store an error if it happens * * Return: @@ -120,10 +120,10 @@ long qemu_maxrampagesize(void); */ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr, uint32_t ram_flags, const char *mem_path, - off_t offset, bool readonly, Error **errp); + off_t offset, Error **errp); RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr, uint32_t ram_flags, int fd, off_t offset, - bool readonly, Error **errp); + Error **errp); RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, MemoryRegion *mr, Error **errp); diff --git a/softmmu/memory.c b/softmmu/memory.c index 7d9494ce70..2cb60ec9b8 100644 --- a/softmmu/memory.c +++ b/softmmu/memory.c @@ -1620,18 +1620,17 @@ void memory_region_init_ram_from_file(MemoryRegion *mr, uint32_t ram_flags, const char *path, ram_addr_t offset, - bool readonly, Error **errp) { Error *err = NULL; memory_region_init(mr, owner, name, size); mr->ram = true; - mr->readonly = readonly; + mr->readonly = !!(ram_flags & RAM_READONLY); mr->terminates = true; mr->destructor = memory_region_destructor_ram; mr->align = align; mr->ram_block = qemu_ram_alloc_from_file(size, mr, ram_flags, path, - offset, readonly, &err); + offset, &err); if (err) { mr->size = int128_zero(); object_unparent(OBJECT(mr)); @@ -1651,10 +1650,11 @@ void memory_region_init_ram_from_fd(MemoryRegion *mr, Error *err = NULL; memory_region_init(mr, owner, name, size); mr->ram = true; + mr->readonly = !!(ram_flags & RAM_READONLY); mr->terminates = true; mr->destructor = memory_region_destructor_ram; mr->ram_block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, offset, - false, &err); + &err); if (err) { mr->size = int128_zero(); object_unparent(OBJECT(mr)); diff --git a/softmmu/physmem.c b/softmmu/physmem.c index 3df73542e1..6add537b2a 100644 --- a/softmmu/physmem.c +++ b/softmmu/physmem.c @@ -1351,7 +1351,6 @@ static int file_ram_open(const char *path, static void *file_ram_alloc(RAMBlock *block, ram_addr_t memory, int fd, - bool readonly, bool truncate, off_t offset, Error **errp) @@ -1409,7 +1408,7 @@ static void *file_ram_alloc(RAMBlock *block, perror("ftruncate"); } - qemu_map_flags = readonly ? QEMU_MAP_READONLY : 0; + qemu_map_flags = (block->flags & RAM_READONLY) ? QEMU_MAP_READONLY : 0; qemu_map_flags |= (block->flags & RAM_SHARED) ? QEMU_MAP_SHARED : 0; qemu_map_flags |= (block->flags & RAM_PMEM) ? QEMU_MAP_SYNC : 0; qemu_map_flags |= (block->flags & RAM_NORESERVE) ? QEMU_MAP_NORESERVE : 0; @@ -1877,7 +1876,7 @@ static void ram_block_add(RAMBlock *new_block, Error **errp) #ifdef CONFIG_POSIX RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr, uint32_t ram_flags, int fd, off_t offset, - bool readonly, Error **errp) + Error **errp) { RAMBlock *new_block; Error *local_err = NULL; @@ -1885,7 +1884,8 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr, /* Just support these ram flags by now. */ assert((ram_flags & ~(RAM_SHARED | RAM_PMEM | RAM_NORESERVE | - RAM_PROTECTED | RAM_NAMED_FILE)) == 0); + RAM_PROTECTED | RAM_NAMED_FILE | RAM_READONLY | + RAM_READONLY_FD)) == 0); if (xen_enabled()) { error_setg(errp, "-mem-path not supported with Xen"); @@ -1920,8 +1920,8 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr, new_block->used_length = size; new_block->max_length = size; new_block->flags = ram_flags; - new_block->host = file_ram_alloc(new_block, size, fd, readonly, - !file_size, offset, errp); + new_block->host = file_ram_alloc(new_block, size, fd, !file_size, offset, + errp); if (!new_block->host) { g_free(new_block); return NULL; @@ -1940,20 +1940,19 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr, RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr, uint32_t ram_flags, const char *mem_path, - off_t offset, bool readonly, Error **errp) + off_t offset, Error **errp) { int fd; bool created; RAMBlock *block; - fd = file_ram_open(mem_path, memory_region_name(mr), readonly, &created, - errp); + fd = file_ram_open(mem_path, memory_region_name(mr), + !!(ram_flags & RAM_READONLY_FD), &created, errp); if (fd < 0) { return NULL; } - block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, offset, readonly, - errp); + block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, offset, errp); if (!block) { if (created) { unlink(mem_path);