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 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 64AE1E77188 for ; Tue, 24 Dec 2024 17:19:37 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tQ8YN-00056h-W3; Tue, 24 Dec 2024 12:18:44 -0500 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 1tQ8YM-00056U-5V for qemu-devel@nongnu.org; Tue, 24 Dec 2024 12:18:42 -0500 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 1tQ8YJ-0001bx-Tk for qemu-devel@nongnu.org; Tue, 24 Dec 2024 12:18:41 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1735060717; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=h89+gd01L7u9JKcyI1FnUcrNi9Esg0/O3cQQXb47Ql8=; b=XrlmeUzp8QDBZXE0Dpzgrcl8o0ar4JIdPs+0/7DRes34SGNGkWL4U4z2swW/nZ0Mbdqp8A 9Xb5Bd5MSQy3jyXI8OtvBAwoQpX3SaM1z+WMED2bpP4FXbaOPPnNT688u2igIr8cbqJkXF NICVLxMHvnUBLMyrdz9rOhxOF6GMVuE= Received: from mail-qt1-f198.google.com (mail-qt1-f198.google.com [209.85.160.198]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-3-GedNp19bPROHL_3gaO-UNA-1; Tue, 24 Dec 2024 12:18:31 -0500 X-MC-Unique: GedNp19bPROHL_3gaO-UNA-1 X-Mimecast-MFC-AGG-ID: GedNp19bPROHL_3gaO-UNA Received: by mail-qt1-f198.google.com with SMTP id d75a77b69052e-467b19b55d6so66563661cf.2 for ; Tue, 24 Dec 2024 09:18:30 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1735060710; x=1735665510; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=h89+gd01L7u9JKcyI1FnUcrNi9Esg0/O3cQQXb47Ql8=; b=knQ00sSoA6akicuqb1BZN3vHPBnIGmKVp8hZSA92sEVa8iBoCdQPEopZ1a/x1q/ZRW 8HTHNb9HglvnZITxRI+MhfB/67pobkvJ/trrkabYvZEt0iyTOm+zu3VQexSJlao9imRp otyI+jdy0mePJQELQShQrZGsgGYbsk68cLfCnMPupCgFdWcdW7hB6zjkNDzX6dKSRaTA PYKZLIhFhoXoRMAKQ6RP5wkAcGhZqQL5DyBPW2kdcCxFwPd1SdQh9zPOvxQLXpLYif+n JzBDS09Yjg0kIP0FJEKWAfe2YvOz7MryfB4ibxPuFuUpDjjQDyLfTciN3AauUzRFXRNW 80Zw== X-Gm-Message-State: AOJu0YwfanigWdANJ+VoqOyb3CeUHqxShQ/52iaf4Zs9c0+iHu4zANoy PYsTAtz9tpSTOW7wslP26AWy9zWQE0e/2jvXp0bMdffCahzyMCQzOwzahwiffdA5YmVFKePoEM6 sJe8ab97ag50rva9r9xol8LM6oj6gk7ddg6sLXmKAFVehhDltKHKQ X-Gm-Gg: ASbGncvvDvPCxGoRqv0Om2ZsZ7ByQyJlHBCZU3V4VOQ+m1cqxBhjYVpYztmtMGMMrur 4Wj3ctKsd5XwyIoeAEqDtgwX8dCjS777HmbwHKK792sMVabupJt6eudR1vokseJ5qIoIyK0wccx AL4hdBmJdSOGnCy1HfNz8+i9joGARTjc6/aqAHiUq67xOeOUEbE1y/hhOyMVhIQMXGmcTZB9Unm EKV0kLgq8S0pFQJjaer6Sar8SgPn0hbK8HWwfLVFqNr5yHNrkuN2YB1eLgrelkx7bXWGPxQRTAE aUtjGrEaeHO6wMh6VA== X-Received: by 2002:a05:622a:588:b0:467:86a9:f7d4 with SMTP id d75a77b69052e-46a4a8cc950mr300470411cf.16.1735060710478; Tue, 24 Dec 2024 09:18:30 -0800 (PST) X-Google-Smtp-Source: AGHT+IGeT86JpAO7DiIrordB27UgWaQjNeUddJHWs9tpIzZ3abGcerXNKhofCB5NRvl8owoUCT/T4g== X-Received: by 2002:a05:622a:588:b0:467:86a9:f7d4 with SMTP id d75a77b69052e-46a4a8cc950mr300469931cf.16.1735060710050; Tue, 24 Dec 2024 09:18:30 -0800 (PST) Received: from x1n (pool-99-254-114-190.cpe.net.cable.rogers.com. [99.254.114.190]) by smtp.gmail.com with ESMTPSA id af79cd13be357-7b9ac2e827dsm485305385a.49.2024.12.24.09.18.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 24 Dec 2024 09:18:28 -0800 (PST) Date: Tue, 24 Dec 2024 12:18:26 -0500 From: Peter Xu To: Steve Sistare Cc: qemu-devel@nongnu.org, Fabiano Rosas , David Hildenbrand , Marcel Apfelbaum , Eduardo Habkost , Philippe Mathieu-Daude , Paolo Bonzini , "Daniel P. Berrange" , Markus Armbruster Subject: Re: [PATCH V5 02/23] physmem: qemu_ram_alloc_from_fd extensions Message-ID: References: <1735057028-308595-1-git-send-email-steven.sistare@oracle.com> <1735057028-308595-3-git-send-email-steven.sistare@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1735057028-308595-3-git-send-email-steven.sistare@oracle.com> Received-SPF: pass client-ip=170.10.129.124; envelope-from=peterx@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -21 X-Spam_score: -2.2 X-Spam_bar: -- X-Spam_report: (-2.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.133, 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_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=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 On Tue, Dec 24, 2024 at 08:16:47AM -0800, Steve Sistare wrote: > Extend qemu_ram_alloc_from_fd to support resizable ram, and define > qemu_ram_resize_cb to clean up the API. > > Add a grow parameter to extend the file if necessary. However, if > grow is false, a zero-sized file is always extended. > > Signed-off-by: Steve Sistare > --- > include/exec/ram_addr.h | 13 +++++++++---- > system/memory.c | 4 ++-- > system/physmem.c | 35 ++++++++++++++++++++--------------- > 3 files changed, 31 insertions(+), 21 deletions(-) > > diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h > index ff157c1..94bb3cc 100644 > --- a/include/exec/ram_addr.h > +++ b/include/exec/ram_addr.h > @@ -111,23 +111,30 @@ long qemu_maxrampagesize(void); > * > * Parameters: > * @size: the size in bytes of the ram block > + * @max_size: the maximum size of the block after resizing > * @mr: the memory region where the ram block is > + * @resized: callback after calls to qemu_ram_resize > * @ram_flags: RamBlock flags. Supported flags: RAM_SHARED, RAM_PMEM, > * RAM_NORESERVE, RAM_PROTECTED, RAM_NAMED_FILE, RAM_READONLY, > * RAM_READONLY_FD, RAM_GUEST_MEMFD > * @mem_path or @fd: specify the backing file or device > * @offset: Offset into target file > + * @grow: extend file if necessary (but an empty file is always extended). > * @errp: pointer to Error*, to store an error if it happens > * > * Return: > * On success, return a pointer to the ram block. > * On failure, return NULL. > */ > +typedef void (*qemu_ram_resize_cb)(const char *, uint64_t length, void *host); > + > RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr, > uint32_t ram_flags, const char *mem_path, > off_t offset, Error **errp); > -RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr, > +RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, ram_addr_t max_size, > + qemu_ram_resize_cb resized, MemoryRegion *mr, > uint32_t ram_flags, int fd, off_t offset, > + bool grow, > Error **errp); > > RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, > @@ -135,9 +142,7 @@ RAMBlock *qemu_ram_alloc_from_ptr(ram_addr_t size, void *host, > RAMBlock *qemu_ram_alloc(ram_addr_t size, uint32_t ram_flags, MemoryRegion *mr, > Error **errp); > RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t max_size, > - void (*resized)(const char*, > - uint64_t length, > - void *host), > + qemu_ram_resize_cb resized, > MemoryRegion *mr, Error **errp); > void qemu_ram_free(RAMBlock *block); > > diff --git a/system/memory.c b/system/memory.c > index 78e17e0..290c522 100644 > --- a/system/memory.c > +++ b/system/memory.c > @@ -1680,8 +1680,8 @@ bool memory_region_init_ram_from_fd(MemoryRegion *mr, > 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, > - &err); > + mr->ram_block = qemu_ram_alloc_from_fd(size, size, NULL, mr, ram_flags, fd, > + offset, false, &err); > if (err) { > mr->size = int128_zero(); > object_unparent(OBJECT(mr)); > diff --git a/system/physmem.c b/system/physmem.c > index c76503a..48c544f 100644 > --- a/system/physmem.c > +++ b/system/physmem.c > @@ -1942,8 +1942,10 @@ out_free: > } > > #ifdef CONFIG_POSIX > -RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr, > +RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, ram_addr_t max_size, > + qemu_ram_resize_cb resized, MemoryRegion *mr, > uint32_t ram_flags, int fd, off_t offset, > + bool grow, > Error **errp) > { > RAMBlock *new_block; > @@ -1953,7 +1955,9 @@ 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 | RAM_READONLY | > - RAM_READONLY_FD | RAM_GUEST_MEMFD)) == 0); > + RAM_READONLY_FD | RAM_GUEST_MEMFD | > + RAM_RESIZEABLE)) == 0); > + assert(max_size >= size); > > if (xen_enabled()) { > error_setg(errp, "-mem-path not supported with Xen"); > @@ -1968,12 +1972,14 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr, > > size = TARGET_PAGE_ALIGN(size); > size = REAL_HOST_PAGE_ALIGN(size); > + max_size = TARGET_PAGE_ALIGN(max_size); > + max_size = REAL_HOST_PAGE_ALIGN(max_size); > > file_size = get_file_size(fd); > - if (file_size > offset && file_size < (offset + size)) { > + if (file_size && file_size < offset + max_size && !grow) { Is this a bugfix for the case offset < fsize? If so, better make it a small patch and copy stable.. $ touch ramfile $ truncate -s 64M ramfile $ ./qemu-system-x86_64 -object memory-backend-file,mem-path=./ramfile,offset=128M,size=128M,id=mem1,prealloc=on qemu-system-x86_64: qemu_prealloc_mem: preallocating memory failed: Bad address So yes, it's a bug.. > error_setg(errp, "backing store size 0x%" PRIx64 > " does not match 'size' option 0x" RAM_ADDR_FMT, > - file_size, size); > + file_size, max_size); > return NULL; > } > > @@ -1988,11 +1994,13 @@ RAMBlock *qemu_ram_alloc_from_fd(ram_addr_t size, MemoryRegion *mr, > new_block = g_malloc0(sizeof(*new_block)); > new_block->mr = mr; > new_block->used_length = size; > - new_block->max_length = size; > + new_block->max_length = max_size; > + new_block->resized = resized; > new_block->flags = ram_flags; > new_block->guest_memfd = -1; > - new_block->host = file_ram_alloc(new_block, size, fd, !file_size, offset, > - errp); > + new_block->host = file_ram_alloc(new_block, max_size, fd, > + file_size < offset + max_size, Same here, looks like relevant to above. In general, we want to either fail properly detecting wrong-sized files, or making sure qemu can boot correctly with the fd. I confess pretty corner cases.. but still. So the whole patch looks correct, but maybe need a split. > + offset, errp); > if (!new_block->host) { > g_free(new_block); > return NULL; > @@ -2044,7 +2052,8 @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr, > return NULL; > } > > - block = qemu_ram_alloc_from_fd(size, mr, ram_flags, fd, offset, errp); > + block = qemu_ram_alloc_from_fd(size, size, NULL, mr, ram_flags, fd, offset, > + false, errp); > if (!block) { > if (created) { > unlink(mem_path); > @@ -2059,9 +2068,7 @@ RAMBlock *qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr, > > static > RAMBlock *qemu_ram_alloc_internal(ram_addr_t size, ram_addr_t max_size, > - void (*resized)(const char*, > - uint64_t length, > - void *host), > + qemu_ram_resize_cb resized, > void *host, uint32_t ram_flags, > MemoryRegion *mr, Error **errp) > { > @@ -2113,10 +2120,8 @@ RAMBlock *qemu_ram_alloc(ram_addr_t size, uint32_t ram_flags, > } > > RAMBlock *qemu_ram_alloc_resizeable(ram_addr_t size, ram_addr_t maxsz, > - void (*resized)(const char*, > - uint64_t length, > - void *host), > - MemoryRegion *mr, Error **errp) > + qemu_ram_resize_cb resized, > + MemoryRegion *mr, Error **errp) > { > return qemu_ram_alloc_internal(size, maxsz, resized, NULL, > RAM_RESIZEABLE, mr, errp); > -- > 1.8.3.1 > -- Peter Xu