From patchwork Wed Jan 7 19:49:15 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 426397 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 8CAF714011B for ; Thu, 8 Jan 2015 06:52:44 +1100 (AEDT) Received: from localhost ([::1]:42573 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y8weo-0002tr-Rk for incoming@patchwork.ozlabs.org; Wed, 07 Jan 2015 14:52:42 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51872) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y8wbb-0005Qz-L6 for qemu-devel@nongnu.org; Wed, 07 Jan 2015 14:49:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Y8wba-0008Uh-HW for qemu-devel@nongnu.org; Wed, 07 Jan 2015 14:49:23 -0500 Received: from mail.kernel.org ([198.145.29.136]:52682) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y8wba-0008UW-7v for qemu-devel@nongnu.org; Wed, 07 Jan 2015 14:49:22 -0500 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1CD9520375; Wed, 7 Jan 2015 19:49:21 +0000 (UTC) Received: from redhat.com (bzq-79-182-177-46.red.bezeqint.net [79.182.177.46]) (using TLSv1.2 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BD3242037F; Wed, 7 Jan 2015 19:49:18 +0000 (UTC) Date: Wed, 7 Jan 2015 21:49:15 +0200 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Message-ID: <1420660083-9961-7-git-send-email-mst@redhat.com> References: <1420660083-9961-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1420660083-9961-1-git-send-email-mst@redhat.com> X-Mailer: git-send-email 2.0.0.545.gd9cabeb X-Mutt-Fcc: =sent X-Virus-Scanned: ClamAV using ClamSMTP X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 198.145.29.136 Cc: Amit Shah , pbonzini@redhat.com, imammedo@redhat.com, dgilbert@redhat.com, Juan Quintela Subject: [Qemu-devel] [PATCH v3 6/8] memory: API to allocate resizeable RAM MR X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Add API to allocate resizeable RAM MR. This looks just like regular RAM generally, but has a special property that only a portion of it (used_length) is actually used, and migrated. This used_length size can change across reboots. Follow up patches will change used_length for such blocks at migration, making it easier to extend devices using such RAM (notably ACPI, but in the future thinkably other ROMs) without breaking migration compatibility or wasting ROM (guest) memory. Device is notified on resize, so it can adjust if necessary. Note: nothing prevents making all RAM resizeable in this way. However, reviewers felt that only enabling this selectively will make some class of errors easier to detect. Signed-off-by: Michael S. Tsirkin --- include/exec/memory.h | 24 ++++++++++++++++++++++++ memory.c | 17 +++++++++++++++++ 2 files changed, 41 insertions(+) diff --git a/include/exec/memory.h b/include/exec/memory.h index 0882221..0cd96b1 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -321,6 +321,30 @@ void memory_region_init_ram(MemoryRegion *mr, uint64_t size, Error **errp); +/** + * memory_region_init_resizeable_ram: Initialize memory region with resizeable + * RAM. Accesses into the region will + * modify memory directly. Only an initial + * portion of this RAM is actually used. + * The used size can change across reboots. + * + * @mr: the #MemoryRegion to be initialized. + * @owner: the object that tracks the region's reference count + * @name: the name of the region. + * @size: used size of the region. + * @max_size: max size of the region. + * @resized: callback to notify owner about used size change. + * @errp: pointer to Error*, to store an error if it happens. + */ +void memory_region_init_resizeable_ram(MemoryRegion *mr, + struct Object *owner, + const char *name, + uint64_t size, + uint64_t max_size, + void (*resized)(const char*, + uint64_t length, + void *host), + Error **errp); #ifdef __linux__ /** * memory_region_init_ram_from_file: Initialize RAM memory region with a diff --git a/memory.c b/memory.c index 618470b..c343bf3 100644 --- a/memory.c +++ b/memory.c @@ -1152,6 +1152,23 @@ void memory_region_init_ram(MemoryRegion *mr, mr->ram_addr = qemu_ram_alloc(size, mr, errp); } +void memory_region_init_resizeable_ram(MemoryRegion *mr, + Object *owner, + const char *name, + uint64_t size, + uint64_t max_size, + void (*resized)(const char*, + uint64_t length, + void *host), + Error **errp) +{ + memory_region_init(mr, owner, name, size); + mr->ram = true; + mr->terminates = true; + mr->destructor = memory_region_destructor_ram; + mr->ram_addr = qemu_ram_alloc_resizeable(size, max_size, resized, mr, errp); +} + #ifdef __linux__ void memory_region_init_ram_from_file(MemoryRegion *mr, struct Object *owner,