From patchwork Fri Jul 12 14:32:03 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juan Quintela X-Patchwork-Id: 1131424 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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 ozlabs.org (Postfix) with ESMTPS id 45lb7m47Fzz9sBF for ; Sat, 13 Jul 2019 00:35:48 +1000 (AEST) Received: from localhost ([::1]:50090 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hlweI-0008E6-DH for incoming@patchwork.ozlabs.org; Fri, 12 Jul 2019 10:35:46 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45058) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hlwbT-0005nu-MS for qemu-devel@nongnu.org; Fri, 12 Jul 2019 10:32:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hlwbS-0001xP-Hs for qemu-devel@nongnu.org; Fri, 12 Jul 2019 10:32:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37945) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hlwbS-0001x2-CQ for qemu-devel@nongnu.org; Fri, 12 Jul 2019 10:32:50 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AC6C4C057F2F; Fri, 12 Jul 2019 14:32:49 +0000 (UTC) Received: from localhost.localdomain (unknown [10.36.118.16]) by smtp.corp.redhat.com (Postfix) with ESMTP id 98F7E60A9A; Fri, 12 Jul 2019 14:32:47 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Date: Fri, 12 Jul 2019 16:32:03 +0200 Message-Id: <20190712143207.4214-16-quintela@redhat.com> In-Reply-To: <20190712143207.4214-1-quintela@redhat.com> References: <20190712143207.4214-1-quintela@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.32]); Fri, 12 Jul 2019 14:32:49 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 15/19] kvm: Persistent per kvmslot dirty bitmap X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Laurent Vivier , Thomas Huth , kvm@vger.kernel.org, Juan Quintela , "Dr. David Alan Gilbert" , Peter Xu , Paolo Bonzini , Richard Henderson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" From: Peter Xu When synchronizing dirty bitmap from kernel KVM we do it in a per-kvmslot fashion and we allocate the userspace bitmap for each of the ioctl. This patch instead make the bitmap cache be persistent then we don't need to g_malloc0() every time. More importantly, the cached per-kvmslot dirty bitmap will be further used when we want to add support for the KVM_CLEAR_DIRTY_LOG and this cached bitmap will be used to guarantee we won't clear any unknown dirty bits otherwise that can be a severe data loss issue for migration code. Signed-off-by: Peter Xu Reviewed-by: Juan Quintela Reviewed-by: Dr. David Alan Gilbert Message-Id: <20190603065056.25211-9-peterx@redhat.com> Signed-off-by: Juan Quintela --- accel/kvm/kvm-all.c | 10 +++++++--- include/sysemu/kvm_int.h | 2 ++ 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c index a3df19da56..23ace52b9e 100644 --- a/accel/kvm/kvm-all.c +++ b/accel/kvm/kvm-all.c @@ -516,17 +516,19 @@ static int kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml, */ size = ALIGN(((mem->memory_size) >> TARGET_PAGE_BITS), /*HOST_LONG_BITS*/ 64) / 8; - d.dirty_bitmap = g_malloc0(size); + if (!mem->dirty_bmap) { + /* Allocate on the first log_sync, once and for all */ + mem->dirty_bmap = g_malloc0(size); + } + d.dirty_bitmap = mem->dirty_bmap; d.slot = mem->slot | (kml->as_id << 16); if (kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d) == -1) { DPRINTF("ioctl failed %d\n", errno); - g_free(d.dirty_bitmap); return -1; } kvm_get_dirty_pages_log_range(section, d.dirty_bitmap); - g_free(d.dirty_bitmap); } return 0; @@ -801,6 +803,8 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml, } /* unregister the slot */ + g_free(mem->dirty_bmap); + mem->dirty_bmap = NULL; mem->memory_size = 0; mem->flags = 0; err = kvm_set_user_memory_region(kml, mem, false); diff --git a/include/sysemu/kvm_int.h b/include/sysemu/kvm_int.h index f838412491..687a2ee423 100644 --- a/include/sysemu/kvm_int.h +++ b/include/sysemu/kvm_int.h @@ -21,6 +21,8 @@ typedef struct KVMSlot int slot; int flags; int old_flags; + /* Dirty bitmap cache for the slot */ + unsigned long *dirty_bmap; } KVMSlot; typedef struct KVMMemoryListener {