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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 855BEC76191 for ; Mon, 15 Jul 2019 13:54:12 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 614B02086C for ; Mon, 15 Jul 2019 13:54:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 614B02086C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:38982 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hn1Qg-0000j8-Sb for qemu-devel@archiver.kernel.org; Mon, 15 Jul 2019 09:54:10 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54138) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hn1PQ-0003oy-1i for qemu-devel@nongnu.org; Mon, 15 Jul 2019 09:52:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hn1PO-0003cD-VA for qemu-devel@nongnu.org; Mon, 15 Jul 2019 09:52:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52068) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hn1PO-0003br-Pi for qemu-devel@nongnu.org; Mon, 15 Jul 2019 09:52:50 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 1DA67368E6; Mon, 15 Jul 2019 13:52:50 +0000 (UTC) Received: from localhost.localdomain (unknown [10.36.118.16]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4D08B5B681; Mon, 15 Jul 2019 13:52:47 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Date: Mon, 15 Jul 2019 15:51:18 +0200 Message-Id: <20190715135125.17770-15-quintela@redhat.com> In-Reply-To: <20190715135125.17770-1-quintela@redhat.com> References: <20190715135125.17770-1-quintela@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Mon, 15 Jul 2019 13:52:50 +0000 (UTC) Content-Transfer-Encoding: quoted-printable 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 14/21] 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+qemu-devel=archiver.kernel.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(KVMMemory= Listener *kml, */ size =3D ALIGN(((mem->memory_size) >> TARGET_PAGE_BITS), /*HOST_LONG_BITS*/ 64) / 8; - d.dirty_bitmap =3D g_malloc0(size); + if (!mem->dirty_bmap) { + /* Allocate on the first log_sync, once and for all */ + mem->dirty_bmap =3D g_malloc0(size); + } =20 + d.dirty_bitmap =3D mem->dirty_bmap; d.slot =3D mem->slot | (kml->as_id << 16); if (kvm_vm_ioctl(s, KVM_GET_DIRTY_LOG, &d) =3D=3D -1) { DPRINTF("ioctl failed %d\n", errno); - g_free(d.dirty_bitmap); return -1; } =20 kvm_get_dirty_pages_log_range(section, d.dirty_bitmap); - g_free(d.dirty_bitmap); } =20 return 0; @@ -801,6 +803,8 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml, } =20 /* unregister the slot */ + g_free(mem->dirty_bmap); + mem->dirty_bmap =3D NULL; mem->memory_size =3D 0; mem->flags =3D 0; err =3D 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; =20 typedef struct KVMMemoryListener { --=20 2.21.0