From nobody Mon Feb 9 22:19:54 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com ARC-Seal: i=1; a=rsa-sha256; t=1562843014; cv=none; d=zoho.com; s=zohoarc; b=cB2rdovqXfNC+8coX9tXk6IyIsMrJv+nZK87G6J1H1xm2ecw3ju93Ze5BrgjqwSk7j5pdvg+gUKCvLkOxGZb/wcZDbjI2u4L6/J7JmsC/juUf5DW1plcqOWReBuzCJMzJEqpiAiOcA5CW/jhqdE8yPPxuSRWPQDD9u9F3vRRYy0= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zoho.com; s=zohoarc; t=1562843014; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To:ARC-Authentication-Results; bh=GBdBaRLGdGkl6UutFmy8pnLV7nt9yvqJ/6mnzkK1d20=; b=EWOEMDOYKyC7bsDBC5xKKep7e9REPz+/1YSuWMiXJkzgUs/fkS1urjk8dAT+Ll9l8+3XuRiRmBEQBp4FYNRg0jGKI//xq5Qp7kymiwB8iAMzYXYd4jaIfTnX089e5Wf6FnU2GxQnR8xhSgXWsTB6kqmBWFKi4f87lOzJMrMYTl0= ARC-Authentication-Results: i=1; mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1562843014133844.9360867974764; Thu, 11 Jul 2019 04:03:34 -0700 (PDT) Received: from localhost ([::1]:40504 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hlWrK-0006nO-5F for importer@patchew.org; Thu, 11 Jul 2019 07:03:30 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:47747) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hlWij-0002jb-51 for qemu-devel@nongnu.org; Thu, 11 Jul 2019 06:54:38 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hlWii-00076N-3S for qemu-devel@nongnu.org; Thu, 11 Jul 2019 06:54:37 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40312) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hlWih-00075v-TO for qemu-devel@nongnu.org; Thu, 11 Jul 2019 06:54:36 -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 6163430820C9; Thu, 11 Jul 2019 10:45:05 +0000 (UTC) Received: from localhost.localdomain (unknown [10.36.118.16]) by smtp.corp.redhat.com (Postfix) with ESMTP id 3DC0760600; Thu, 11 Jul 2019 10:44:59 +0000 (UTC) From: Juan Quintela To: qemu-devel@nongnu.org Date: Thu, 11 Jul 2019 12:44:08 +0200 Message-Id: <20190711104412.31233-16-quintela@redhat.com> In-Reply-To: <20190711104412.31233-1-quintela@redhat.com> References: <20190711104412.31233-1-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 [10.5.110.47]); Thu, 11 Jul 2019 10:45:05 +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 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+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" 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 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(KVMMemoryLi= stener *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