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: 11042383 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B8743112C for ; Fri, 12 Jul 2019 14:32:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A779828BF4 for ; Fri, 12 Jul 2019 14:32:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 9B94728C1C; Fri, 12 Jul 2019 14:32:52 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B66D328BF4 for ; Fri, 12 Jul 2019 14:32:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727506AbfGLOcu (ORCPT ); Fri, 12 Jul 2019 10:32:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:41094 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727229AbfGLOcu (ORCPT ); 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 Cc: Laurent Vivier , Richard Henderson , Paolo Bonzini , kvm@vger.kernel.org, "Dr. David Alan Gilbert" , Juan Quintela , Thomas Huth , Peter Xu Subject: [PULL 15/19] kvm: Persistent per kvmslot dirty bitmap 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) Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 {