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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 68D9CC2D0E5 for ; Wed, 25 Mar 2020 17:47:05 +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 3669D2074D for ; Wed, 25 Mar 2020 17:47:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="VqJ2RW1I" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3669D2074D 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]:40910 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jHA7M-0000Hz-EQ for qemu-devel@archiver.kernel.org; Wed, 25 Mar 2020 13:47:04 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:36181) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jHA50-0006fK-6A for qemu-devel@nongnu.org; Wed, 25 Mar 2020 13:44:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jHA4y-0002CT-Tx for qemu-devel@nongnu.org; Wed, 25 Mar 2020 13:44:38 -0400 Received: from us-smtp-delivery-74.mimecast.com ([63.128.21.74]:20575) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jHA4y-0002Bv-PM for qemu-devel@nongnu.org; Wed, 25 Mar 2020 13:44:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1585158276; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5FdXOkrbohr7uS5cNFXsajo0Z52raWFVu2MXQ2gQtwg=; b=VqJ2RW1IkvMbOUJw/xv/mZJKvGOmap7g6ME4hdmz5bLiDqhj6IpkFyOKCacZjl8bIyKiWU ccpKrAqo4zSeY/85u+WitL9MAVNk7EsHrvuFpZhS7KikdQ0hOwQjQwoua7i6oQeqqcG4tQ qf8gXSRr/5RJkT1RUkl4TueAJ7+q7tY= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-334-AWEW6vosNWaHX3FByJ3-kQ-1; Wed, 25 Mar 2020 13:44:34 -0400 X-MC-Unique: AWEW6vosNWaHX3FByJ3-kQ-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7A856800D4E for ; Wed, 25 Mar 2020 17:44:33 +0000 (UTC) Received: from work-vm (ovpn-114-213.ams2.redhat.com [10.36.114.213]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CDD8E100164D; Wed, 25 Mar 2020 17:44:27 +0000 (UTC) Date: Wed, 25 Mar 2020 17:44:24 +0000 From: "Dr. David Alan Gilbert" To: Peter Xu Subject: Re: [PATCH RFC 4/9] KVM: Create the KVMSlot dirty bitmap on flag changes Message-ID: <20200325174424.GC2635@work-vm> References: <20200205141749.378044-1-peterx@redhat.com> <20200205141749.378044-5-peterx@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200205141749.378044-5-peterx@redhat.com> User-Agent: Mutt/1.13.3 (2020-01-12) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 63.128.21.74 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: Paolo Bonzini , qemu-devel@nongnu.org, "Michael S . Tsirkin" Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" * Peter Xu (peterx@redhat.com) wrote: > Previously we have two places that will create the per KVMSlot dirty > bitmap: >=20 > 1. When a newly created KVMSlot has dirty logging enabled, > 2. When the first log_sync() happens for a memory slot. >=20 > The 2nd case is lazy-init, while the 1st case is not (which is a fix > of what the 2nd case missed). >=20 > To do explicit initialization of dirty bitmaps, what we're missing is > to create the dirty bitmap when the slot changed from not-dirty-track > to dirty-track. Do that in kvm_slot_update_flags(). >=20 > With that, we can safely remove the 2nd lazy-init. >=20 > This change will be needed for kvm dirty ring because kvm dirty ring > does not use the log_sync() interface at all. >=20 > Since at it, move all the pre-checks into kvm_slot_init_dirty_bitmap(). 'While at it' or just Also > Signed-off-by: Peter Xu Reviewed-by: Dr. David Alan Gilbert > --- > accel/kvm/kvm-all.c | 23 +++++++++-------------- > 1 file changed, 9 insertions(+), 14 deletions(-) >=20 > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index 4be3cd2352..bb635c775f 100644 > --- a/accel/kvm/kvm-all.c > +++ b/accel/kvm/kvm-all.c > @@ -162,6 +162,8 @@ static NotifierList kvm_irqchip_change_notifiers =3D > #define kvm_slots_lock(kml) qemu_mutex_lock(&(kml)->slots_lock) > #define kvm_slots_unlock(kml) qemu_mutex_unlock(&(kml)->slots_lock) > =20 > +static void kvm_slot_init_dirty_bitmap(KVMSlot *mem); > + > int kvm_get_max_memslots(void) > { > KVMState *s =3D KVM_STATE(current_accel()); > @@ -442,6 +444,7 @@ static int kvm_slot_update_flags(KVMMemoryListener *k= ml, KVMSlot *mem, > return 0; > } > =20 > + kvm_slot_init_dirty_bitmap(mem); > return kvm_set_user_memory_region(kml, mem, false); > } > =20 > @@ -526,8 +529,12 @@ static int kvm_get_dirty_pages_log_range(MemoryRegio= nSection *section, > #define ALIGN(x, y) (((x)+(y)-1) & ~((y)-1)) > =20 > /* Allocate the dirty bitmap for a slot */ > -static void kvm_memslot_init_dirty_bitmap(KVMSlot *mem) > +static void kvm_slot_init_dirty_bitmap(KVMSlot *mem) > { > + if (!(mem->flags & KVM_MEM_LOG_DIRTY_PAGES) || mem->dirty_bmap) { > + return; > + } > + > /* > * XXX bad kernel interface alert > * For dirty bitmap, kernel allocates array of size aligned to > @@ -578,11 +585,6 @@ static int kvm_physical_sync_dirty_bitmap(KVMMemoryL= istener *kml, > goto out; > } > =20 > - if (!mem->dirty_bmap) { > - /* Allocate on the first log_sync, once and for all */ > - kvm_memslot_init_dirty_bitmap(mem); > - } > - > 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) { > @@ -1079,14 +1081,7 @@ static void kvm_set_phys_mem(KVMMemoryListener *km= l, > mem->start_addr =3D start_addr; > mem->ram =3D ram; > mem->flags =3D kvm_mem_flags(mr); > - > - if (mem->flags & KVM_MEM_LOG_DIRTY_PAGES) { > - /* > - * Reallocate the bmap; it means it doesn't disappear in > - * middle of a migrate. > - */ > - kvm_memslot_init_dirty_bitmap(mem); > - } > + kvm_slot_init_dirty_bitmap(mem); > err =3D kvm_set_user_memory_region(kml, mem, true); > if (err) { > fprintf(stderr, "%s: error registering slot: %s\n", __func__= , > --=20 > 2.24.1 >=20 >=20 -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK