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 60DE2C2D0E5 for ; Wed, 25 Mar 2020 20:02:01 +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 2CBED20658 for ; Wed, 25 Mar 2020 20:02:01 +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="Pu7HCy5d" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2CBED20658 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]:42470 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jHCDw-00022x-6P for qemu-devel@archiver.kernel.org; Wed, 25 Mar 2020 16:02:00 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60592) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jHCCj-0001cM-6A for qemu-devel@nongnu.org; Wed, 25 Mar 2020 16:00:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1jHCCh-000775-Ph for qemu-devel@nongnu.org; Wed, 25 Mar 2020 16:00:45 -0400 Received: from us-smtp-delivery-74.mimecast.com ([216.205.24.74]:48541) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1jHCCh-00076e-Kr for qemu-devel@nongnu.org; Wed, 25 Mar 2020 16:00:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1585166443; 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=Out3+up1KnYabG/lOAODomaCFL0g2H18za564DgpqiM=; b=Pu7HCy5dYmLJuTl91j5AKGJVfxQNJBgbIfyHwEsPUQYCp3bjVkuJ0VpUh3kVM8dzR8Siyg TMXdSf/rztzO/fYaCG7Q24roNj/PoynVCoEdDXWw+FlHznCgtqzP4udXSA/NHA/xpxDgHq AEajZTtJCOIhx9+jp5NklJi4qEDguHw= 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-177-Q32BP7-ZNGyHj-G2gPTQmw-1; Wed, 25 Mar 2020 16:00:41 -0400 X-MC-Unique: Q32BP7-ZNGyHj-G2gPTQmw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5D0C4107B765 for ; Wed, 25 Mar 2020 20:00:40 +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 B537C19925; Wed, 25 Mar 2020 20:00:33 +0000 (UTC) Date: Wed, 25 Mar 2020 20:00:31 +0000 From: "Dr. David Alan Gilbert" To: Peter Xu Subject: Re: [PATCH RFC 8/9] KVM: Add dirty-ring-size property Message-ID: <20200325200031.GG2635@work-vm> References: <20200205141749.378044-1-peterx@redhat.com> <20200205141749.378044-9-peterx@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200205141749.378044-9-peterx@redhat.com> User-Agent: Mutt/1.13.3 (2020-01-12) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 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] [fuzzy] X-Received-From: 216.205.24.74 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: > Add a parameter for size of dirty ring. If zero, dirty ring is > disabled. Otherwise dirty ring will be enabled with the per-vcpu size > as specified. If dirty ring cannot be enabled due to unsupported > kernel, it'll fallback to dirty logging. By default, dirty ring is > not enabled (dirty-ring-size=3D=3D0). >=20 > Signed-off-by: Peter Xu > --- > accel/kvm/kvm-all.c | 64 +++++++++++++++++++++++++++++++++++++++++++++ > qemu-options.hx | 3 +++ > 2 files changed, 67 insertions(+) >=20 > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index ea7b8f7ca5..6d145a8b98 100644 > --- a/accel/kvm/kvm-all.c > +++ b/accel/kvm/kvm-all.c > @@ -127,6 +127,8 @@ struct KVMState > KVMMemoryListener *ml; > AddressSpace *as; > } *as; > + int kvm_dirty_ring_size; > + int kvm_dirty_gfn_count; /* If nonzero, then kvm dirty ring enabl= ed */ > }; > =20 > KVMState *kvm_state; > @@ -2077,6 +2079,33 @@ static int kvm_init(MachineState *ms) > s->memory_listener.listener.coalesced_io_add =3D kvm_coalesce_mmio_r= egion; > s->memory_listener.listener.coalesced_io_del =3D kvm_uncoalesce_mmio= _region; > =20 > + /* > + * Enable KVM dirty ring if supported, otherwise fall back to > + * dirty logging mode > + */ > + if (s->kvm_dirty_ring_size > 0) { > + /* Read the max supported pages */ > + ret =3D kvm_vm_check_extension(kvm_state, KVM_CAP_DIRTY_LOG_RING= ); > + if (ret > 0) { > + if (s->kvm_dirty_ring_size > ret) { > + error_report("KVM dirty ring size %d too big (maximum is= %d). " > + "Please use a smaller value.", > + s->kvm_dirty_ring_size, ret); > + goto err; > + } > + > + ret =3D kvm_vm_enable_cap(s, KVM_CAP_DIRTY_LOG_RING, 0, > + s->kvm_dirty_ring_size); > + if (ret) { > + error_report("Enabling of KVM dirty ring failed: %d", re= t); > + goto err; > + } > + > + s->kvm_dirty_gfn_count =3D > + s->kvm_dirty_ring_size / sizeof(struct kvm_dirty_gfn); What happens if I was to pass dirty-ring-size=3D1 ? Then the count would be 0 and things would get upset somewhere? Do you need to check for a minimum postive value? > + } > + } > + > kvm_memory_listener_register(s, &s->memory_listener, > &address_space_memory, 0); > memory_listener_register(&kvm_io_listener, > @@ -3037,6 +3066,33 @@ bool kvm_kernel_irqchip_split(void) > return kvm_state->kernel_irqchip_split =3D=3D ON_OFF_AUTO_ON; > } > =20 > +static void kvm_get_dirty_ring_size(Object *obj, Visitor *v, > + const char *name, void *opaque, > + Error **errp) > +{ > + KVMState *s =3D KVM_STATE(obj); > + int64_t value =3D s->kvm_dirty_ring_size; > + > + visit_type_int(v, name, &value, errp); > +} > + > +static void kvm_set_dirty_ring_size(Object *obj, Visitor *v, > + const char *name, void *opaque, > + Error **errp) > +{ > + KVMState *s =3D KVM_STATE(obj); > + Error *error =3D NULL; > + int64_t value; > + > + visit_type_int(v, name, &value, &error); > + if (error) { > + error_propagate(errp, error); > + return; > + } > + > + s->kvm_dirty_ring_size =3D value; > +} > + > static void kvm_accel_instance_init(Object *obj) > { > KVMState *s =3D KVM_STATE(obj); > @@ -3044,6 +3100,8 @@ static void kvm_accel_instance_init(Object *obj) > s->kvm_shadow_mem =3D -1; > s->kernel_irqchip_allowed =3D true; > s->kernel_irqchip_split =3D ON_OFF_AUTO_AUTO; > + /* By default off */ > + s->kvm_dirty_ring_size =3D 0; > } > =20 > static void kvm_accel_class_init(ObjectClass *oc, void *data) > @@ -3065,6 +3123,12 @@ static void kvm_accel_class_init(ObjectClass *oc, = void *data) > NULL, NULL, &error_abort); > object_class_property_set_description(oc, "kvm-shadow-mem", > "KVM shadow MMU size", &error_abort); > + > + object_class_property_add(oc, "dirty-ring-size", "int", > + kvm_get_dirty_ring_size, kvm_set_dirty_ring_size, > + NULL, NULL, &error_abort); I don't think someone passing in a non-number should cause an abort; it should exit, but I don't think it should abort/core. > + object_class_property_set_description(oc, "dirty-ring-size", > + "KVM dirty ring size (<=3D0 to disable)", &error_abort); > } > =20 > static const TypeInfo kvm_accel_type =3D { > diff --git a/qemu-options.hx b/qemu-options.hx > index 224a8e8712..140bd38726 100644 > --- a/qemu-options.hx > +++ b/qemu-options.hx > @@ -119,6 +119,7 @@ DEF("accel", HAS_ARG, QEMU_OPTION_accel, > " kernel-irqchip=3Don|off|split controls accelerated = irqchip support (default=3Don)\n" > " kvm-shadow-mem=3Dsize of KVM shadow MMU in bytes\n" > " tb-size=3Dn (TCG translation block cache size)\n" > + " dirty-ring-size=3Dn (KVM dirty ring size in Bytes)\= n" > " thread=3Dsingle|multi (enable multi-threaded TCG)\n= ", QEMU_ARCH_ALL) > STEXI > @item -accel @var{name}[,prop=3D@var{value}[,...]] > @@ -140,6 +141,8 @@ irqchip completely is not recommended except for debu= gging purposes. > Defines the size of the KVM shadow MMU. > @item tb-size=3D@var{n} > Controls the size (in MiB) of the TCG translation block cache. > +@item dirty-ring-size=3D@val{n} > +Controls the size (in Bytes) of KVM dirty ring (<=3D0 to disable). I don't see the point in allowing < 0 ; I'd ban it. Dave > @item thread=3Dsingle|multi > Controls number of TCG threads. When the TCG is multi-threaded there wil= l be one > thread per vCPU therefor taking advantage of additional host cores. The = default > --=20 > 2.24.1 >=20 >=20 -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK