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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 81111C433E2 for ; Wed, 16 Sep 2020 19:04:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 20A96206DB for ; Wed, 16 Sep 2020 19:04:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="VtIYidXf" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728066AbgIPTE3 (ORCPT ); Wed, 16 Sep 2020 15:04:29 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:32298 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727422AbgIPRqU (ORCPT ); Wed, 16 Sep 2020 13:46:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600278367; 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=ZLmHQQTvYZ1vyzqk0TBru3JZL4lsKVfVuFbc/jCl0b0=; b=VtIYidXfFA6uvgpsyl6DS7Fw7UHcmMOZXlnFiQ4+gR2qEUYEadf1MwU7wPVpAEN23YQwcs gABbFKoPFUEVIUwPcMZdvgJ0mF23tTFLfcqeIY0zvG1cxPqpw4FxeCp/i52jTCorYMdVxB EagJWQqmXb5n4QCnRfzphjxpDUBtpPs= 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-364-XOPxXcRAN1KoDzSHz7IBQQ-1; Wed, 16 Sep 2020 07:05:42 -0400 X-MC-Unique: XOPxXcRAN1KoDzSHz7IBQQ-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 5300080EF84; Wed, 16 Sep 2020 11:05:41 +0000 (UTC) Received: from gondolin (ovpn-112-252.ams2.redhat.com [10.36.112.252]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7815F5FC36; Wed, 16 Sep 2020 11:05:27 +0000 (UTC) Date: Wed, 16 Sep 2020 13:05:24 +0200 From: Cornelia Huck To: Matthew Rosato Cc: alex.williamson@redhat.com, pmorel@linux.ibm.com, schnelle@linux.ibm.com, rth@twiddle.net, david@redhat.com, thuth@redhat.com, pasic@linux.ibm.com, borntraeger@de.ibm.com, mst@redhat.com, pbonzini@redhat.com, qemu-s390x@nongnu.org, qemu-devel@nongnu.org, kvm@vger.kernel.org Subject: Re: [PATCH v3 5/5] s390x/pci: Honor DMA limits set by vfio Message-ID: <20200916130524.48e11b26.cohuck@redhat.com> In-Reply-To: <1600197283-25274-6-git-send-email-mjrosato@linux.ibm.com> References: <1600197283-25274-1-git-send-email-mjrosato@linux.ibm.com> <1600197283-25274-6-git-send-email-mjrosato@linux.ibm.com> Organization: Red Hat GmbH MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, 15 Sep 2020 15:14:43 -0400 Matthew Rosato wrote: > When an s390 guest is using lazy unmapping, it can result in a very > large number of oustanding DMA requests, far beyond the default > limit configured for vfio. Let's track DMA usage similar to vfio > in the host, and trigger the guest to flush their DMA mappings > before vfio runs out. > > Signed-off-by: Matthew Rosato > --- > hw/s390x/s390-pci-bus.c | 56 +++++++++++++++++++++++++++++++++++++++++++----- > hw/s390x/s390-pci-bus.h | 9 ++++++++ > hw/s390x/s390-pci-inst.c | 34 +++++++++++++++++++++++------ > hw/s390x/s390-pci-inst.h | 3 +++ > 4 files changed, 91 insertions(+), 11 deletions(-) (...) > @@ -737,6 +740,41 @@ static void s390_pci_iommu_free(S390pciState *s, PCIBus *bus, int32_t devfn) > object_unref(OBJECT(iommu)); > } > > +static S390PCIDMACount *s390_start_dma_count(S390pciState *s, VFIODevice *vdev) Should these go into the new vfio-related file? > +{ > + int id = vdev->group->container->fd; > + S390PCIDMACount *cnt; > + uint32_t avail; > + > + if (!s390_pci_update_dma_avail(id, &avail)) { > + return NULL; > + } > + > + QTAILQ_FOREACH(cnt, &s->zpci_dma_limit, link) { > + if (cnt->id == id) { > + cnt->users++; > + return cnt; > + } > + } > + > + cnt = g_new0(S390PCIDMACount, 1); > + cnt->id = id; > + cnt->users = 1; > + cnt->avail = avail; > + QTAILQ_INSERT_TAIL(&s->zpci_dma_limit, cnt, link); > + return cnt; > +} > + > +static void s390_end_dma_count(S390pciState *s, S390PCIDMACount *cnt) > +{ > + assert(cnt); > + > + cnt->users--; > + if (cnt->users == 0) { > + QTAILQ_REMOVE(&s->zpci_dma_limit, cnt, link); > + } > +} > + > static void s390_pcihost_realize(DeviceState *dev, Error **errp) > { > PCIBus *b; > @@ -764,6 +802,7 @@ static void s390_pcihost_realize(DeviceState *dev, Error **errp) > s->bus_no = 0; > QTAILQ_INIT(&s->pending_sei); > QTAILQ_INIT(&s->zpci_devs); > + QTAILQ_INIT(&s->zpci_dma_limit); > > css_register_io_adapters(CSS_IO_ADAPTER_PCI, true, false, > S390_ADAPTER_SUPPRESSIBLE, errp); > @@ -902,6 +941,7 @@ static void s390_pcihost_plug(HotplugHandler *hotplug_dev, DeviceState *dev, > { > S390pciState *s = S390_PCI_HOST_BRIDGE(hotplug_dev); > PCIDevice *pdev = NULL; > + VFIOPCIDevice *vpdev = NULL; > S390PCIBusDevice *pbdev = NULL; > > if (object_dynamic_cast(OBJECT(dev), TYPE_PCI_BRIDGE)) { > @@ -941,17 +981,20 @@ static void s390_pcihost_plug(HotplugHandler *hotplug_dev, DeviceState *dev, > } > } > > + pbdev->pdev = pdev; > + pbdev->iommu = s390_pci_get_iommu(s, pci_get_bus(pdev), pdev->devfn); > + pbdev->iommu->pbdev = pbdev; > + pbdev->state = ZPCI_FS_DISABLED; > + > if (object_dynamic_cast(OBJECT(dev), "vfio-pci")) { > pbdev->fh |= FH_SHM_VFIO; > + vpdev = container_of(pbdev->pdev, VFIOPCIDevice, pdev); > + pbdev->iommu->dma_limit = s390_start_dma_count(s, > + &vpdev->vbasedev); I think you can just pass s and pbdev to that function... that would move dealing with vfio specifics from this file. > } else { > pbdev->fh |= FH_SHM_EMUL; > } > > - pbdev->pdev = pdev; > - pbdev->iommu = s390_pci_get_iommu(s, pci_get_bus(pdev), pdev->devfn); > - pbdev->iommu->pbdev = pbdev; > - pbdev->state = ZPCI_FS_DISABLED; > - > if (s390_pci_msix_init(pbdev)) { > error_setg(errp, "MSI-X support is mandatory " > "in the S390 architecture"); (...) > diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c > index 2f7a7d7..cc34b17 100644 > --- a/hw/s390x/s390-pci-inst.c > +++ b/hw/s390x/s390-pci-inst.c > @@ -32,6 +32,9 @@ > } \ > } while (0) > > +#define inc_dma_avail(iommu) if (iommu->dma_limit) iommu->dma_limit->avail++; I was thinking more of something like static inline void inc_dma_avail(S390PCIIOMMU *iommu) { if (iommu->dma_limit) { iommu->dma_limit->avail++; } } > +#define dec_dma_avail(iommu) if (iommu->dma_limit) iommu->dma_limit->avail--; > + > static void s390_set_status_code(CPUS390XState *env, > uint8_t r, uint64_t status_code) > { (...)