From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45004) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dpA9n-0006N1-UI for qemu-devel@nongnu.org; Tue, 05 Sep 2017 05:28:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dpA9j-0006g3-6b for qemu-devel@nongnu.org; Tue, 05 Sep 2017 05:28:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:47746) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dpA9i-0006fd-VU for qemu-devel@nongnu.org; Tue, 05 Sep 2017 05:28:27 -0400 Date: Tue, 5 Sep 2017 11:28:22 +0200 From: Cornelia Huck Message-ID: <20170905112822.0e9319cd.cohuck@redhat.com> In-Reply-To: <1504239778-29893-4-git-send-email-zyimin@linux.vnet.ibm.com> References: <1504239778-29893-1-git-send-email-zyimin@linux.vnet.ibm.com> <1504239778-29893-4-git-send-email-zyimin@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH v2 3/3] s390x/pci: add iommu replay callback List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Yi Min Zhao Cc: qemu-devel@nongnu.org, borntraeger@de.ibm.com, pasic@linux.vnet.ibm.com, pmorel@linux.vnet.ibm.com, agraf@suse.de, richard.henderson@linaro.org On Fri, 1 Sep 2017 06:22:58 +0200 Yi Min Zhao wrote: > Let's introduce iommu replay callback for s390 pci iommu memory region. > Currently we don't need any dma mapping replay. So let it return > directly. This implementation will avoid meaningless loops calling > translation callback. > > Reviewed-by: Pierre Morel > Reviewed-by: Halil Pasic > Signed-off-by: Yi Min Zhao > --- > hw/s390x/s390-pci-bus.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/hw/s390x/s390-pci-bus.c b/hw/s390x/s390-pci-bus.c > index bd8a3e1e1c..69f45e3715 100644 > --- a/hw/s390x/s390-pci-bus.c > +++ b/hw/s390x/s390-pci-bus.c > @@ -397,6 +397,16 @@ static IOMMUTLBEntry s390_translate_iommu(IOMMUMemoryRegion *mr, hwaddr addr, > return ret; > } > > +static void s390_pci_iommu_replay(IOMMUMemoryRegion *iommu, > + IOMMUNotifier *notifier) > +{ > + /* It's impossible to plug a pci device on s390x that already has iommu > + * mappings which need to be replayed, that is due to the "one iommu per > + * zpci device" construct. So we don't need iommu replay currently. I must say that 'currently' still throws me off. Does this refer to vfio? If yes, reword to something like 'Should we support migration of vfio-pci devices in the future, we need to revisit this.'? > + */ > + return; > +} > + > static S390PCIIOMMU *s390_pci_get_iommu(S390pciState *s, PCIBus *bus, > int devfn) > { > @@ -1045,6 +1055,7 @@ static void s390_iommu_memory_region_class_init(ObjectClass *klass, void *data) > IOMMUMemoryRegionClass *imrc = IOMMU_MEMORY_REGION_CLASS(klass); > > imrc->translate = s390_translate_iommu; > + imrc->replay = s390_pci_iommu_replay; > } > > static const TypeInfo s390_iommu_memory_region_info = {