Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756128Ab3E0Cof (ORCPT ); Sun, 26 May 2013 22:44:35 -0400 Received: from mail-ob0-f175.google.com ([209.85.214.175]:41910 "EHLO mail-ob0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755779Ab3E0Coc (ORCPT ); Sun, 26 May 2013 22:44:32 -0400 Message-ID: <51A2C888.4050704@ozlabs.ru> Date: Mon, 27 May 2013 12:44:24 +1000 From: Alexey Kardashevskiy User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130402 Thunderbird/17.0.5 MIME-Version: 1.0 To: Scott Wood CC: David Gibson , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, kvm-ppc@vger.kernel.org, Alexander Graf , Paul Mackerras , linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH 3/4] KVM: PPC: Add support for IOMMU in-kernel handling References: <1369105607-20957-4-git-send-email-aik@ozlabs.ru> <1369256817.1374.29@scott-Lenovo-G560> <20130525024524.GA6112@boomeroo.fritz.box> In-Reply-To: <20130525024524.GA6112@boomeroo.fritz.box> Content-Type: text/plain; charset=KOI8-R Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3397 Lines: 96 On 05/25/2013 12:45 PM, David Gibson wrote: > On Wed, May 22, 2013 at 04:06:57PM -0500, Scott Wood wrote: >> On 05/20/2013 10:06:46 PM, Alexey Kardashevskiy wrote: >>> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c >>> index 8465c2a..da6bf61 100644 >>> --- a/arch/powerpc/kvm/powerpc.c >>> @@ -396,6 +396,7 @@ int kvm_dev_ioctl_check_extension(long ext) >>> +++ b/arch/powerpc/kvm/powerpc.c >>> break; >>> #endif >>> case KVM_CAP_SPAPR_MULTITCE: >>> + case KVM_CAP_SPAPR_TCE_IOMMU: >>> r = 1; >>> break; >>> default: >> >> Don't advertise SPAPR capabilities if it's not book3s -- and >> probably there's some additional limitation that would be >> appropriate. > > So, in the case of MULTITCE, that's not quite right. PR KVM can > emulate a PAPR system on a BookE machine, and there's no reason not to > allow TCE acceleration as well. We can't make it dependent on PAPR > mode being selected, because that's enabled per-vcpu, whereas these > capabilities are queried on the VM before the vcpus are created. > > CAP_SPAPR_TCE_IOMMU should be dependent on the presence of suitable > host side hardware (i.e. a PAPR style IOMMU), though. The capability says that the ioctl is supported. If there is no IOMMU group registered, than it will fail with a reasonable error and nobody gets hurt. What is the problem? >> >>> @@ -1025,6 +1026,17 @@ long kvm_arch_vm_ioctl(struct file *filp, >>> r = kvm_vm_ioctl_create_spapr_tce(kvm, &create_tce); >>> goto out; >>> } >>> + case KVM_CREATE_SPAPR_TCE_IOMMU: { >>> + struct kvm_create_spapr_tce_iommu create_tce_iommu; >>> + struct kvm *kvm = filp->private_data; >>> + >>> + r = -EFAULT; >>> + if (copy_from_user(&create_tce_iommu, argp, >>> + sizeof(create_tce_iommu))) >>> + goto out; >>> + r = kvm_vm_ioctl_create_spapr_tce_iommu(kvm, >>> &create_tce_iommu); >>> + goto out; >>> + } >>> #endif /* CONFIG_PPC_BOOK3S_64 */ >>> >>> #ifdef CONFIG_KVM_BOOK3S_64_HV >>> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h >>> index 5a2afda..450c82a 100644 >>> --- a/include/uapi/linux/kvm.h >>> +++ b/include/uapi/linux/kvm.h >>> @@ -667,6 +667,7 @@ struct kvm_ppc_smmu_info { >>> #define KVM_CAP_PPC_RTAS 91 >>> #define KVM_CAP_IRQ_XICS 92 >>> #define KVM_CAP_SPAPR_MULTITCE (0x110000 + 89) >>> +#define KVM_CAP_SPAPR_TCE_IOMMU (0x110000 + 90) >> >> Hmm... > > Ah, yeah, that needs to be fixed. Those were interim numbers so that > we didn't have to keep changing our internal trees as new upstream > ioctls got added to the list. We need to get a proper number for the > merge, though. > >>> @@ -939,6 +940,9 @@ struct kvm_s390_ucas_mapping { >>> #define KVM_GET_DEVICE_ATTR _IOW(KVMIO, 0xe2, struct >>> kvm_device_attr) >>> #define KVM_HAS_DEVICE_ATTR _IOW(KVMIO, 0xe3, struct >>> kvm_device_attr) >>> >>> +/* ioctl for SPAPR TCE IOMMU */ >>> +#define KVM_CREATE_SPAPR_TCE_IOMMU _IOW(KVMIO, 0xe4, struct >>> kvm_create_spapr_tce_iommu) >> >> Shouldn't this go under the vm ioctl section? The KVM_CREATE_SPAPR_TCE_IOMMU ioctl (the version for emulated devices) is in this section so I decided to keep them together. Wrong? -- Alexey -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/