From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Williamson Subject: Re: [PATCH 0/2] VFIO: Accept IOMMU group (PE) ID Date: Fri, 18 Sep 2015 09:47:32 -0600 Message-ID: <1442591252.23936.254.camel@redhat.com> References: <1442557469-22185-1-git-send-email-gwshan@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org, kvm@vger.kernel.org, david@gibson.dropbear.id.au To: Gavin Shan Return-path: Received: from mx1.redhat.com ([209.132.183.28]:48998 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753629AbbIRPre (ORCPT ); Fri, 18 Sep 2015 11:47:34 -0400 In-Reply-To: <1442557469-22185-1-git-send-email-gwshan@linux.vnet.ibm.com> Sender: kvm-owner@vger.kernel.org List-ID: On Fri, 2015-09-18 at 16:24 +1000, Gavin Shan wrote: > This allows to accept IOMMU group (PE) ID from the parameter from userland > when handling EEH operation so that the operation only affects the target > IOMMU group (PE). If the IOMMU group (PE) ID in the parameter from userland > is invalid, all IOMMU groups (PEs) attached to the specified container are > affected as before. > > Gavin Shan (2): > drivers/vfio: Support EEH API revision > drivers/vfio: Support IOMMU group for EEH operations > > drivers/vfio/vfio_iommu_spapr_tce.c | 50 ++++++++++++++++++++++++++++++++++--- > drivers/vfio/vfio_spapr_eeh.c | 46 ++++++++++++++++++++++------------ > include/linux/vfio.h | 13 +++++++--- > include/uapi/linux/vfio.h | 6 +++++ > 4 files changed, 93 insertions(+), 22 deletions(-) This interface is terrible. A function named foo_enabled() should return a bool, yes or no, don't try to overload it to also return a version. AFAICT, patch 2/2 breaks current users by changing the offset of the union in struct vfio_eeh_pe_err. Also, we generally pass group file descriptors rather than a group ID because we can prove the ownership of the group through the file descriptor and we don't need to worry about races with the group because we can hold a reference to it.