Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751286AbdH2C67 (ORCPT ); Mon, 28 Aug 2017 22:58:59 -0400 Received: from mail-pg0-f65.google.com ([74.125.83.65]:36796 "EHLO mail-pg0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751221AbdH2C65 (ORCPT ); Mon, 28 Aug 2017 22:58:57 -0400 Subject: Re: [RFC PATCH v5 0/5] vfio-pci: Add support for mmapping MSI-X table From: Alexey Kardashevskiy To: linuxppc-dev@lists.ozlabs.org Cc: David Gibson , kvm-ppc@vger.kernel.org, kvm@vger.kernel.org, Yongji Xie , Eric Auger , Kyle Mahlkuch , Alex Williamson , Jike Song , Bjorn Helgaas , Robin Murphy , Joerg Roedel , Arvind Yadav , Benjamin Herrenschmidt , David Woodhouse , Kirti Wankhede , Mauricio Faria de Oliveira , Neo Jia , Paul Mackerras , Vlad Tsyrklevich , iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org References: <20170807072548.3023-1-aik@ozlabs.ru> <8f5f7b82-3c10-7f39-b587-db4c4424f04c@ozlabs.ru> <3be3fca3-7f66-0f13-b93a-d3db40a8a934@ozlabs.ru> Message-ID: <79581f70-a4c9-dac9-a671-4de7f55bd86e@ozlabs.ru> Date: Tue, 29 Aug 2017 12:58:46 +1000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <3be3fca3-7f66-0f13-b93a-d3db40a8a934@ozlabs.ru> Content-Type: text/plain; charset=utf-8 Content-Language: en-AU Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3013 Lines: 96 On 21/08/17 12:47, Alexey Kardashevskiy wrote: > Folks, > > Ok, people did talk, exchanged ideas, lovely :) What happens now? Do I > repost this or go back to PCI bus flags or something else? Thanks. Anyone, any help? How do we proceed with this? Thanks. > > > > On 14/08/17 19:45, Alexey Kardashevskiy wrote: >> Folks, >> >> Is there anything to change besides those compiler errors and David's >> comment in 5/5? Or the while patchset is too bad? Thanks. >> >> >> >> On 07/08/17 17:25, Alexey Kardashevskiy wrote: >>> This is a followup for "[PATCH kernel v4 0/6] vfio-pci: Add support for mmapping MSI-X table" >>> http://www.spinics.net/lists/kvm/msg152232.html >>> >>> This time it is using "caps" in IOMMU groups. The main question is if PCI >>> bus flags or IOMMU domains are still better (and which one). >> >>> >>> >>> >>> Here is some background: >>> >>> Current vfio-pci implementation disallows to mmap the page >>> containing MSI-X table in case that users can write directly >>> to MSI-X table and generate an incorrect MSIs. >>> >>> However, this will cause some performance issue when there >>> are some critical device registers in the same page as the >>> MSI-X table. We have to handle the mmio access to these >>> registers in QEMU emulation rather than in guest. >>> >>> To solve this issue, this series allows to expose MSI-X table >>> to userspace when hardware enables the capability of interrupt >>> remapping which can ensure that a given PCI device can only >>> shoot the MSIs assigned for it. And we introduce a new bus_flags >>> PCI_BUS_FLAGS_MSI_REMAP to test this capability on PCI side >>> for different archs. >>> >>> >>> This is based on sha1 >>> 26c5cebfdb6c "Merge branch 'parisc-4.13-4' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux" >>> >>> Please comment. Thanks. >>> >>> Changelog: >>> >>> v5: >>> * redid the whole thing via so-called IOMMU group capabilities >>> >>> v4: >>> * rebased on recent upstream >>> * got all 6 patches from v2 (v3 was missing some) >>> >>> >>> >>> >>> Alexey Kardashevskiy (5): >>> iommu: Add capabilities to a group >>> iommu: Set IOMMU_GROUP_CAP_ISOLATE_MSIX if MSI controller enables IRQ >>> remapping >>> iommu/intel/amd: Set IOMMU_GROUP_CAP_ISOLATE_MSIX if IRQ remapping is >>> enabled >>> powerpc/iommu: Set IOMMU_GROUP_CAP_ISOLATE_MSIX >>> vfio-pci: Allow to expose MSI-X table to userspace when safe >>> >>> include/linux/iommu.h | 20 ++++++++++++++++++++ >>> include/linux/vfio.h | 1 + >>> arch/powerpc/kernel/iommu.c | 1 + >>> drivers/iommu/amd_iommu.c | 3 +++ >>> drivers/iommu/intel-iommu.c | 3 +++ >>> drivers/iommu/iommu.c | 35 +++++++++++++++++++++++++++++++++++ >>> drivers/vfio/pci/vfio_pci.c | 20 +++++++++++++++++--- >>> drivers/vfio/pci/vfio_pci_rdwr.c | 5 ++++- >>> drivers/vfio/vfio.c | 15 +++++++++++++++ >>> 9 files changed, 99 insertions(+), 4 deletions(-) >>> >> >> > > -- Alexey