From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754555AbbLKI4m (ORCPT ); Fri, 11 Dec 2015 03:56:42 -0500 Received: from e23smtp03.au.ibm.com ([202.81.31.145]:43197 "EHLO e23smtp03.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754513AbbLKI4k (ORCPT ); Fri, 11 Dec 2015 03:56:40 -0500 X-IBM-Helo: d23dlp01.au.ibm.com X-IBM-MailFrom: xyjxie@linux.vnet.ibm.com X-IBM-RcptTo: kvm@vger.kernel.org;linux-api@vger.kernel.org;linux-kernel@vger.kernel.org From: Yongji Xie To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, linuxppc-dev@lists.ozlabs.org Cc: aik@ozlabs.ru, alex.williamson@redhat.com, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, warrier@linux.vnet.ibm.com, zhong@linux.vnet.ibm.com, nikunj@linux.vnet.ibm.com, Yongji Xie Subject: [RFC PATCH 3/3] vfio-pci: Allow to mmap MSI-X table if EEH is supported Date: Fri, 11 Dec 2015 16:53:14 +0800 Message-Id: <1449823994-3356-4-git-send-email-xyjxie@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1449823994-3356-1-git-send-email-xyjxie@linux.vnet.ibm.com> References: <1449823994-3356-1-git-send-email-xyjxie@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15121108-0009-0000-0000-00000283FBCD Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Current vfio-pci implementation disallows to mmap MSI-X table in case that user get to touch this directly. However, EEH mechanism could ensure that a given pci device can only shoot the MSIs assigned for its PE and guest kernel also would not write to MSI-X table in pci_enable_msix() because para-virtualization on PPC64 platform. So MSI-X table is safe to access directly from the guest with EEH mechanism enabled. This patch adds support for this case and allow to mmap MSI-X table if EEH is supported on PPC64 platform. And we also add a VFIO_DEVICE_FLAGS_PCI_MSIX_MMAP flag to notify userspace that it's safe to mmap MSI-X table. Signed-off-by: Yongji Xie --- drivers/vfio/pci/vfio_pci.c | 5 ++++- drivers/vfio/pci/vfio_pci_private.h | 5 +++++ include/uapi/linux/vfio.h | 2 ++ 3 files changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index dbcad99..85d9980 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -446,6 +446,9 @@ static long vfio_pci_ioctl(void *device_data, if (vfio_pci_bar_page_aligned()) info.flags |= VFIO_DEVICE_FLAGS_PCI_PAGE_ALIGNED; + if (vfio_msix_table_mmap_enabled()) + info.flags |= VFIO_DEVICE_FLAGS_PCI_MSIX_MMAP; + info.num_regions = VFIO_PCI_NUM_REGIONS; info.num_irqs = VFIO_PCI_NUM_IRQS; @@ -871,7 +874,7 @@ static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma) if (phys_len < PAGE_SIZE || req_start + req_len > phys_len) return -EINVAL; - if (index == vdev->msix_bar) { + if (index == vdev->msix_bar && !vfio_msix_table_mmap_enabled()) { /* * Disallow mmaps overlapping the MSI-X table; users don't * get to touch this directly. We could find somewhere diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h index 319352a..835619e 100644 --- a/drivers/vfio/pci/vfio_pci_private.h +++ b/drivers/vfio/pci/vfio_pci_private.h @@ -74,6 +74,11 @@ static inline bool vfio_pci_bar_page_aligned(void) return IS_ENABLED(CONFIG_PPC64); } +static inline bool vfio_msix_table_mmap_enabled(void) +{ + return IS_ENABLED(CONFIG_EEH); +} + extern void vfio_pci_intx_mask(struct vfio_pci_device *vdev); extern void vfio_pci_intx_unmask(struct vfio_pci_device *vdev); diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h index 1fc8066..289e662 100644 --- a/include/uapi/linux/vfio.h +++ b/include/uapi/linux/vfio.h @@ -173,6 +173,8 @@ struct vfio_device_info { #define VFIO_DEVICE_FLAGS_AMBA (1 << 3) /* vfio-amba device */ /* Platform support all PCI MMIO BARs to be page aligned */ #define VFIO_DEVICE_FLAGS_PCI_PAGE_ALIGNED (1 << 4) +/* Platform support mmapping PCI MSI-X vector table */ +#define VFIO_DEVICE_FLAGS_PCI_MSIX_MMAP (1 << 5) __u32 num_regions; /* Max region index + 1 */ __u32 num_irqs; /* Max IRQ index + 1 */ }; -- 1.7.9.5