From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg Rose Subject: [RFC net-next PATCH 1/4] pci: Add flag indicating device has been assigned by KVM Date: Wed, 27 Jul 2011 15:17:49 -0700 Message-ID: <20110727221749.8435.19000.stgit@gitlad.jf.intel.com> References: <20110727221406.8435.44324.stgit@gitlad.jf.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: davem@davemloft.net, bhutchings@solarflare.com, jeffrey.t.kirsher@intel.com To: netdev@vger.kernel.org Return-path: Received: from mga01.intel.com ([192.55.52.88]:35576 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755304Ab1G0WRx (ORCPT ); Wed, 27 Jul 2011 18:17:53 -0400 In-Reply-To: <20110727221406.8435.44324.stgit@gitlad.jf.intel.com> Sender: netdev-owner@vger.kernel.org List-ID: Device drivers that create and destroy SR-IOV virtual functions via calls to pci_enable_sriov() and pci_disable_sriov can cause catastrophic failures if they attempt to destroy VFs while they are assigned to guest virtual machines. By adding a flag for use by the KVM module to indicate that a device is assigned a device driver can check that flag and avoid destroying VFs while they are assigned and avoid system failures. Signed-off-by: Greg Rose --- include/linux/pci.h | 2 ++ virt/kvm/assigned-dev.c | 2 ++ virt/kvm/iommu.c | 4 ++++ 3 files changed, 8 insertions(+), 0 deletions(-) diff --git a/include/linux/pci.h b/include/linux/pci.h index 2d29218..a297ca2 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -174,6 +174,8 @@ enum pci_dev_flags { PCI_DEV_FLAGS_MSI_INTX_DISABLE_BUG = (__force pci_dev_flags_t) 1, /* Device configuration is irrevocably lost if disabled into D3 */ PCI_DEV_FLAGS_NO_D3 = (__force pci_dev_flags_t) 2, + /* Provide indication device is assigned by KVM */ + PCI_DEV_FLAGS_ASSIGNED = (__force pci_dev_flags_t) 4, }; enum pci_irq_reroute_variant { diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c index 6cc4b97..f401de1 100644 --- a/virt/kvm/assigned-dev.c +++ b/virt/kvm/assigned-dev.c @@ -205,6 +205,8 @@ static void kvm_free_assigned_device(struct kvm *kvm, else pci_restore_state(assigned_dev->dev); + assigned_dev->dev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED; + pci_release_regions(assigned_dev->dev); pci_disable_device(assigned_dev->dev); pci_dev_put(assigned_dev->dev); diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c index 62a9caf..cffc530 100644 --- a/virt/kvm/iommu.c +++ b/virt/kvm/iommu.c @@ -181,6 +181,8 @@ int kvm_assign_device(struct kvm *kvm, goto out_unmap; } + pdev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED; + printk(KERN_DEBUG "assign device %x:%x:%x.%x\n", assigned_dev->host_segnr, assigned_dev->host_busnr, @@ -209,6 +211,8 @@ int kvm_deassign_device(struct kvm *kvm, iommu_detach_device(domain, &pdev->dev); + pdev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED; + printk(KERN_DEBUG "deassign device %x:%x:%x.%x\n", assigned_dev->host_segnr, assigned_dev->host_busnr,