From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Williamson Subject: Re: [PATCH] x86/pci: Some buggy virtual functions incorrectly report 1 for intx. Date: Mon, 16 Jul 2018 15:17:57 -0600 Message-ID: <20180716151757.28206fae@t450s.home> References: <1531773745-41876-1-git-send-email-ashok.raj@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1531773745-41876-1-git-send-email-ashok.raj@intel.com> Sender: stable-owner@vger.kernel.org To: Ashok Raj Cc: iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Joerg Roedel , Bjorn Helgaas , Gage Eads List-Id: iommu@lists.linux-foundation.org On Mon, 16 Jul 2018 13:42:25 -0700 Ashok Raj wrote: > PCI_INTERRUPT_PIN should always read 0 for SRIOV Virtual Functions. > > Some SRIOV devices have some bugs in RTL and VF's end up reading 1 > instead of 0 for the PIN. > > We could enforce it by default in vfio_pci_nointx. > > Reported-by: Gage Eads > Tested-by: Gage Eads > Signed-off-by: Ashok Raj > Cc: linux-kernel@vger.kernel.org > Cc: stable@vger.kernel.org > Cc: iommu@lists.linux-foundation.org > Cc: Joerg Roedel > Cc: Bjorn Helgaas > Cc: Gage Eads > --- > drivers/vfio/pci/vfio_pci.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c > index b423a30..bc3f4fa 100644 > --- a/drivers/vfio/pci/vfio_pci.c > +++ b/drivers/vfio/pci/vfio_pci.c > @@ -192,6 +192,13 @@ static void vfio_pci_disable(struct vfio_pci_device *vdev); > */ > static bool vfio_pci_nointx(struct pci_dev *pdev) > { > + /* > + * Per PCI, no VF's should have INTx > + * Simply disable it here > + */ > + if (pdev->is_virtfn) > + return true; > + > switch (pdev->vendor) { > case PCI_VENDOR_ID_INTEL: > switch (pdev->device) { Nak, this is not what vfio_pci_nointx() is meant for, it's been tried before and it was broken: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/vfio/pci/vfio_pci.c?id=834814e80268c818f354c8f402e0c6604ed75589 This would cause *every* VF to print: dev_info(&pdev->dev, "Masking broken INTx support\n"); If the device is incapable of generating INTx then it's probably better to drop it at vfio_pci_get_irq_count(). Please also note the subject is misidentified, this is a "vfio/pci" patch, not an "x86/pci" patch. kvm@vger is the official list for vfio patches. Thanks, Alex