diff options
| author | Alex Williamson <alex.williamson@redhat.com> | 2018-09-25 13:01:27 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-11-25 09:52:55 +0100 |
| commit | 03c3736e79150e878d612a4c88919a8bf3123ab6 (patch) | |
| tree | 3195e10853f65fde1dad97e293f6c135596e51e8 /drivers/vfio | |
| parent | be363e27ec3c3a99793da2be6c07eafb95709c6b (diff) | |
vfio/pci: Mask buggy SR-IOV VF INTx support
[ Upstream commit db04264fe9bc0f2b62e036629f9afb530324b693 ]
The SR-IOV spec requires that VFs must report zero for the INTx pin
register as VFs are precluded from INTx support. It's much easier for
the host kernel to understand whether a device is a VF and therefore
whether a non-zero pin register value is bogus than it is to do the
same in userspace. Override the INTx count for such devices and
virtualize the pin register to provide a consistent view of the device
to the user.
As this is clearly a spec violation, warn about it to support hardware
validation, but also provide a known whitelist as it doesn't do much
good to continue complaining if the hardware vendor doesn't plan to
fix it.
Known devices with this issue: 8086:270c
Tested-by: Gage Eads <gage.eads@intel.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/vfio')
| -rw-r--r-- | drivers/vfio/pci/vfio_pci.c | 8 | ||||
| -rw-r--r-- | drivers/vfio/pci/vfio_pci_config.c | 27 |
2 files changed, 33 insertions, 2 deletions
diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c index a1a712d18e02..da3f0ed18c76 100644 --- a/drivers/vfio/pci/vfio_pci.c +++ b/drivers/vfio/pci/vfio_pci.c @@ -426,10 +426,14 @@ static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type) { if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) { u8 pin; + + if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) || + vdev->nointx || vdev->pdev->is_virtfn) + return 0; + pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin); - if (IS_ENABLED(CONFIG_VFIO_PCI_INTX) && !vdev->nointx && pin) - return 1; + return pin ? 1 : 0; } else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) { u8 pos; u16 flags; diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c index 06a20ea183dd..84905d074c4f 100644 --- a/drivers/vfio/pci/vfio_pci_config.c +++ b/drivers/vfio/pci/vfio_pci_config.c @@ -1609,6 +1609,15 @@ static int vfio_ecap_init(struct vfio_pci_device *vdev) } /* + * Nag about hardware bugs, hopefully to have vendors fix them, but at least + * to collect a list of dependencies for the VF INTx pin quirk below. + */ +static const struct pci_device_id known_bogus_vf_intx_pin[] = { + { PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x270c) }, + {} +}; + +/* * For each device we allocate a pci_config_map that indicates the * capability occupying each dword and thus the struct perm_bits we * use for read and write. We also allocate a virtualized config @@ -1673,6 +1682,24 @@ int vfio_config_init(struct vfio_pci_device *vdev) if (pdev->is_virtfn) { *(__le16 *)&vconfig[PCI_VENDOR_ID] = cpu_to_le16(pdev->vendor); *(__le16 *)&vconfig[PCI_DEVICE_ID] = cpu_to_le16(pdev->device); + + /* + * Per SR-IOV spec rev 1.1, 3.4.1.18 the interrupt pin register + * does not apply to VFs and VFs must implement this register + * as read-only with value zero. Userspace is not readily able + * to identify whether a device is a VF and thus that the pin + * definition on the device is bogus should it violate this + * requirement. We already virtualize the pin register for + * other purposes, so we simply need to replace the bogus value + * and consider VFs when we determine INTx IRQ count. + */ + if (vconfig[PCI_INTERRUPT_PIN] && + !pci_match_id(known_bogus_vf_intx_pin, pdev)) + pci_warn(pdev, + "Hardware bug: VF reports bogus INTx pin %d\n", + vconfig[PCI_INTERRUPT_PIN]); + + vconfig[PCI_INTERRUPT_PIN] = 0; /* Gratuitous for good VFs */ } if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) || vdev->nointx) |