Return-Path: From: Greg Kroah-Hartman Subject: [PATCH 4.4 314/342] xen/pciback: Check PF instead of VF for PCI_COMMAND_MEMORY To: Cc: Greg Kroah-Hartman , , Konrad Rzeszutek Wilk , Jan Beulich , David Vrabel Message-Id: <20160301234538.027257370@linuxfoundation.org> In-Reply-To: <20160301234527.990448862@linuxfoundation.org> References: <20160301234527.990448862@linuxfoundation.org> Date: Tue, 01 Mar 2016 23:55:29 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Konrad Rzeszutek Wilk commit 8d47065f7d1980dde52abb874b301054f3013602 upstream. Commit 408fb0e5aa7fda0059db282ff58c3b2a4278baa0 (xen/pciback: Don't allow MSI-X ops if PCI_COMMAND_MEMORY is not set) prevented enabling MSI-X on passed-through virtual functions, because it checked the VF for PCI_COMMAND_MEMORY but this is not a valid bit for VFs. Instead, check the physical function for PCI_COMMAND_MEMORY. Signed-off-by: Konrad Rzeszutek Wilk Reviewed-by: Jan Beulich Signed-off-by: David Vrabel Signed-off-by: Greg Kroah-Hartman --- drivers/xen/xen-pciback/pciback_ops.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/xen/xen-pciback/pciback_ops.c +++ b/drivers/xen/xen-pciback/pciback_ops.c @@ -227,8 +227,9 @@ int xen_pcibk_enable_msix(struct xen_pci /* * PCI_COMMAND_MEMORY must be enabled, otherwise we may not be able * to access the BARs where the MSI-X entries reside. + * But VF devices are unique in which the PF needs to be checked. */ - pci_read_config_word(dev, PCI_COMMAND, &cmd); + pci_read_config_word(pci_physfn(dev), PCI_COMMAND, &cmd); if (dev->msi_enabled || !(cmd & PCI_COMMAND_MEMORY)) return -ENXIO;