From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from Galois.linutronix.de ([146.0.238.70]:47388 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751914AbcHILYv (ORCPT ); Tue, 9 Aug 2016 07:24:51 -0400 Date: Tue, 9 Aug 2016 13:22:30 +0200 (CEST) From: Thomas Gleixner To: LKML cc: x86@kernel.org, Bjorn Helgaas , linux-pci@vger.kernel.org, Jan Kiszka , Benedikt Spranger Subject: x86/PCI: Scan all functions during probing Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-pci-owner@vger.kernel.org List-ID: From: Benedikt Spranger PCI and PCIBIOS probing only scans devices at function number 0/8/16/... Subdevices (e.g. multiqueue) have function numbers which are not a multiple of 8. Simple hypervisors (e.g. Jailhouse) pass subdevices directly w/o providing virtual PCI mappings like KVM. As a consequence a simple PCI passthrough from Jailhouse to a linux guest is not able to detect such devices. Changing the probe functions to scan all function numbers makes it work. This has no side effects and there is no reason to force the 0/8/16... probing scheme. Signed-off-by: Benedikt Spranger Signed-off-by: Thomas Gleixner --- arch/x86/pci/legacy.c | 2 +- drivers/pci/probe.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) --- a/arch/x86/pci/legacy.c +++ b/arch/x86/pci/legacy.c @@ -42,7 +42,7 @@ void pcibios_scan_specific_bus(int busn) if (pci_find_bus(0, busn)) return; - for (devfn = 0; devfn < 256; devfn += 8) { + for (devfn = 0; devfn < 256; devfn++) { if (!raw_pci_read(0, busn, devfn, PCI_VENDOR_ID, 2, &l) && l != 0x0000 && l != 0xffff) { DBG("Found device at %02x:%02x [%04x]\n", busn, devfn, l); --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2063,7 +2063,7 @@ unsigned int pci_scan_child_bus(struct p dev_dbg(&bus->dev, "scanning bus\n"); /* Go find them, Rover! */ - for (devfn = 0; devfn < 0x100; devfn += 8) + for (devfn = 0; devfn < 0x100; devfn++) pci_scan_slot(bus, devfn); /* Reserve buses for SR-IOV capability. */