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author | Jan Kiszka <jan.kiszka@siemens.com> | 2018-03-07 08:39:13 +0100 |
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committer | Thomas Gleixner <tglx@linutronix.de> | 2018-03-08 12:30:37 +0100 |
commit | 690f4304104f37e473bd5e43fc5247f5cd35b225 (patch) | |
tree | 0df929dd720cb38ad5f35ea94ab850dd7a06553c /drivers/pci | |
parent | 63338a38db955cb4e0352c11b78732157c78d30b (diff) | |
download | linux-690f4304104f37e473bd5e43fc5247f5cd35b225.tar.gz linux-690f4304104f37e473bd5e43fc5247f5cd35b225.tar.bz2 linux-690f4304104f37e473bd5e43fc5247f5cd35b225.zip |
PCI: Scan all functions when running over Jailhouse
Per PCIe r4.0, sec 7.5.1.1.9, multi-function devices are required to have a
function 0. Therefore, Linux scans for devices at function 0 (devfn
0/8/16/...) and only scans for other functions if function 0 has its
Multi-Function Device bit set or ARI or SR-IOV indicate there are more
functions.
The Jailhouse hypervisor may pass individual functions of a multi-function
device to a guest without passing function 0, which means a Linux guest
won't find them.
Change Linux PCI probing so it scans all function numbers when running as a
guest over Jailhouse.
This is technically prohibited by the spec, so it is possible that PCI
devices without the Multi-Function Device bit set may have unexpected
behavior in response to this probe.
Originally-by: Benedikt Spranger <b.spranger@linutronix.de>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: jailhouse-dev@googlegroups.com
Cc: Benedikt Spranger <b.spranger@linutronix.de>
Cc: linux-pci@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Link: https://lkml.kernel.org/r/06e279b2a3e06cf6689ab3975f8ab592bba02362.1520408357.git.jan.kiszka@siemens.com
Diffstat (limited to 'drivers/pci')
-rw-r--r-- | drivers/pci/probe.c | 22 |
1 files changed, 19 insertions, 3 deletions
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index ef5377438a1e..3c365dc996e7 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -16,6 +16,7 @@ #include <linux/pci-aspm.h> #include <linux/aer.h> #include <linux/acpi.h> +#include <linux/hypervisor.h> #include <linux/irqdomain.h> #include <linux/pm_runtime.h> #include "pci.h" @@ -2518,14 +2519,29 @@ static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus, { unsigned int used_buses, normal_bridges = 0, hotplug_bridges = 0; unsigned int start = bus->busn_res.start; - unsigned int devfn, cmax, max = start; + unsigned int devfn, fn, cmax, max = start; struct pci_dev *dev; + int nr_devs; dev_dbg(&bus->dev, "scanning bus\n"); /* Go find them, Rover! */ - for (devfn = 0; devfn < 0x100; devfn += 8) - pci_scan_slot(bus, devfn); + for (devfn = 0; devfn < 256; devfn += 8) { + nr_devs = pci_scan_slot(bus, devfn); + + /* + * The Jailhouse hypervisor may pass individual functions of a + * multi-function device to a guest without passing function 0. + * Look for them as well. + */ + if (jailhouse_paravirt() && nr_devs == 0) { + for (fn = 1; fn < 8; fn++) { + dev = pci_scan_single_device(bus, devfn + fn); + if (dev) + dev->multifunction = 1; + } + } + } /* Reserve buses for SR-IOV capability */ used_buses = pci_iov_bus_range(bus); |