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| author | Jan Kiszka <jan.kiszka@siemens.com> | 2018-03-07 08:39:13 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-03-08 12:30:37 +0100 |
| commit | 690f4304104f37e473bd5e43fc5247f5cd35b225 (patch) | |
| tree | 0df929dd720cb38ad5f35ea94ab850dd7a06553c /arch | |
| parent | jailhouse: Provide detection for non-x86 systems (diff) | |
| download | linux-690f4304104f37e473bd5e43fc5247f5cd35b225.tar.xz 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 'arch')
| -rw-r--r-- | arch/x86/pci/legacy.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/pci/legacy.c b/arch/x86/pci/legacy.c index 1cb01abcb1be..dfbe6ac38830 100644 --- a/arch/x86/pci/legacy.c +++ b/arch/x86/pci/legacy.c @@ -4,6 +4,7 @@ #include <linux/init.h> #include <linux/export.h> #include <linux/pci.h> +#include <asm/jailhouse_para.h> #include <asm/pci_x86.h> /* @@ -34,13 +35,14 @@ int __init pci_legacy_init(void) void pcibios_scan_specific_bus(int busn) { + int stride = jailhouse_paravirt() ? 1 : 8; int devfn; u32 l; if (pci_find_bus(0, busn)) return; - for (devfn = 0; devfn < 256; devfn += 8) { + for (devfn = 0; devfn < 256; devfn += stride) { 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); |