Commit 189c6c33 authored by Niklas Schnelle's avatar Niklas Schnelle Committed by Bjorn Helgaas
Browse files

PCI: Extend isolated function probing to s390 

Like the jailhouse hypervisor, s390's PCI architecture allows passing
isolated PCI functions to a guest OS instance. As of now this is was not
utilized even with multi-function support as the s390 PCI code makes sure
that only virtual PCI busses including a function with devfn 0 are
presented to the PCI subsystem. A subsequent change will remove this
restriction.

Allow probing such functions by replacing the existing check for
jailhouse_paravirt() with a new hypervisor_isolated_pci_functions() helper.

Link: https://lore.kernel.org/r/20220628143100.3228092-5-schnelle@linux.ibm.com


Signed-off-by: default avatarNiklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarPierre Morel <pmorel@linux.ibm.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
parent db360b1e

drivers/pci/probe.c

+1 −1
Original line number Diff line number Diff line
@@ -2668,7 +2668,7 @@ int pci_scan_slot(struct pci_bus *bus, int devfn) 
			 * a hypervisor that passes through individual PCI

			 * functions.

			 */

			if (!jailhouse_paravirt())

			if (!hypervisor_isolated_pci_functions())

				break;

		}

		fn = next_fn(bus, dev, fn);

include/linux/hypervisor.h

+8 −0
Original line number Diff line number Diff line
@@ -32,4 +32,12 @@ static inline bool jailhouse_paravirt(void) 


#endif /* !CONFIG_X86 */



static inline bool hypervisor_isolated_pci_functions(void)

{

	if (IS_ENABLED(CONFIG_S390))

		return true;



	return jailhouse_paravirt();

}



#endif /* __LINUX_HYPEVISOR_H */