xen/pci: don't use PCI BIOS service for configuration space accesses

The accessing PCI configuration space with the PCI BIOS32 service does
not work in PV guests.

On systems without MMCONFIG or where the BIOS hasn't marked the
MMCONFIG region as reserved in the e820 map, the BIOS service is
probed (even though direct access is preferred) and this hangs.

CC: stable@kernel.org
Acked-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[upstream git commit 76a8df7b49168509df02461f83fab117a4a86e08]
Conflicts:

	arch/x86/xen/enlighten.c

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 9494a6a13e534e2348b1574f107dd4377237a2d9..94cf8df0705645cbcee4dddc054a09df13ce4ba1 100644 (file)
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -62,6 +62,7 @@
 #include <asm/reboot.h>
 #include <asm/stackprotector.h>
 #include <asm/hypervisor.h>
+#include <asm/pci_x86.h>
 
 #include "xen-ops.h"
 #include "mmu.h"
@@ -1299,8 +1300,10 @@ asmlinkage void __init xen_start_kernel(void)
                /* Make sure ACS will be enabled */
                pci_request_acs();
        }
-               
-
+#ifdef CONFIG_PCI
+       /* PCI BIOS service won't work from a PV guest. */
+       pci_probe &= ~PCI_PROBE_BIOS;
+#endif
        xen_raw_console_write("about to get started...\n");
 
        xen_setup_runstate_info(0);