On 14/03/2019 17:55, Anthony PERARD wrote: > On Wed, Mar 06, 2019 at 12:40:56PM +0000, Igor Druzhinin wrote: >> On Xen, hvmloader firmware leaves address decoding enabled for >> enumerated PCI device before jumping into OVMF. OVMF seems to >> expect it to be disabled and tries to size PCI BARs in several places >> without disabling it which causes BAR64, for example, being >> incorrectly placed by QEMU. >> >> Fix it by disabling PCI address decoding explicitly before the >> first attempt to size BARs on Xen. >> >> Contributed-under: TianoCore Contribution Agreement 1.1 >> Signed-off-by: Igor Druzhinin <igor.druzhi...@citrix.com> >> --- >> OvmfPkg/Library/PciHostBridgeLib/XenSupport.c | 34 >> +++++++++++++++++++++++++++ >> 1 file changed, 34 insertions(+) >> >> diff --git a/OvmfPkg/Library/PciHostBridgeLib/XenSupport.c >> b/OvmfPkg/Library/PciHostBridgeLib/XenSupport.c >> index 408fb24..9940335 100644 >> --- a/OvmfPkg/Library/PciHostBridgeLib/XenSupport.c >> +++ b/OvmfPkg/Library/PciHostBridgeLib/XenSupport.c >> @@ -55,6 +55,33 @@ PcatPciRootBridgeBarExisted ( >> EnableInterrupts (); >> } >> >> +#define EFI_PCI_COMMAND_DECODE ((UINT16)(EFI_PCI_COMMAND_IO_SPACE | \ >> + EFI_PCI_COMMAND_MEMORY_SPACE)) >> +STATIC >> +VOID >> +PcatPciRootBridgeDecoding ( >> + IN UINTN Address, >> + IN BOOLEAN Enabled, >> + OUT UINT16 *OriginalValue >> + ) >> +{ >> + UINT16 Value; >> + >> + // >> + // Preserve the original value >> + // >> + Value = *OriginalValue; >> + *OriginalValue = PciRead16 (Address); >> + >> + if (!Enabled) { >> + if (*OriginalValue & EFI_PCI_COMMAND_DECODE) >> + PciWrite16 (Address, *OriginalValue & ~EFI_PCI_COMMAND_DECODE); > > The edk2 coding style ask to always use { } with if: > https://github.com/tianocore/tianocore.github.io/wiki/Code-Style-C > >> + } else { >> + if (Value & EFI_PCI_COMMAND_DECODE) >> + PciWrite16 (Address, Value); > > here too. > >> + } >> +} >> + >> STATIC >> VOID >> PcatPciRootBridgeParseBars ( >> @@ -76,6 +103,7 @@ PcatPciRootBridgeParseBars ( >> UINT32 Value; >> UINT32 OriginalUpperValue; >> UINT32 UpperValue; >> + UINT16 OriginalCommand; >> UINT64 Mask; >> UINTN Offset; >> UINT64 Base; >> @@ -83,6 +111,12 @@ PcatPciRootBridgeParseBars ( >> UINT64 Limit; >> PCI_ROOT_BRIDGE_APERTURE *MemAperture; >> >> + // Disable address decoding for every device before OVMF starts sizing it >> + PcatPciRootBridgeDecoding ( >> + PCI_LIB_ADDRESS (Bus, Device, Function, PCI_COMMAND_OFFSET), >> + FALSE, &OriginalCommand > > Is it on purpose that the original register value is stored in > OriginalCommand, but never used again?
Those are probably remnants of extended patch version for XenServer - will remove together with other suggestions from you and Laszlo. Igor _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel