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? > + ); > + > for (Offset = BarOffsetBase; Offset < BarOffsetEnd; Offset += sizeof > (UINT32)) { > PcatPciRootBridgeBarExisted ( > PCI_LIB_ADDRESS (Bus, Device, Function, Offset), Thanks, -- Anthony PERARD _______________________________________________ edk2-devel mailing list edk2-devel@lists.01.org https://lists.01.org/mailman/listinfo/edk2-devel