From 0c40c9c925ca1cc15b9cbeae31723b0b784b932e Mon Sep 17 00:00:00 2001 From: Igor Druzhinin Date: Thu, 25 Apr 2019 21:23:58 +0100 Subject: OvmfPkg/XenSupport: turn off address decoding before BAR sizing 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. Signed-off-by: Igor Druzhinin Acked-by: Laszlo Ersek Acked-by: Anthony PERARD --- OvmfPkg/Library/PciHostBridgeLib/XenSupport.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'OvmfPkg') diff --git a/OvmfPkg/Library/PciHostBridgeLib/XenSupport.c b/OvmfPkg/Library/PciHostBridgeLib/XenSupport.c index 76fca533c1..b41bd6b300 100644 --- a/OvmfPkg/Library/PciHostBridgeLib/XenSupport.c +++ b/OvmfPkg/Library/PciHostBridgeLib/XenSupport.c @@ -49,6 +49,22 @@ PcatPciRootBridgeBarExisted ( EnableInterrupts (); } +#define PCI_COMMAND_DECODE ((UINT16)(EFI_PCI_COMMAND_IO_SPACE | \ + EFI_PCI_COMMAND_MEMORY_SPACE)) +STATIC +VOID +PcatPciRootBridgeDecodingDisable ( + IN UINTN Address + ) +{ + UINT16 Value; + + Value = PciRead16 (Address); + if (Value & PCI_COMMAND_DECODE) { + PciWrite16 (Address, Value & ~(UINT32)PCI_COMMAND_DECODE); + } +} + STATIC VOID PcatPciRootBridgeParseBars ( @@ -75,6 +91,11 @@ PcatPciRootBridgeParseBars ( UINT64 Limit; PCI_ROOT_BRIDGE_APERTURE *MemAperture; + // Disable address decoding for every device before OVMF starts sizing it + PcatPciRootBridgeDecodingDisable ( + PCI_LIB_ADDRESS (Bus, Device, Function, PCI_COMMAND_OFFSET) + ); + for (Offset = BarOffsetBase; Offset < BarOffsetEnd; Offset += sizeof (UINT32)) { PcatPciRootBridgeBarExisted ( PCI_LIB_ADDRESS (Bus, Device, Function, Offset), -- cgit v1.2.3