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authorIgor Druzhinin <igor.druzhinin@citrix.com>2019-04-25 21:23:58 +0100
committerLaszlo Ersek <lersek@redhat.com>2019-04-30 18:42:35 +0200
commit0c40c9c925ca1cc15b9cbeae31723b0b784b932e (patch)
tree76f71abcf86f14bea051f2f2b0ea16e89da37c6c /OvmfPkg/Library/PciHostBridgeLib
parentd63610df60f784676090deba63aeca8c9dc631d1 (diff)
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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 <igor.druzhinin@citrix.com> Acked-by: Laszlo Ersek <lersek@redhat.com> Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Diffstat (limited to 'OvmfPkg/Library/PciHostBridgeLib')
-rw-r--r--OvmfPkg/Library/PciHostBridgeLib/XenSupport.c21
1 files changed, 21 insertions, 0 deletions
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),