On 04/25/19 22:23, 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.
>
> Signed-off-by: Igor Druzhinin <igor.druzhi...@citrix.com>
> ---
> Changes in v3:
> - dropped unused arguments and rename PcatPciRootBridgeDecoding function
> - make mask application more clear as suggested
> ---
> OvmfPkg/Library/PciHostBridgeLib/XenSupport.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/OvmfPkg/Library/PciHostBridgeLib/XenSupport.c
> b/OvmfPkg/Library/PciHostBridgeLib/XenSupport.c
> index 76fca53..b41bd6b 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),
>
Acked-by: Laszlo Ersek <ler...@redhat.com>
Someone from the Xen community please ACK this too, and then we can push
the series.
Thanks,
Laszlo
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