Re: [Xen-devel] [edk2] OVMF broken under Xen (in PCI initialisation)

[Gary Lin <glin@xxxxxxxx>]

On Tue, Apr 26, 2016 at 09:40:42AM +0000, Ni, Ruiyu wrote:
> Gary,
> I can reproduce the issue and have debugged to get the reason.
> In MdeModulePkg/Bus/Pci/PciBusDxe/PciEnumeratorSupport.c:
> PciEnumeratorLight() calls PciRootBridgeIo->Configuration()
> while the Configuration returns EFI_UNSUPPORTED resulting
> the PciBus driver exits earlier.
> You could try to manually set MinBus to 0 and MaxBus to 0xFF.
> 
Do you mean to set MinBus and MaxBus in PciGetBusRange() ?
Should I also keep the EFI_UNSUPPORTED code in Configuration() ?

> The second change you need to make is in PciIo.c:
> Change GetMmioAddressTranslationOffset() to return 0 instead
> of -1 when error occurs
> 

Should I also remove "ASSERT (FALSE);" ?

Cheers,

Gary Lin

> With the above 2 changes, can you check whether the system can
> boot?
> 
> If it can boot, then we need to think about what the proper fix is.
> For OVMF above Xen, the PCI resources are assigned by Xen other than
> PciBus driver. So PciRootBridgeIo->Configuration() doesn't know
> the resource assignment information.
> With old PciHostBridge driver, the Configuration() returns BUS resource
> descriptor with MinBus = MaxBus = 0 (default value), so that the PciBus
> driver can detect all devices in BUS 0, but I guess devices in BUS 1+ cannot
> be detected.
> 
> Does Xen pass the resource assignment information through some memory
> blob to firmware? If yes, we could think about let PciHostBridgeLib pass that
> information to PciHostBridge driver. If no, we also could let PciHostBridgeLib
> collect the information (IO/MEM/BUS resource assignment) and pass that
> to PciHostBridgeDxe driver.
> 
> And we need to have a way to tell PciHostBridgeDxe the resource information
> passed from PciHostBridgeLib is available resource to assign, or already 
> allocated.
> Maybe just depends on the PcdPciBusDisableEnumeration. still thinking.
> 
> 
> Regards,
> Ray
> 
> >-----Original Message-----
> >From: Gary Lin [mailto:glin@xxxxxxxx]
> >Sent: Tuesday, April 26, 2016 4:40 PM
> >To: Ni, Ruiyu <ruiyu.ni@xxxxxxxxx>
> >Cc: edk2-devel@xxxxxxxxxxxx; Xen Devel <xen-devel@xxxxxxxxxxxxx>
> >Subject: Re: [edk2] OVMF broken under Xen (in PCI initialisation)
> >
> >On Tue, Apr 26, 2016 at 08:19:49AM +0000, Ni, Ruiyu wrote:
> >> Gary,
> >> Maybe the system boots to Shell well but the video isn't initialized 
> >> properly.
> >> Can you build the firmware using "-D DEBUG_ON_SERIAL_PORT" switch and
> >> give me the boot log?
> >>
> >Hi Ray,
> >
> >I already did and it's how I make the firmware spit the log :-(
> >
> >Thanks,
> >
> >Gary Lin
> >
> >> Regards,
> >> Ray
> >>
> >> From: Gary Lin [mailto:glin@xxxxxxxx]
> >> Sent: Tuesday, April 26, 2016 3:35 PM
> >> To: Ni, Ruiyu <ruiyu.ni@xxxxxxxxx>
> >> Cc: Anthony PERARD <anthony.perard@xxxxxxxxxx>; edk2-devel@xxxxxxxxxxxx; 
> >> Xen Devel <xen-devel@xxxxxxxxxxxxx>
> >> Subject: Re: [edk2] OVMF broken under Xen (in PCI initialisation)
> >>
> >> On Tue, Apr 26, 2016 at 06:43:56AM +0000, Ni, Ruiyu wrote:
> >> >
> >> >
> >> > Regards,
> >> > Ray
> >> >
> >> > >-----Original Message-----
> >> > >From: edk2-devel [mailto:edk2-devel-bounces@xxxxxxxxxxxx] On Behalf Of 
> >> > >Anthony PERARD
> >> > >Sent: Friday, April 22, 2016 10:48 PM
> >> > >To: edk2-devel@xxxxxxxxxxxx<mailto:edk2-devel@xxxxxxxxxxxx>
> >> > >Cc: Xen Devel <xen-devel@xxxxxxxxxxxxx<mailto:xen-devel@xxxxxxxxxxxxx>>
> >> > >Subject: [edk2] OVMF broken under Xen (in PCI initialisation)
> >> > >
> >> > >Hi,
> >> > >
> >> > >Following the switch to MdeModulePkg/Bus/Pci/PciHostBridgeDxe, the pci 
> >> > >root
> >> > >bridge does not finish to initialize and breaks under Xen.
> >> > >
> >> > >There are several issue probably due to the use of
> >> > >PcdPciDisableBusEnumeration=TRUE.
> >> > >
> >> > >First one:
> >> > >ASSERT MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c(99): 
> >> > >Bridge->Mem.Limit <
> >0x0000000100000000ULL
> >> > >
> >> > >This patch would fix the first assert:
> >> > >diff --git a/OvmfPkg/PlatformPei/Xen.c b/OvmfPkg/PlatformPei/Xen.c
> >> > >index 7fa9019..15ec7a7 100644
> >> > >--- a/OvmfPkg/PlatformPei/Xen.c
> >> > >+++ b/OvmfPkg/PlatformPei/Xen.c
> >> > >@@ -227,5 +227,11 @@ InitializeXen (
> >> > >
> >> > >   PcdSetBool (PcdPciDisableBusEnumeration, TRUE);
> >> > >
> >> > >+  // Values from hvmloader
> >> > >+#define PCI_MEM_END         0xFC000000
> >> > >+#define HVM_BELOW_4G_MMIO_START 0xF0000000
> >> > >+  PcdSet64 (PcdPciMmio32Base, HVM_BELOW_4G_MMIO_START);
> >> > >+  PcdSet64 (PcdPciMmio32Size, PCI_MEM_END - HVM_BELOW_4G_MMIO_START);
> >> > >+
> >> > >   return EFI_SUCCESS;
> >> > > }
> >> > >
> >> > >
> >> > >But that not enough, next assert is:
> >> > >ASSERT MdeModulePkg/Bus/Pci/PciBusDxe/PciDeviceSupport.c(807): 
> >> > >RootBridge != ((void *) 0)
> >> > >
> >> > >I have worked around this one with the following patch. That would
> >> > >correspond to how the former implementation in OvmfPkg was initializing 
> >> > >the
> >> > >struct. Maybe a better way would be to fill ResAllocated under Xen,
> >> > >somehow. Under Xen, the ResAllocNode status is not allocated, so no
> >> > >Descriptor are created.
> >> > >
> >> > >diff --git a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
> >> > >b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
> >> > >index cda9b49..eda92b6 100644
> >> > >--- a/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
> >> > >+++ b/MdeModulePkg/Bus/Pci/PciHostBridgeDxe/PciRootBridgeIo.c
> >> > >@@ -1509,15 +1509,13 @@ RootBridgeIoConfiguration (
> >> > >
> >> > >     ResAllocNode = &RootBridge->ResAllocNode[Index];
> >> > >
> >> > >-    if (ResAllocNode->Status != ResAllocated) {
> >> > >-      continue;
> >> > >-    }
> >> > >-
> >> > >     Descriptor->Desc = ACPI_ADDRESS_SPACE_DESCRIPTOR;
> >> > >     Descriptor->Len  = sizeof (EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR) - 3;
> >> > >+    if (ResAllocNode->Status != ResAllocated) {
> >> > >     Descriptor->AddrRangeMin  = ResAllocNode->Base;
> >> > >     Descriptor->AddrRangeMax  = ResAllocNode->Base + 
> >> > > ResAllocNode->Length - 1;
> >> > >     Descriptor->AddrLen       = ResAllocNode->Length;
> >> > >+    }
> >> > >     switch (ResAllocNode->Type) {
> >> > >
> >> > I think a more proper fix is to return EFI_UNSUPPORTED without returning 
> >> > any
> >> > descriptors when the PcdPciDisableBusEnumeration is TRUE.
> >> > Per UEFI Spec, EFI_UNSUPPORTED means "The current configuration of this 
> >> > PCI
> >> > root bridge could not be retrieved." It's true when the PCD is true.
> >> >
> >> > >
> >> > >That leads to one last assert:
> >> > >> QemuVideo: Cirrus 5446 detected
> >> > >> InstallProtocolInterface: 09576E91-6D3F-11D2-8E39-00A0C969723B 
> >> > >> 7B9EF598
> >> > >> Adding Mode 0 as Cirrus Internal Mode 0: 640x480, 32-bit, 60 Hz
> >> > >> Adding Mode 1 as Cirrus Internal Mode 1: 800x600, 32-bit, 60 Hz
> >> > >> Adding Mode 2 as Cirrus Internal Mode 2: 1024x768, 24-bit, 60 Hz
> >> > >> PixelBlueGreenRedReserved8BitPerColor
> >> > >> ASSERT 
> >> > >> /local/home/sheep/work/ovmf/MdeModulePkg/Bus/Pci/PciBusDxe/PciIo.c(1789):
> >> > >>  ((BOOLEAN)(0==1))
> >> > >For this one, I've workaround by reverting patch 7b0a1ea
> >> > >(MdeModuelPkg/PciBus: Return AddrTranslationOffset in GetBarAttributes).
> >> > >That issue was introduce while still using the USE_OLD_PCI_HOST.
> >> > >
> >> > >Any idee or pointer on how to fix those issues ?
> >> >
> >> > When the PciRootBridgeIo.Configuration() returns EFI_UNSUPPORTED, this 
> >> > assertion
> >> > can be fixed as well. Correct?
> >>
> >> I tried to make RootBridgeIoConfiguration() return EFI_UNSUPPORTED
> >> (see the attachment), and those asserts were gone. However, the system
> >> stuck somewhere after loading shell.efi. Here are the messages from the
> >> debug log:
> >>
> >> BdsLibConnectAll
> >> Select Item: 0xE
> >> Memory  Previous  Current    Next
> >>  Type    Pages     Pages     Pages
> >> ======  ========  ========  ========
> >>   0A    00000004  00000001  00000004
> >>   09    00000008  00000011  00000015
> >>   00    00000004  00000001  00000004
> >>   06    00000024  00000057  0000006C
> >>   05    00000030  00000063  0000007B
> >>   03    00000180  0000048D  000005B0
> >>   04    00000F00  00000B65  00000F00
> >> Booting EFI Internal Shell
> >> InstallProtocolInterface: 5B1B31A1-9562-11D2-8E3F-00A0C969723B 3EA580C0
> >> Loading driver at 0x0003E03F000 EntryPoint=0x0003E03F240 Shell.efi
> >> InstallProtocolInterface: BC62157E-3E33-4FEC-9920-2D3B36D750DF 3EA58B98
> >> InstallProtocolInterface: 387477C2-69C7-11D2-8E39-00A0C969723B 3EA54320
> >> InstallProtocolInterface: 752F3136-4E16-4FDC-A22A-E5F46812F4CA 3EA53CD8
> >> InstallProtocolInterface: 6302D008-7F9B-4F30-87AC-60C9FEF5DA4E 3E16B580
> >>
> >> I couldn't find out where it stuck unless there is a way to attach gdb
> >> to Xen HVM for source level debugging :-(
> >>
> >> Thanks,
> >>
> >> Gary Lin
> >> _______________________________________________
> >> edk2-devel mailing list
> >> edk2-devel@xxxxxxxxxxxx
> >> https://lists.01.org/mailman/listinfo/edk2-devel
> >>
> _______________________________________________
> edk2-devel mailing list
> edk2-devel@xxxxxxxxxxxx
> https://lists.01.org/mailman/listinfo/edk2-devel
> 

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