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

["Ni, Ruiyu" <ruiyu.ni@xxxxxxxxx>]

Gary,
Thanks for the try.

I now understand why the issue happens.
1. PciEnumeratorLight() depends on the MinBus returned from
PciRootBridgeIo.Configuration().
2. PciRootBridgeIo.Configuration() returns the resource descriptors
initialized by PciHostBridge.NotifyPhase(EfiPciHostBridgeAllocateResources).
3. PciHostBridge.NotifyPhase(EfiPciHostBridgeAllocateResources)
is not called when PcdPciDisableBusEnumeration is TRUE

I am thinking about let PciRootBridgeIo.Configuration() returns
the correct resource consumption information even when
PcdPciDisableBusEnumeration is TRUE.

I can add a new field to PCI_ROOT_BRIDGE structure defined in
MdeModulePkg/Include/Library/PciHostBridgeLib.h to indicate
that the resources filled in PCI_ROOT_BRIDGE.Bus/Io/Mem/
MemAbove4G/PMem/PMemAbove4G are already assigned
to PCI bus. So that PciRootBridgeIo.Configuration() can return
these value even when
PciHostBridge.NotifyPhase(EfiPciHostBridgeAllocateResources)
is not called due to PcdPciDisableBusEnumeration is TRUE. 

Do you know whether Xen passes the PCI device resource
information to firmware?

Copying Laszlo.

Regards,
Ray

>-----Original Message-----
>From: Gary Lin [mailto:glin@xxxxxxxx]
>Sent: Wednesday, April 27, 2016 4:27 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 Wed, Apr 27, 2016 at 07:18:21AM +0000, Ni, Ruiyu wrote:
>> Gary,
>> In PciEnumeratorLight(), please directly assign 0 to MinBus when
>> Configuration() returns error, instead of calling PciGetBusRange() to
>> extract MinBus from the descriptors returned from Configuration().
>>
>OK, I ignored PciGetBusRange() and the check of the return status of
>Configuration(). Since MinBus is already initialized, I don't bother to
>change the value anyway. The change is attached.
>
>And yes, this time the shell showed.
>
>Thanks,
>
>Gary Lin
>
>> Regards,
>> Ray
>>
>> >-----Original Message-----
>> >From: Gary Lin [mailto:glin@xxxxxxxx]
>> >Sent: Wednesday, April 27, 2016 2:54 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 Wed, Apr 27, 2016 at 05:39:40AM +0000, Ni, Ruiyu wrote:
>> >>
>> >>
>> >> Regards,
>> >> Ray
>> >>
>> >> >-----Original Message-----
>> >> >From: Gary Lin [mailto:glin@xxxxxxxx]
>> >> >Sent: Wednesday, April 27, 2016 12:29 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 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() ?
>> >> Keep returning EFI_UNSUPPORTED in Configuration() and set
>> >> MinBus/MaxBus in PciGetBusRange().
>> >>
>> >> >
>> >> >> 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);" ?
>> >>
>> >>
>> >> ASSERT() won't be hit.
>> >>
>> >It didn't work (see my attached patch) :(
>> >BTW, if Configuration() already returns EFI_UNSUPPORTED, then there is
>> >no way to invoke PciGetBusRange(). Besides, MaxBus was never used in
>> >PciEnumeratorLight(), so it's meaningless to assign any value to it.
>> >
>> >Cheers,
>> >
>> >Gary Lin
>> >
>> >> >
>> >> >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
>> >> >>
>> >> _______________________________________________
>> >> edk2-devel mailing list
>> >> edk2-devel@xxxxxxxxxxxx
>> >> https://lists.01.org/mailman/listinfo/edk2-devel
>> >>

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