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

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

Regards,
Ray

>-----Original Message-----
>From: Gary Lin [mailto:glin@suse.com]
>Sent: Wednesday, April 27, 2016 12:29 PM
>To: Ni, Ruiyu <ruiyu.ni@intel.com>
>Cc: edk2-devel@lists.01.org; Xen Devel <xen-devel@lists.xen.org>
>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.

>
>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@suse.com]
>> >Sent: Tuesday, April 26, 2016 4:40 PM
>> >To: Ni, Ruiyu <ruiyu.ni@intel.com>
>> >Cc: edk2-devel@lists.01.org; Xen Devel <xen-devel@lists.xen.org>
>> >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@suse.com]
>> >> Sent: Tuesday, April 26, 2016 3:35 PM
>> >> To: Ni, Ruiyu <ruiyu.ni@intel.com>
>> >> Cc: Anthony PERARD <anthony.perard@citrix.com>; edk2-devel@lists.01.org; Xen Devel <xen-devel@lists.xen.org>
>> >> 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@lists.01.org] On Behalf Of Anthony PERARD
>> >> > >Sent: Friday, April 22, 2016 10:48 PM
>> >> > >To: edk2-devel@lists.01.org<mailto:edk2-devel@lists.01.org>
>> >> > >Cc: Xen Devel <xen-devel@lists.xen.org<mailto:xen-devel@lists.xen.org>>
>> >> > >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
>> >> _______________________________________________
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>> >> edk2-devel@lists.01.org
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>> >>
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