On 06/01/16 09:51, Gary Lin wrote:
> On Tue, May 31, 2016 at 12:21:45AM -0700, Jordan Justen wrote:
>> On 2016-05-30 20:19:42, Gary Lin wrote:
>>> When OVMF tried to load the file-based NvVars,
>>
>> Tangent: Will Xen ever add a r/w flash emulation for variables like
>> QEMU/KVM?
>>
>>> it checked all the PCI
>>> instances and connected the drivers to the mass storage device. However,
>>> Xen registered its PCI device with a special class id (0xFF80), so
>>> ConnectRecursivelyIfPciMassStorage() couldn't recognize it and skipped the
>>> driver connecting for Xen PCI devices. In the end, the Xen block device
>>> wasn't initialized until EfiBootManagerConnectAll() was called, and it's
>>> already too late to load NvVars.
>>>
>>> This commit connects the Xen drivers in ConnectRecursivelyIfPciMassStorage()
>>> so that Xen can use the file-based NvVars.
>>>
>>> Cc: Jordan Justen <[email protected]>
>>> Cc: Laszlo Ersek <[email protected]>
>>> Contributed-under: TianoCore Contribution Agreement 1.0
>>> Signed-off-by: Gary Lin <[email protected]>
>>> ---
>>> OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c | 12
>>> ++++++++++--
>>> .../PlatformBootManagerLib/PlatformBootManagerLib.inf | 1 +
>>> 2 files changed, 11 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c
>>> b/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c
>>> index befcc57..249b8bc 100644
>>> --- a/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c
>>> +++ b/OvmfPkg/Library/PlatformBootManagerLib/BdsPlatform.c
>>> @@ -1049,8 +1049,15 @@ ConnectRecursivelyIfPciMassStorage (
>>> EFI_STATUS Status;
>>> EFI_DEVICE_PATH_PROTOCOL *DevicePath;
>>> CHAR16 *DevPathStr;
>>> + BOOLEAN IsPciMassStorage;
>>>
>>
>> I don't think the debug message change is worth adding this variable.
>>
>>> - if (IS_CLASS1 (PciHeader, PCI_CLASS_MASS_STORAGE)) {
>>> + IsPciMassStorage = IS_CLASS1 (PciHeader, PCI_CLASS_MASS_STORAGE);
>>> + //
>>> + // Recognize PCI Mass Storage, and Xen PCI devices
>>> + //
>>> + if (IsPciMassStorage ||
>>> + (PcdGetBool (PcdPciDisableBusEnumeration) &&
>>
>> How about instead get XenDetected from OvmfPkg/AcpiPlatformDxe/Xen.c?
>> Then use that rather than PcdPciDisableBusEnumeration?
>>
> I didn't notice that XenDetected is in AcpiPlatformDxe until I started
> to implement the code. Is there any suggested library to move XenDetected
> to? A standalone header/library for the function seems too much but I
> didn't feel it belongs to any existed libraries in OvmfPkg.
I think Jordan meant to copy the XenDetected() function verbatim, from
AcpiPlatformDxe to PlatformBootManagerLib. This function is really small
so it shouldn't be a problem.
Also, since the XenDetected() function looks for a GUID HOB (IIRC),
which performs a linear search in the HOB list, Jordan suggested the
speedup below (with the static variable caching the result of the
search). It is relevant because ConnectRecursivelyIfPciMassStorage() is
called several times.
That's how I understood Jordan anyway.
Thanks,
Laszlo
> Thanks,
>
> Gary Lin
>
>> I think XenDetected could be improved for multiple uses by adding a
>> static INTN:
>>
>> * Initialize to -1, for need to locate HOB
>>
>> * 0 for Xen is not detected
>>
>> * 1 for Xen is detected.
>>
>> -Jordan
>>
>>> + IS_CLASS2 (PciHeader, 0xFF, 0x80))) {
>>> DevicePath = NULL;
>>> Status = gBS->HandleProtocol (
>>> Handle,
>>> @@ -1068,7 +1075,8 @@ ConnectRecursivelyIfPciMassStorage (
>>> if (DevPathStr != NULL) {
>>> DEBUG((
>>> EFI_D_INFO,
>>> - "Found Mass Storage device: %s\n",
>>> + "Found %s device: %s\n",
>>> + IsPciMassStorage ? L"Mass Storage" : L"Xen",
>>> DevPathStr
>>> ));
>>> FreePool(DevPathStr);
>>> diff --git
>>> a/OvmfPkg/Library/PlatformBootManagerLib/PlatformBootManagerLib.inf
>>> b/OvmfPkg/Library/PlatformBootManagerLib/PlatformBootManagerLib.inf
>>> index 5fcee3c..cd28be0 100644
>>> --- a/OvmfPkg/Library/PlatformBootManagerLib/PlatformBootManagerLib.inf
>>> +++ b/OvmfPkg/Library/PlatformBootManagerLib/PlatformBootManagerLib.inf
>>> @@ -62,6 +62,7 @@ [Pcd]
>>> gUefiOvmfPkgTokenSpaceGuid.PcdOvmfHostBridgePciDevId
>>> gEfiMdePkgTokenSpaceGuid.PcdPlatformBootTimeOut
>>> gEfiIntelFrameworkModulePkgTokenSpaceGuid.PcdShellFile
>>> + gEfiMdeModulePkgTokenSpaceGuid.PcdPciDisableBusEnumeration
>>>
>>> [Pcd.IA32, Pcd.X64]
>>> gEfiMdePkgTokenSpaceGuid.PcdFSBClock
>>> --
>>> 2.8.3
>>>
>>
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