Re: [PATCH] OvmfPkg/XenHypercallLib: enable virt extensions for ARM

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

On 16 November 2017 at 21:42, Laszlo Ersek <lersek@redhat.com> wrote:
> On 11/16/17 17:56, Ard Biesheuvel wrote:
>> XenHypercallLib uses the 'hvc' instruction, which is not implemented
>> on all ARMv7 CPUs, and so we need to explicitly specify a CPU that
>> has the virtualization extensions.
>>
>> This override used to be set at the platform level, but this was removed
>> in commit 0d36a219c7bdbb27d775b50837823b2a9928147c
>> ('ArmPlatformPkg/PL031RealTimeClockLib: drop ArmPlatformSysConfigLib
>> reference), under the assumption that all users of the 'hvc' instruction
>> had already been fixed.
>>
>> So fix this for GNU binutils by adding the 'virt' arch extension
>> directive, and for RVCT by setting the --cpu command line option to a
>> CPU that is virt capable.
>>
>> Contributed-under: TianoCore Contribution Agreement 1.1
>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
>> ---
>>  OvmfPkg/Library/XenHypercallLib/Arm/Hypercall.S     | 2 ++
>>  OvmfPkg/Library/XenHypercallLib/XenHypercallLib.inf | 3 +++
>>  2 files changed, 5 insertions(+)
>>
>> diff --git a/OvmfPkg/Library/XenHypercallLib/Arm/Hypercall.S b/OvmfPkg/Library/XenHypercallLib/Arm/Hypercall.S
>> index c12c8658b729..0adf65840a2f 100644
>> --- a/OvmfPkg/Library/XenHypercallLib/Arm/Hypercall.S
>> +++ b/OvmfPkg/Library/XenHypercallLib/Arm/Hypercall.S
>> @@ -16,6 +16,8 @@
>>  #include <IndustryStandard/Xen/arch-arm/xen.h>
>>
>>    .text
>> +  .arch_extension virt
>> +
>>  GCC_ASM_EXPORT(XenHypercall2)
>>
>>  ASM_PFX(XenHypercall2):
>> diff --git a/OvmfPkg/Library/XenHypercallLib/XenHypercallLib.inf b/OvmfPkg/Library/XenHypercallLib/XenHypercallLib.inf
>> index f4503a4b01f4..d268e540feca 100644
>> --- a/OvmfPkg/Library/XenHypercallLib/XenHypercallLib.inf
>> +++ b/OvmfPkg/Library/XenHypercallLib/XenHypercallLib.inf
>> @@ -64,3 +64,6 @@ [LibraryClasses.IA32, LibraryClasses.X64]
>>
>>  [Guids.IA32, Guids.X64]
>>    gEfiXenInfoGuid
>> +
>> +[BuildOptions.ARM]
>> +  RVCT:*_*_ARM_PLATFORM_FLAGS == --cpu Cortex-A15
>>
>
> Acked-by: Laszlo Ersek <lersek@redhat.com>
>

Pushed as 12c6484058a8c5a8751c51eb24e9bb95497649c6