[PATCH V2] arm64: KVM: Fix HCR_EL2 and VTCR_EL2 configuration bits

Christopher Covington cov at codeaurora.org
Mon May 13 13:16:51 EDT 2013


On 05/13/2013 12:02 PM, Marc Zyngier wrote:
> On Mon, 13 May 2013 11:23:05 -0400, Christopher Covington
> <cov at codeaurora.org> wrote:
>> Hi Pranavkumar,
>>
>> On 05/10/2013 03:23 AM, Pranavkumar Sawargaonkar wrote:
>>> This patch does following fixes:
>>>
>>> 1. Make HCR_* flags as unsigned long long constants
>>> Reason : By default, compiler assumes numeric constants as
>>> signed hence sign extending it when assigned to unsigned variable
>>> such as hcr_el2 (in VCPU context). This accidently sets HCR_ID and
>>> HCR_CD making entire guest memory non-cacheable. On real HW, this
>>> breaks Stage2 ttbl walks and also breaks VirtIO.
>>>
>>> 2. VTCR_EL2_ORGN0_WBWA and VTCR_EL2_IRGN0_WBWA macros.
>>>
>>> Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar at linaro.org>
>>> Signed-off-by: Anup Patel <anup.patel at linaro.org>
>>> ---
>>>  arch/arm64/include/asm/kvm_arm.h |   73
>>>  +++++++++++++++++++-------------------
>>>  1 file changed, 37 insertions(+), 36 deletions(-)
>>>
>>> diff --git a/arch/arm64/include/asm/kvm_arm.h
>>> b/arch/arm64/include/asm/kvm_arm.h
>>> index 8ced0ca..14ead69 100644
>>> --- a/arch/arm64/include/asm/kvm_arm.h
>>> +++ b/arch/arm64/include/asm/kvm_arm.h
>>> @@ -18,44 +18,45 @@
>>>  #ifndef __ARM64_KVM_ARM_H__
>>>  #define __ARM64_KVM_ARM_H__
>>>  
>>> +#include <linux/const.h>
>>>  #include <asm/types.h>
>>>  
>>>  /* Hyp Configuration Register (HCR) bits */
>>> -#define HCR_ID		(1 << 33)
>>> -#define HCR_CD		(1 << 32)
>>> +#define HCR_ID		(UL(0x1) << 33)
>>> +#define HCR_CD		(UL(0x1) << 32)
>>
>> Consider using the BIT() macro from linux/bitops.h to improve
> readability.
> 
> This would probably cause problems when using these macros from assembly
> code.

It does indeed cause problems. What a shame. How about a quick local
definition, to perhaps be eventually replaced by a more accessible shared
definition?

Christopher

-- 
Employee of Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by the Linux Foundation.



More information about the linux-arm-kernel mailing list