Re: [Xen-devel] [PATCH 01/18] xen/arm: Introduce a helper to get default HCR_EL2 flags

[Wei Chen <Wei.Chen@xxxxxxx>]

Hi Stefano,

On 2017/3/15 8:24, Stefano Stabellini wrote:
> On Mon, 13 Mar 2017, Wei Chen wrote:
>> We want to add HCR_EL2 register to Xen context switch. And each copy
>> of HCR_EL2 in vcpu structure will be initialized with the same set
>> of trap flags as the HCR_EL2 register. We introduce a helper here to
>> represent these flags to be reused easily.
>>
>> Signed-off-by: Wei Chen <Wei.Chen@xxxxxxx>
>> ---
>>  xen/arch/arm/traps.c            | 11 ++++++++---
>>  xen/include/asm-arm/processor.h |  2 ++
>>  2 files changed, 10 insertions(+), 3 deletions(-)
>>
>> diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
>> index 614501f..d343c66 100644
>> --- a/xen/arch/arm/traps.c
>> +++ b/xen/arch/arm/traps.c
>> @@ -115,6 +115,13 @@ static void __init parse_vwfi(const char *s)
>>  }
>>  custom_param("vwfi", parse_vwfi);
>>
>> +register_t get_default_hcr_flags(void)
>> +{
>> +    return  (HCR_PTW|HCR_BSU_INNER|HCR_AMO|HCR_IMO|HCR_FMO|HCR_VM|
>> +             (vwfi != NATIVE ? (HCR_TWI|HCR_TWE) : 0) |
>> +             HCR_TSC|HCR_TAC|HCR_SWIO|HCR_TIDCP|HCR_FB);
>> +}
>
> I haven't finished reading this series yet, but I would make this a
> static inline function if possible
>

I had considered to use static inline before. But it must move the

static enum {
        TRAP,
        NATIVE,
} vwfi;

to the header file at the same time. But get_default_hcr_flags would
not be used frequently. So I thought it didn't have enough value to
change a less relevant code to make this function become static inline.

>
>>  void init_traps(void)
>>  {
>>      /* Setup Hyp vector base */
>> @@ -139,9 +146,7 @@ void init_traps(void)
>>                   CPTR_EL2);
>>
>>      /* Setup hypervisor traps */
>> -    WRITE_SYSREG(HCR_PTW|HCR_BSU_INNER|HCR_AMO|HCR_IMO|HCR_FMO|HCR_VM|
>> -                 (vwfi != NATIVE ? (HCR_TWI|HCR_TWE) : 0) |
>> -                 HCR_TSC|HCR_TAC|HCR_SWIO|HCR_TIDCP|HCR_FB,HCR_EL2);
>> +    WRITE_SYSREG(get_default_hcr_flags(), HCR_EL2);
>>      isb();
>>  }
>>
>> diff --git a/xen/include/asm-arm/processor.h 
>> b/xen/include/asm-arm/processor.h
>> index afc0e9a..4b6338b 100644
>> --- a/xen/include/asm-arm/processor.h
>> +++ b/xen/include/asm-arm/processor.h
>> @@ -708,6 +708,8 @@ int call_smc(register_t function_id, register_t arg0, 
>> register_t arg1,
>>
>>  void do_trap_guest_error(struct cpu_user_regs *regs);
>>
>> +register_t get_default_hcr_flags(void);
>> +
>>  #endif /* __ASSEMBLY__ */
>>  #endif /* __ASM_ARM_PROCESSOR_H */
>>  /*
>> --
>> 2.7.4
>>
>>
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@xxxxxxxxxxxxx
>> https://lists.xen.org/xen-devel
>>
>


-- 
Regards,
Wei Chen

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