> diff --git a/arch/x86/include/asm/trap_pf.h b/arch/x86/include/asm/trap_pf.h
> index 10b1de500ab1..107f9d947e8d 100644
> --- a/arch/x86/include/asm/trap_pf.h
> +++ b/arch/x86/include/asm/trap_pf.h
> @@ -12,6 +12,7 @@
> * bit 4 == 1: fault was an instruction fetch
> * bit 5 == 1: protection keys block access
> * bit 15 == 1: SGX MMU page-fault
> + * bit 31 == 1: fault was an RMP violation
> */
> enum x86_pf_error_code {
> X86_PF_PROT = 1 << 0,
> @@ -21,6 +22,7 @@ enum x86_pf_error_code {
> X86_PF_INSTR = 1 << 4,
> X86_PF_PK = 1 << 5,
> X86_PF_SGX = 1 << 15,
> + X86_PF_RMP = 1ull << 31,
> };
Man, I hope AMD and Intel are talking to each other about these bits. :)
Either way, this is hitting the limits of what I know about how enums
are implemented. I had internalized that they are just an 'int', but
that doesn't seem quite right. It sounds like they must be implemented
using *an* integer type, but not necessarily 'int' itself.
Either way, '1<<31' doesn't fit in a 32-bit signed int. But, gcc at
least doesn't seem to blow the enum up into a 64-bit type, which is nice.
Could we at least start declaring these with BIT()?
On 3/24/21 1:03 PM, Dave Hansen wrote:
>> diff --git a/arch/x86/include/asm/trap_pf.h b/arch/x86/include/asm/trap_pf.h
>> index 10b1de500ab1..107f9d947e8d 100644
>> --- a/arch/x86/include/asm/trap_pf.h
>> +++ b/arch/x86/include/asm/trap_pf.h
>> @@ -12,6 +12,7 @@
>> * bit 4 == 1: fault was an instruction fetch
>> * bit 5 == 1: protection keys block access
>> * bit 15 == 1: SGX MMU page-fault
>> + * bit 31 == 1: fault was an RMP violation
>> */
>> enum x86_pf_error_code {
>> X86_PF_PROT = 1 << 0,
>> @@ -21,6 +22,7 @@ enum x86_pf_error_code {
>> X86_PF_INSTR = 1 << 4,
>> X86_PF_PK = 1 << 5,
>> X86_PF_SGX = 1 << 15,
>> + X86_PF_RMP = 1ull << 31,
>> };
> Man, I hope AMD and Intel are talking to each other about these bits. :)
>
> Either way, this is hitting the limits of what I know about how enums
> are implemented. I had internalized that they are just an 'int', but
> that doesn't seem quite right. It sounds like they must be implemented
> using *an* integer type, but not necessarily 'int' itself.
>
> Either way, '1<<31' doesn't fit in a 32-bit signed int. But, gcc at
> least doesn't seem to blow the enum up into a 64-bit type, which is nice.
>
> Could we at least start declaring these with BIT()?
Sure, I can bit the BIT() macro to define the bits. Do you want me to
update all of the fault codes to use BIT() or just the one I am adding
in this patch ?
On 3/25/21 7:32 AM, Brijesh Singh wrote:
>>> enum x86_pf_error_code {
>>> X86_PF_PROT = 1 << 0,
>>> @@ -21,6 +22,7 @@ enum x86_pf_error_code {
>>> X86_PF_INSTR = 1 << 4,
>>> X86_PF_PK = 1 << 5,
>>> X86_PF_SGX = 1 << 15,
>>> + X86_PF_RMP = 1ull << 31,
>>> };
...
>> Could we at least start declaring these with BIT()?
>
> Sure, I can bit the BIT() macro to define the bits. Do you want me to
> update all of the fault codes to use BIT() or just the one I am adding
> in this patch ?
Please update all of them for consistency.