Re: [PATCH 1/2] x86/vmx: Calculate model-specific LBRs once at start of day

[Andrew Cooper <Andrew.Cooper3@xxxxxxxxxx>]

On 10/01/2023 4:26 pm, Jan Beulich wrote:
> On 09.01.2023 13:08, Andrew Cooper wrote:
>> There is no point repeating this calculation at runtime, especially as it is
>> in the fallback path of the WRSMR/RDMSR handlers.
>>
>> Move the infrastructure higher in vmx.c to avoid forward declarations,
>> renaming last_branch_msr_get() to get_model_specific_lbr() to highlight that
>> these are model-specific only.
>>
>> No practical change.
>>
>> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
> with one nit:
>
>> --- a/xen/arch/x86/hvm/vmx/vmx.c
>> +++ b/xen/arch/x86/hvm/vmx/vmx.c
>> @@ -396,6 +396,142 @@ void vmx_pi_hooks_deassign(struct domain *d)
>>      domain_unpause(d);
>>  }
>>  
>> +static const struct lbr_info {
>> +    u32 base, count;
>> +} p4_lbr[] = {
>> +    { MSR_P4_LER_FROM_LIP,          1 },
>> +    { MSR_P4_LER_TO_LIP,            1 },
>> +    { MSR_P4_LASTBRANCH_TOS,        1 },
>> +    { MSR_P4_LASTBRANCH_0_FROM_LIP, NUM_MSR_P4_LASTBRANCH_FROM_TO },
>> +    { MSR_P4_LASTBRANCH_0_TO_LIP,   NUM_MSR_P4_LASTBRANCH_FROM_TO },
>> +    { 0, 0 }
>> +}, c2_lbr[] = {
>> +    { MSR_IA32_LASTINTFROMIP,       1 },
>> +    { MSR_IA32_LASTINTTOIP,         1 },
>> +    { MSR_C2_LASTBRANCH_TOS,        1 },
>> +    { MSR_C2_LASTBRANCH_0_FROM_IP,  NUM_MSR_C2_LASTBRANCH_FROM_TO },
>> +    { MSR_C2_LASTBRANCH_0_TO_IP,    NUM_MSR_C2_LASTBRANCH_FROM_TO },
>> +    { 0, 0 }
>> +}, nh_lbr[] = {
>> +    { MSR_IA32_LASTINTFROMIP,       1 },
>> +    { MSR_IA32_LASTINTTOIP,         1 },
>> +    { MSR_NHL_LBR_SELECT,           1 },
>> +    { MSR_NHL_LASTBRANCH_TOS,       1 },
>> +    { MSR_P4_LASTBRANCH_0_FROM_LIP, NUM_MSR_P4_LASTBRANCH_FROM_TO },
>> +    { MSR_P4_LASTBRANCH_0_TO_LIP,   NUM_MSR_P4_LASTBRANCH_FROM_TO },
>> +    { 0, 0 }
>> +}, sk_lbr[] = {
>> +    { MSR_IA32_LASTINTFROMIP,       1 },
>> +    { MSR_IA32_LASTINTTOIP,         1 },
>> +    { MSR_NHL_LBR_SELECT,           1 },
>> +    { MSR_NHL_LASTBRANCH_TOS,       1 },
>> +    { MSR_SKL_LASTBRANCH_0_FROM_IP, NUM_MSR_SKL_LASTBRANCH },
>> +    { MSR_SKL_LASTBRANCH_0_TO_IP,   NUM_MSR_SKL_LASTBRANCH },
>> +    { MSR_SKL_LASTBRANCH_0_INFO,    NUM_MSR_SKL_LASTBRANCH },
>> +    { 0, 0 }
>> +}, at_lbr[] = {
>> +    { MSR_IA32_LASTINTFROMIP,       1 },
>> +    { MSR_IA32_LASTINTTOIP,         1 },
>> +    { MSR_C2_LASTBRANCH_TOS,        1 },
>> +    { MSR_C2_LASTBRANCH_0_FROM_IP,  NUM_MSR_ATOM_LASTBRANCH_FROM_TO },
>> +    { MSR_C2_LASTBRANCH_0_TO_IP,    NUM_MSR_ATOM_LASTBRANCH_FROM_TO },
>> +    { 0, 0 }
>> +}, sm_lbr[] = {
>> +    { MSR_IA32_LASTINTFROMIP,       1 },
>> +    { MSR_IA32_LASTINTTOIP,         1 },
>> +    { MSR_SM_LBR_SELECT,            1 },
>> +    { MSR_SM_LASTBRANCH_TOS,        1 },
>> +    { MSR_C2_LASTBRANCH_0_FROM_IP,  NUM_MSR_ATOM_LASTBRANCH_FROM_TO },
>> +    { MSR_C2_LASTBRANCH_0_TO_IP,    NUM_MSR_ATOM_LASTBRANCH_FROM_TO },
>> +    { 0, 0 }
>> +}, gm_lbr[] = {
>> +    { MSR_IA32_LASTINTFROMIP,       1 },
>> +    { MSR_IA32_LASTINTTOIP,         1 },
>> +    { MSR_SM_LBR_SELECT,            1 },
>> +    { MSR_SM_LASTBRANCH_TOS,        1 },
>> +    { MSR_GM_LASTBRANCH_0_FROM_IP,  NUM_MSR_GM_LASTBRANCH_FROM_TO },
>> +    { MSR_GM_LASTBRANCH_0_TO_IP,    NUM_MSR_GM_LASTBRANCH_FROM_TO },
>> +    { 0, 0 }
>> +};
>> +static const struct lbr_info * __ro_after_init model_specific_lbr;
>> +
>> +static const struct __init lbr_info *get_model_specific_lbr(void)
> Please move __init:
>
> static const struct lbr_info *__init get_model_specific_lbr(void)

Yeah, I noticed and fixed both style errors here.  Also an extraneous
space before __ro_after_init.

~Andrew