[Devel] [PATCH rh7 v1 05/36] kvm/x86: Use is_64_bit_mode() helper

[Andrey Smetanin]

On 02/16/2016 11:34 AM, Konstantin Khorenko wrote:
> This is a part of
>
> commit a449c7aa51e10c9bde0ea9bee4e682d6d067ebab
> Author: Nadav Amit <namit at cs.technion.ac.il>
> Date:   Wed Jun 18 17:19:24 2014 +0300
>
>      KVM: x86: Hypercall handling does not considers opsize correctly
>
>      Currently, the hypercall handling routine only considers LME as an
> indication
>      to whether the guest uses 32/64-bit mode. This is incosistent with
> hyperv
>      hypercalls handling and against the common sense of considering
> cs.l as well.
>      This patch uses is_64_bit_mode instead of is_long_mode for that
> matter. In
>      addition, the result is masked in respect to the guest execution
> mode. Last, it
>      changes kvm_hv_hypercall to use is_64_bit_mode as well to simplify
> the code.
>
>      Signed-off-by: Nadav Amit <namit at cs.technion.ac.il>
>      Signed-off-by: Paolo Bonzini <pbonzini at redhat.com>
>
> What about other hunks of this commit?
It's not related with Hyper-V SynIC support, so please
skip this patch too. I have tested that all patches can be
applied and compiled without these two:
'[PATCH rh7 v1 02/36] kvm/x86: Vcpu based page access routines usage'
'[PATCH rh7 v1 05/36] kvm/x86: Use is_64_bit_mode() helper'
>
> --
> Best regards,
>
> Konstantin Khorenko,
> Virtuozzo Linux Kernel Team
>
> On 02/10/2016 06:17 PM, Andrey Smetanin wrote:
>> Signed-off-by: Andrey Smetanin <asmetanin at virtuozzo.com>
>> ---
>>   arch/x86/kvm/hyperv.c | 4 +---
>>   1 file changed, 1 insertion(+), 3 deletions(-)
>>
>> diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
>> index 8102d69..a8160d2 100644
>> --- a/arch/x86/kvm/hyperv.c
>> +++ b/arch/x86/kvm/hyperv.c
>> @@ -321,7 +321,6 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
>>       u64 param, ingpa, outgpa, ret;
>>       uint16_t code, rep_idx, rep_cnt, res = HV_STATUS_SUCCESS,
>> rep_done = 0;
>>       bool fast, longmode;
>> -    int cs_db, cs_l;
>>
>>       /*
>>        * hypercall generates UD from non zero cpl and real mode
>> @@ -332,8 +331,7 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
>>           return 0;
>>       }
>>
>> -    kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
>> -    longmode = is_long_mode(vcpu) && cs_l == 1;
>> +    longmode = is_64_bit_mode(vcpu);
>>
>>       if (!longmode) {
>>           param = ((u64)kvm_register_read(vcpu, VCPU_REGS_RDX) << 32) |
>>