Re: [PATCH v9 2/5] arm64: KVM: encapsulate kvm_cpu_context in kvm_host_data

[Suzuki K Poulose <suzuki.poulose@arm.com>]

On 10/01/2019 15:16, Andrew Murray wrote:
> On Thu, Jan 10, 2019 at 11:36:01AM +0000, Suzuki K Poulose wrote:
>> Hi Andrew,
>>
>> On 07/01/2019 14:41, Andrew Murray wrote:
>>> The virt/arm core allocates a kvm_cpu_context_t percpu, at present this is
>>> a typedef to kvm_cpu_context and is used to store host cpu context. The
>>> kvm_cpu_context structure is also used elsewhere to hold vcpu context.
>>> In order to use the percpu to hold additional future host information we
>>> encapsulate kvm_cpu_context in a new structure and rename the typedef and
>>> percpu to match.
>>>
>>> Signed-off-by: Andrew Murray <andrew.murray@arm.com>
>>> ---
>>>    arch/arm/include/asm/kvm_host.h   |  8 ++++++--
>>>    arch/arm64/include/asm/kvm_asm.h  |  4 ++--
>>>    arch/arm64/include/asm/kvm_host.h | 14 +++++++++-----
>>>    arch/arm64/kernel/asm-offsets.c   |  2 +-
>>>    virt/kvm/arm/arm.c                | 12 +++++++-----
>>>    5 files changed, 25 insertions(+), 15 deletions(-)
>>>
>>> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
>>> index 79906ce..71645ba 100644
>>> --- a/arch/arm/include/asm/kvm_host.h
>>> +++ b/arch/arm/include/asm/kvm_host.h
>>> @@ -145,7 +145,11 @@ struct kvm_cpu_context {
>>>    	u32 cp15[NR_CP15_REGS];
>>>    };
>>> -typedef struct kvm_cpu_context kvm_cpu_context_t;
>>> +struct kvm_host_data {
>>> +	struct kvm_cpu_context host_ctxt;
>>> +};
>>> +
>>> +typedef struct kvm_host_data kvm_host_data_t;
>>>    struct kvm_vcpu_arch {
>>>    	struct kvm_cpu_context ctxt;
>>> @@ -163,7 +167,7 @@ struct kvm_vcpu_arch {
>>>    	struct kvm_vcpu_fault_info fault;
>>>    	/* Host FP context */
>>> -	kvm_cpu_context_t *host_cpu_context;
>>> +	struct kvm_cpu_context *host_cpu_context;
>>>    	/* VGIC state */
>>>    	struct vgic_cpu vgic_cpu;
>>> diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
>>> index 102b5a5..6a9bfd4 100644
>>> --- a/arch/arm64/include/asm/kvm_asm.h
>>> +++ b/arch/arm64/include/asm/kvm_asm.h
>>> @@ -102,12 +102,12 @@ extern u32 __init_stage2_translation(void);
>>>    .endm
>>>    .macro get_host_ctxt reg, tmp
>>> -	hyp_adr_this_cpu \reg, kvm_host_cpu_state, \tmp
>>> +	hyp_adr_this_cpu \reg, kvm_host_data, \tmp
>>>    .endm
>>
>> minor nit: We now load "kvm_host_data" instead of the host_ctxt here,
>> even though they both are same. Do we need to make this explicitly load
>> the address of the host_ctxt member to make sure this doesn't break
>> with future changes to the structure ?
>> i.e,
>> 	add	\reg, \reg, #HOST_DATA_CONTEXT
>>
>> Otherwise,
>>
>> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> 
> Thanks for spotting this.
> 
> Are you happy for me to add the Reviewed-by tag if I squash in the following?

Yes, that looks fine to me.

Cheers
Suzuki