Re: [PATCH v2 2/3] KVM: VMX: Rename {vmx,nested_vmx}_vcpu_setup() and minor cleanup

[Xiaoyao Li <xiaoyao.li@intel.com>]

On 10/19/2019 1:09 AM, Sean Christopherson wrote:
> On Fri, Oct 18, 2019 at 05:37:22PM +0800, Xiaoyao Li wrote:
>> Rename {vmx,nested_vmx}_vcpu_setup() to {vmx,nested_vmx}_vmcs_setup,
>> to match what they really do.
>>
>> Aslo remove the vmcs unrelated codes to vmx_vcpu_create().
> 
> Do this in a separate patch, just in case there is a dependencies we're
> missing.
> 
>> The initialization of vmx->hv_deadline_tsc can be removed here, because
>> it will be called in vmx_vcpu_reset() as the flow:
>>
>> kvm_arch_vcpu_setup()
>>    -> kvm_vcpu_reset()
>>         -> vmx_vcpu_reset()
> 
> Definitely needs to be in a separate patch.
> 

OK, I'll split it into 3 patches.

>>
>> Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
>> ---
>> Changes in v2:
>>    - move out the vmcs unrelated codes
>> ---
>>   arch/x86/kvm/vmx/nested.c |  2 +-
>>   arch/x86/kvm/vmx/nested.h |  2 +-
>>   arch/x86/kvm/vmx/vmx.c    | 45 +++++++++++++++++----------------------
>>   3 files changed, 22 insertions(+), 27 deletions(-)
>>
>> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
>> index 5e231da00310..7935422d311f 100644
>> --- a/arch/x86/kvm/vmx/nested.c
>> +++ b/arch/x86/kvm/vmx/nested.c
>> @@ -5768,7 +5768,7 @@ static int vmx_set_nested_state(struct kvm_vcpu *vcpu,
>>   	return ret;
>>   }
>>   
>> -void nested_vmx_vcpu_setup(void)
>> +void nested_vmx_vmcs_setup(void)
> 
> "vmcs_setup" sounds like we're allocating and loading a VMCS.  Maybe
> {nested_,}vmx_set_initial_vmcs_state() a la vmx_set_constant_host_state()?
> 
>>   {
>>   	if (enable_shadow_vmcs) {
>>   		vmcs_write64(VMREAD_BITMAP, __pa(vmx_vmread_bitmap));
>> diff --git a/arch/x86/kvm/vmx/nested.h b/arch/x86/kvm/vmx/nested.h
>> index 187d39bf0bf1..2be1ba7482c9 100644
>> --- a/arch/x86/kvm/vmx/nested.h
>> +++ b/arch/x86/kvm/vmx/nested.h
>> @@ -11,7 +11,7 @@ void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps,
>>   				bool apicv);
>>   void nested_vmx_hardware_unsetup(void);
>>   __init int nested_vmx_hardware_setup(int (*exit_handlers[])(struct kvm_vcpu *));
>> -void nested_vmx_vcpu_setup(void);
>> +void nested_vmx_vmcs_setup(void);
>>   void nested_vmx_free_vcpu(struct kvm_vcpu *vcpu);
>>   int nested_vmx_enter_non_root_mode(struct kvm_vcpu *vcpu, bool from_vmentry);
>>   bool nested_vmx_exit_reflected(struct kvm_vcpu *vcpu, u32 exit_reason);
>> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
>> index ef567df344bf..b083316a598d 100644
>> --- a/arch/x86/kvm/vmx/vmx.c
>> +++ b/arch/x86/kvm/vmx/vmx.c
>> @@ -4161,15 +4161,10 @@ static void ept_set_mmio_spte_mask(void)
>>   
>>   #define VMX_XSS_EXIT_BITMAP 0
>>   
>> -/*
>> - * Sets up the vmcs for emulated real mode.
>> - */
>> -static void vmx_vcpu_setup(struct vcpu_vmx *vmx)
>> +static void vmx_vmcs_setup(struct vcpu_vmx *vmx)
>>   {
>> -	int i;
>> -
>>   	if (nested)
>> -		nested_vmx_vcpu_setup();
>> +		nested_vmx_vmcs_setup();
>>   
>>   	if (cpu_has_vmx_msr_bitmap())
>>   		vmcs_write64(MSR_BITMAP, __pa(vmx->vmcs01.msr_bitmap));
>> @@ -4178,7 +4173,6 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx)
>>   
>>   	/* Control */
>>   	pin_controls_set(vmx, vmx_pin_based_exec_ctrl(vmx));
>> -	vmx->hv_deadline_tsc = -1;
>>   
>>   	exec_controls_set(vmx, vmx_exec_control(vmx));
>>   
>> @@ -4227,21 +4221,6 @@ static void vmx_vcpu_setup(struct vcpu_vmx *vmx)
>>   	if (vmcs_config.vmentry_ctrl & VM_ENTRY_LOAD_IA32_PAT)
>>   		vmcs_write64(GUEST_IA32_PAT, vmx->vcpu.arch.pat);
>>   
>> -	for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i) {
>> -		u32 index = vmx_msr_index[i];
>> -		u32 data_low, data_high;
>> -		int j = vmx->nmsrs;
>> -
>> -		if (rdmsr_safe(index, &data_low, &data_high) < 0)
>> -			continue;
>> -		if (wrmsr_safe(index, data_low, data_high) < 0)
>> -			continue;
>> -		vmx->guest_msrs[j].index = i;
>> -		vmx->guest_msrs[j].data = 0;
>> -		vmx->guest_msrs[j].mask = -1ull;
>> -		++vmx->nmsrs;
>> -	}
>> -
>>   	vm_exit_controls_set(vmx, vmx_vmexit_ctrl());
>>   
>>   	/* 22.2.1, 20.8.1 */
>> @@ -6710,7 +6689,7 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
>>   	int err;
>>   	struct vcpu_vmx *vmx;
>>   	unsigned long *msr_bitmap;
>> -	int cpu;
>> +	int i, cpu;
>>   
>>   	BUILD_BUG_ON_MSG(offsetof(struct vcpu_vmx, vcpu) != 0,
>>   		"struct kvm_vcpu must be at offset 0 for arch usercopy region");
>> @@ -6786,9 +6765,25 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
>>   	cpu = get_cpu();
>>   	vmx_vcpu_load(&vmx->vcpu, cpu);
>>   	vmx->vcpu.cpu = cpu;
>> -	vmx_vcpu_setup(vmx);
>> +	vmx_vmcs_setup(vmx);
>>   	vmx_vcpu_put(&vmx->vcpu);
>>   	put_cpu();
>> +
>> +	for (i = 0; i < ARRAY_SIZE(vmx_msr_index); ++i) {
>> +		u32 index = vmx_msr_index[i];
>> +		u32 data_low, data_high;
>> +		int j = vmx->nmsrs;
>> +
>> +		if (rdmsr_safe(index, &data_low, &data_high) < 0)
>> +			continue;
>> +		if (wrmsr_safe(index, data_low, data_high) < 0)
>> +			continue;
>> +		vmx->guest_msrs[j].index = i;
>> +		vmx->guest_msrs[j].data = 0;
>> +		vmx->guest_msrs[j].mask = -1ull;
>> +		++vmx->nmsrs;
>> +	}
> 
> I'd put this immediately after guest_msrs is allocated.  Yeah, we'll waste
> a few cycles if allocating vmcs01 fails, but that should be a very rare
> event.
> 

OK.

>> +
>>   	if (cpu_need_virtualize_apic_accesses(&vmx->vcpu)) {
>>   		err = alloc_apic_access_page(kvm);
>>   		if (err)
>> -- 
>> 2.19.1
>>