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

[Sean Christopherson <sean.j.christopherson@intel.com>]

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.

> 
> 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.

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