Re: [PATCH 4/4] KVM: x86/mmu: Make .write_log_dirty a nested operation

[Paolo Bonzini]

On 22/06/20 23:58, Sean Christopherson wrote:
> Move .write_log_dirty() into kvm_x86_nested_ops to help differentiate it
> from the non-nested dirty log hooks.  And because it's a nested-only
> operation.
> 
> Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
> ---
>  arch/x86/include/asm/kvm_host.h |  2 +-
>  arch/x86/kvm/mmu/paging_tmpl.h  |  2 +-
>  arch/x86/kvm/vmx/nested.c       | 38 +++++++++++++++++++++++++++++++++
>  arch/x86/kvm/vmx/vmx.c          | 38 ---------------------------------
>  4 files changed, 40 insertions(+), 40 deletions(-)
> 
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 446ea70a554d..4e6219cb3933 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -1220,7 +1220,6 @@ struct kvm_x86_ops {
>  	void (*enable_log_dirty_pt_masked)(struct kvm *kvm,
>  					   struct kvm_memory_slot *slot,
>  					   gfn_t offset, unsigned long mask);
> -	int (*write_log_dirty)(struct kvm_vcpu *vcpu, gpa_t l2_gpa);
>  
>  	/* pmu operations of sub-arch */
>  	const struct kvm_pmu_ops *pmu_ops;
> @@ -1281,6 +1280,7 @@ struct kvm_x86_nested_ops {
>  			 struct kvm_nested_state __user *user_kvm_nested_state,
>  			 struct kvm_nested_state *kvm_state);
>  	bool (*get_vmcs12_pages)(struct kvm_vcpu *vcpu);
> +	int (*write_log_dirty)(struct kvm_vcpu *vcpu, gpa_t l2_gpa);
>  
>  	int (*enable_evmcs)(struct kvm_vcpu *vcpu,
>  			    uint16_t *vmcs_version);
> diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
> index 60e7b2308876..c733196fd45b 100644
> --- a/arch/x86/kvm/mmu/paging_tmpl.h
> +++ b/arch/x86/kvm/mmu/paging_tmpl.h
> @@ -260,7 +260,7 @@ static int FNAME(update_accessed_dirty_bits)(struct kvm_vcpu *vcpu,
>  				!(pte & PT_GUEST_DIRTY_MASK)) {
>  			trace_kvm_mmu_set_dirty_bit(table_gfn, index, sizeof(pte));
>  #if PTTYPE == PTTYPE_EPT
> -			if (kvm_x86_ops.write_log_dirty(vcpu, addr))
> +			if (kvm_x86_ops.nested_ops->write_log_dirty(vcpu, addr))
>  				return -EINVAL;
>  #endif
>  			pte |= PT_GUEST_DIRTY_MASK;
> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> index adb11b504d5c..db9abcbeefd1 100644
> --- a/arch/x86/kvm/vmx/nested.c
> +++ b/arch/x86/kvm/vmx/nested.c
> @@ -3205,6 +3205,43 @@ static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu)
>  	return true;
>  }
>  
> +static int nested_vmx_write_pml_buffer(struct kvm_vcpu *vcpu, gpa_t gpa)
> +{
> +	struct vmcs12 *vmcs12;
> +	struct vcpu_vmx *vmx = to_vmx(vcpu);
> +	gpa_t dst;
> +
> +	if (WARN_ON_ONCE(!is_guest_mode(vcpu)))
> +		return 0;
> +
> +	if (WARN_ON_ONCE(vmx->nested.pml_full))
> +		return 1;
> +
> +	/*
> +	 * Check if PML is enabled for the nested guest. Whether eptp bit 6 is
> +	 * set is already checked as part of A/D emulation.
> +	 */
> +	vmcs12 = get_vmcs12(vcpu);
> +	if (!nested_cpu_has_pml(vmcs12))
> +		return 0;
> +
> +	if (vmcs12->guest_pml_index >= PML_ENTITY_NUM) {
> +		vmx->nested.pml_full = true;
> +		return 1;
> +	}
> +
> +	gpa &= ~0xFFFull;
> +	dst = vmcs12->pml_address + sizeof(u64) * vmcs12->guest_pml_index;
> +
> +	if (kvm_write_guest_page(vcpu->kvm, gpa_to_gfn(dst), &gpa,
> +				 offset_in_page(dst), sizeof(gpa)))
> +		return 0;
> +
> +	vmcs12->guest_pml_index--;
> +
> +	return 0;
> +}
> +
>  /*
>   * Intel's VMX Instruction Reference specifies a common set of prerequisites
>   * for running VMX instructions (except VMXON, whose prerequisites are
> @@ -6503,6 +6540,7 @@ struct kvm_x86_nested_ops vmx_nested_ops = {
>  	.get_state = vmx_get_nested_state,
>  	.set_state = vmx_set_nested_state,
>  	.get_vmcs12_pages = nested_get_vmcs12_pages,
> +	.write_log_dirty = nested_vmx_write_pml_buffer,
>  	.enable_evmcs = nested_enable_evmcs,
>  	.get_evmcs_version = nested_get_evmcs_version,
>  };
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index adf83047bb21..8bf06a59f356 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -7501,43 +7501,6 @@ static void vmx_flush_log_dirty(struct kvm *kvm)
>  	kvm_flush_pml_buffers(kvm);
>  }
>  
> -static int vmx_write_pml_buffer(struct kvm_vcpu *vcpu, gpa_t gpa)
> -{
> -	struct vmcs12 *vmcs12;
> -	struct vcpu_vmx *vmx = to_vmx(vcpu);
> -	gpa_t dst;
> -
> -	if (WARN_ON_ONCE(!is_guest_mode(vcpu)))
> -		return 0;
> -
> -	if (WARN_ON_ONCE(vmx->nested.pml_full))
> -		return 1;
> -
> -	/*
> -	 * Check if PML is enabled for the nested guest. Whether eptp bit 6 is
> -	 * set is already checked as part of A/D emulation.
> -	 */
> -	vmcs12 = get_vmcs12(vcpu);
> -	if (!nested_cpu_has_pml(vmcs12))
> -		return 0;
> -
> -	if (vmcs12->guest_pml_index >= PML_ENTITY_NUM) {
> -		vmx->nested.pml_full = true;
> -		return 1;
> -	}
> -
> -	gpa &= ~0xFFFull;
> -	dst = vmcs12->pml_address + sizeof(u64) * vmcs12->guest_pml_index;
> -
> -	if (kvm_write_guest_page(vcpu->kvm, gpa_to_gfn(dst), &gpa,
> -				 offset_in_page(dst), sizeof(gpa)))
> -		return 0;
> -
> -	vmcs12->guest_pml_index--;
> -
> -	return 0;
> -}
> -
>  static void vmx_enable_log_dirty_pt_masked(struct kvm *kvm,
>  					   struct kvm_memory_slot *memslot,
>  					   gfn_t offset, unsigned long mask)
> @@ -7966,7 +7929,6 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
>  	.slot_disable_log_dirty = vmx_slot_disable_log_dirty,
>  	.flush_log_dirty = vmx_flush_log_dirty,
>  	.enable_log_dirty_pt_masked = vmx_enable_log_dirty_pt_masked,
> -	.write_log_dirty = vmx_write_pml_buffer,
>  
>  	.pre_block = vmx_pre_block,
>  	.post_block = vmx_post_block,
> 

Queued, thanks (patch 1 for 5.8).

Paolo