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Message-ID: <78f8ff04c20c45525321247336e16d06063e57d0.camel@redhat.com>
Subject: Re: [RFC 19/33] KVM: x86: Decouple
 kvm_range_has_memory_attributes() from struct kvm's mem_attr_array
From:   Maxim Levitsky <mlevitsk@redhat.com>
To:     Nicolas Saenz Julienne <nsaenz@amazon.com>, kvm@vger.kernel.org
Cc:     linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org,
        pbonzini@redhat.com, seanjc@google.com, vkuznets@redhat.com,
        anelkz@amazon.com, graf@amazon.com, dwmw@amazon.co.uk,
        jgowans@amazon.com, corbert@lwn.net, kys@microsoft.com,
        haiyangz@microsoft.com, decui@microsoft.com, x86@kernel.org,
        linux-doc@vger.kernel.org
Date:   Tue, 28 Nov 2023 09:42:38 +0200
In-Reply-To: <20231108111806.92604-20-nsaenz@amazon.com>
References: <20231108111806.92604-1-nsaenz@amazon.com>
         <20231108111806.92604-20-nsaenz@amazon.com>
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On Wed, 2023-11-08 at 11:17 +0000, Nicolas Saenz Julienne wrote:
> Decouple kvm_range_has_memory_attributes() from struct kvm's
> mem_attr_array to allow other memory attribute sources to use the
> function.
> 
> Signed-off-by: Nicolas Saenz Julienne <nsaenz@amazon.com>
> ---
>  arch/x86/kvm/mmu/mmu.c   | 3 ++-
>  include/linux/kvm_host.h | 4 ++--
>  virt/kvm/kvm_main.c      | 9 +++++----
>  3 files changed, 9 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 96421234ca88..4ace2f8660b0 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -7297,7 +7297,8 @@ static bool hugepage_has_attrs(struct kvm *kvm, struct kvm_memory_slot *slot,
>  	const unsigned long end = start + KVM_PAGES_PER_HPAGE(level);
>  
>  	if (level == PG_LEVEL_2M)
> -		return kvm_range_has_memory_attributes(kvm, start, end, attrs);
> +		return kvm_range_has_memory_attributes(&kvm->mem_attr_array,
> +						       start, end, attrs);
>  
>  	for (gfn = start; gfn < end; gfn += KVM_PAGES_PER_HPAGE(level - 1)) {
>  		if (hugepage_test_mixed(slot, gfn, level - 1) ||
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 4242588e3dfb..32cf05637647 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -2391,8 +2391,8 @@ kvm_get_memory_attributes(struct xarray *mem_attr_array, gfn_t gfn)
>  	return xa_to_value(xa_load(mem_attr_array, gfn));
>  }
>  
> -bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end,
> -				     unsigned long attrs);
> +bool kvm_range_has_memory_attributes(struct xarray *mem_attr_array, gfn_t start,
> +				     gfn_t end, unsigned long attrs);
>  bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm,
>  					struct kvm_gfn_range *range);
>  bool kvm_arch_post_set_memory_attributes(struct kvm *kvm,
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index fde004a0ac46..6bb23eaf7aa6 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -2440,10 +2440,10 @@ static int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm,
>   * Returns true if _all_ gfns in the range [@start, @end) have attributes
>   * matching @attrs.
>   */
> -bool kvm_range_has_memory_attributes(struct kvm *kvm, gfn_t start, gfn_t end,
> -				     unsigned long attrs)
> +bool kvm_range_has_memory_attributes(struct xarray *mem_attr_array, gfn_t start,
> +				     gfn_t end, unsigned long attrs)
>  {
> -	XA_STATE(xas, &kvm->mem_attr_array, start);
> +	XA_STATE(xas, mem_attr_array, start);
>  	unsigned long index;
>  	bool has_attrs;
>  	void *entry;
> @@ -2582,7 +2582,8 @@ static int kvm_vm_set_mem_attributes(struct kvm *kvm, gfn_t start, gfn_t end,
>  	mutex_lock(&kvm->slots_lock);
>  
>  	/* Nothing to do if the entire range as the desired attributes. */
> -	if (kvm_range_has_memory_attributes(kvm, start, end, attributes))
> +	if (kvm_range_has_memory_attributes(&kvm->mem_attr_array, start, end,
> +					    attributes))
>  		goto out_unlock;
>  
>  	/*


Same comments as for previous patch + how about 
'kvm_gfn_range_has_memory_attributes'

(I didn't review the memfd patch series and it shows :( )

Best regards,
	Maxim Levitsky