Re: [PATCH v10 03/16] KVM: Rename kvm_arch_has_private_mem() to kvm_arch_supports_gmem()

[Shivank Garg <shivankg@amd.com>]

On 5/27/2025 11:32 PM, Fuad Tabba wrote:
> The function kvm_arch_has_private_mem() is used to indicate whether
> guest_memfd is supported by the architecture, which until now implies
> that its private. To decouple guest_memfd support from whether the
> memory is private, rename this function to kvm_arch_supports_gmem().
> 
> Reviewed-by: Gavin Shan <gshan@redhat.com>
> Reviewed-by: Ira Weiny <ira.weiny@intel.com>
> Co-developed-by: David Hildenbrand <david@redhat.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>
> Signed-off-by: Fuad Tabba <tabba@google.com>
> ---
>  arch/x86/include/asm/kvm_host.h | 8 ++++----
>  arch/x86/kvm/mmu/mmu.c          | 8 ++++----
>  include/linux/kvm_host.h        | 6 +++---
>  virt/kvm/kvm_main.c             | 6 +++---
>  4 files changed, 14 insertions(+), 14 deletions(-)
> 
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 52f6f6d08558..4a83fbae7056 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -2254,9 +2254,9 @@ void kvm_configure_mmu(bool enable_tdp, int tdp_forced_root_level,
>  
>  
>  #ifdef CONFIG_KVM_GMEM
> -#define kvm_arch_has_private_mem(kvm) ((kvm)->arch.has_private_mem)
> +#define kvm_arch_supports_gmem(kvm) ((kvm)->arch.has_private_mem)
>  #else
> -#define kvm_arch_has_private_mem(kvm) false
> +#define kvm_arch_supports_gmem(kvm) false
>  #endif
>  
>  #define kvm_arch_has_readonly_mem(kvm) (!(kvm)->arch.has_protected_state)
> @@ -2309,8 +2309,8 @@ enum {
>  #define HF_SMM_INSIDE_NMI_MASK	(1 << 2)
>  
>  # define KVM_MAX_NR_ADDRESS_SPACES	2
> -/* SMM is currently unsupported for guests with private memory. */
> -# define kvm_arch_nr_memslot_as_ids(kvm) (kvm_arch_has_private_mem(kvm) ? 1 : 2)
> +/* SMM is currently unsupported for guests with guest_memfd (esp private) memory. */
> +# define kvm_arch_nr_memslot_as_ids(kvm) (kvm_arch_supports_gmem(kvm) ? 1 : 2)
>  # define kvm_arch_vcpu_memslots_id(vcpu) ((vcpu)->arch.hflags & HF_SMM_MASK ? 1 : 0)
>  # define kvm_memslots_for_spte_role(kvm, role) __kvm_memslots(kvm, (role).smm)
>  #else
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 8d1b632e33d2..b66f1bf24e06 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -4917,7 +4917,7 @@ long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu,
>  	if (r)
>  		return r;
>  
> -	if (kvm_arch_has_private_mem(vcpu->kvm) &&
> +	if (kvm_arch_supports_gmem(vcpu->kvm) &&
>  	    kvm_mem_is_private(vcpu->kvm, gpa_to_gfn(range->gpa)))
>  		error_code |= PFERR_PRIVATE_ACCESS;
>  
> @@ -7705,7 +7705,7 @@ bool kvm_arch_pre_set_memory_attributes(struct kvm *kvm,
>  	 * Zapping SPTEs in this case ensures KVM will reassess whether or not
>  	 * a hugepage can be used for affected ranges.
>  	 */
> -	if (WARN_ON_ONCE(!kvm_arch_has_private_mem(kvm)))
> +	if (WARN_ON_ONCE(!kvm_arch_supports_gmem(kvm)))
>  		return false;
>  
>  	if (WARN_ON_ONCE(range->end <= range->start))
> @@ -7784,7 +7784,7 @@ bool kvm_arch_post_set_memory_attributes(struct kvm *kvm,
>  	 * a range that has PRIVATE GFNs, and conversely converting a range to
>  	 * SHARED may now allow hugepages.
>  	 */
> -	if (WARN_ON_ONCE(!kvm_arch_has_private_mem(kvm)))
> +	if (WARN_ON_ONCE(!kvm_arch_supports_gmem(kvm)))
>  		return false;
>  
>  	/*
> @@ -7840,7 +7840,7 @@ void kvm_mmu_init_memslot_memory_attributes(struct kvm *kvm,
>  {
>  	int level;
>  
> -	if (!kvm_arch_has_private_mem(kvm))
> +	if (!kvm_arch_supports_gmem(kvm))
>  		return;
>  
>  	for (level = PG_LEVEL_2M; level <= KVM_MAX_HUGEPAGE_LEVEL; level++) {
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 7ca23837fa52..6ca7279520cf 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -719,11 +719,11 @@ static inline int kvm_arch_vcpu_memslots_id(struct kvm_vcpu *vcpu)
>  #endif
>  
>  /*
> - * Arch code must define kvm_arch_has_private_mem if support for private memory
> + * Arch code must define kvm_arch_supports_gmem if support for guest_memfd
>   * is enabled.
>   */
> -#if !defined(kvm_arch_has_private_mem) && !IS_ENABLED(CONFIG_KVM_GMEM)
> -static inline bool kvm_arch_has_private_mem(struct kvm *kvm)
> +#if !defined(kvm_arch_supports_gmem) && !IS_ENABLED(CONFIG_KVM_GMEM)
> +static inline bool kvm_arch_supports_gmem(struct kvm *kvm)
>  {
>  	return false;
>  }
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 4996cac41a8f..2468d50a9ed4 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -1531,7 +1531,7 @@ static int check_memory_region_flags(struct kvm *kvm,
>  {
>  	u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES;
>  
> -	if (kvm_arch_has_private_mem(kvm))
> +	if (kvm_arch_supports_gmem(kvm))
>  		valid_flags |= KVM_MEM_GUEST_MEMFD;
>  
>  	/* Dirty logging private memory is not currently supported. */
> @@ -2362,7 +2362,7 @@ static int kvm_vm_ioctl_clear_dirty_log(struct kvm *kvm,
>  #ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES
>  static u64 kvm_supported_mem_attributes(struct kvm *kvm)
>  {
> -	if (!kvm || kvm_arch_has_private_mem(kvm))
> +	if (!kvm || kvm_arch_supports_gmem(kvm))
>  		return KVM_MEMORY_ATTRIBUTE_PRIVATE;
>  
>  	return 0;
> @@ -4844,7 +4844,7 @@ static int kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
>  #endif
>  #ifdef CONFIG_KVM_GMEM
>  	case KVM_CAP_GUEST_MEMFD:
> -		return !kvm || kvm_arch_has_private_mem(kvm);
> +		return !kvm || kvm_arch_supports_gmem(kvm);
>  #endif
>  	default:
>  		break;

Reviewed-by: Shivank Garg <shivankg@amd.com>