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charset="UTF-8" From: Ackerley Tng Refactor kvm_max_private_mapping_level() to accept a NULL kvm_page_fault pointer and rename it to kvm_gmem_max_mapping_level(). The max_mapping_level x86 operation (previously private_max_mapping_level) is designed to potentially be called without an active page fault, for instance, when kvm_mmu_max_mapping_level() is determining the maximum mapping level for a gfn proactively. Allow NULL fault pointer: Modify kvm_max_private_mapping_level() to safely handle a NULL fault argument. This aligns its interface with the kvm_x86_ops.max_mapping_level operation it wraps, which can also be called with NULL. Rename function to kvm_gmem_max_mapping_level(): This reinforces that the function's scope is for guest_memfd-backed memory, which can be either private or non-private, removing any remaining "private" connotation from its name. Optimize max_level checks: Introduce a check in the caller to skip querying for max_mapping_level if the current max_level is already PG_LEVEL_4K, as no further reduction is possible. Acked-by: David Hildenbrand Suggested-by: Sean Christoperson Signed-off-by: Ackerley Tng Signed-off-by: Fuad Tabba --- arch/x86/kvm/mmu/mmu.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index bb925994cbc5..6bd28fda0fd3 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4467,17 +4467,13 @@ static inline u8 kvm_max_level_for_order(int order) return PG_LEVEL_4K; } -static u8 kvm_max_private_mapping_level(struct kvm *kvm, - struct kvm_page_fault *fault, - int gmem_order) +static u8 kvm_gmem_max_mapping_level(struct kvm *kvm, int order, + struct kvm_page_fault *fault) { - u8 max_level = fault->max_level; u8 req_max_level; + u8 max_level; - if (max_level == PG_LEVEL_4K) - return PG_LEVEL_4K; - - max_level = min(kvm_max_level_for_order(gmem_order), max_level); + max_level = kvm_max_level_for_order(order); if (max_level == PG_LEVEL_4K) return PG_LEVEL_4K; @@ -4513,7 +4509,9 @@ static int kvm_mmu_faultin_pfn_private(struct kvm_vcpu *vcpu, } fault->map_writable = !(fault->slot->flags & KVM_MEM_READONLY); - fault->max_level = kvm_max_private_mapping_level(vcpu->kvm, fault, max_order); + if (fault->max_level >= PG_LEVEL_4K) + fault->max_level = kvm_gmem_max_mapping_level(vcpu->kvm, + max_order, fault); return RET_PF_CONTINUE; } -- 2.50.0.727.gbf7dc18ff4-goog