KVM: x86/mmu: fix determination of max NPT mapping level for private pages

Ackerley Tng · bonzini · commit aca0ec970d76 · 2024-08-01T14:13:11.000-04:00
The `if (req_max_level)` test was meant ignore req_max_level if PG_LEVEL_NONE was returned. Hence, this function should return max_level instead of the ignored req_max_level. This is only a latent issue for now, since guest_memfd does not support large pages. Signed-off-by: Ackerley Tng <ackerleytng@google.com> Message-ID: <20240801173955.1975034-1-ackerleytng@google.com> Fixes: f32fb32 ("KVM: x86: Add hook for determining max NPT mapping level") Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
@@ -4335,7 +4335,7 @@ static u8 kvm_max_private_mapping_level(struct kvm *kvm, kvm_pfn_t pfn,
 	if (req_max_level)
 		max_level = min(max_level, req_max_level);
 
-	return req_max_level;
+	return max_level;
 }
 
 static int kvm_faultin_pfn_private(struct kvm_vcpu *vcpu,

Original file line number	Diff line number	Diff line change
`@@ -4335,7 +4335,7 @@ static u8 kvm_max_private_mapping_level(struct kvm *kvm, kvm_pfn_t pfn,`
`4335`	`4335`	`if (req_max_level)`
`4336`	`4336`	`max_level = min(max_level, req_max_level);`
`4337`	`4337`
`4338`		`- return req_max_level;`
	`4338`	`+ return max_level;`
`4339`	`4339`	`}`
`4340`	`4340`
`4341`	`4341`	`static int kvm_faultin_pfn_private(struct kvm_vcpu *vcpu,`