KVM: X86: Change the type of access u32 to u64

Change the type of access u32 to u64 for FNAME(walk_addr) and
->gva_to_gpa().

The kinds of accesses are usually combinations of UWX, and VMX/SVM's
nested paging adds a new factor of access: is it an access for a guest
page table or for a final guest physical address.

And SMAP relies a factor for supervisor access: explicit or implicit.

So @access in FNAME(walk_addr) and ->gva_to_gpa() is better to include
all these information to do the walk.

Although @access(u32) has enough bits to encode all the kinds, this
patch extends it to u64:
	o Extra bits will be in the higher 32 bits, so that we can
	  easily obtain the traditional access mode (UWX) by converting
	  it to u32.
	o Reuse the value for the access kind defined by SVM's nested
	  paging (PFERR_GUEST_FINAL_MASK and PFERR_GUEST_PAGE_MASK) as
	  @error_code in kvm_handle_page_fault().

Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Message-Id: <20220311070346.45023-2-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index bf8dbc4bb12a..74efeaefa8f8 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -214,8 +214,10 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
  */
 static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
 				  unsigned pte_access, unsigned pte_pkey,
-				  unsigned pfec)
+				  u64 access)
 {
+	/* strip nested paging fault error codes */
+	unsigned int pfec = access;
 	int cpl = static_call(kvm_x86_get_cpl)(vcpu);
 	unsigned long rflags = static_call(kvm_x86_get_rflags)(vcpu);
 
@@ -317,12 +319,12 @@ static inline void kvm_update_page_stats(struct kvm *kvm, int level, int count)
 	atomic64_add(count, &kvm->stat.pages[level - 1]);
 }
 
-gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u32 access,
+gpa_t translate_nested_gpa(struct kvm_vcpu *vcpu, gpa_t gpa, u64 access,
 			   struct x86_exception *exception);
 
 static inline gpa_t kvm_translate_gpa(struct kvm_vcpu *vcpu,
 				      struct kvm_mmu *mmu,
-				      gpa_t gpa, u32 access,
+				      gpa_t gpa, u64 access,
 				      struct x86_exception *exception)
 {
 	if (mmu != &vcpu->arch.nested_mmu)