[PATCH] KVM: x86/mmu: Avoid mixing gpa_t with gfn_t in walk_addr_generic()

[Vitaly Kuznetsov]

translate_gpa() returns a GPA, assigning it to 'real_gfn' seems obviously
wrong. There is no real issue because both 'gpa_t' and 'gfn_t' are u64 and
we don't use the value in 'real_gfn' as a GFN, we do

 real_gfn = gpa_to_gfn(real_gfn);

instead. 'If you see a "buffalo" sign on an elephant's cage, do not trust
your eyes', but let's fix it for good.

No functional change intended.

Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com>
---
 arch/x86/kvm/mmu/paging_tmpl.h | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index a6d484ea110b..58234bfaca07 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -360,7 +360,6 @@ static int FNAME(walk_addr_generic)(struct guest_walker 
*walker,
        ++walker->level;
 
        do {
-               gfn_t real_gfn;
                unsigned long host_addr;
 
                pt_access = pte_access;
@@ -375,7 +374,7 @@ static int FNAME(walk_addr_generic)(struct guest_walker 
*walker,
                walker->table_gfn[walker->level - 1] = table_gfn;
                walker->pte_gpa[walker->level - 1] = pte_gpa;
 
-               real_gfn = mmu->translate_gpa(vcpu, gfn_to_gpa(table_gfn),
+               real_gpa = mmu->translate_gpa(vcpu, gfn_to_gpa(table_gfn),
                                              nested_access,
                                              &walker->fault);
 
@@ -389,12 +388,10 @@ static int FNAME(walk_addr_generic)(struct guest_walker 
*walker,
                 * information to fix the exit_qualification or exit_info_1
                 * fields.
                 */
-               if (unlikely(real_gfn == UNMAPPED_GVA))
+               if (unlikely(real_gpa == UNMAPPED_GVA))
                        return 0;
 
-               real_gfn = gpa_to_gfn(real_gfn);
-
-               host_addr = kvm_vcpu_gfn_to_hva_prot(vcpu, real_gfn,
+               host_addr = kvm_vcpu_gfn_to_hva_prot(vcpu, gpa_to_gfn(real_gpa),
                                            &walker->pte_writable[walker->level 
- 1]);
                if (unlikely(kvm_is_error_hva(host_addr)))
                        goto error;
-- 
2.25.4