KVM: X86: Rename gpte_is_8_bytes to has_4_byte_gpte and invert the direction

This bit is very close to mean "role.quadrant is not in use", except that
it is false also when the MMU is mapping guest physical addresses
directly.  In that case, role.quadrant is indeed not in use, but there
are no guest PTEs at all.

Changing the name and direction of the bit removes the special case,
since a guest with paging disabled, or not considering guest paging
structures as is the case for two-dimensional paging, does not have
to deal with 4-byte guest PTEs.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Message-Id: <20211124122055.64424-10-jiangshanlai@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f1414df18e11..5d48ba6d1487 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -296,14 +296,14 @@ struct kvm_kernel_irq_routing_entry;
  *
  *   - invalid shadow pages are not accounted, so the bits are effectively 18
  *
- *   - quadrant will only be used if gpte_is_8_bytes=0 (non-PAE paging);
+ *   - quadrant will only be used if has_4_byte_gpte=1 (non-PAE paging);
  *     execonly and ad_disabled are only used for nested EPT which has
- *     gpte_is_8_bytes=1.  Therefore, 2 bits are always unused.
+ *     has_4_byte_gpte=0.  Therefore, 2 bits are always unused.
  *
  *   - the 4 bits of level are effectively limited to the values 2/3/4/5,
  *     as 4k SPs are not tracked (allowed to go unsync).  In addition non-PAE
  *     paging has exactly one upper level, making level completely redundant
- *     when gpte_is_8_bytes=0.
+ *     when has_4_byte_gpte=1.
  *
  *   - on top of this, smep_andnot_wp and smap_andnot_wp are only set if
  *     cr0_wp=0, therefore these three bits only give rise to 5 possibilities.
@@ -315,7 +315,7 @@ union kvm_mmu_page_role {
 	u32 word;
 	struct {
 		unsigned level:4;
-		unsigned gpte_is_8_bytes:1;
+		unsigned has_4_byte_gpte:1;
 		unsigned quadrant:2;
 		unsigned direct:1;
 		unsigned access:3;