KVM: x86/mmu: remove redundant bits from extended role

Before the separation of the CPU and the MMU role, CR0.PG was not
available in the base MMU role, because two-dimensional paging always
used direct=1 in the MMU role.  However, now that the raw role is
snapshotted in mmu->cpu_role, the value of CR0.PG always matches both
!cpu_role.base.direct and cpu_role.base.level > 0.  There is no need to
store it again in union kvm_mmu_extended_role; instead, write an is_cr0_pg
accessor by hand that takes care of the conversion.  Use cpu_role.base.level
since the future of the direct field is unclear.

Likewise, CR4.PAE is now always present in the CPU role as
!cpu_role.base.has_4_byte_gpte.  The inversion makes certain tests on
the MMU role easier, and is easily hidden by the is_cr4_pae accessor
when operating on the CPU role.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

arch/x86/include/asm/kvm_host.h

@@ -367,8 +367,6 @@ union kvm_mmu_extended_role {
 	struct {
 		unsigned int valid:1;
 		unsigned int execonly:1;
-		unsigned int cr0_pg:1;
-		unsigned int cr4_pae:1;
 		unsigned int cr4_pse:1;
 		unsigned int cr4_pke:1;
 		unsigned int cr4_smap:1;

arch/x86/kvm/mmu/mmu.c

@@ -224,16 +224,24 @@ static inline bool __maybe_unused is_##reg##_##name(struct kvm_mmu *mmu)	\
 {								\
 	return !!(mmu->cpu_role. base_or_ext . reg##_##name);	\
 }
-BUILD_MMU_ROLE_ACCESSOR(ext,  cr0, pg);
 BUILD_MMU_ROLE_ACCESSOR(base, cr0, wp);
 BUILD_MMU_ROLE_ACCESSOR(ext,  cr4, pse);
-BUILD_MMU_ROLE_ACCESSOR(ext,  cr4, pae);
 BUILD_MMU_ROLE_ACCESSOR(ext,  cr4, smep);
 BUILD_MMU_ROLE_ACCESSOR(ext,  cr4, smap);
 BUILD_MMU_ROLE_ACCESSOR(ext,  cr4, pke);
 BUILD_MMU_ROLE_ACCESSOR(ext,  cr4, la57);
 BUILD_MMU_ROLE_ACCESSOR(base, efer, nx);
 
+static inline bool is_cr0_pg(struct kvm_mmu *mmu)
+{
+        return mmu->cpu_role.base.level > 0;
+}
+
+static inline bool is_cr4_pae(struct kvm_mmu *mmu)
+{
+        return !mmu->cpu_role.base.has_4_byte_gpte;
+}
+
 static struct kvm_mmu_role_regs vcpu_to_role_regs(struct kvm_vcpu *vcpu)
 {
 	struct kvm_mmu_role_regs regs = {
@@ -4755,8 +4763,6 @@ kvm_calc_cpu_role(struct kvm_vcpu *vcpu, const struct kvm_mmu_role_regs *regs)
 	else
 		role.base.level = PT32_ROOT_LEVEL;
 
-	role.ext.cr0_pg = 1;
-	role.ext.cr4_pae = ____is_cr4_pae(regs);
 	role.ext.cr4_smep = ____is_cr4_smep(regs);
 	role.ext.cr4_smap = ____is_cr4_smap(regs);
 	role.ext.cr4_pse = ____is_cr4_pse(regs);