KVM: MMU: Optimize is_last_gpte()
Instead of branchy code depending on level, gpte.ps, and mmu configuration,
prepare everything in a bitmap during mode changes and look it up during
runtime.
Reviewed-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 1b4c14d..134ea7b 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -103,24 +103,6 @@
return (ret != orig_pte);
}
-static bool FNAME(is_last_gpte)(struct guest_walker *walker,
- struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,
- pt_element_t gpte)
-{
- if (walker->level == PT_PAGE_TABLE_LEVEL)
- return true;
-
- if ((walker->level == PT_DIRECTORY_LEVEL) && is_large_pte(gpte) &&
- (PTTYPE == 64 || is_pse(vcpu)))
- return true;
-
- if ((walker->level == PT_PDPE_LEVEL) && is_large_pte(gpte) &&
- (mmu->root_level == PT64_ROOT_LEVEL))
- return true;
-
- return false;
-}
-
static int FNAME(update_accessed_dirty_bits)(struct kvm_vcpu *vcpu,
struct kvm_mmu *mmu,
struct guest_walker *walker,
@@ -247,7 +229,7 @@
pte_access = pt_access & gpte_access(vcpu, pte);
walker->ptes[walker->level - 1] = pte;
- } while (!FNAME(is_last_gpte)(walker, vcpu, mmu, pte));
+ } while (!is_last_gpte(mmu, walker->level, pte));
eperm |= permission_fault(mmu, pte_access, access);
if (unlikely(eperm)) {