KVM: MMU: large page support
Create large pages mappings if the guest PTE's are marked as such and
the underlying memory is hugetlbfs backed. If the largepage contains
write-protected pages, a large pte is not used.
Gives a consistent 2% improvement for data copies on ram mounted
filesystem, without NPT/EPT.
Anthony measures a 4% improvement on 4-way kernbench, with NPT.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 994278f..9750bb3 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -103,6 +103,10 @@
unsigned long flags;
unsigned long *rmap;
unsigned long *dirty_bitmap;
+ struct {
+ unsigned long rmap_pde;
+ int write_count;
+ } *lpage_info;
unsigned long userspace_addr;
int user_alloc;
};
@@ -169,6 +173,7 @@
int user_alloc);
gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn);
struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn);
+unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn);
void kvm_release_page_clean(struct page *page);
void kvm_release_page_dirty(struct page *page);
int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset,