KVM: MMU: filter out the mmio pfn from the fault pfn

If the page fault is caused by mmio, the gfn can not be found in memslots, and
'bad_pfn' is returned on gfn_to_hva path, so we can use 'bad_pfn' to identify
the mmio page fault.
And, to clarify the meaning of mmio pfn, we return fault page instead of bad
page when the gfn is not allowd to prefetch

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index c8e023902f7..eabb21a30c3 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -327,12 +327,17 @@ static inline struct kvm_memslots *kvm_memslots(struct kvm *kvm)
 static inline int is_error_hpa(hpa_t hpa) { return hpa >> HPA_MSB; }
 
 extern struct page *bad_page;
+extern struct page *fault_page;
+
 extern pfn_t bad_pfn;
+extern pfn_t fault_pfn;
 
 int is_error_page(struct page *page);
 int is_error_pfn(pfn_t pfn);
 int is_hwpoison_pfn(pfn_t pfn);
 int is_fault_pfn(pfn_t pfn);
+int is_noslot_pfn(pfn_t pfn);
+int is_invalid_pfn(pfn_t pfn);
 int kvm_is_error_hva(unsigned long addr);
 int kvm_set_memory_region(struct kvm *kvm,
                           struct kvm_userspace_memory_region *mem,