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>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index d5ef9eb..56f3c70 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -101,8 +101,8 @@
static struct page *hwpoison_page;
static pfn_t hwpoison_pfn;
-static struct page *fault_page;
-static pfn_t fault_pfn;
+struct page *fault_page;
+pfn_t fault_pfn;
inline int kvm_is_mmio_pfn(pfn_t pfn)
{
@@ -931,6 +931,18 @@
}
EXPORT_SYMBOL_GPL(is_fault_pfn);
+int is_noslot_pfn(pfn_t pfn)
+{
+ return pfn == bad_pfn;
+}
+EXPORT_SYMBOL_GPL(is_noslot_pfn);
+
+int is_invalid_pfn(pfn_t pfn)
+{
+ return pfn == hwpoison_pfn || pfn == fault_pfn;
+}
+EXPORT_SYMBOL_GPL(is_invalid_pfn);
+
static inline unsigned long bad_hva(void)
{
return PAGE_OFFSET;