KVM: x86: improve reexecute_instruction
The current reexecute_instruction can not well detect the failed instruction
emulation. It allows guest to retry all the instructions except it accesses
on error pfn
For example, some cases are nested-write-protect - if the page we want to
write is used as PDE but it chains to itself. Under this case, we should
stop the emulation and report the case to userspace
Reviewed-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index f75e1fe..77d56a4 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -497,6 +497,13 @@
u64 msr_val;
struct gfn_to_hva_cache data;
} pv_eoi;
+
+ /*
+ * Indicate whether the access faults on its page table in guest
+ * which is set when fix page fault and used to detect unhandeable
+ * instruction.
+ */
+ bool write_fault_to_shadow_pgtable;
};
struct kvm_lpage_info {