[Xen-devel] [PATCH] vmx: fix single stepping on debugger

[Kouya Shimura <kouya@xxxxxxxxxxxxxx>]

The debuggee domain will die with unexpected trap
on single stepping of emulated instruction.

Signed-off-by: Kouya Shimura <kouya@xxxxxxxxxxxxxx>

diff -r 5fd51e1e9c79 xen/arch/x86/hvm/vmx/realmode.c
--- a/xen/arch/x86/hvm/vmx/realmode.c   Wed Nov 05 10:57:21 2008 +0000
+++ b/xen/arch/x86/hvm/vmx/realmode.c   Tue Nov 11 09:45:52 2008 +0900
@@ -148,6 +148,14 @@ static void realmode_emulate_one(struct 
             hvmemul_ctxt->exn_insn_len = 0;
         }
 
+        if ( curr->domain->debugger_attached &&
+            ( hvmemul_ctxt->exn_vector == TRAP_debug ||
+              hvmemul_ctxt->exn_vector == TRAP_int3 ) )
+        {
+            domain_pause_for_debugger();
+            return;
+        }
+
         if ( curr->arch.hvm_vcpu.guest_cr[0] & X86_CR0_PE )
         {
             gdprintk(XENLOG_ERR, "Exception %02x in protected mode.\n",
diff -r 5fd51e1e9c79 xen/arch/x86/hvm/vmx/vmx.c
--- a/xen/arch/x86/hvm/vmx/vmx.c        Wed Nov 05 10:57:21 2008 +0000
+++ b/xen/arch/x86/hvm/vmx/vmx.c        Tue Nov 11 09:45:52 2008 +0900
@@ -1154,8 +1154,6 @@ static void vmx_inject_exception(
 {
     struct vcpu *curr = current;
 
-    vmx_inject_hw_exception(curr, trapnr, errcode);
-
     if ( trapnr == TRAP_page_fault )
         curr->arch.hvm_vcpu.guest_cr[2] = cr2;
 
@@ -1164,7 +1162,14 @@ static void vmx_inject_exception(
     {
         __restore_debug_registers(curr);
         write_debugreg(6, read_debugreg(6) | 0x4000);
+        if ( curr->domain->debugger_attached )
+        {
+            domain_pause_for_debugger();
+            return;
+        }
     }
+
+    vmx_inject_hw_exception(curr, trapnr, errcode);
 }
 
 static int vmx_event_pending(struct vcpu *v)

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel