x86 vmx: Update EIP when appropriate during task switch

Signed-off-by: Kouya Shimura <kouya@jp.fujitsu.com>
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>

diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index cc2f17fcfbb2ae22a8237300a643b2fb791bd81a..d19163faec4c1bfd8eb15dfa591089b3fbbdb55c 100644 (file)
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -2507,14 +2507,21 @@ asmlinkage void vmx_vmexit_handler(struct cpu_user_regs *regs)
     case EXIT_REASON_TASK_SWITCH: {
         const enum hvm_task_switch_reason reasons[] = {
             TSW_call_or_int, TSW_iret, TSW_jmp, TSW_call_or_int };
-        int32_t errcode = -1;
+        int32_t ecode = -1, source;
         exit_qualification = __vmread(EXIT_QUALIFICATION);
-        if ( (idtv_info & INTR_INFO_VALID_MASK) &&
-             (idtv_info & INTR_INFO_DELIVER_CODE_MASK) )
-            errcode = __vmread(IDT_VECTORING_ERROR_CODE);
-        hvm_task_switch((uint16_t)exit_qualification,
-                        reasons[(exit_qualification >> 30) & 3],
-                        errcode);
+        source = (exit_qualification >> 30) & 3;
+        inst_len = __get_instruction_length(); /* Safe: See SDM 3B 23.2.4 */
+        if ( (source == 3) && (idtv_info & INTR_INFO_VALID_MASK) )
+        {
+            /* ExtInt, NMI, HWException: no instruction to skip over. */
+            if ( !(idtv_info & (1u<<10)) ) /* 0 <= IntrType <= 3? */
+                inst_len = 0;
+            /* If there's an error code then we pass it along. */
+            if ( idtv_info & INTR_INFO_DELIVER_CODE_MASK )
+                ecode = __vmread(IDT_VECTORING_ERROR_CODE);
+        }
+        regs->eip += inst_len;
+        hvm_task_switch((uint16_t)exit_qualification, reasons[source], ecode);
         break;
     }
     case EXIT_REASON_CPUID: