[Qemu-devel] [PATCH] SVM: Trap on correct IP

[Alexander Graf]

Hi,

Currently HLT always traps at the IP after the hlt instruction. SVM
requires its trap on the instruction's IP though, which breaks the
current implementation as soon as an HLT intercept occurs.

This patch does the SVM intercept with an IP value before the HLT
instruction.

Alex

Signed-off-by: Alexander Graf <address@hidden>

Index: target-i386/helper.h
===================================================================
--- target-i386/helper.h        (revision 4744)
+++ target-i386/helper.h        (working copy)
@@ -60,7 +60,7 @@
 DEF_HELPER(void, helper_syscall, (int next_eip_addend))
 DEF_HELPER(void, helper_sysret, (int dflag))
 #endif
-DEF_HELPER(void, helper_hlt, (void))
+DEF_HELPER(void, helper_hlt, (int next_eip_addend))
 DEF_HELPER(void, helper_monitor, (target_ulong ptr))
 DEF_HELPER(void, helper_mwait, (void))
 DEF_HELPER(void, helper_debug, (void))
Index: target-i386/op_helper.c
===================================================================
--- target-i386/op_helper.c     (revision 4744)
+++ target-i386/op_helper.c     (working copy)
@@ -4547,9 +4547,10 @@
 }
 #endif
 
-void helper_hlt(void)
+void helper_hlt(int next_eip_addend)
 {
     helper_svm_check_intercept_param(SVM_EXIT_HLT, 0);
+    EIP+=next_eip_addend;
     
     env->hflags &= ~HF_INHIBIT_IRQ_MASK; /* needed if sti is just before */
     env->halted = 1;
@@ -4575,7 +4576,7 @@
         /* more than one CPU: do not sleep because another CPU may
            wake this one */
     } else {
-        helper_hlt();
+        helper_hlt(0);
     }
 }
 
Index: target-i386/translate.c
===================================================================
--- target-i386/translate.c     (revision 4744)
+++ target-i386/translate.c     (working copy)
@@ -6420,8 +6420,8 @@
         } else {
             if (s->cc_op != CC_OP_DYNAMIC)
                 gen_op_set_cc_op(s->cc_op);
-            gen_jmp_im(s->pc - s->cs_base);
-            tcg_gen_helper_0_0(helper_hlt);
+            gen_jmp_im(pc_start - s->cs_base);
+            tcg_gen_helper_0_1(helper_hlt, tcg_const_i32(s->pc - pc_start));
             s->is_jmp = 3;
         }
         break;