target/i386: implement DR7.GD
DR7.GD triggers a #DB exception on any access to debug registers.
The GD bit is cleared so that the #DB handler itself can access
the debug registers.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/target/i386/tcg/sysemu/bpt_helper.c b/target/i386/tcg/sysemu/bpt_helper.c
index 4d96a48..c1d5fce 100644
--- a/target/i386/tcg/sysemu/bpt_helper.c
+++ b/target/i386/tcg/sysemu/bpt_helper.c
@@ -238,6 +238,12 @@
}
}
+ if (env->dr[7] & DR7_GD) {
+ env->dr[7] &= ~DR7_GD;
+ env->dr[6] |= DR6_BD;
+ raise_exception_ra(env, EXCP01_DB, GETPC());
+ }
+
return env->dr[reg];
}
@@ -251,6 +257,12 @@
}
}
+ if (env->dr[7] & DR7_GD) {
+ env->dr[7] &= ~DR7_GD;
+ env->dr[6] |= DR6_BD;
+ raise_exception_ra(env, EXCP01_DB, GETPC());
+ }
+
if (reg < 4) {
if (hw_breakpoint_enabled(env->dr[7], reg)
&& hw_breakpoint_type(env->dr[7], reg) != DR7_TYPE_IO_RW) {
