* [Qemu-devel] [PATCH] SVM: Trap on correct IP
@ 2008-06-18 0:34 Alexander Graf
2008-06-18 4:59 ` Alexander Graf
0 siblings, 1 reply; 3+ messages in thread
From: Alexander Graf @ 2008-06-18 0:34 UTC (permalink / raw)
To: qemu-devel
[-- Attachment #1: Type: text/plain, Size: 333 bytes --]
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 <agraf@suse.de>
[-- Attachment #2: qemu-svm-hlt.patch --]
[-- Type: text/x-patch, Size: 1783 bytes --]
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;
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [Qemu-devel] [PATCH] SVM: Trap on correct IP
2008-06-18 0:34 [Qemu-devel] [PATCH] SVM: Trap on correct IP Alexander Graf
@ 2008-06-18 4:59 ` Alexander Graf
2008-06-18 9:41 ` Fabrice Bellard
0 siblings, 1 reply; 3+ messages in thread
From: Alexander Graf @ 2008-06-18 4:59 UTC (permalink / raw)
To: qemu-devel
[-- Attachment #1: Type: text/plain, Size: 466 bytes --]
Alexander Graf wrote:
> 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 <agraf@suse.de>
>
>
This version should also fix MWAIT.
Signed-off-by: Alexander Graf <agraf@suse.de>
[-- Attachment #2: qemu-svm-hlt.patch --]
[-- Type: text/x-patch, Size: 2780 bytes --]
Index: target-i386/helper.h
===================================================================
--- target-i386/helper.h (revision 4744)
+++ target-i386/helper.h (working copy)
@@ -60,9 +60,9 @@
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_mwait, (int next_eip_addend))
DEF_HELPER(void, helper_debug, (void))
DEF_HELPER(void, helper_raise_interrupt, (int intno, int next_eip_addend))
DEF_HELPER(void, helper_raise_exception, (int exception_index))
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;
@@ -4565,7 +4566,7 @@
helper_svm_check_intercept_param(SVM_EXIT_MONITOR, 0);
}
-void helper_mwait(void)
+void helper_mwait(int next_eip_addend)
{
if ((uint32_t)ECX != 0)
raise_exception(EXCP0D_GPF);
@@ -4575,7 +4576,8 @@
/* more than one CPU: do not sleep because another CPU may
wake this one */
} else {
- helper_hlt();
+ /* XXX: is it ok to intercept HLT when MWAIT is not intercepted? */
+ helper_hlt(next_eip_addend);
}
}
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;
@@ -6541,8 +6541,8 @@
gen_op_set_cc_op(s->cc_op);
s->cc_op = CC_OP_DYNAMIC;
}
- gen_jmp_im(s->pc - s->cs_base);
- tcg_gen_helper_0_0(helper_mwait);
+ gen_jmp_im(pc_start - s->cs_base);
+ tcg_gen_helper_0_1(helper_mwait, tcg_const_i32(s->pc - pc_start));
gen_eob(s);
break;
default:
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [Qemu-devel] [PATCH] SVM: Trap on correct IP
2008-06-18 4:59 ` Alexander Graf
@ 2008-06-18 9:41 ` Fabrice Bellard
0 siblings, 0 replies; 3+ messages in thread
From: Fabrice Bellard @ 2008-06-18 9:41 UTC (permalink / raw)
To: Alexander Graf; +Cc: qemu-devel
Your patch introduces a bug in mwait. Try my commited patch instead.
Fabrice.
Alexander Graf wrote:
> Alexander Graf wrote:
>> 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 <agraf@suse.de>
>>
>>
> This version should also fix MWAIT.
>
> Signed-off-by: Alexander Graf <agraf@suse.de>
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2008-06-18 9:41 UTC | newest]
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2008-06-18 0:34 [Qemu-devel] [PATCH] SVM: Trap on correct IP Alexander Graf
2008-06-18 4:59 ` Alexander Graf
2008-06-18 9:41 ` Fabrice Bellard
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