[PATCH v1 1/3] i386: Remove the limitation of IP payloads for Intel PT

[Luwei Kang]

The Intel PT packets which contain IP payloads will have LIP values, and it
will include the CS base component if the CPUID.(EAX=14H,ECX=0H).ECX.[bit31]
is set. But it will disabled the Intel PT in kvm guest because of the need
of live migration safe(c078ca9 i386: Disable Intel PT if packets IP payloads
have LIP values).

This patch will revert the previous limitation because the Intel new hardware
will set this bit and LIP == RIP for most/all real code.

Signed-off-by: Luwei Kang <address@hidden>
---
 target/i386/cpu.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 69f518a..8c0d1e4 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -688,8 +688,6 @@ static CPUCacheInfo legacy_l3_cache = {
  * bit[02]: Support Single-Range Output scheme;
  */
 #define INTEL_PT_MINIMAL_ECX     0x7
-/* generated packets which contain IP payloads have LIP values */
-#define INTEL_PT_IP_LIP          (1 << 31)
 #define INTEL_PT_ADDR_RANGES_NUM 0x2 /* Number of configurable address ranges 
*/
 #define INTEL_PT_ADDR_RANGES_NUM_MASK 0x3
 #define INTEL_PT_MTC_BITMAP      (0x0249 << 16) /* Support ART(0,3,6,9) */
@@ -6281,8 +6279,7 @@ static void x86_cpu_filter_features(X86CPU *cpu, bool 
verbose)
            ((eax_1 & INTEL_PT_ADDR_RANGES_NUM_MASK) <
                                            INTEL_PT_ADDR_RANGES_NUM) ||
            ((ebx_1 & (INTEL_PT_PSB_BITMAP | INTEL_PT_CYCLE_BITMAP)) !=
-                (INTEL_PT_PSB_BITMAP | INTEL_PT_CYCLE_BITMAP)) ||
-           (ecx_0 & INTEL_PT_IP_LIP)) {
+                (INTEL_PT_PSB_BITMAP | INTEL_PT_CYCLE_BITMAP))) {
             /*
              * Processor Trace capabilities aren't configurable, so if the
              * host can't emulate the capabilities we report on
-- 
1.8.3.1