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From: Luwei Kang <luwei.kang@intel.com>
To: pbonzini@redhat.com, rth@twiddle.net, ehabkost@redhat.com
Cc: Luwei Kang <luwei.kang@intel.com>,
	qemu-devel@nongnu.org, beeman.strong@intel.com
Subject: [PATCH v1 1/3] i386: Remove the limitation of IP payloads for Intel PT
Date: Tue, 25 Feb 2020 05:38:30 +0800	[thread overview]
Message-ID: <1582580312-19864-2-git-send-email-luwei.kang@intel.com> (raw)
In-Reply-To: <1582580312-19864-1-git-send-email-luwei.kang@intel.com>

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 <luwei.kang@intel.com>
---
 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



  reply	other threads:[~2020-02-24 13:41 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-24 21:38 [PATCH v1 0/3] Remove the limitation of Intel PT CPUID info Luwei Kang
2020-02-24 21:38 ` Luwei Kang [this message]
2020-09-25 16:15   ` [PATCH v1 1/3] i386: Remove the limitation of IP payloads for Intel PT Eduardo Habkost
2020-09-25 16:42     ` Strong, Beeman
2020-09-25 16:54       ` Eduardo Habkost
2020-09-25 20:23         ` Paolo Bonzini
2020-09-25 20:29           ` Eduardo Habkost
2020-09-25 20:40             ` Paolo Bonzini
2020-09-28  5:19               ` Kang, Luwei
2020-09-28  7:35                 ` Paolo Bonzini
2020-09-28 12:42                   ` Kang, Luwei
2020-09-28 14:12                     ` Eduardo Habkost
2020-09-29  2:28                       ` Kang, Luwei
2020-09-29  3:44                         ` Eduardo Habkost
2020-09-28 16:46                     ` Paolo Bonzini
2020-09-29  2:28                       ` Kang, Luwei
2020-02-24 21:38 ` [PATCH v1 2/3] i386: Remove the CPUID limitation of " Luwei Kang
2020-02-24 21:38 ` [PATCH v1 3/3] i386: Mark the 'INTEL_PT' CPUID bit as unmigratable Luwei Kang
2020-03-30  9:56 ` [PATCH v1 0/3] Remove the limitation of Intel PT CPUID info Kang, Luwei
2020-09-18 22:02   ` Eduardo Habkost
2020-09-21  7:49     ` Kang, Luwei
2020-09-21 16:50       ` Eduardo Habkost
2020-09-23  2:52         ` Kang, Luwei
2020-09-23 14:15           ` Eduardo Habkost
2020-09-24 12:47             ` Kang, Luwei
2020-09-24 13:34               ` Eduardo Habkost
2020-09-25  8:20                 ` Kang, Luwei

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