x86/hvm/trace: Use a different trace type for AMD processors

A long-standing usability sub-optimality with xenalyze is the
necessity to specify `--svm-mode` when analyzing AMD processors.  This
fundamentally comes about because the same trace event ID is used for
both VMX and SVM, but the contents of the trace must be interpreted
differently.

Instead, allocate separate trace events for VMX and SVM vmexits in
Xen; this will allow all readers to properly interpret the meaning of
the vmexit reason.

In xenalyze, first remove the redundant call to init_hvm_data();
there's no way to get to hvm_vmexit_process() without it being already
initialized by the set_vcpu_type call in hvm_process().

Replace this with set_hvm_exit_reson_data(), and move setting of
hvm->exit_reason_* into that function.

Modify hvm_process and hvm_vmexit_process to handle all four potential
values appropriately.

If SVM entries are encountered, set opt.svm_mode so that other
SVM-specific functionality is triggered.

Remove the `--svm-mode` command-line option, since it's now redundant.

Signed-off-by: George Dunlap <george.dunlap@cloud.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>

diff --git a/tools/xentrace/xenalyze.c b/tools/xentrace/xenalyze.c
index ce6a85d50bf98cadfef9bde069cac475adb4ebcb..9c4463b0e8ae6d3fedc0e15100f223b5c0850197 100644 (file)
--- a/tools/xentrace/xenalyze.c
+++ b/tools/xentrace/xenalyze.c
@@ -1437,14 +1437,6 @@ void init_hvm_data(struct hvm_data *h, struct vcpu_data *v) {
 
     h->init = 1;
 
-    if(opt.svm_mode) {
-        h->exit_reason_max = HVM_SVM_EXIT_REASON_MAX;
-        h->exit_reason_name = hvm_svm_exit_reason_name;
-    } else {
-        h->exit_reason_max = HVM_VMX_EXIT_REASON_MAX;
-        h->exit_reason_name = hvm_vmx_exit_reason_name;
-    }
-
     if(opt.histogram_interrupt_eip) {
         int count = ((1ULL<<ADDR_SPACE_BITS)/opt.histogram_interrupt_increment);
         size_t size = count * sizeof(int);
@@ -1462,6 +1454,18 @@ void init_hvm_data(struct hvm_data *h, struct vcpu_data *v) {
         h->summary.guest_interrupt[i].count=0;
 }
 
+void set_hvm_exit_reason_data(struct hvm_data *h, unsigned event) {
+    if (((event & ~TRC_64_FLAG) == TRC_HVM_SVM_EXIT) ||
+        opt.svm_mode) {
+        opt.svm_mode = 1;
+        h->exit_reason_max = HVM_SVM_EXIT_REASON_MAX;
+        h->exit_reason_name = hvm_svm_exit_reason_name;
+    } else {
+        h->exit_reason_max = HVM_VMX_EXIT_REASON_MAX;
+        h->exit_reason_name = hvm_vmx_exit_reason_name;
+    }
+}
+
 /* PV data */
 enum {
     PV_HYPERCALL=1,
@@ -5088,13 +5092,13 @@ void hvm_vmexit_process(struct record_info *ri, struct hvm_data *h,
 
     r = (typeof(r))ri->d;
 
-    if(!h->init)
-        init_hvm_data(h, v);
+    if(!h->exit_reason_name)
+        set_hvm_exit_reason_data(h, ri->event);
 
     h->vmexit_valid=1;
     bzero(&h->inflight, sizeof(h->inflight));
 
-    if(ri->event == TRC_HVM_VMEXIT64) {
+    if(ri->event & TRC_64_FLAG) {
         if(v->guest_paging_levels != 4)
         {
             if ( verbosity >= 6 )
@@ -5316,8 +5320,10 @@ void hvm_process(struct pcpu_info *p)
         break;
     default:
         switch(ri->event) {
-        case TRC_HVM_VMEXIT:
-        case TRC_HVM_VMEXIT64:
+        case TRC_HVM_VMX_EXIT:
+        case TRC_HVM_VMX_EXIT64:
+        case TRC_HVM_SVM_EXIT:
+        case TRC_HVM_SVM_EXIT64:
             UPDATE_VOLUME(p, hvm[HVM_VOL_VMEXIT], ri->size);
             hvm_vmexit_process(ri, h, v);
             break;
@@ -10884,11 +10890,6 @@ const struct argp_option cmd_opts[] =  {
       .arg = "HZ",
       .doc = "Cpu speed of the tracing host, used to convert tsc into seconds.", },
 
-    { .name = "svm-mode",
-      .key = OPT_SVM_MODE,
-      .group = OPT_GROUP_HARDWARE,
-      .doc = "Assume AMD SVM-style vmexit error codes.  (Default is Intel VMX.)", },
-
     { .name = "progress",
       .key = OPT_PROGRESS,
       .doc = "Progress dialog.  Requires the zenity (GTK+) executable.", },

diff --git a/xen/arch/x86/hvm/svm/svm.c b/xen/arch/x86/hvm/svm/svm.c
index db530d55f2dd941e1eea11e35b3b3df18b66962b..988250dbc154e89e3f15e071497a344a7629f8d2 100644 (file)
--- a/xen/arch/x86/hvm/svm/svm.c
+++ b/xen/arch/x86/hvm/svm/svm.c
@@ -2571,10 +2571,10 @@ void asmlinkage svm_vmexit_handler(void)
     exit_reason = vmcb->exitcode;
 
     if ( hvm_long_mode_active(v) )
-        TRACE_TIME(TRC_HVM_VMEXIT64 | (vcpu_guestmode ? TRC_HVM_NESTEDFLAG : 0),
+        TRACE_TIME(TRC_HVM_SVM_EXIT64 | (vcpu_guestmode ? TRC_HVM_NESTEDFLAG : 0),
                    exit_reason, regs->rip, regs->rip >> 32);
     else
-        TRACE_TIME(TRC_HVM_VMEXIT | (vcpu_guestmode ? TRC_HVM_NESTEDFLAG : 0),
+        TRACE_TIME(TRC_HVM_SVM_EXIT | (vcpu_guestmode ? TRC_HVM_NESTEDFLAG : 0),
                    exit_reason, regs->eip);
 
     if ( vcpu_guestmode )

diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c
index 8ba996546f9aea4da1c02f173f935191fb657bc7..f16faa6a615cb32ffc2be7c6db40517686c9c715 100644 (file)
--- a/xen/arch/x86/hvm/vmx/vmx.c
+++ b/xen/arch/x86/hvm/vmx/vmx.c
@@ -4105,9 +4105,9 @@ void asmlinkage vmx_vmexit_handler(struct cpu_user_regs *regs)
     __vmread(VM_EXIT_REASON, &exit_reason);
 
     if ( hvm_long_mode_active(v) )
-        TRACE_TIME(TRC_HVM_VMEXIT64, exit_reason, regs->rip, regs->rip >> 32);
+        TRACE_TIME(TRC_HVM_VMX_EXIT64, exit_reason, regs->rip, regs->rip >> 32);
     else
-        TRACE_TIME(TRC_HVM_VMEXIT, exit_reason, regs->eip);
+        TRACE_TIME(TRC_HVM_VMX_EXIT, exit_reason, regs->eip);
 
     perfc_incra(vmexits, (uint16_t)exit_reason);
 

diff --git a/xen/include/public/trace.h b/xen/include/public/trace.h
index 3c9f9c3c18b2387baf343660bf93afe230b10581..141efa0ea7b97f8881f3f7fb0de1fdd69206fe18 100644 (file)
--- a/xen/include/public/trace.h
+++ b/xen/include/public/trace.h
@@ -178,8 +178,10 @@
 /* trace events per subclass */
 #define TRC_HVM_NESTEDFLAG      (0x400)
 #define TRC_HVM_VMENTRY         (TRC_HVM_ENTRYEXIT + 0x01)
-#define TRC_HVM_VMEXIT          (TRC_HVM_ENTRYEXIT + 0x02)
-#define TRC_HVM_VMEXIT64        (TRC_HVM_ENTRYEXIT + TRC_64_FLAG + 0x02)
+#define TRC_HVM_VMX_EXIT        (TRC_HVM_ENTRYEXIT + 0x02)
+#define TRC_HVM_VMX_EXIT64      (TRC_HVM_ENTRYEXIT + TRC_64_FLAG + 0x02)
+#define TRC_HVM_SVM_EXIT        (TRC_HVM_ENTRYEXIT + 0x03)
+#define TRC_HVM_SVM_EXIT64      (TRC_HVM_ENTRYEXIT + TRC_64_FLAG + 0x03)
 #define TRC_HVM_PF_XEN          (TRC_HVM_HANDLER + 0x01)
 #define TRC_HVM_PF_XEN64        (TRC_HVM_HANDLER + TRC_64_FLAG + 0x01)
 #define TRC_HVM_PF_INJECT       (TRC_HVM_HANDLER + 0x02)