diff mbox series

[WIP,03/14] xenalyze: Basic nested virt processing

Message ID 20240626133853.4150731-4-george.dunlap@cloud.com (mailing list archive)
State New, archived
Headers show
Series AMD Nested Virt Preparation | expand

Commit Message

George Dunlap June 26, 2024, 1:38 p.m. UTC
On SVM, VMEXIT that occur in when an L1 is in non-root mode ("nested
exits") are tagged with the TRC_HVM_NESTEDFLAG flag.  Expand xenalyze
to do basic handling of these records:

- Refactor hvm_process to filter out both TRC_HVM_NESTEDFLAG and
  TRC_64_FLAG when deciding how to process

- Create separate "trace volume" sub-categories for them (HVM_VOL_*),
  tweaking layout so things continue to align

- Visually distinquish nested from non-nested vmexits and vmentries in
  dump mode

At the moment, nested VMEXITs which are passed through to the L1
hypervisor won't have any HVM handlers; note in hvm_data when a vmexit
was nested, and don't warn when no handlers occur.

While here:
 - Expand one of the error messages with a bit more information
 - Replace repeated `ri->event & TRC_64_FLAG` instances with `flag64`
 - Remove a stray whitespace at the end of a line
 - Add a missing newline to a warning statement

Signed-off-by: George Dunlap <george.dunlap@cloud.com>
---
 tools/xentrace/xenalyze.c | 66 ++++++++++++++++++++++++++-------------
 1 file changed, 45 insertions(+), 21 deletions(-)
diff mbox series

Patch

diff --git a/tools/xentrace/xenalyze.c b/tools/xentrace/xenalyze.c
index d95e52695f..52ee7a5f9f 100644
--- a/tools/xentrace/xenalyze.c
+++ b/tools/xentrace/xenalyze.c
@@ -986,7 +986,9 @@  const char * hvm_event_handler_name[HVM_EVENT_HANDLER_MAX] = {
 
 enum {
     HVM_VOL_VMENTRY,
+    HVM_VOL_VMENTRY_NESTED,
     HVM_VOL_VMEXIT,
+    HVM_VOL_VMEXIT_NESTED,
     HVM_VOL_HANDLER,
     HVM_VOL_EMUL,
     HVM_VOL_MAX
@@ -1014,6 +1016,8 @@  const char *guest_interrupt_case_name[] = {
 const char *hvm_vol_name[HVM_VOL_MAX] = {
     [HVM_VOL_VMENTRY]="vmentry",
     [HVM_VOL_VMEXIT] ="vmexit",
+    [HVM_VOL_VMENTRY_NESTED]="vmentry(n)",
+    [HVM_VOL_VMEXIT_NESTED] ="vmexit(n)",
     [HVM_VOL_HANDLER]="handler",
     [HVM_VOL_EMUL]="emul",
 };
@@ -1380,7 +1384,7 @@  struct hvm_data {
     tsc_t exit_tsc, arc_cycles, entry_tsc;
     unsigned long long rip;
     unsigned exit_reason, event_handler;
-    unsigned int short_summary_done:1, prealloc_unpin:1, wrmap_bf:1;
+    bool nested_vmexit, short_summary_done, prealloc_unpin, wrmap_bf;
 
     /* Immediate processing */
     void *d;
@@ -1807,7 +1811,7 @@  void volume_summary(struct trace_volume *vol)
             case TOPLEVEL_HVM:
                 for(k=0; k<HVM_VOL_MAX; k++) {
                     if(vol->hvm[k])
-                        printf(" +-%-7s: %10lld\n",
+                        printf(" +-%-10s: %10lld\n",
                                hvm_vol_name[k], vol->hvm[k]);
                 }
 
@@ -4633,6 +4637,9 @@  void hvm_generic_postprocess(struct hvm_data *h)
         /* Some exits we don't expect a handler; just return */
         if(opt.svm_mode)
         {
+            /* Nested vmexits passed on to L1's have no handlers for now */
+            if(h->nested_vmexit)
+                return;
             switch(h->exit_reason)
             {
             case VMEXIT_VINTR: /* Equivalent of PENDING_VIRT_INTR */
@@ -4660,8 +4667,10 @@  void hvm_generic_postprocess(struct hvm_data *h)
         if ( !warned[h->exit_reason] )
         {
             /* If we aren't a known exception, warn and log results */
-            fprintf(warn, "%s: Strange, exit %x(%s) missing a handler\n",
-                    __func__, h->exit_reason,
+            fprintf(warn, "%s: d%dv%d Strange, exit %x(%s) missing a handler\n",
+                    __func__,
+                    h->v->d->did, h->v->vid,
+                    h->exit_reason,
                     (h->exit_reason > h->exit_reason_max)
                       ? "[clipped]"
                       : h->exit_reason_name[h->exit_reason]);
@@ -5067,6 +5076,9 @@  static inline void runstate_update(struct vcpu_data *v, int new_runstate,
 
 void hvm_vmexit_process(struct record_info *ri, struct hvm_data *h,
                         struct vcpu_data *v) {
+    bool flag64 = ri->event & TRC_64_FLAG;
+    bool nested = ri->event & TRC_HVM_NESTEDFLAG;
+
     struct {
         union {
             struct {
@@ -5080,7 +5092,7 @@  void hvm_vmexit_process(struct record_info *ri, struct hvm_data *h,
         };
     } *r;
 
-    if ( ri->event & TRC_64_FLAG )
+    if(flag64)
     {
         if (check_extra_words(ri, sizeof(r->x64), "vmexit"))
             return;
@@ -5097,9 +5109,10 @@  void hvm_vmexit_process(struct record_info *ri, struct hvm_data *h,
         set_hvm_exit_reason_data(h, ri->event);
 
     h->vmexit_valid=1;
+    h->nested_vmexit=nested;
     bzero(&h->inflight, sizeof(h->inflight));
 
-    if(ri->event & TRC_64_FLAG) {
+    if(flag64) {
         if(v->guest_paging_levels != 4)
         {
             if ( verbosity >= 6 )
@@ -5145,14 +5158,16 @@  void hvm_vmexit_process(struct record_info *ri, struct hvm_data *h,
     if(opt.dump_all) {
         if ( h->exit_reason < h->exit_reason_max
              && h->exit_reason_name[h->exit_reason] != NULL)
-            printf("]%s vmexit exit_reason %s eip %llx%s\n",
+            printf("]%s vmexit%s exit_reason %s eip %llx%s\n",
                    ri->dump_header,
+                   nested ? "(n)" : "",
                    h->exit_reason_name[h->exit_reason],
                    h->rip,
                    find_symbol(h->rip));
         else
-            printf("]%s vmexit exit_reason %x eip %llx%s\n",
+            printf("]%s vmexit%s exit_reason %x eip %llx%s\n",
                    ri->dump_header,
+                   nested ? "(n)" : "",
                    h->exit_reason,
                    h->rip,
                    find_symbol(h->rip));
@@ -5244,11 +5259,13 @@  void hvm_close_vmexit(struct hvm_data *h, tsc_t tsc) {
 }
 
 void hvm_vmentry_process(struct record_info *ri, struct hvm_data *h) {
+    bool nested = ri->event & TRC_HVM_NESTEDFLAG;
     if(!h->init)
     {
         if(opt.dump_all)
-            printf("!%s vmentry\n",
-                   ri->dump_header);
+            printf("!%s vmentry%s\n",
+                   ri->dump_header,
+                   nested ? "(n)" : "");
         return;
     }
 
@@ -5283,15 +5300,18 @@  void hvm_vmentry_process(struct record_info *ri, struct hvm_data *h) {
     if(!h->vmexit_valid)
     {
         if(opt.dump_all)
-            printf("!%s vmentry\n",
-                   ri->dump_header);
+            printf("!%s vmentry%s\n",
+                   ri->dump_header,
+                   nested ? "(n)" : "");
         return;
     }
 
     if(opt.dump_all) {
         unsigned long long arc_cycles = ri->tsc - h->exit_tsc;
-        printf("]%s vmentry cycles %lld %s\n",
-               ri->dump_header, arc_cycles, (arc_cycles>10000)?"!":"");
+        printf("]%s vmentry%s cycles %lld %s\n",
+               ri->dump_header,
+               nested ? "(n)" : "",
+               arc_cycles, (arc_cycles>10000)?"!":"");
     }
 
     hvm_close_vmexit(h, ri->tsc);
@@ -5323,16 +5343,20 @@  void hvm_process(struct pcpu_info *p)
         /* FIXME: Collect analysis on this */
         break;
     default:
-        switch(ri->event) {
+        switch(ri->event & ~(TRC_HVM_NESTEDFLAG|TRC_64_FLAG)) {
         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);
+            if (ri->event & TRC_HVM_NESTEDFLAG)
+                UPDATE_VOLUME(p, hvm[HVM_VOL_VMEXIT_NESTED], ri->size);
+            else
+                UPDATE_VOLUME(p, hvm[HVM_VOL_VMEXIT], ri->size);
             hvm_vmexit_process(ri, h, v);
             break;
         case TRC_HVM_VMENTRY:
-            UPDATE_VOLUME(p, hvm[HVM_VOL_VMENTRY], ri->size);
+            if (ri->event & TRC_HVM_NESTEDFLAG)
+                UPDATE_VOLUME(p, hvm[HVM_VOL_VMENTRY_NESTED], ri->size);
+            else
+                UPDATE_VOLUME(p, hvm[HVM_VOL_VMENTRY], ri->size);
             hvm_vmentry_process(ri, &p->current->hvm);
             break;
         default:
@@ -6977,7 +7001,7 @@  void vcpu_start(struct pcpu_info *p, struct vcpu_data *v,
         /* Change default domain to 'queued' */
         runstate_update(p->current, RUNSTATE_QUEUED, p->first_tsc);
 
-        /* 
+        /*
          * Set current to NULL, so that if another vcpu (not in INIT)
          * is scheduled here, we don't trip over the check in
          * vcpu_next_update()
@@ -6997,7 +7021,7 @@  void vcpu_start(struct pcpu_info *p, struct vcpu_data *v,
 
         return;
     } else if ( v->delayed_init ) {
-        fprintf(warn, "d%dv%d RUNSTATE_RUNNING detected, leaving INIT",
+        fprintf(warn, "d%dv%d RUNSTATE_RUNNING detected, leaving INIT\n",
                 v->d->did, v->vid);
         v->delayed_init = 0;
     }