qapi: introduce x-query-jit QMP command

This is a counterpart to the HMP "info jit" command. It is being
added with an "x-" prefix because this QMP command is intended as an
ad hoc debugging tool and will thus not be modelled in QAPI as fully
structured data, nor will it have long term guaranteed stability.
The existing HMP command is rewritten to call the QMP command.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

3 files changed, 75 insertions, 57 deletions

diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index c9764c1325..4212645cb6 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -20,6 +20,9 @@
 #include "qemu/osdep.h"
 #include "qemu-common.h"
 #include "qemu/qemu-print.h"
+#include "qapi/error.h"
+#include "qapi/qapi-commands-machine.h"
+#include "qapi/type-helpers.h"
 #include "hw/core/tcg-cpu-ops.h"
 #include "trace.h"
 #include "disas/disas.h"
@@ -38,6 +41,7 @@
 #include "exec/cpu-all.h"
 #include "sysemu/cpu-timers.h"
 #include "sysemu/replay.h"
+#include "sysemu/tcg.h"
 #include "exec/helper-proto.h"
 #include "tb-hash.h"
 #include "tb-context.h"
@@ -1028,23 +1032,38 @@ void tcg_exec_unrealizefn(CPUState *cpu)
 
 #ifndef CONFIG_USER_ONLY
 
-void dump_drift_info(void)
+void dump_drift_info(GString *buf)
 {
     if (!icount_enabled()) {
         return;
     }
 
-    qemu_printf("Host - Guest clock  %"PRIi64" ms\n",
-                (cpu_get_clock() - icount_get()) / SCALE_MS);
+    g_string_append_printf(buf, "Host - Guest clock  %"PRIi64" ms\n",
+                           (cpu_get_clock() - icount_get()) / SCALE_MS);
     if (icount_align_option) {
-        qemu_printf("Max guest delay     %"PRIi64" ms\n",
-                    -max_delay / SCALE_MS);
-        qemu_printf("Max guest advance   %"PRIi64" ms\n",
-                    max_advance / SCALE_MS);
+        g_string_append_printf(buf, "Max guest delay     %"PRIi64" ms\n",
+                               -max_delay / SCALE_MS);
+        g_string_append_printf(buf, "Max guest advance   %"PRIi64" ms\n",
+                               max_advance / SCALE_MS);
     } else {
-        qemu_printf("Max guest delay     NA\n");
-        qemu_printf("Max guest advance   NA\n");
+        g_string_append_printf(buf, "Max guest delay     NA\n");
+        g_string_append_printf(buf, "Max guest advance   NA\n");
     }
 }
 
+HumanReadableText *qmp_x_query_jit(Error **errp)
+{
+    g_autoptr(GString) buf = g_string_new("");
+
+    if (!tcg_enabled()) {
+        error_setg(errp, "JIT information is only available with accel=tcg");
+        return NULL;
+    }
+
+    dump_exec_info(buf);
+    dump_drift_info(buf);
+
+    return human_readable_text_from_str(buf);
+}
+
 #endif /* !CONFIG_USER_ONLY */
diff --git a/accel/tcg/hmp.c b/accel/tcg/hmp.c
index a6e72fdb3e..01c767a464 100644
--- a/accel/tcg/hmp.c
+++ b/accel/tcg/hmp.c
@@ -1,20 +1,11 @@
 #include "qemu/osdep.h"
 #include "qemu/error-report.h"
+#include "qapi/error.h"
+#include "qapi/qapi-commands-machine.h"
 #include "exec/exec-all.h"
 #include "monitor/monitor.h"
 #include "sysemu/tcg.h"
 
-static void hmp_info_jit(Monitor *mon, const QDict *qdict)
-{
-    if (!tcg_enabled()) {
-        error_report("JIT information is only available with accel=tcg");
-        return;
-    }
-
-    dump_exec_info();
-    dump_drift_info();
-}
-
 static void hmp_info_opcount(Monitor *mon, const QDict *qdict)
 {
     dump_opcount_info();
@@ -22,7 +13,7 @@ static void hmp_info_opcount(Monitor *mon, const QDict *qdict)
 
 static void hmp_tcg_register(void)
 {
-    monitor_register_hmp("jit", true, hmp_info_jit);
+    monitor_register_hmp_info_hrt("jit", qmp_x_query_jit);
     monitor_register_hmp("opcount", true, hmp_info_opcount);
 }
 
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index fb9ebfad9e..8f17a91858 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -1991,7 +1991,7 @@ void cpu_io_recompile(CPUState *cpu, uintptr_t retaddr)
     cpu_loop_exit_noexc(cpu);
 }
 
-static void print_qht_statistics(struct qht_stats hst)
+static void print_qht_statistics(struct qht_stats hst, GString *buf)
 {
     uint32_t hgram_opts;
     size_t hgram_bins;
@@ -2000,9 +2000,11 @@ static void print_qht_statistics(struct qht_stats hst)
     if (!hst.head_buckets) {
         return;
     }
-    qemu_printf("TB hash buckets     %zu/%zu (%0.2f%% head buckets used)\n",
-                hst.used_head_buckets, hst.head_buckets,
-                (double)hst.used_head_buckets / hst.head_buckets * 100);
+    g_string_append_printf(buf, "TB hash buckets     %zu/%zu "
+                           "(%0.2f%% head buckets used)\n",
+                           hst.used_head_buckets, hst.head_buckets,
+                           (double)hst.used_head_buckets /
+                           hst.head_buckets * 100);
 
     hgram_opts =  QDIST_PR_BORDER | QDIST_PR_LABELS;
     hgram_opts |= QDIST_PR_100X   | QDIST_PR_PERCENT;
@@ -2010,8 +2012,9 @@ static void print_qht_statistics(struct qht_stats hst)
         hgram_opts |= QDIST_PR_NODECIMAL;
     }
     hgram = qdist_pr(&hst.occupancy, 10, hgram_opts);
-    qemu_printf("TB hash occupancy   %0.2f%% avg chain occ. Histogram: %s\n",
-                qdist_avg(&hst.occupancy) * 100, hgram);
+    g_string_append_printf(buf, "TB hash occupancy   %0.2f%% avg chain occ. "
+                           "Histogram: %s\n",
+                           qdist_avg(&hst.occupancy) * 100, hgram);
     g_free(hgram);
 
     hgram_opts = QDIST_PR_BORDER | QDIST_PR_LABELS;
@@ -2023,8 +2026,9 @@ static void print_qht_statistics(struct qht_stats hst)
         hgram_opts |= QDIST_PR_NODECIMAL | QDIST_PR_NOBINRANGE;
     }
     hgram = qdist_pr(&hst.chain, hgram_bins, hgram_opts);
-    qemu_printf("TB hash avg chain   %0.3f buckets. Histogram: %s\n",
-                qdist_avg(&hst.chain), hgram);
+    g_string_append_printf(buf, "TB hash avg chain   %0.3f buckets. "
+                           "Histogram: %s\n",
+                           qdist_avg(&hst.chain), hgram);
     g_free(hgram);
 }
 
@@ -2061,7 +2065,7 @@ static gboolean tb_tree_stats_iter(gpointer key, gpointer value, gpointer data)
     return false;
 }
 
-void dump_exec_info(void)
+void dump_exec_info(GString *buf)
 {
     struct tb_tree_stats tst = {};
     struct qht_stats hst;
@@ -2070,44 +2074,48 @@ void dump_exec_info(void)
     tcg_tb_foreach(tb_tree_stats_iter, &tst);
     nb_tbs = tst.nb_tbs;
     /* XXX: avoid using doubles ? */
-    qemu_printf("Translation buffer state:\n");
+    g_string_append_printf(buf, "Translation buffer state:\n");
     /*
      * Report total code size including the padding and TB structs;
      * otherwise users might think "-accel tcg,tb-size" is not honoured.
      * For avg host size we use the precise numbers from tb_tree_stats though.
      */
-    qemu_printf("gen code size       %zu/%zu\n",
-                tcg_code_size(), tcg_code_capacity());
-    qemu_printf("TB count            %zu\n", nb_tbs);
-    qemu_printf("TB avg target size  %zu max=%zu bytes\n",
-                nb_tbs ? tst.target_size / nb_tbs : 0,
-                tst.max_target_size);
-    qemu_printf("TB avg host size    %zu bytes (expansion ratio: %0.1f)\n",
-                nb_tbs ? tst.host_size / nb_tbs : 0,
-                tst.target_size ? (double)tst.host_size / tst.target_size : 0);
-    qemu_printf("cross page TB count %zu (%zu%%)\n", tst.cross_page,
-                nb_tbs ? (tst.cross_page * 100) / nb_tbs : 0);
-    qemu_printf("direct jump count   %zu (%zu%%) (2 jumps=%zu %zu%%)\n",
-                tst.direct_jmp_count,
-                nb_tbs ? (tst.direct_jmp_count * 100) / nb_tbs : 0,
-                tst.direct_jmp2_count,
-                nb_tbs ? (tst.direct_jmp2_count * 100) / nb_tbs : 0);
+    g_string_append_printf(buf, "gen code size       %zu/%zu\n",
+                           tcg_code_size(), tcg_code_capacity());
+    g_string_append_printf(buf, "TB count            %zu\n", nb_tbs);
+    g_string_append_printf(buf, "TB avg target size  %zu max=%zu bytes\n",
+                           nb_tbs ? tst.target_size / nb_tbs : 0,
+                           tst.max_target_size);
+    g_string_append_printf(buf, "TB avg host size    %zu bytes "
+                           "(expansion ratio: %0.1f)\n",
+                           nb_tbs ? tst.host_size / nb_tbs : 0,
+                           tst.target_size ?
+                           (double)tst.host_size / tst.target_size : 0);
+    g_string_append_printf(buf, "cross page TB count %zu (%zu%%)\n",
+                           tst.cross_page,
+                           nb_tbs ? (tst.cross_page * 100) / nb_tbs : 0);
+    g_string_append_printf(buf, "direct jump count   %zu (%zu%%) "
+                           "(2 jumps=%zu %zu%%)\n",
+                           tst.direct_jmp_count,
+                           nb_tbs ? (tst.direct_jmp_count * 100) / nb_tbs : 0,
+                           tst.direct_jmp2_count,
+                           nb_tbs ? (tst.direct_jmp2_count * 100) / nb_tbs : 0);
 
     qht_statistics_init(&tb_ctx.htable, &hst);
-    print_qht_statistics(hst);
+    print_qht_statistics(hst, buf);
     qht_statistics_destroy(&hst);
 
-    qemu_printf("\nStatistics:\n");
-    qemu_printf("TB flush count      %u\n",
-                qatomic_read(&tb_ctx.tb_flush_count));
-    qemu_printf("TB invalidate count %u\n",
-                qatomic_read(&tb_ctx.tb_phys_invalidate_count));
+    g_string_append_printf(buf, "\nStatistics:\n");
+    g_string_append_printf(buf, "TB flush count      %u\n",
+                           qatomic_read(&tb_ctx.tb_flush_count));
+    g_string_append_printf(buf, "TB invalidate count %u\n",
+                           qatomic_read(&tb_ctx.tb_phys_invalidate_count));
 
     tlb_flush_counts(&flush_full, &flush_part, &flush_elide);
-    qemu_printf("TLB full flushes    %zu\n", flush_full);
-    qemu_printf("TLB partial flushes %zu\n", flush_part);
-    qemu_printf("TLB elided flushes  %zu\n", flush_elide);
-    tcg_dump_info();
+    g_string_append_printf(buf, "TLB full flushes    %zu\n", flush_full);
+    g_string_append_printf(buf, "TLB partial flushes %zu\n", flush_part);
+    g_string_append_printf(buf, "TLB elided flushes  %zu\n", flush_elide);
+    tcg_dump_info(buf);
 }
 
 void dump_opcount_info(void)