perf: 'perf kvm' tool for monitoring guest performance from host

Here is the patch of userspace perf tool.

Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

1 files changed, 205 insertions, 75 deletions

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 571fb25f7eb9..e3fa8d3d11b4 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -112,7 +112,11 @@ static int event__synthesize_mmap_events(pid_t pid, pid_t tgid,
                 event_t ev = {
                         .header = {
                                 .type = PERF_RECORD_MMAP,
-                                .misc = 0, /* Just like the kernel, see kernel/perf_event.c __perf_event_mmap */
+                                /*
+                                 * Just like the kernel, see __perf_event_mmap
+                                 * in kernel/perf_event.c
+                                 */
+                                .misc = PERF_RECORD_MISC_USER,
                          },
                 };
                 int n;
@@ -167,11 +171,23 @@ static int event__synthesize_mmap_events(pid_t pid, pid_t tgid,
 }
 
 int event__synthesize_modules(event__handler_t process,
-                              struct perf_session *session)
+                              struct perf_session *session,
+                              struct kernel_info *kerninfo)
 {
         struct rb_node *nd;
+        struct map_groups *kmaps = &kerninfo->kmaps;
+        u16 misc;
 
-        for (nd = rb_first(&session->kmaps.maps[MAP__FUNCTION]);
+        /*
+         * kernel uses 0 for user space maps, see kernel/perf_event.c
+         * __perf_event_mmap
+         */
+        if (is_host_kernel(kerninfo))
+                misc = PERF_RECORD_MISC_KERNEL;
+        else
+                misc = PERF_RECORD_MISC_GUEST_KERNEL;
+
+        for (nd = rb_first(&kmaps->maps[MAP__FUNCTION]);
              nd; nd = rb_next(nd)) {
                 event_t ev;
                 size_t size;
@@ -182,12 +198,13 @@ int event__synthesize_modules(event__handler_t process,
 
                 size = ALIGN(pos->dso->long_name_len + 1, sizeof(u64));
                 memset(&ev, 0, sizeof(ev));
-                ev.mmap.header.misc = 1; /* kernel uses 0 for user space maps, see kernel/perf_event.c __perf_event_mmap */
+                ev.mmap.header.misc = misc;
                 ev.mmap.header.type = PERF_RECORD_MMAP;
                 ev.mmap.header.size = (sizeof(ev.mmap) -
                                         (sizeof(ev.mmap.filename) - size));
                 ev.mmap.start = pos->start;
                 ev.mmap.len   = pos->end - pos->start;
+                ev.mmap.pid   = kerninfo->pid;
 
                 memcpy(ev.mmap.filename, pos->dso->long_name,
                        pos->dso->long_name_len + 1);
@@ -250,13 +267,18 @@ static int find_symbol_cb(void *arg, const char *name, char type, u64 start)
 
 int event__synthesize_kernel_mmap(event__handler_t process,
                                   struct perf_session *session,
+                                  struct kernel_info *kerninfo,
                                   const char *symbol_name)
 {
         size_t size;
+        const char *filename, *mmap_name;
+        char path[PATH_MAX];
+        char name_buff[PATH_MAX];
+        struct map *map;
+
         event_t ev = {
                 .header = {
                         .type = PERF_RECORD_MMAP,
-                        .misc = 1, /* kernel uses 0 for user space maps, see kernel/perf_event.c __perf_event_mmap */
                 },
         };
         /*
@@ -266,16 +288,37 @@ int event__synthesize_kernel_mmap(event__handler_t process,
          */
         struct process_symbol_args args = { .name = symbol_name, };
 
-        if (kallsyms__parse("/proc/kallsyms", &args, find_symbol_cb) <= 0)
+        mmap_name = kern_mmap_name(kerninfo, name_buff);
+        if (is_host_kernel(kerninfo)) {
+                /*
+                 * kernel uses PERF_RECORD_MISC_USER for user space maps,
+                 * see kernel/perf_event.c __perf_event_mmap
+                 */
+                ev.header.misc = PERF_RECORD_MISC_KERNEL;
+                filename = "/proc/kallsyms";
+        } else {
+                ev.header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
+                if (is_default_guest(kerninfo))
+                        filename = (char *) symbol_conf.default_guest_kallsyms;
+                else {
+                        sprintf(path, "%s/proc/kallsyms", kerninfo->root_dir);
+                        filename = path;
+                }
+        }
+
+        if (kallsyms__parse(filename, &args, find_symbol_cb) <= 0)
                 return -ENOENT;
 
+        map = kerninfo->vmlinux_maps[MAP__FUNCTION];
         size = snprintf(ev.mmap.filename, sizeof(ev.mmap.filename),
-                        "[kernel.kallsyms.%s]", symbol_name) + 1;
+                        "%s%s", mmap_name, symbol_name) + 1;
         size = ALIGN(size, sizeof(u64));
-        ev.mmap.header.size = (sizeof(ev.mmap) - (sizeof(ev.mmap.filename) - size));
+        ev.mmap.header.size = (sizeof(ev.mmap) -
+                        (sizeof(ev.mmap.filename) - size));
         ev.mmap.pgoff = args.start;
-        ev.mmap.start = session->vmlinux_maps[MAP__FUNCTION]->start;
-        ev.mmap.len   = session->vmlinux_maps[MAP__FUNCTION]->end - ev.mmap.start ;
+        ev.mmap.start = map->start;
+        ev.mmap.len   = map->end - ev.mmap.start;
+        ev.mmap.pid   = kerninfo->pid;
 
         return process(&ev, session);
 }
@@ -329,22 +372,50 @@ int event__process_lost(event_t *self, struct perf_session *session)
         return 0;
 }
 
-int event__process_mmap(event_t *self, struct perf_session *session)
+static void event_set_kernel_mmap_len(struct map **maps, event_t *self)
+{
+        maps[MAP__FUNCTION]->start = self->mmap.start;
+        maps[MAP__FUNCTION]->end   = self->mmap.start + self->mmap.len;
+        /*
+         * Be a bit paranoid here, some perf.data file came with
+         * a zero sized synthesized MMAP event for the kernel.
+         */
+        if (maps[MAP__FUNCTION]->end == 0)
+                maps[MAP__FUNCTION]->end = ~0UL;
+}
+
+static int event__process_kernel_mmap(event_t *self,
+                        struct perf_session *session)
 {
-        struct thread *thread;
         struct map *map;
+        char kmmap_prefix[PATH_MAX];
+        struct kernel_info *kerninfo;
+        enum dso_kernel_type kernel_type;
+        bool is_kernel_mmap;
+
+        kerninfo = kerninfo__findnew(&session->kerninfo_root, self->mmap.pid);
+        if (!kerninfo) {
+                pr_err("Can't find id %d's kerninfo\n", self->mmap.pid);
+                goto out_problem;
+        }
 
-        dump_printf(" %d/%d: [%#Lx(%#Lx) @ %#Lx]: %s\n",
-                    self->mmap.pid, self->mmap.tid, self->mmap.start,
-                    self->mmap.len, self->mmap.pgoff, self->mmap.filename);
+        kern_mmap_name(kerninfo, kmmap_prefix);
+        if (is_host_kernel(kerninfo))
+                kernel_type = DSO_TYPE_KERNEL;
+        else
+                kernel_type = DSO_TYPE_GUEST_KERNEL;
 
-        if (self->mmap.pid == 0) {
-                static const char kmmap_prefix[] = "[kernel.kallsyms.";
+        is_kernel_mmap = memcmp(self->mmap.filename,
+                                kmmap_prefix,
+                                strlen(kmmap_prefix)) == 0;
+        if (self->mmap.filename[0] == '/' ||
+            (!is_kernel_mmap && self->mmap.filename[0] == '[')) {
 
-                if (self->mmap.filename[0] == '/') {
-                        char short_module_name[1024];
-                        char *name = strrchr(self->mmap.filename, '/'), *dot;
+                char short_module_name[1024];
+                char *name, *dot;
 
+                if (self->mmap.filename[0] == '/') {
+                        name = strrchr(self->mmap.filename, '/');
                         if (name == NULL)
                                 goto out_problem;
 
@@ -352,59 +423,86 @@ int event__process_mmap(event_t *self, struct perf_session *session)
                         dot = strrchr(name, '.');
                         if (dot == NULL)
                                 goto out_problem;
-
                         snprintf(short_module_name, sizeof(short_module_name),
-                                 "[%.*s]", (int)(dot - name), name);
+                                        "[%.*s]", (int)(dot - name), name);
                         strxfrchar(short_module_name, '-', '_');
-
-                        map = perf_session__new_module_map(session,
-                                                           self->mmap.start,
-                                                           self->mmap.filename);
-                        if (map == NULL)
-                                goto out_problem;
-
-                        name = strdup(short_module_name);
-                        if (name == NULL)
-                                goto out_problem;
-
-                        map->dso->short_name = name;
-                        map->end = map->start + self->mmap.len;
-                } else if (memcmp(self->mmap.filename, kmmap_prefix,
-                                sizeof(kmmap_prefix) - 1) == 0) {
-                        const char *symbol_name = (self->mmap.filename +
-                                                   sizeof(kmmap_prefix) - 1);
+                } else
+                        strcpy(short_module_name, self->mmap.filename);
+
+                map = map_groups__new_module(&kerninfo->kmaps,
+                                self->mmap.start,
+                                self->mmap.filename,
+                                kerninfo);
+                if (map == NULL)
+                        goto out_problem;
+
+                name = strdup(short_module_name);
+                if (name == NULL)
+                        goto out_problem;
+
+                map->dso->short_name = name;
+                map->end = map->start + self->mmap.len;
+        } else if (is_kernel_mmap) {
+                const char *symbol_name = (self->mmap.filename +
+                                strlen(kmmap_prefix));
+                /*
+                 * Should be there already, from the build-id table in
+                 * the header.
+                 */
+                struct dso *kernel = __dsos__findnew(&kerninfo->dsos__kernel,
+                                kmmap_prefix);
+                if (kernel == NULL)
+                        goto out_problem;
+
+                kernel->kernel = kernel_type;
+                if (__map_groups__create_kernel_maps(&kerninfo->kmaps,
+                                        kerninfo->vmlinux_maps, kernel) < 0)
+                        goto out_problem;
+
+                event_set_kernel_mmap_len(kerninfo->vmlinux_maps, self);
+                perf_session__set_kallsyms_ref_reloc_sym(kerninfo->vmlinux_maps,
+                                symbol_name,
+                                self->mmap.pgoff);
+                if (is_default_guest(kerninfo)) {
                         /*
-                         * Should be there already, from the build-id table in
-                         * the header.
+                         * preload dso of guest kernel and modules
                          */
-                        struct dso *kernel = __dsos__findnew(&dsos__kernel,
-                                                             "[kernel.kallsyms]");
-                        if (kernel == NULL)
-                                goto out_problem;
-
-                        kernel->kernel = 1;
-                        if (__perf_session__create_kernel_maps(session, kernel) < 0)
-                                goto out_problem;
+                        dso__load(kernel,
+                                kerninfo->vmlinux_maps[MAP__FUNCTION],
+                                NULL);
+                }
+        }
+        return 0;
+out_problem:
+        return -1;
+}
 
-                        session->vmlinux_maps[MAP__FUNCTION]->start = self->mmap.start;
-                        session->vmlinux_maps[MAP__FUNCTION]->end   = self->mmap.start + self->mmap.len;
-                        /*
-                         * Be a bit paranoid here, some perf.data file came with
-                         * a zero sized synthesized MMAP event for the kernel.
-                         */
-                        if (session->vmlinux_maps[MAP__FUNCTION]->end == 0)
-                                session->vmlinux_maps[MAP__FUNCTION]->end = ~0UL;
+int event__process_mmap(event_t *self, struct perf_session *session)
+{
+        struct kernel_info *kerninfo;
+        struct thread *thread;
+        struct map *map;
+        u8 cpumode = self->header.misc & PERF_RECORD_MISC_CPUMODE_MASK;
+        int ret = 0;
 
-                        perf_session__set_kallsyms_ref_reloc_sym(session, symbol_name,
-                                                                 self->mmap.pgoff);
-                }
+        dump_printf(" %d/%d: [%#Lx(%#Lx) @ %#Lx]: %s\n",
+                        self->mmap.pid, self->mmap.tid, self->mmap.start,
+                        self->mmap.len, self->mmap.pgoff, self->mmap.filename);
+
+        if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL ||
+            cpumode == PERF_RECORD_MISC_KERNEL) {
+                ret = event__process_kernel_mmap(self, session);
+                if (ret < 0)
+                        goto out_problem;
                 return 0;
         }
 
         thread = perf_session__findnew(session, self->mmap.pid);
-        map = map__new(self->mmap.start, self->mmap.len, self->mmap.pgoff,
-                       self->mmap.pid, self->mmap.filename, MAP__FUNCTION,
-                       session->cwd, session->cwdlen);
+        kerninfo = kerninfo__findhost(&session->kerninfo_root);
+        map = map__new(&kerninfo->dsos__user, self->mmap.start,
+                        self->mmap.len, self->mmap.pgoff,
+                        self->mmap.pid, self->mmap.filename,
+                        MAP__FUNCTION, session->cwd, session->cwdlen);
 
         if (thread == NULL || map == NULL)
                 goto out_problem;
@@ -444,22 +542,52 @@ int event__process_task(event_t *self, struct perf_session *session)
 
 void thread__find_addr_map(struct thread *self,
                            struct perf_session *session, u8 cpumode,
-                           enum map_type type, u64 addr,
+                           enum map_type type, pid_t pid, u64 addr,
                            struct addr_location *al)
 {
         struct map_groups *mg = &self->mg;
+        struct kernel_info *kerninfo = NULL;
 
         al->thread = self;
         al->addr = addr;
+        al->cpumode = cpumode;
+        al->filtered = false;
 
-        if (cpumode == PERF_RECORD_MISC_KERNEL) {
+        if (cpumode == PERF_RECORD_MISC_KERNEL && perf_host) {
                 al->level = 'k';
-                mg = &session->kmaps;
-        } else if (cpumode == PERF_RECORD_MISC_USER)
+                kerninfo = kerninfo__findhost(&session->kerninfo_root);
+                mg = &kerninfo->kmaps;
+        } else if (cpumode == PERF_RECORD_MISC_USER && perf_host) {
                 al->level = '.';
-        else {
-                al->level = 'H';
+                kerninfo = kerninfo__findhost(&session->kerninfo_root);
+        } else if (cpumode == PERF_RECORD_MISC_GUEST_KERNEL && perf_guest) {
+                al->level = 'g';
+                kerninfo = kerninfo__find(&session->kerninfo_root, pid);
+                if (!kerninfo) {
+                        al->map = NULL;
+                        return;
+                }
+                mg = &kerninfo->kmaps;
+        } else {
+                /*
+                 * 'u' means guest os user space.
+                 * TODO: We don't support guest user space. Might support late.
+                 */
+                if (cpumode == PERF_RECORD_MISC_GUEST_USER && perf_guest)
+                        al->level = 'u';
+                else
+                        al->level = 'H';
                 al->map = NULL;
+
+                if ((cpumode == PERF_RECORD_MISC_GUEST_USER ||
+                        cpumode == PERF_RECORD_MISC_GUEST_KERNEL) &&
+                        !perf_guest)
+                        al->filtered = true;
+                if ((cpumode == PERF_RECORD_MISC_USER ||
+                        cpumode == PERF_RECORD_MISC_KERNEL) &&
+                        !perf_host)
+                        al->filtered = true;
+
                 return;
         }
 try_again:
@@ -474,8 +602,11 @@ try_again:
                  * "[vdso]" dso, but for now lets use the old trick of looking
                  * in the whole kernel symbol list.
                  */
-                if ((long long)al->addr < 0 && mg != &session->kmaps) {
-                        mg = &session->kmaps;
+                if ((long long)al->addr < 0 &&
+                        cpumode == PERF_RECORD_MISC_KERNEL &&
+                        kerninfo &&
+                        mg != &kerninfo->kmaps)  {
+                        mg = &kerninfo->kmaps;
                         goto try_again;
                 }
         } else
@@ -484,11 +615,11 @@ try_again:
 
 void thread__find_addr_location(struct thread *self,
                                 struct perf_session *session, u8 cpumode,
-                                enum map_type type, u64 addr,
+                                enum map_type type, pid_t pid, u64 addr,
                                 struct addr_location *al,
                                 symbol_filter_t filter)
 {
-        thread__find_addr_map(self, session, cpumode, type, addr, al);
+        thread__find_addr_map(self, session, cpumode, type, pid, addr, al);
         if (al->map != NULL)
                 al->sym = map__find_symbol(al->map, al->addr, filter);
         else
@@ -524,7 +655,7 @@ int event__preprocess_sample(const event_t *self, struct perf_session *session,
         dump_printf(" ... thread: %s:%d\n", thread->comm, thread->pid);
 
         thread__find_addr_map(thread, session, cpumode, MAP__FUNCTION,
-                              self->ip.ip, al);
+                              self->ip.pid, self->ip.ip, al);
         dump_printf(" ...... dso: %s\n",
                     al->map ? al->map->dso->long_name :
                         al->level == 'H' ? "[hypervisor]" : "<not found>");
@@ -554,7 +685,6 @@ int event__preprocess_sample(const event_t *self, struct perf_session *session,
             !strlist__has_entry(symbol_conf.sym_list, al->sym->name))
                 goto out_filtered;
 
-        al->filtered = false;
         return 0;
 
 out_filtered: