* [PULL 1/5] linux-user: Clean up when exiting due to a signal
2023-01-16 22:36 [PULL 0/5] tcg patch queue Richard Henderson
@ 2023-01-16 22:36 ` Richard Henderson
2023-01-16 22:36 ` [PULL 2/5] accel/tcg: Add debuginfo support Richard Henderson
` (5 subsequent siblings)
6 siblings, 0 replies; 20+ messages in thread
From: Richard Henderson @ 2023-01-16 22:36 UTC (permalink / raw)
To: qemu-devel; +Cc: peter.maydell, Ilya Leoshkevich, Alex Bennée
From: Ilya Leoshkevich <iii@linux.ibm.com>
When exiting due to an exit() syscall, qemu-user calls
preexit_cleanup(), but this is currently not the case when exiting due
to a signal. This leads to various buffers not being flushed (e.g.,
for gprof, for gcov, and for the upcoming perf support).
Add the missing call.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230112152013.125680-2-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
linux-user/signal.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/linux-user/signal.c b/linux-user/signal.c
index 61c6fa3fcf..098f3a787d 100644
--- a/linux-user/signal.c
+++ b/linux-user/signal.c
@@ -695,7 +695,7 @@ void cpu_loop_exit_sigbus(CPUState *cpu, target_ulong addr,
/* abort execution with signal */
static G_NORETURN
-void dump_core_and_abort(int target_sig)
+void dump_core_and_abort(CPUArchState *cpu_env, int target_sig)
{
CPUState *cpu = thread_cpu;
CPUArchState *env = cpu->env_ptr;
@@ -724,6 +724,8 @@ void dump_core_and_abort(int target_sig)
target_sig, strsignal(host_sig), "core dumped" );
}
+ preexit_cleanup(cpu_env, 128 + target_sig);
+
/* The proper exit code for dying from an uncaught signal is
* -<signal>. The kernel doesn't allow exit() or _exit() to pass
* a negative value. To get the proper exit code we need to
@@ -1058,12 +1060,12 @@ static void handle_pending_signal(CPUArchState *cpu_env, int sig,
sig != TARGET_SIGURG &&
sig != TARGET_SIGWINCH &&
sig != TARGET_SIGCONT) {
- dump_core_and_abort(sig);
+ dump_core_and_abort(cpu_env, sig);
}
} else if (handler == TARGET_SIG_IGN) {
/* ignore sig */
} else if (handler == TARGET_SIG_ERR) {
- dump_core_and_abort(sig);
+ dump_core_and_abort(cpu_env, sig);
} else {
/* compute the blocked signals during the handler execution */
sigset_t *blocked_set;
--
2.34.1
^ permalink raw reply related [flat|nested] 20+ messages in thread* [PULL 2/5] accel/tcg: Add debuginfo support
2023-01-16 22:36 [PULL 0/5] tcg patch queue Richard Henderson
2023-01-16 22:36 ` [PULL 1/5] linux-user: Clean up when exiting due to a signal Richard Henderson
@ 2023-01-16 22:36 ` Richard Henderson
2023-01-16 22:36 ` [PULL 3/5] tcg: add perfmap and jitdump Richard Henderson
` (4 subsequent siblings)
6 siblings, 0 replies; 20+ messages in thread
From: Richard Henderson @ 2023-01-16 22:36 UTC (permalink / raw)
To: qemu-devel; +Cc: peter.maydell, Ilya Leoshkevich
From: Ilya Leoshkevich <iii@linux.ibm.com>
Add libdw-based functions for loading and querying debuginfo. Load
debuginfo from the system and the linux-user loaders.
This is useful for the upcoming perf support, which can then put
human-readable guest symbols instead of raw guest PCs into perfmap and
jitdump files.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20230112152013.125680-3-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
meson.build | 8 ++++
accel/tcg/debuginfo.h | 77 +++++++++++++++++++++++++++++++++
accel/tcg/debuginfo.c | 96 ++++++++++++++++++++++++++++++++++++++++++
hw/core/loader.c | 5 +++
linux-user/elfload.c | 3 ++
accel/tcg/meson.build | 1 +
linux-user/meson.build | 1 +
7 files changed, 191 insertions(+)
create mode 100644 accel/tcg/debuginfo.h
create mode 100644 accel/tcg/debuginfo.c
diff --git a/meson.build b/meson.build
index 5d68a8fd23..6d212f6c8e 100644
--- a/meson.build
+++ b/meson.build
@@ -1648,6 +1648,12 @@ if libbpf.found() and not cc.links('''
endif
endif
+# libdw
+libdw = dependency('libdw',
+ method: 'pkg-config',
+ kwargs: static_kwargs,
+ required: false)
+
#################
# config-host.h #
#################
@@ -1923,6 +1929,7 @@ config_host_data.set('CONFIG_DBUS_DISPLAY', dbus_display)
config_host_data.set('CONFIG_CFI', get_option('cfi'))
config_host_data.set('CONFIG_SELINUX', selinux.found())
config_host_data.set('CONFIG_XEN_BACKEND', xen.found())
+config_host_data.set('CONFIG_LIBDW', libdw.found())
if xen.found()
# protect from xen.version() having less than three components
xen_version = xen.version().split('.') + ['0', '0']
@@ -3976,6 +3983,7 @@ summary_info += {'libudev': libudev}
# Dummy dependency, keep .found()
summary_info += {'FUSE lseek': fuse_lseek.found()}
summary_info += {'selinux': selinux}
+summary_info += {'libdw': libdw}
summary(summary_info, bool_yn: true, section: 'Dependencies')
if not supported_cpus.contains(cpu)
diff --git a/accel/tcg/debuginfo.h b/accel/tcg/debuginfo.h
new file mode 100644
index 0000000000..7542cfe6e0
--- /dev/null
+++ b/accel/tcg/debuginfo.h
@@ -0,0 +1,77 @@
+/*
+ * Debug information support.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef ACCEL_TCG_DEBUGINFO_H
+#define ACCEL_TCG_DEBUGINFO_H
+
+/*
+ * Debuginfo describing a certain address.
+ */
+struct debuginfo_query {
+ uint64_t address; /* Input: address. */
+ int flags; /* Input: debuginfo subset. */
+ const char *symbol; /* Symbol that the address is part of. */
+ uint64_t offset; /* Offset from the symbol. */
+ const char *file; /* Source file associated with the address. */
+ int line; /* Line number in the source file. */
+};
+
+/*
+ * Debuginfo subsets.
+ */
+#define DEBUGINFO_SYMBOL BIT(1)
+#define DEBUGINFO_LINE BIT(2)
+
+#if defined(CONFIG_TCG) && defined(CONFIG_LIBDW)
+/*
+ * Load debuginfo for the specified guest ELF image.
+ * Return true on success, false on failure.
+ */
+void debuginfo_report_elf(const char *name, int fd, uint64_t bias);
+
+/*
+ * Take the debuginfo lock.
+ */
+void debuginfo_lock(void);
+
+/*
+ * Fill each on N Qs with the debuginfo about Q->ADDRESS as specified by
+ * Q->FLAGS:
+ *
+ * - DEBUGINFO_SYMBOL: update Q->SYMBOL and Q->OFFSET. If symbol debuginfo is
+ * missing, then leave them as is.
+ * - DEBUINFO_LINE: update Q->FILE and Q->LINE. If line debuginfo is missing,
+ * then leave them as is.
+ *
+ * This function must be called under the debuginfo lock. The results can be
+ * accessed only until the debuginfo lock is released.
+ */
+void debuginfo_query(struct debuginfo_query *q, size_t n);
+
+/*
+ * Release the debuginfo lock.
+ */
+void debuginfo_unlock(void);
+#else
+static inline void debuginfo_report_elf(const char *image_name, int image_fd,
+ uint64_t load_bias)
+{
+}
+
+static inline void debuginfo_lock(void)
+{
+}
+
+static inline void debuginfo_query(struct debuginfo_query *q, size_t n)
+{
+}
+
+static inline void debuginfo_unlock(void)
+{
+}
+#endif
+
+#endif
diff --git a/accel/tcg/debuginfo.c b/accel/tcg/debuginfo.c
new file mode 100644
index 0000000000..71c66d04d1
--- /dev/null
+++ b/accel/tcg/debuginfo.c
@@ -0,0 +1,96 @@
+/*
+ * Debug information support.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/lockable.h"
+
+#include <elfutils/libdwfl.h>
+
+#include "debuginfo.h"
+
+static QemuMutex lock;
+static Dwfl *dwfl;
+static const Dwfl_Callbacks dwfl_callbacks = {
+ .find_elf = NULL,
+ .find_debuginfo = dwfl_standard_find_debuginfo,
+ .section_address = NULL,
+ .debuginfo_path = NULL,
+};
+
+__attribute__((constructor))
+static void debuginfo_init(void)
+{
+ qemu_mutex_init(&lock);
+}
+
+void debuginfo_report_elf(const char *name, int fd, uint64_t bias)
+{
+ QEMU_LOCK_GUARD(&lock);
+
+ if (dwfl) {
+ dwfl_report_begin_add(dwfl);
+ } else {
+ dwfl = dwfl_begin(&dwfl_callbacks);
+ }
+
+ if (dwfl) {
+ dwfl_report_elf(dwfl, name, name, fd, bias, true);
+ dwfl_report_end(dwfl, NULL, NULL);
+ }
+}
+
+void debuginfo_lock(void)
+{
+ qemu_mutex_lock(&lock);
+}
+
+void debuginfo_query(struct debuginfo_query *q, size_t n)
+{
+ const char *symbol, *file;
+ Dwfl_Module *dwfl_module;
+ Dwfl_Line *dwfl_line;
+ GElf_Off dwfl_offset;
+ GElf_Sym dwfl_sym;
+ size_t i;
+ int line;
+
+ if (!dwfl) {
+ return;
+ }
+
+ for (i = 0; i < n; i++) {
+ dwfl_module = dwfl_addrmodule(dwfl, q[i].address);
+ if (!dwfl_module) {
+ continue;
+ }
+
+ if (q[i].flags & DEBUGINFO_SYMBOL) {
+ symbol = dwfl_module_addrinfo(dwfl_module, q[i].address,
+ &dwfl_offset, &dwfl_sym,
+ NULL, NULL, NULL);
+ if (symbol) {
+ q[i].symbol = symbol;
+ q[i].offset = dwfl_offset;
+ }
+ }
+
+ if (q[i].flags & DEBUGINFO_LINE) {
+ dwfl_line = dwfl_module_getsrc(dwfl_module, q[i].address);
+ if (dwfl_line) {
+ file = dwfl_lineinfo(dwfl_line, NULL, &line, 0, NULL, NULL);
+ if (file) {
+ q[i].file = file;
+ q[i].line = line;
+ }
+ }
+ }
+ }
+}
+
+void debuginfo_unlock(void)
+{
+ qemu_mutex_unlock(&lock);
+}
diff --git a/hw/core/loader.c b/hw/core/loader.c
index 0548830733..55dbe2e199 100644
--- a/hw/core/loader.c
+++ b/hw/core/loader.c
@@ -61,6 +61,7 @@
#include "hw/boards.h"
#include "qemu/cutils.h"
#include "sysemu/runstate.h"
+#include "accel/tcg/debuginfo.h"
#include <zlib.h>
@@ -503,6 +504,10 @@ ssize_t load_elf_ram_sym(const char *filename,
clear_lsb, data_swab, as, load_rom, sym_cb);
}
+ if (ret != ELF_LOAD_FAILED) {
+ debuginfo_report_elf(filename, fd, 0);
+ }
+
fail:
close(fd);
return ret;
diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 20894b633f..5928c14dfc 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -19,6 +19,7 @@
#include "qemu/selfmap.h"
#include "qapi/error.h"
#include "target_signal.h"
+#include "accel/tcg/debuginfo.h"
#ifdef _ARCH_PPC64
#undef ARCH_DLINFO
@@ -3261,6 +3262,8 @@ static void load_elf_image(const char *image_name, int image_fd,
load_symbols(ehdr, image_fd, load_bias);
}
+ debuginfo_report_elf(image_name, image_fd, load_bias);
+
mmap_unlock();
close(image_fd);
diff --git a/accel/tcg/meson.build b/accel/tcg/meson.build
index 75e1dffb4d..55b3b4dd7e 100644
--- a/accel/tcg/meson.build
+++ b/accel/tcg/meson.build
@@ -12,6 +12,7 @@ tcg_ss.add(files(
tcg_ss.add(when: 'CONFIG_USER_ONLY', if_true: files('user-exec.c'))
tcg_ss.add(when: 'CONFIG_SOFTMMU', if_false: files('user-exec-stub.c'))
tcg_ss.add(when: 'CONFIG_PLUGIN', if_true: [files('plugin-gen.c')])
+tcg_ss.add(when: libdw, if_true: files('debuginfo.c'))
specific_ss.add_all(when: 'CONFIG_TCG', if_true: tcg_ss)
specific_ss.add(when: ['CONFIG_SOFTMMU', 'CONFIG_TCG'], if_true: files(
diff --git a/linux-user/meson.build b/linux-user/meson.build
index de4320af05..7171dc60be 100644
--- a/linux-user/meson.build
+++ b/linux-user/meson.build
@@ -22,6 +22,7 @@ linux_user_ss.add(files(
'uname.c',
))
linux_user_ss.add(rt)
+linux_user_ss.add(libdw)
linux_user_ss.add(when: 'TARGET_HAS_BFLT', if_true: files('flatload.c'))
linux_user_ss.add(when: 'TARGET_I386', if_true: files('vm86.c'))
--
2.34.1
^ permalink raw reply related [flat|nested] 20+ messages in thread* [PULL 3/5] tcg: add perfmap and jitdump
2023-01-16 22:36 [PULL 0/5] tcg patch queue Richard Henderson
2023-01-16 22:36 ` [PULL 1/5] linux-user: Clean up when exiting due to a signal Richard Henderson
2023-01-16 22:36 ` [PULL 2/5] accel/tcg: Add debuginfo support Richard Henderson
@ 2023-01-16 22:36 ` Richard Henderson
2023-06-02 17:21 ` Peter Maydell
2023-06-29 11:31 ` Philippe Mathieu-Daudé
2023-01-16 22:36 ` [PULL 4/5] util/bufferiszero: Use __attribute__((target)) for avx2/avx512 Richard Henderson
` (3 subsequent siblings)
6 siblings, 2 replies; 20+ messages in thread
From: Richard Henderson @ 2023-01-16 22:36 UTC (permalink / raw)
To: qemu-devel
Cc: peter.maydell, Ilya Leoshkevich, Vanderson M . do Rosario,
Alex Bennée
From: Ilya Leoshkevich <iii@linux.ibm.com>
Add ability to dump /tmp/perf-<pid>.map and jit-<pid>.dump.
The first one allows the perf tool to map samples to each individual
translation block. The second one adds the ability to resolve symbol
names, line numbers and inspect JITed code.
Example of use:
perf record qemu-x86_64 -perfmap ./a.out
perf report
or
perf record -k 1 qemu-x86_64 -jitdump ./a.out
DEBUGINFOD_URLS= perf inject -j -i perf.data -o perf.data.jitted
perf report -i perf.data.jitted
Co-developed-by: Vanderson M. do Rosario <vandersonmr2@gmail.com>
Co-developed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Message-Id: <20230112152013.125680-4-iii@linux.ibm.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
docs/devel/tcg.rst | 23 +++
accel/tcg/perf.h | 49 +++++
accel/tcg/perf.c | 375 ++++++++++++++++++++++++++++++++++++++
accel/tcg/translate-all.c | 7 +
linux-user/exit.c | 2 +
linux-user/main.c | 15 ++
softmmu/vl.c | 11 ++
tcg/tcg.c | 2 +
accel/tcg/meson.build | 1 +
qemu-options.hx | 20 ++
10 files changed, 505 insertions(+)
create mode 100644 accel/tcg/perf.h
create mode 100644 accel/tcg/perf.c
diff --git a/docs/devel/tcg.rst b/docs/devel/tcg.rst
index 136a7a0d96..b4096a17df 100644
--- a/docs/devel/tcg.rst
+++ b/docs/devel/tcg.rst
@@ -188,3 +188,26 @@ memory areas instead calls out to C code for device emulation.
Finally, the MMU helps tracking dirty pages and pages pointed to by
translation blocks.
+Profiling JITted code
+---------------------
+
+The Linux ``perf`` tool will treat all JITted code as a single block as
+unlike the main code it can't use debug information to link individual
+program counter samples with larger functions. To overcome this
+limitation you can use the ``-perfmap`` or the ``-jitdump`` option to generate
+map files. ``-perfmap`` is lightweight and produces only guest-host mappings.
+``-jitdump`` additionally saves JITed code and guest debug information (if
+available); its output needs to be integrated with the ``perf.data`` file
+before the final report can be viewed.
+
+.. code::
+
+ perf record $QEMU -perfmap $REMAINING_ARGS
+ perf report
+
+ perf record -k 1 $QEMU -jitdump $REMAINING_ARGS
+ DEBUGINFOD_URLS= perf inject -j -i perf.data -o perf.data.jitted
+ perf report -i perf.data.jitted
+
+Note that qemu-system generates mappings only for ``-kernel`` files in ELF
+format.
diff --git a/accel/tcg/perf.h b/accel/tcg/perf.h
new file mode 100644
index 0000000000..f92dd52c69
--- /dev/null
+++ b/accel/tcg/perf.h
@@ -0,0 +1,49 @@
+/*
+ * Linux perf perf-<pid>.map and jit-<pid>.dump integration.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef ACCEL_TCG_PERF_H
+#define ACCEL_TCG_PERF_H
+
+#if defined(CONFIG_TCG) && defined(CONFIG_LINUX)
+/* Start writing perf-<pid>.map. */
+void perf_enable_perfmap(void);
+
+/* Start writing jit-<pid>.dump. */
+void perf_enable_jitdump(void);
+
+/* Add information about TCG prologue to profiler maps. */
+void perf_report_prologue(const void *start, size_t size);
+
+/* Add information about JITted guest code to profiler maps. */
+void perf_report_code(uint64_t guest_pc, TranslationBlock *tb,
+ const void *start);
+
+/* Stop writing perf-<pid>.map and/or jit-<pid>.dump. */
+void perf_exit(void);
+#else
+static inline void perf_enable_perfmap(void)
+{
+}
+
+static inline void perf_enable_jitdump(void)
+{
+}
+
+static inline void perf_report_prologue(const void *start, size_t size)
+{
+}
+
+static inline void perf_report_code(uint64_t guest_pc, TranslationBlock *tb,
+ const void *start)
+{
+}
+
+static inline void perf_exit(void)
+{
+}
+#endif
+
+#endif
diff --git a/accel/tcg/perf.c b/accel/tcg/perf.c
new file mode 100644
index 0000000000..ae19f6e28f
--- /dev/null
+++ b/accel/tcg/perf.c
@@ -0,0 +1,375 @@
+/*
+ * Linux perf perf-<pid>.map and jit-<pid>.dump integration.
+ *
+ * The jitdump spec can be found at [1].
+ *
+ * [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/plain/tools/perf/Documentation/jitdump-specification.txt
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "elf.h"
+#include "exec/exec-all.h"
+#include "qemu/timer.h"
+#include "tcg/tcg.h"
+
+#include "debuginfo.h"
+#include "perf.h"
+
+static FILE *safe_fopen_w(const char *path)
+{
+ int saved_errno;
+ FILE *f;
+ int fd;
+
+ /* Delete the old file, if any. */
+ unlink(path);
+
+ /* Avoid symlink attacks by using O_CREAT | O_EXCL. */
+ fd = open(path, O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR);
+ if (fd == -1) {
+ return NULL;
+ }
+
+ /* Convert fd to FILE*. */
+ f = fdopen(fd, "w");
+ if (f == NULL) {
+ saved_errno = errno;
+ close(fd);
+ errno = saved_errno;
+ return NULL;
+ }
+
+ return f;
+}
+
+static FILE *perfmap;
+
+void perf_enable_perfmap(void)
+{
+ char map_file[32];
+
+ snprintf(map_file, sizeof(map_file), "/tmp/perf-%d.map", getpid());
+ perfmap = safe_fopen_w(map_file);
+ if (perfmap == NULL) {
+ warn_report("Could not open %s: %s, proceeding without perfmap",
+ map_file, strerror(errno));
+ }
+}
+
+/* Get PC and size of code JITed for guest instruction #INSN. */
+static void get_host_pc_size(uintptr_t *host_pc, uint16_t *host_size,
+ const void *start, size_t insn)
+{
+ uint16_t start_off = insn ? tcg_ctx->gen_insn_end_off[insn - 1] : 0;
+
+ if (host_pc) {
+ *host_pc = (uintptr_t)start + start_off;
+ }
+ if (host_size) {
+ *host_size = tcg_ctx->gen_insn_end_off[insn] - start_off;
+ }
+}
+
+static const char *pretty_symbol(const struct debuginfo_query *q, size_t *len)
+{
+ static __thread char buf[64];
+ int tmp;
+
+ if (!q->symbol) {
+ tmp = snprintf(buf, sizeof(buf), "guest-0x%"PRIx64, q->address);
+ if (len) {
+ *len = MIN(tmp + 1, sizeof(buf));
+ }
+ return buf;
+ }
+
+ if (!q->offset) {
+ if (len) {
+ *len = strlen(q->symbol) + 1;
+ }
+ return q->symbol;
+ }
+
+ tmp = snprintf(buf, sizeof(buf), "%s+0x%"PRIx64, q->symbol, q->offset);
+ if (len) {
+ *len = MIN(tmp + 1, sizeof(buf));
+ }
+ return buf;
+}
+
+static void write_perfmap_entry(const void *start, size_t insn,
+ const struct debuginfo_query *q)
+{
+ uint16_t host_size;
+ uintptr_t host_pc;
+
+ get_host_pc_size(&host_pc, &host_size, start, insn);
+ fprintf(perfmap, "%"PRIxPTR" %"PRIx16" %s\n",
+ host_pc, host_size, pretty_symbol(q, NULL));
+}
+
+static FILE *jitdump;
+
+#define JITHEADER_MAGIC 0x4A695444
+#define JITHEADER_VERSION 1
+
+struct jitheader {
+ uint32_t magic;
+ uint32_t version;
+ uint32_t total_size;
+ uint32_t elf_mach;
+ uint32_t pad1;
+ uint32_t pid;
+ uint64_t timestamp;
+ uint64_t flags;
+};
+
+enum jit_record_type {
+ JIT_CODE_LOAD = 0,
+ JIT_CODE_DEBUG_INFO = 2,
+};
+
+struct jr_prefix {
+ uint32_t id;
+ uint32_t total_size;
+ uint64_t timestamp;
+};
+
+struct jr_code_load {
+ struct jr_prefix p;
+
+ uint32_t pid;
+ uint32_t tid;
+ uint64_t vma;
+ uint64_t code_addr;
+ uint64_t code_size;
+ uint64_t code_index;
+};
+
+struct debug_entry {
+ uint64_t addr;
+ int lineno;
+ int discrim;
+ const char name[];
+};
+
+struct jr_code_debug_info {
+ struct jr_prefix p;
+
+ uint64_t code_addr;
+ uint64_t nr_entry;
+ struct debug_entry entries[];
+};
+
+static uint32_t get_e_machine(void)
+{
+ Elf64_Ehdr elf_header;
+ FILE *exe;
+ size_t n;
+
+ QEMU_BUILD_BUG_ON(offsetof(Elf32_Ehdr, e_machine) !=
+ offsetof(Elf64_Ehdr, e_machine));
+
+ exe = fopen("/proc/self/exe", "r");
+ if (exe == NULL) {
+ return EM_NONE;
+ }
+
+ n = fread(&elf_header, sizeof(elf_header), 1, exe);
+ fclose(exe);
+ if (n != 1) {
+ return EM_NONE;
+ }
+
+ return elf_header.e_machine;
+}
+
+void perf_enable_jitdump(void)
+{
+ struct jitheader header;
+ char jitdump_file[32];
+ void *perf_marker;
+
+ if (!use_rt_clock) {
+ warn_report("CLOCK_MONOTONIC is not available, proceeding without jitdump");
+ return;
+ }
+
+ snprintf(jitdump_file, sizeof(jitdump_file), "jit-%d.dump", getpid());
+ jitdump = safe_fopen_w(jitdump_file);
+ if (jitdump == NULL) {
+ warn_report("Could not open %s: %s, proceeding without jitdump",
+ jitdump_file, strerror(errno));
+ return;
+ }
+
+ /*
+ * `perf inject` will see that the mapped file name in the corresponding
+ * PERF_RECORD_MMAP or PERF_RECORD_MMAP2 event is of the form jit-%d.dump
+ * and will process it as a jitdump file.
+ */
+ perf_marker = mmap(NULL, qemu_real_host_page_size(), PROT_READ | PROT_EXEC,
+ MAP_PRIVATE, fileno(jitdump), 0);
+ if (perf_marker == MAP_FAILED) {
+ warn_report("Could not map %s: %s, proceeding without jitdump",
+ jitdump_file, strerror(errno));
+ fclose(jitdump);
+ jitdump = NULL;
+ return;
+ }
+
+ header.magic = JITHEADER_MAGIC;
+ header.version = JITHEADER_VERSION;
+ header.total_size = sizeof(header);
+ header.elf_mach = get_e_machine();
+ header.pad1 = 0;
+ header.pid = getpid();
+ header.timestamp = get_clock();
+ header.flags = 0;
+ fwrite(&header, sizeof(header), 1, jitdump);
+}
+
+void perf_report_prologue(const void *start, size_t size)
+{
+ if (perfmap) {
+ fprintf(perfmap, "%"PRIxPTR" %zx tcg-prologue-buffer\n",
+ (uintptr_t)start, size);
+ }
+}
+
+/* Write a JIT_CODE_DEBUG_INFO jitdump entry. */
+static void write_jr_code_debug_info(const void *start,
+ const struct debuginfo_query *q,
+ size_t icount)
+{
+ struct jr_code_debug_info rec;
+ struct debug_entry ent;
+ uintptr_t host_pc;
+ int insn;
+
+ /* Write the header. */
+ rec.p.id = JIT_CODE_DEBUG_INFO;
+ rec.p.total_size = sizeof(rec) + sizeof(ent) + 1;
+ rec.p.timestamp = get_clock();
+ rec.code_addr = (uintptr_t)start;
+ rec.nr_entry = 1;
+ for (insn = 0; insn < icount; insn++) {
+ if (q[insn].file) {
+ rec.p.total_size += sizeof(ent) + strlen(q[insn].file) + 1;
+ rec.nr_entry++;
+ }
+ }
+ fwrite(&rec, sizeof(rec), 1, jitdump);
+
+ /* Write the main debug entries. */
+ for (insn = 0; insn < icount; insn++) {
+ if (q[insn].file) {
+ get_host_pc_size(&host_pc, NULL, start, insn);
+ ent.addr = host_pc;
+ ent.lineno = q[insn].line;
+ ent.discrim = 0;
+ fwrite(&ent, sizeof(ent), 1, jitdump);
+ fwrite(q[insn].file, strlen(q[insn].file) + 1, 1, jitdump);
+ }
+ }
+
+ /* Write the trailing debug_entry. */
+ ent.addr = (uintptr_t)start + tcg_ctx->gen_insn_end_off[icount - 1];
+ ent.lineno = 0;
+ ent.discrim = 0;
+ fwrite(&ent, sizeof(ent), 1, jitdump);
+ fwrite("", 1, 1, jitdump);
+}
+
+/* Write a JIT_CODE_LOAD jitdump entry. */
+static void write_jr_code_load(const void *start, uint16_t host_size,
+ const struct debuginfo_query *q)
+{
+ static uint64_t code_index;
+ struct jr_code_load rec;
+ const char *symbol;
+ size_t symbol_size;
+
+ symbol = pretty_symbol(q, &symbol_size);
+ rec.p.id = JIT_CODE_LOAD;
+ rec.p.total_size = sizeof(rec) + symbol_size + host_size;
+ rec.p.timestamp = get_clock();
+ rec.pid = getpid();
+ rec.tid = qemu_get_thread_id();
+ rec.vma = (uintptr_t)start;
+ rec.code_addr = (uintptr_t)start;
+ rec.code_size = host_size;
+ rec.code_index = code_index++;
+ fwrite(&rec, sizeof(rec), 1, jitdump);
+ fwrite(symbol, symbol_size, 1, jitdump);
+ fwrite(start, host_size, 1, jitdump);
+}
+
+void perf_report_code(uint64_t guest_pc, TranslationBlock *tb,
+ const void *start)
+{
+ struct debuginfo_query *q;
+ size_t insn;
+
+ if (!perfmap && !jitdump) {
+ return;
+ }
+
+ q = g_try_malloc0_n(tb->icount, sizeof(*q));
+ if (!q) {
+ return;
+ }
+
+ debuginfo_lock();
+
+ /* Query debuginfo for each guest instruction. */
+ for (insn = 0; insn < tb->icount; insn++) {
+ /* FIXME: This replicates the restore_state_to_opc() logic. */
+ q[insn].address = tcg_ctx->gen_insn_data[insn][0];
+ if (TARGET_TB_PCREL) {
+ q[insn].address |= (guest_pc & TARGET_PAGE_MASK);
+ } else {
+#if defined(TARGET_I386)
+ q[insn].address -= tb->cs_base;
+#endif
+ }
+ q[insn].flags = DEBUGINFO_SYMBOL | (jitdump ? DEBUGINFO_LINE : 0);
+ }
+ debuginfo_query(q, tb->icount);
+
+ /* Emit perfmap entries if needed. */
+ if (perfmap) {
+ flockfile(perfmap);
+ for (insn = 0; insn < tb->icount; insn++) {
+ write_perfmap_entry(start, insn, &q[insn]);
+ }
+ funlockfile(perfmap);
+ }
+
+ /* Emit jitdump entries if needed. */
+ if (jitdump) {
+ flockfile(jitdump);
+ write_jr_code_debug_info(start, q, tb->icount);
+ write_jr_code_load(start, tcg_ctx->gen_insn_end_off[tb->icount - 1],
+ q);
+ funlockfile(jitdump);
+ }
+
+ debuginfo_unlock();
+ g_free(q);
+}
+
+void perf_exit(void)
+{
+ if (perfmap) {
+ fclose(perfmap);
+ perfmap = NULL;
+ }
+
+ if (jitdump) {
+ fclose(jitdump);
+ jitdump = NULL;
+ }
+}
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index 51ac1f6c84..979f8e1107 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -62,6 +62,7 @@
#include "tb-hash.h"
#include "tb-context.h"
#include "internal.h"
+#include "perf.h"
/* Make sure all possible CPU event bits fit in tb->trace_vcpu_dstate */
QEMU_BUILD_BUG_ON(CPU_TRACE_DSTATE_MAX_EVENTS >
@@ -406,6 +407,12 @@ TranslationBlock *tb_gen_code(CPUState *cpu,
}
tb->tc.size = gen_code_size;
+ /*
+ * For TARGET_TB_PCREL, attribute all executions of the generated
+ * code to its first mapping.
+ */
+ perf_report_code(pc, tb, tcg_splitwx_to_rx(gen_code_buf));
+
#ifdef CONFIG_PROFILER
qatomic_set(&prof->code_time, prof->code_time + profile_getclock() - ti);
qatomic_set(&prof->code_in_len, prof->code_in_len + tb->size);
diff --git a/linux-user/exit.c b/linux-user/exit.c
index fa6ef0b9b4..607b6da9fc 100644
--- a/linux-user/exit.c
+++ b/linux-user/exit.c
@@ -17,6 +17,7 @@
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
+#include "accel/tcg/perf.h"
#include "exec/gdbstub.h"
#include "qemu.h"
#include "user-internals.h"
@@ -38,4 +39,5 @@ void preexit_cleanup(CPUArchState *env, int code)
#endif
gdb_exit(code);
qemu_plugin_user_exit();
+ perf_exit();
}
diff --git a/linux-user/main.c b/linux-user/main.c
index a17fed045b..4290651c3c 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -53,6 +53,7 @@
#include "signal-common.h"
#include "loader.h"
#include "user-mmap.h"
+#include "accel/tcg/perf.h"
#ifdef CONFIG_SEMIHOSTING
#include "semihosting/semihost.h"
@@ -423,6 +424,16 @@ static void handle_arg_abi_call0(const char *arg)
}
#endif
+static void handle_arg_perfmap(const char *arg)
+{
+ perf_enable_perfmap();
+}
+
+static void handle_arg_jitdump(const char *arg)
+{
+ perf_enable_jitdump();
+}
+
static QemuPluginList plugins = QTAILQ_HEAD_INITIALIZER(plugins);
#ifdef CONFIG_PLUGIN
@@ -493,6 +504,10 @@ static const struct qemu_argument arg_table[] = {
{"xtensa-abi-call0", "QEMU_XTENSA_ABI_CALL0", false, handle_arg_abi_call0,
"", "assume CALL0 Xtensa ABI"},
#endif
+ {"perfmap", "QEMU_PERFMAP", false, handle_arg_perfmap,
+ "", "Generate a /tmp/perf-${pid}.map file for perf"},
+ {"jitdump", "QEMU_JITDUMP", false, handle_arg_jitdump,
+ "", "Generate a jit-${pid}.dump file for perf"},
{NULL, NULL, false, NULL, NULL, NULL}
};
diff --git a/softmmu/vl.c b/softmmu/vl.c
index 9bd0e52d01..9177d95d4e 100644
--- a/softmmu/vl.c
+++ b/softmmu/vl.c
@@ -96,6 +96,9 @@
#include "fsdev/qemu-fsdev.h"
#endif
#include "sysemu/qtest.h"
+#ifdef CONFIG_TCG
+#include "accel/tcg/perf.h"
+#endif
#include "disas/disas.h"
@@ -2926,6 +2929,14 @@ void qemu_init(int argc, char **argv)
case QEMU_OPTION_DFILTER:
qemu_set_dfilter_ranges(optarg, &error_fatal);
break;
+#if defined(CONFIG_TCG) && defined(CONFIG_LINUX)
+ case QEMU_OPTION_perfmap:
+ perf_enable_perfmap();
+ break;
+ case QEMU_OPTION_jitdump:
+ perf_enable_jitdump();
+ break;
+#endif
case QEMU_OPTION_seed:
qemu_guest_random_seed_main(optarg, &error_fatal);
break;
diff --git a/tcg/tcg.c b/tcg/tcg.c
index da91779890..9b7df71e7a 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -61,6 +61,7 @@
#include "exec/log.h"
#include "tcg/tcg-ldst.h"
#include "tcg-internal.h"
+#include "accel/tcg/perf.h"
/* Forward declarations for functions declared in tcg-target.c.inc and
used here. */
@@ -913,6 +914,7 @@ void tcg_prologue_init(TCGContext *s)
#endif
prologue_size = tcg_current_code_size(s);
+ perf_report_prologue(s->code_gen_ptr, prologue_size);
#ifndef CONFIG_TCG_INTERPRETER
flush_idcache_range((uintptr_t)tcg_splitwx_to_rx(s->code_buf),
diff --git a/accel/tcg/meson.build b/accel/tcg/meson.build
index 55b3b4dd7e..77740b1a0d 100644
--- a/accel/tcg/meson.build
+++ b/accel/tcg/meson.build
@@ -13,6 +13,7 @@ tcg_ss.add(when: 'CONFIG_USER_ONLY', if_true: files('user-exec.c'))
tcg_ss.add(when: 'CONFIG_SOFTMMU', if_false: files('user-exec-stub.c'))
tcg_ss.add(when: 'CONFIG_PLUGIN', if_true: [files('plugin-gen.c')])
tcg_ss.add(when: libdw, if_true: files('debuginfo.c'))
+tcg_ss.add(when: 'CONFIG_LINUX', if_true: files('perf.c'))
specific_ss.add_all(when: 'CONFIG_TCG', if_true: tcg_ss)
specific_ss.add(when: ['CONFIG_SOFTMMU', 'CONFIG_TCG'], if_true: files(
diff --git a/qemu-options.hx b/qemu-options.hx
index 3aa3a2f5a3..d59d19704b 100644
--- a/qemu-options.hx
+++ b/qemu-options.hx
@@ -4838,6 +4838,26 @@ SRST
Enable synchronization profiling.
ERST
+#if defined(CONFIG_TCG) && defined(CONFIG_LINUX)
+DEF("perfmap", 0, QEMU_OPTION_perfmap,
+ "-perfmap generate a /tmp/perf-${pid}.map file for perf\n",
+ QEMU_ARCH_ALL)
+SRST
+``-perfmap``
+ Generate a map file for Linux perf tools that will allow basic profiling
+ information to be broken down into basic blocks.
+ERST
+
+DEF("jitdump", 0, QEMU_OPTION_jitdump,
+ "-jitdump generate a jit-${pid}.dump file for perf\n",
+ QEMU_ARCH_ALL)
+SRST
+``-jitdump``
+ Generate a dump file for Linux perf tools that maps basic blocks to symbol
+ names, line numbers and JITted code.
+ERST
+#endif
+
DEFHEADING()
DEFHEADING(Generic object creation:)
--
2.34.1
^ permalink raw reply related [flat|nested] 20+ messages in thread* Re: [PULL 3/5] tcg: add perfmap and jitdump
2023-01-16 22:36 ` [PULL 3/5] tcg: add perfmap and jitdump Richard Henderson
@ 2023-06-02 17:21 ` Peter Maydell
2023-06-03 20:35 ` Ilya Leoshkevich
2023-06-29 11:31 ` Philippe Mathieu-Daudé
1 sibling, 1 reply; 20+ messages in thread
From: Peter Maydell @ 2023-06-02 17:21 UTC (permalink / raw)
To: Richard Henderson
Cc: qemu-devel, Ilya Leoshkevich, Vanderson M . do Rosario, Alex Bennée
On Mon, 16 Jan 2023 at 22:36, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> From: Ilya Leoshkevich <iii@linux.ibm.com>
>
> Add ability to dump /tmp/perf-<pid>.map and jit-<pid>.dump.
> The first one allows the perf tool to map samples to each individual
> translation block. The second one adds the ability to resolve symbol
> names, line numbers and inspect JITed code.
>
> Example of use:
>
> perf record qemu-x86_64 -perfmap ./a.out
> perf report
>
> or
>
> perf record -k 1 qemu-x86_64 -jitdump ./a.out
> DEBUGINFOD_URLS= perf inject -j -i perf.data -o perf.data.jitted
> perf report -i perf.data.jitted
>
> Co-developed-by: Vanderson M. do Rosario <vandersonmr2@gmail.com>
> Co-developed-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> Message-Id: <20230112152013.125680-4-iii@linux.ibm.com>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Hi; Coverity thinks (CID 1507521) that there's a memory leak
in this code:
> +void perf_enable_jitdump(void)
> +{
> + struct jitheader header;
> + char jitdump_file[32];
> + void *perf_marker;
> +
> + if (!use_rt_clock) {
> + warn_report("CLOCK_MONOTONIC is not available, proceeding without jitdump");
> + return;
> + }
> +
> + snprintf(jitdump_file, sizeof(jitdump_file), "jit-%d.dump", getpid());
> + jitdump = safe_fopen_w(jitdump_file);
> + if (jitdump == NULL) {
> + warn_report("Could not open %s: %s, proceeding without jitdump",
> + jitdump_file, strerror(errno));
> + return;
> + }
> +
> + /*
> + * `perf inject` will see that the mapped file name in the corresponding
> + * PERF_RECORD_MMAP or PERF_RECORD_MMAP2 event is of the form jit-%d.dump
> + * and will process it as a jitdump file.
> + */
> + perf_marker = mmap(NULL, qemu_real_host_page_size(), PROT_READ | PROT_EXEC,
> + MAP_PRIVATE, fileno(jitdump), 0);
Here we mmap() something...
> + if (perf_marker == MAP_FAILED) {
> + warn_report("Could not map %s: %s, proceeding without jitdump",
> + jitdump_file, strerror(errno));
> + fclose(jitdump);
> + jitdump = NULL;
> + return;
> + }
> +
> + header.magic = JITHEADER_MAGIC;
> + header.version = JITHEADER_VERSION;
> + header.total_size = sizeof(header);
> + header.elf_mach = get_e_machine();
> + header.pad1 = 0;
> + header.pid = getpid();
> + header.timestamp = get_clock();
> + header.flags = 0;
> + fwrite(&header, sizeof(header), 1, jitdump);
...but we never do anything with that pointer, so the memory
we just mmap()ed is never going to be freed.
Is this doing something particularly magical, or should that
pointer be kept track of somewhere ?
thanks
-- PMM
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PULL 3/5] tcg: add perfmap and jitdump
2023-06-02 17:21 ` Peter Maydell
@ 2023-06-03 20:35 ` Ilya Leoshkevich
0 siblings, 0 replies; 20+ messages in thread
From: Ilya Leoshkevich @ 2023-06-03 20:35 UTC (permalink / raw)
To: Peter Maydell, Richard Henderson
Cc: qemu-devel, Vanderson M . do Rosario, Alex Bennée
On Fri, 2023-06-02 at 18:21 +0100, Peter Maydell wrote:
> On Mon, 16 Jan 2023 at 22:36, Richard Henderson
> <richard.henderson@linaro.org> wrote:
> >
> > From: Ilya Leoshkevich <iii@linux.ibm.com>
> >
> > Add ability to dump /tmp/perf-<pid>.map and jit-<pid>.dump.
> > The first one allows the perf tool to map samples to each
> > individual
> > translation block. The second one adds the ability to resolve
> > symbol
> > names, line numbers and inspect JITed code.
> >
> > Example of use:
> >
> > perf record qemu-x86_64 -perfmap ./a.out
> > perf report
> >
> > or
> >
> > perf record -k 1 qemu-x86_64 -jitdump ./a.out
> > DEBUGINFOD_URLS= perf inject -j -i perf.data -o
> > perf.data.jitted
> > perf report -i perf.data.jitted
> >
> > Co-developed-by: Vanderson M. do Rosario <vandersonmr2@gmail.com>
> > Co-developed-by: Alex Bennée <alex.bennee@linaro.org>
> > Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> > Message-Id: <20230112152013.125680-4-iii@linux.ibm.com>
> > Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>
> Hi; Coverity thinks (CID 1507521) that there's a memory leak
> in this code:
>
> > +void perf_enable_jitdump(void)
> > +{
> > + struct jitheader header;
> > + char jitdump_file[32];
> > + void *perf_marker;
> > +
> > + if (!use_rt_clock) {
> > + warn_report("CLOCK_MONOTONIC is not available, proceeding
> > without jitdump");
> > + return;
> > + }
> > +
> > + snprintf(jitdump_file, sizeof(jitdump_file), "jit-%d.dump",
> > getpid());
> > + jitdump = safe_fopen_w(jitdump_file);
> > + if (jitdump == NULL) {
> > + warn_report("Could not open %s: %s, proceeding without
> > jitdump",
> > + jitdump_file, strerror(errno));
> > + return;
> > + }
> > +
> > + /*
> > + * `perf inject` will see that the mapped file name in the
> > corresponding
> > + * PERF_RECORD_MMAP or PERF_RECORD_MMAP2 event is of the form
> > jit-%d.dump
> > + * and will process it as a jitdump file.
> > + */
> > + perf_marker = mmap(NULL, qemu_real_host_page_size(), PROT_READ
> > | PROT_EXEC,
> > + MAP_PRIVATE, fileno(jitdump), 0);
>
> Here we mmap() something...
>
> > + if (perf_marker == MAP_FAILED) {
> > + warn_report("Could not map %s: %s, proceeding without
> > jitdump",
> > + jitdump_file, strerror(errno));
> > + fclose(jitdump);
> > + jitdump = NULL;
> > + return;
> > + }
> > +
> > + header.magic = JITHEADER_MAGIC;
> > + header.version = JITHEADER_VERSION;
> > + header.total_size = sizeof(header);
> > + header.elf_mach = get_e_machine();
> > + header.pad1 = 0;
> > + header.pid = getpid();
> > + header.timestamp = get_clock();
> > + header.flags = 0;
> > + fwrite(&header, sizeof(header), 1, jitdump);
>
> ...but we never do anything with that pointer, so the memory
> we just mmap()ed is never going to be freed.
>
> Is this doing something particularly magical, or should that
> pointer be kept track of somewhere ?
>
> thanks
> -- PMM
It's magic that points perf to the location of the jitdump file,
but it won't hurt munmap()ping it in perf_exit(). I'll send a patch.
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PULL 3/5] tcg: add perfmap and jitdump
2023-01-16 22:36 ` [PULL 3/5] tcg: add perfmap and jitdump Richard Henderson
2023-06-02 17:21 ` Peter Maydell
@ 2023-06-29 11:31 ` Philippe Mathieu-Daudé
2023-06-29 12:59 ` Richard Henderson
1 sibling, 1 reply; 20+ messages in thread
From: Philippe Mathieu-Daudé @ 2023-06-29 11:31 UTC (permalink / raw)
To: Richard Henderson, qemu-devel
Cc: peter.maydell, Ilya Leoshkevich, Vanderson M . do Rosario,
Alex Bennée
Hi Richard, Alex,
On 16/1/23 23:36, Richard Henderson wrote:
> From: Ilya Leoshkevich <iii@linux.ibm.com>
>
> Add ability to dump /tmp/perf-<pid>.map and jit-<pid>.dump.
> The first one allows the perf tool to map samples to each individual
> translation block. The second one adds the ability to resolve symbol
> names, line numbers and inspect JITed code.
>
> Example of use:
>
> perf record qemu-x86_64 -perfmap ./a.out
> perf report
>
> or
>
> perf record -k 1 qemu-x86_64 -jitdump ./a.out
> DEBUGINFOD_URLS= perf inject -j -i perf.data -o perf.data.jitted
> perf report -i perf.data.jitted
>
> Co-developed-by: Vanderson M. do Rosario <vandersonmr2@gmail.com>
> Co-developed-by: Alex Bennée <alex.bennee@linaro.org>
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
> Message-Id: <20230112152013.125680-4-iii@linux.ibm.com>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
> docs/devel/tcg.rst | 23 +++
> accel/tcg/perf.h | 49 +++++
> accel/tcg/perf.c | 375 ++++++++++++++++++++++++++++++++++++++
> accel/tcg/translate-all.c | 7 +
> linux-user/exit.c | 2 +
> linux-user/main.c | 15 ++
> softmmu/vl.c | 11 ++
> tcg/tcg.c | 2 +
> accel/tcg/meson.build | 1 +
> qemu-options.hx | 20 ++
> 10 files changed, 505 insertions(+)
> create mode 100644 accel/tcg/perf.h
> create mode 100644 accel/tcg/perf.c
> diff --git a/tcg/tcg.c b/tcg/tcg.c
> index da91779890..9b7df71e7a 100644
> --- a/tcg/tcg.c
> +++ b/tcg/tcg.c
> @@ -61,6 +61,7 @@
> #include "exec/log.h"
> #include "tcg/tcg-ldst.h"
> #include "tcg-internal.h"
> +#include "accel/tcg/perf.h"
Is it OK to include an header from QEMU's accel/tcg/ here?
I thought we wanted to keep tcg/ kinda independant (or maybe
this is already too late and this isn't a concern anymore).
> /* Forward declarations for functions declared in tcg-target.c.inc and
> used here. */
> @@ -913,6 +914,7 @@ void tcg_prologue_init(TCGContext *s)
> #endif
>
> prologue_size = tcg_current_code_size(s);
> + perf_report_prologue(s->code_gen_ptr, prologue_size);
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PULL 3/5] tcg: add perfmap and jitdump
2023-06-29 11:31 ` Philippe Mathieu-Daudé
@ 2023-06-29 12:59 ` Richard Henderson
2023-06-30 12:39 ` Ilya Leoshkevich
0 siblings, 1 reply; 20+ messages in thread
From: Richard Henderson @ 2023-06-29 12:59 UTC (permalink / raw)
To: Philippe Mathieu-Daudé, qemu-devel
Cc: peter.maydell, Ilya Leoshkevich, Vanderson M . do Rosario,
Alex Bennée
On 6/29/23 13:31, Philippe Mathieu-Daudé wrote:
>> diff --git a/tcg/tcg.c b/tcg/tcg.c
>> index da91779890..9b7df71e7a 100644
>> --- a/tcg/tcg.c
>> +++ b/tcg/tcg.c
>> @@ -61,6 +61,7 @@
>> #include "exec/log.h"
>> #include "tcg/tcg-ldst.h"
>> #include "tcg-internal.h"
>> +#include "accel/tcg/perf.h"
>
> Is it OK to include an header from QEMU's accel/tcg/ here?
> I thought we wanted to keep tcg/ kinda independant (or maybe
> this is already too late and this isn't a concern anymore).
It's not ideal, no. Perf really should live in tcg/.
r~
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PULL 3/5] tcg: add perfmap and jitdump
2023-06-29 12:59 ` Richard Henderson
@ 2023-06-30 12:39 ` Ilya Leoshkevich
2023-06-30 13:24 ` Richard Henderson
0 siblings, 1 reply; 20+ messages in thread
From: Ilya Leoshkevich @ 2023-06-30 12:39 UTC (permalink / raw)
To: Richard Henderson, Philippe Mathieu-Daudé, qemu-devel
Cc: peter.maydell, Vanderson M . do Rosario, Alex Bennée
On Thu, 2023-06-29 at 14:59 +0200, Richard Henderson wrote:
> On 6/29/23 13:31, Philippe Mathieu-Daudé wrote:
> > > diff --git a/tcg/tcg.c b/tcg/tcg.c
> > > index da91779890..9b7df71e7a 100644
> > > --- a/tcg/tcg.c
> > > +++ b/tcg/tcg.c
> > > @@ -61,6 +61,7 @@
> > > #include "exec/log.h"
> > > #include "tcg/tcg-ldst.h"
> > > #include "tcg-internal.h"
> > > +#include "accel/tcg/perf.h"
> >
> > Is it OK to include an header from QEMU's accel/tcg/ here?
> > I thought we wanted to keep tcg/ kinda independant (or maybe
> > this is already too late and this isn't a concern anymore).
>
> It's not ideal, no. Perf really should live in tcg/.
>
>
> r~
This would require to somehow get rid of this:
#if defined(TARGET_I386)
q[insn].address -= tb->cs_base;
#endif
I'll try to come up with a patch.
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PULL 3/5] tcg: add perfmap and jitdump
2023-06-30 12:39 ` Ilya Leoshkevich
@ 2023-06-30 13:24 ` Richard Henderson
2023-12-07 9:51 ` Philippe Mathieu-Daudé
0 siblings, 1 reply; 20+ messages in thread
From: Richard Henderson @ 2023-06-30 13:24 UTC (permalink / raw)
To: Ilya Leoshkevich, Philippe Mathieu-Daudé, qemu-devel
Cc: peter.maydell, Vanderson M . do Rosario, Alex Bennée
On 6/30/23 14:39, Ilya Leoshkevich wrote:
> On Thu, 2023-06-29 at 14:59 +0200, Richard Henderson wrote:
>> On 6/29/23 13:31, Philippe Mathieu-Daudé wrote:
>>>> diff --git a/tcg/tcg.c b/tcg/tcg.c
>>>> index da91779890..9b7df71e7a 100644
>>>> --- a/tcg/tcg.c
>>>> +++ b/tcg/tcg.c
>>>> @@ -61,6 +61,7 @@
>>>> #include "exec/log.h"
>>>> #include "tcg/tcg-ldst.h"
>>>> #include "tcg-internal.h"
>>>> +#include "accel/tcg/perf.h"
>>>
>>> Is it OK to include an header from QEMU's accel/tcg/ here?
>>> I thought we wanted to keep tcg/ kinda independant (or maybe
>>> this is already too late and this isn't a concern anymore).
>>
>> It's not ideal, no. Perf really should live in tcg/.
>>
>>
>> r~
>
> This would require to somehow get rid of this:
>
> #if defined(TARGET_I386)
> q[insn].address -= tb->cs_base;
> #endif
>
> I'll try to come up with a patch.
Just drop it? Did you really want EIP instead of the full virtual address?
It only makes a difference for 16-bit mode anyway.
r~
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PULL 3/5] tcg: add perfmap and jitdump
2023-06-30 13:24 ` Richard Henderson
@ 2023-12-07 9:51 ` Philippe Mathieu-Daudé
0 siblings, 0 replies; 20+ messages in thread
From: Philippe Mathieu-Daudé @ 2023-12-07 9:51 UTC (permalink / raw)
To: Richard Henderson, Ilya Leoshkevich, qemu-devel
Cc: peter.maydell, Vanderson M . do Rosario, Alex Bennée
Hi Ilya,
On 30/6/23 15:24, Richard Henderson wrote:
> On 6/30/23 14:39, Ilya Leoshkevich wrote:
>> On Thu, 2023-06-29 at 14:59 +0200, Richard Henderson wrote:
>>> On 6/29/23 13:31, Philippe Mathieu-Daudé wrote:
>>>>> diff --git a/tcg/tcg.c b/tcg/tcg.c
>>>>> index da91779890..9b7df71e7a 100644
>>>>> --- a/tcg/tcg.c
>>>>> +++ b/tcg/tcg.c
>>>>> @@ -61,6 +61,7 @@
>>>>> #include "exec/log.h"
>>>>> #include "tcg/tcg-ldst.h"
>>>>> #include "tcg-internal.h"
>>>>> +#include "accel/tcg/perf.h"
>>>>
>>>> Is it OK to include an header from QEMU's accel/tcg/ here?
>>>> I thought we wanted to keep tcg/ kinda independant (or maybe
>>>> this is already too late and this isn't a concern anymore).
>>>
>>> It's not ideal, no. Perf really should live in tcg/.
>>>
>>>
>>> r~
>>
>> This would require to somehow get rid of this:
>>
>> #if defined(TARGET_I386)
>> q[insn].address -= tb->cs_base;
>> #endif
>>
>> I'll try to come up with a patch.
>
> Just drop it? Did you really want EIP instead of the full virtual address?
> It only makes a difference for 16-bit mode anyway.
Any update here? Have you tried 'perf' on non-x86 hosts?
There is a "This replicates the restore_state_to_opc() logic"
comment but only x86 restore_state_to_opc() logic is used,
so I'm rather confused here.
Thanks,
Phil.
^ permalink raw reply [flat|nested] 20+ messages in thread
* [PULL 4/5] util/bufferiszero: Use __attribute__((target)) for avx2/avx512
2023-01-16 22:36 [PULL 0/5] tcg patch queue Richard Henderson
` (2 preceding siblings ...)
2023-01-16 22:36 ` [PULL 3/5] tcg: add perfmap and jitdump Richard Henderson
@ 2023-01-16 22:36 ` Richard Henderson
2023-01-16 22:36 ` [PULL 5/5] accel/tcg: Split out cpu_exec_{setjmp,loop} Richard Henderson
` (2 subsequent siblings)
6 siblings, 0 replies; 20+ messages in thread
From: Richard Henderson @ 2023-01-16 22:36 UTC (permalink / raw)
To: qemu-devel; +Cc: peter.maydell, Daniel P . Berrangé
Use the attribute, which is supported by clang, instead of
the #pragma, which is not supported and, for some reason,
also not detected by the meson probe, so we fail by -Werror.
Include only <immintrin.h> as that is the outermost "official"
header for these intrinsics -- emmintrin.h and smmintrin -- are
older SSE2 and SSE4 specific headers, while the immintrin.h
includes all of the Intel intrinsics.
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
meson.build | 8 ++------
util/bufferiszero.c | 41 ++++++-----------------------------------
2 files changed, 8 insertions(+), 41 deletions(-)
diff --git a/meson.build b/meson.build
index 6d212f6c8e..58d8cd68a6 100644
--- a/meson.build
+++ b/meson.build
@@ -2338,11 +2338,9 @@ config_host_data.set('CONFIG_CPUID_H', have_cpuid_h)
config_host_data.set('CONFIG_AVX2_OPT', get_option('avx2') \
.require(have_cpuid_h, error_message: 'cpuid.h not available, cannot enable AVX2') \
.require(cc.links('''
- #pragma GCC push_options
- #pragma GCC target("avx2")
#include <cpuid.h>
#include <immintrin.h>
- static int bar(void *a) {
+ static int __attribute__((target("avx2"))) bar(void *a) {
__m256i x = *(__m256i *)a;
return _mm256_testz_si256(x, x);
}
@@ -2352,11 +2350,9 @@ config_host_data.set('CONFIG_AVX2_OPT', get_option('avx2') \
config_host_data.set('CONFIG_AVX512F_OPT', get_option('avx512f') \
.require(have_cpuid_h, error_message: 'cpuid.h not available, cannot enable AVX512F') \
.require(cc.links('''
- #pragma GCC push_options
- #pragma GCC target("avx512f")
#include <cpuid.h>
#include <immintrin.h>
- static int bar(void *a) {
+ static int __attribute__((target("avx512f"))) bar(void *a) {
__m512i x = *(__m512i *)a;
return _mm512_test_epi64_mask(x, x);
}
diff --git a/util/bufferiszero.c b/util/bufferiszero.c
index ec3cd4ca15..1790ded7d4 100644
--- a/util/bufferiszero.c
+++ b/util/bufferiszero.c
@@ -64,18 +64,11 @@ buffer_zero_int(const void *buf, size_t len)
}
#if defined(CONFIG_AVX512F_OPT) || defined(CONFIG_AVX2_OPT) || defined(__SSE2__)
-/* Do not use push_options pragmas unnecessarily, because clang
- * does not support them.
- */
-#if defined(CONFIG_AVX512F_OPT) || defined(CONFIG_AVX2_OPT)
-#pragma GCC push_options
-#pragma GCC target("sse2")
-#endif
-#include <emmintrin.h>
+#include <immintrin.h>
/* Note that each of these vectorized functions require len >= 64. */
-static bool
+static bool __attribute__((target("sse2")))
buffer_zero_sse2(const void *buf, size_t len)
{
__m128i t = _mm_loadu_si128(buf);
@@ -104,20 +97,9 @@ buffer_zero_sse2(const void *buf, size_t len)
return _mm_movemask_epi8(_mm_cmpeq_epi8(t, zero)) == 0xFFFF;
}
-#if defined(CONFIG_AVX512F_OPT) || defined(CONFIG_AVX2_OPT)
-#pragma GCC pop_options
-#endif
#ifdef CONFIG_AVX2_OPT
-/* Note that due to restrictions/bugs wrt __builtin functions in gcc <= 4.8,
- * the includes have to be within the corresponding push_options region, and
- * therefore the regions themselves have to be ordered with increasing ISA.
- */
-#pragma GCC push_options
-#pragma GCC target("sse4")
-#include <smmintrin.h>
-
-static bool
+static bool __attribute__((target("sse4")))
buffer_zero_sse4(const void *buf, size_t len)
{
__m128i t = _mm_loadu_si128(buf);
@@ -145,12 +127,7 @@ buffer_zero_sse4(const void *buf, size_t len)
return _mm_testz_si128(t, t);
}
-#pragma GCC pop_options
-#pragma GCC push_options
-#pragma GCC target("avx2")
-#include <immintrin.h>
-
-static bool
+static bool __attribute__((target("avx2")))
buffer_zero_avx2(const void *buf, size_t len)
{
/* Begin with an unaligned head of 32 bytes. */
@@ -176,15 +153,10 @@ buffer_zero_avx2(const void *buf, size_t len)
return _mm256_testz_si256(t, t);
}
-#pragma GCC pop_options
#endif /* CONFIG_AVX2_OPT */
#ifdef CONFIG_AVX512F_OPT
-#pragma GCC push_options
-#pragma GCC target("avx512f")
-#include <immintrin.h>
-
-static bool
+static bool __attribute__((target("avx512f")))
buffer_zero_avx512(const void *buf, size_t len)
{
/* Begin with an unaligned head of 64 bytes. */
@@ -210,8 +182,7 @@ buffer_zero_avx512(const void *buf, size_t len)
return !_mm512_test_epi64_mask(t, t);
}
-#pragma GCC pop_options
-#endif
+#endif /* CONFIG_AVX512F_OPT */
/* Note that for test_buffer_is_zero_next_accel, the most preferred
--
2.34.1
^ permalink raw reply related [flat|nested] 20+ messages in thread* [PULL 5/5] accel/tcg: Split out cpu_exec_{setjmp,loop}
2023-01-16 22:36 [PULL 0/5] tcg patch queue Richard Henderson
` (3 preceding siblings ...)
2023-01-16 22:36 ` [PULL 4/5] util/bufferiszero: Use __attribute__((target)) for avx2/avx512 Richard Henderson
@ 2023-01-16 22:36 ` Richard Henderson
2023-01-17 15:47 ` [PULL 0/5] tcg patch queue Peter Maydell
2023-01-20 9:41 ` Thomas Huth
6 siblings, 0 replies; 20+ messages in thread
From: Richard Henderson @ 2023-01-16 22:36 UTC (permalink / raw)
To: qemu-devel; +Cc: peter.maydell, Philippe Mathieu-Daudé
Recently the g_assert(cpu == current_cpu) test has been
intermittently failing with gcc. Reorg the code around
the setjmp to minimize the lifetime of the cpu variable
affected by the setjmp.
This appears to fix the existing issue with clang as well.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1147
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
---
accel/tcg/cpu-exec.c | 111 +++++++++++++++++++++----------------------
1 file changed, 54 insertions(+), 57 deletions(-)
diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index 356fe348de..8927092537 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -909,64 +909,10 @@ static inline void cpu_loop_exec_tb(CPUState *cpu, TranslationBlock *tb,
/* main execution loop */
-int cpu_exec(CPUState *cpu)
+static int __attribute__((noinline))
+cpu_exec_loop(CPUState *cpu, SyncClocks *sc)
{
int ret;
- SyncClocks sc = { 0 };
-
- /* replay_interrupt may need current_cpu */
- current_cpu = cpu;
-
- if (cpu_handle_halt(cpu)) {
- return EXCP_HALTED;
- }
-
- rcu_read_lock();
-
- cpu_exec_enter(cpu);
-
- /* Calculate difference between guest clock and host clock.
- * This delay includes the delay of the last cycle, so
- * what we have to do is sleep until it is 0. As for the
- * advance/delay we gain here, we try to fix it next time.
- */
- init_delay_params(&sc, cpu);
-
- /* prepare setjmp context for exception handling */
- if (sigsetjmp(cpu->jmp_env, 0) != 0) {
-#if defined(__clang__)
- /*
- * Some compilers wrongly smash all local variables after
- * siglongjmp (the spec requires that only non-volatile locals
- * which are changed between the sigsetjmp and siglongjmp are
- * permitted to be trashed). There were bug reports for gcc
- * 4.5.0 and clang. The bug is fixed in all versions of gcc
- * that we support, but is still unfixed in clang:
- * https://bugs.llvm.org/show_bug.cgi?id=21183
- *
- * Reload an essential local variable here for those compilers.
- * Newer versions of gcc would complain about this code (-Wclobbered),
- * so we only perform the workaround for clang.
- */
- cpu = current_cpu;
-#else
- /* Non-buggy compilers preserve this; assert the correct value. */
- g_assert(cpu == current_cpu);
-#endif
-
-#ifndef CONFIG_SOFTMMU
- clear_helper_retaddr();
- if (have_mmap_lock()) {
- mmap_unlock();
- }
-#endif
- if (qemu_mutex_iothread_locked()) {
- qemu_mutex_unlock_iothread();
- }
- qemu_plugin_disable_mem_helpers(cpu);
-
- assert_no_pages_locked();
- }
/* if an exception is pending, we execute it here */
while (!cpu_handle_exception(cpu, &ret)) {
@@ -1033,9 +979,60 @@ int cpu_exec(CPUState *cpu)
/* Try to align the host and virtual clocks
if the guest is in advance */
- align_clocks(&sc, cpu);
+ align_clocks(sc, cpu);
}
}
+ return ret;
+}
+
+static int cpu_exec_setjmp(CPUState *cpu, SyncClocks *sc)
+{
+ /* Prepare setjmp context for exception handling. */
+ if (unlikely(sigsetjmp(cpu->jmp_env, 0) != 0)) {
+ /* Non-buggy compilers preserve this; assert the correct value. */
+ g_assert(cpu == current_cpu);
+
+#ifndef CONFIG_SOFTMMU
+ clear_helper_retaddr();
+ if (have_mmap_lock()) {
+ mmap_unlock();
+ }
+#endif
+ if (qemu_mutex_iothread_locked()) {
+ qemu_mutex_unlock_iothread();
+ }
+ qemu_plugin_disable_mem_helpers(cpu);
+
+ assert_no_pages_locked();
+ }
+
+ return cpu_exec_loop(cpu, sc);
+}
+
+int cpu_exec(CPUState *cpu)
+{
+ int ret;
+ SyncClocks sc = { 0 };
+
+ /* replay_interrupt may need current_cpu */
+ current_cpu = cpu;
+
+ if (cpu_handle_halt(cpu)) {
+ return EXCP_HALTED;
+ }
+
+ rcu_read_lock();
+ cpu_exec_enter(cpu);
+
+ /*
+ * Calculate difference between guest clock and host clock.
+ * This delay includes the delay of the last cycle, so
+ * what we have to do is sleep until it is 0. As for the
+ * advance/delay we gain here, we try to fix it next time.
+ */
+ init_delay_params(&sc, cpu);
+
+ ret = cpu_exec_setjmp(cpu, &sc);
cpu_exec_exit(cpu);
rcu_read_unlock();
--
2.34.1
^ permalink raw reply related [flat|nested] 20+ messages in thread* Re: [PULL 0/5] tcg patch queue
2023-01-16 22:36 [PULL 0/5] tcg patch queue Richard Henderson
` (4 preceding siblings ...)
2023-01-16 22:36 ` [PULL 5/5] accel/tcg: Split out cpu_exec_{setjmp,loop} Richard Henderson
@ 2023-01-17 15:47 ` Peter Maydell
2023-01-20 9:41 ` Thomas Huth
6 siblings, 0 replies; 20+ messages in thread
From: Peter Maydell @ 2023-01-17 15:47 UTC (permalink / raw)
To: Richard Henderson; +Cc: qemu-devel
On Mon, 16 Jan 2023 at 22:36, Richard Henderson
<richard.henderson@linaro.org> wrote:
>
> The following changes since commit fb7e7990342e59cf67dbd895c1a1e3fb1741df7a:
>
> tests/qtest/qom-test: Do not print tested properties by default (2023-01-16 15:00:57 +0000)
>
> are available in the Git repository at:
>
> https://gitlab.com/rth7680/qemu.git tags/pull-tcg-20230116
>
> for you to fetch changes up to 61710a7e23a63546da0071ea32adb96476fa5d07:
>
> accel/tcg: Split out cpu_exec_{setjmp,loop} (2023-01-16 10:14:12 -1000)
>
> ----------------------------------------------------------------
> - Reorg cpu_tb_exec around setjmp.
> - Use __attribute__((target)) for buffer_is_zero.
> - Add perfmap and jitdump for perf support.
>
> ----------------------------------------------------------------
Applied, thanks.
Please update the changelog at https://wiki.qemu.org/ChangeLog/8.0
for any user-visible changes.
-- PMM
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PULL 0/5] tcg patch queue
2023-01-16 22:36 [PULL 0/5] tcg patch queue Richard Henderson
` (5 preceding siblings ...)
2023-01-17 15:47 ` [PULL 0/5] tcg patch queue Peter Maydell
@ 2023-01-20 9:41 ` Thomas Huth
2023-01-20 10:50 ` Alex Bennée
` (2 more replies)
6 siblings, 3 replies; 20+ messages in thread
From: Thomas Huth @ 2023-01-20 9:41 UTC (permalink / raw)
To: Richard Henderson, qemu-devel, Ilya Leoshkevich; +Cc: peter.maydell
On 16/01/2023 23.36, Richard Henderson wrote:
> The following changes since commit fb7e7990342e59cf67dbd895c1a1e3fb1741df7a:
>
> tests/qtest/qom-test: Do not print tested properties by default (2023-01-16 15:00:57 +0000)
>
> are available in the Git repository at:
>
> https://gitlab.com/rth7680/qemu.git tags/pull-tcg-20230116
>
> for you to fetch changes up to 61710a7e23a63546da0071ea32adb96476fa5d07:
>
> accel/tcg: Split out cpu_exec_{setjmp,loop} (2023-01-16 10:14:12 -1000)
>
> ----------------------------------------------------------------
> - Reorg cpu_tb_exec around setjmp.
> - Use __attribute__((target)) for buffer_is_zero.
> - Add perfmap and jitdump for perf support.
>
> ----------------------------------------------------------------
> Ilya Leoshkevich (3):
> linux-user: Clean up when exiting due to a signal
> accel/tcg: Add debuginfo support
> tcg: add perfmap and jitdump
>
> Richard Henderson (2):
> util/bufferiszero: Use __attribute__((target)) for avx2/avx512
> accel/tcg: Split out cpu_exec_{setjmp,loop}
Hi Richard, hi Ilya,
with the recent QEMU master branch (commit 701ed34), I'm now seeing failures
in Travis:
https://app.travis-ci.com/github/huth/qemu/jobs/593786529#L14411
Everything was still fine a couple of days ago (commit fb7e799):
https://app.travis-ci.com/github/huth/qemu/builds/259755664
... so it seems this is likely related to this pull request. Could you
please have a look?
Thanks,
Thomas
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PULL 0/5] tcg patch queue
2023-01-20 9:41 ` Thomas Huth
@ 2023-01-20 10:50 ` Alex Bennée
2023-01-20 10:53 ` Ilya Leoshkevich
2023-01-21 6:07 ` Richard Henderson
2 siblings, 0 replies; 20+ messages in thread
From: Alex Bennée @ 2023-01-20 10:50 UTC (permalink / raw)
To: Thomas Huth
Cc: Richard Henderson, Ilya Leoshkevich, peter.maydell, qemu-devel
Thomas Huth <thuth@redhat.com> writes:
> On 16/01/2023 23.36, Richard Henderson wrote:
>> The following changes since commit fb7e7990342e59cf67dbd895c1a1e3fb1741df7a:
>> tests/qtest/qom-test: Do not print tested properties by default
>> (2023-01-16 15:00:57 +0000)
>> are available in the Git repository at:
>> https://gitlab.com/rth7680/qemu.git tags/pull-tcg-20230116
>> for you to fetch changes up to
>> 61710a7e23a63546da0071ea32adb96476fa5d07:
>> accel/tcg: Split out cpu_exec_{setjmp,loop} (2023-01-16 10:14:12
>> -1000)
>> ----------------------------------------------------------------
>> - Reorg cpu_tb_exec around setjmp.
>> - Use __attribute__((target)) for buffer_is_zero.
>> - Add perfmap and jitdump for perf support.
>> ----------------------------------------------------------------
>> Ilya Leoshkevich (3):
>> linux-user: Clean up when exiting due to a signal
>> accel/tcg: Add debuginfo support
>> tcg: add perfmap and jitdump
>> Richard Henderson (2):
>> util/bufferiszero: Use __attribute__((target)) for avx2/avx512
>> accel/tcg: Split out cpu_exec_{setjmp,loop}
>
> Hi Richard, hi Ilya,
>
> with the recent QEMU master branch (commit 701ed34), I'm now seeing
> failures in Travis:
>
> https://app.travis-ci.com/github/huth/qemu/jobs/593786529#L14411
>
> Everything was still fine a couple of days ago (commit fb7e799):
>
> https://app.travis-ci.com/github/huth/qemu/builds/259755664
>
> ... so it seems this is likely related to this pull request. Could you
> please have a look?
Hmm maybe the code motion has revealed another form of the compiler bug.
I guess these bugs don't die, they just refract.
>
> Thanks,
> Thomas
--
Alex Bennée
Virtualisation Tech Lead @ Linaro
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PULL 0/5] tcg patch queue
2023-01-20 9:41 ` Thomas Huth
2023-01-20 10:50 ` Alex Bennée
@ 2023-01-20 10:53 ` Ilya Leoshkevich
2023-01-20 12:51 ` Thomas Huth
2023-01-21 6:07 ` Richard Henderson
2 siblings, 1 reply; 20+ messages in thread
From: Ilya Leoshkevich @ 2023-01-20 10:53 UTC (permalink / raw)
To: Thomas Huth, Richard Henderson, Alex Bennée, qemu-devel
Cc: peter.maydell
On Fri, 2023-01-20 at 10:41 +0100, Thomas Huth wrote:
> On 16/01/2023 23.36, Richard Henderson wrote:
> > The following changes since commit
> > fb7e7990342e59cf67dbd895c1a1e3fb1741df7a:
> >
> > tests/qtest/qom-test: Do not print tested properties by default
> > (2023-01-16 15:00:57 +0000)
> >
> > are available in the Git repository at:
> >
> > https://gitlab.com/rth7680/qemu.git tags/pull-tcg-20230116
> >
> > for you to fetch changes up to
> > 61710a7e23a63546da0071ea32adb96476fa5d07:
> >
> > accel/tcg: Split out cpu_exec_{setjmp,loop} (2023-01-16 10:14:12
> > -1000)
> >
> > ----------------------------------------------------------------
> > - Reorg cpu_tb_exec around setjmp.
> > - Use __attribute__((target)) for buffer_is_zero.
> > - Add perfmap and jitdump for perf support.
> >
> > ----------------------------------------------------------------
> > Ilya Leoshkevich (3):
> > linux-user: Clean up when exiting due to a signal
> > accel/tcg: Add debuginfo support
> > tcg: add perfmap and jitdump
> >
> > Richard Henderson (2):
> > util/bufferiszero: Use __attribute__((target)) for
> > avx2/avx512
> > accel/tcg: Split out cpu_exec_{setjmp,loop}
>
> Hi Richard, hi Ilya,
>
> with the recent QEMU master branch (commit 701ed34), I'm now seeing
> failures
> in Travis:
>
> https://app.travis-ci.com/github/huth/qemu/jobs/593786529#L14411
>
> Everything was still fine a couple of days ago (commit fb7e799):
>
> https://app.travis-ci.com/github/huth/qemu/builds/259755664
>
> ... so it seems this is likely related to this pull request. Could
> you
> please have a look?
>
> Thanks,
> Thomas
>
I would expect this to be (temporarily) fixed by [1], but we probably
don't set GITLAB_CI in Travis. Would it make sense to set it? It looks
as if this variable is currently used only to skip certain tests.
If not, then maybe split it into QEMU_CI, GITLAB_CI and TRAVIS_CI?
https://lists.gnu.org/archive/html/qemu-devel/2023-01/msg04438.html
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PULL 0/5] tcg patch queue
2023-01-20 10:53 ` Ilya Leoshkevich
@ 2023-01-20 12:51 ` Thomas Huth
2023-01-20 16:49 ` Alex Bennée
0 siblings, 1 reply; 20+ messages in thread
From: Thomas Huth @ 2023-01-20 12:51 UTC (permalink / raw)
To: Ilya Leoshkevich, Richard Henderson, Alex Bennée, qemu-devel
Cc: peter.maydell
On 20/01/2023 11.53, Ilya Leoshkevich wrote:
> On Fri, 2023-01-20 at 10:41 +0100, Thomas Huth wrote:
>> On 16/01/2023 23.36, Richard Henderson wrote:
>>> The following changes since commit
>>> fb7e7990342e59cf67dbd895c1a1e3fb1741df7a:
>>>
>>> tests/qtest/qom-test: Do not print tested properties by default
>>> (2023-01-16 15:00:57 +0000)
>>>
>>> are available in the Git repository at:
>>>
>>> https://gitlab.com/rth7680/qemu.git tags/pull-tcg-20230116
>>>
>>> for you to fetch changes up to
>>> 61710a7e23a63546da0071ea32adb96476fa5d07:
>>>
>>> accel/tcg: Split out cpu_exec_{setjmp,loop} (2023-01-16 10:14:12
>>> -1000)
>>>
>>> ----------------------------------------------------------------
>>> - Reorg cpu_tb_exec around setjmp.
>>> - Use __attribute__((target)) for buffer_is_zero.
>>> - Add perfmap and jitdump for perf support.
>>>
>>> ----------------------------------------------------------------
>>> Ilya Leoshkevich (3):
>>> linux-user: Clean up when exiting due to a signal
>>> accel/tcg: Add debuginfo support
>>> tcg: add perfmap and jitdump
>>>
>>> Richard Henderson (2):
>>> util/bufferiszero: Use __attribute__((target)) for
>>> avx2/avx512
>>> accel/tcg: Split out cpu_exec_{setjmp,loop}
>>
>> Hi Richard, hi Ilya,
>>
>> with the recent QEMU master branch (commit 701ed34), I'm now seeing
>> failures
>> in Travis:
>>
>> https://app.travis-ci.com/github/huth/qemu/jobs/593786529#L14411
>>
>> Everything was still fine a couple of days ago (commit fb7e799):
>>
>> https://app.travis-ci.com/github/huth/qemu/builds/259755664
>>
>> ... so it seems this is likely related to this pull request. Could
>> you
>> please have a look?
>>
>> Thanks,
>> Thomas
>>
>
> I would expect this to be (temporarily) fixed by [1], but we probably
> don't set GITLAB_CI in Travis. Would it make sense to set it? It looks
> as if this variable is currently used only to skip certain tests.
>
> If not, then maybe split it into QEMU_CI, GITLAB_CI and TRAVIS_CI?
>
> https://lists.gnu.org/archive/html/qemu-devel/2023-01/msg04438.html
Ah, ok, so this test has issues in gitlab, too!
For Travis, I think we should either check the CI or TRAVIS environment
variables:
https://docs.travis-ci.com/user/environment-variables/#default-environment-variables
Thomas
^ permalink raw reply [flat|nested] 20+ messages in thread* Re: [PULL 0/5] tcg patch queue
2023-01-20 12:51 ` Thomas Huth
@ 2023-01-20 16:49 ` Alex Bennée
0 siblings, 0 replies; 20+ messages in thread
From: Alex Bennée @ 2023-01-20 16:49 UTC (permalink / raw)
To: Thomas Huth
Cc: Ilya Leoshkevich, Richard Henderson, qemu-devel, peter.maydell
Thomas Huth <thuth@redhat.com> writes:
> On 20/01/2023 11.53, Ilya Leoshkevich wrote:
>> On Fri, 2023-01-20 at 10:41 +0100, Thomas Huth wrote:
>>> On 16/01/2023 23.36, Richard Henderson wrote:
>>>> The following changes since commit
>>>> fb7e7990342e59cf67dbd895c1a1e3fb1741df7a:
>>>>
>>>> tests/qtest/qom-test: Do not print tested properties by default
>>>> (2023-01-16 15:00:57 +0000)
>>>>
>>>> are available in the Git repository at:
>>>>
>>>> https://gitlab.com/rth7680/qemu.git tags/pull-tcg-20230116
>>>>
>>>> for you to fetch changes up to
>>>> 61710a7e23a63546da0071ea32adb96476fa5d07:
>>>>
>>>> accel/tcg: Split out cpu_exec_{setjmp,loop} (2023-01-16 10:14:12
>>>> -1000)
>>>>
>>>> ----------------------------------------------------------------
>>>> - Reorg cpu_tb_exec around setjmp.
>>>> - Use __attribute__((target)) for buffer_is_zero.
>>>> - Add perfmap and jitdump for perf support.
>>>>
>>>> ----------------------------------------------------------------
>>>> Ilya Leoshkevich (3):
>>>> linux-user: Clean up when exiting due to a signal
>>>> accel/tcg: Add debuginfo support
>>>> tcg: add perfmap and jitdump
>>>>
>>>> Richard Henderson (2):
>>>> util/bufferiszero: Use __attribute__((target)) for
>>>> avx2/avx512
>>>> accel/tcg: Split out cpu_exec_{setjmp,loop}
>>>
>>> Hi Richard, hi Ilya,
>>>
>>> with the recent QEMU master branch (commit 701ed34), I'm now seeing
>>> failures
>>> in Travis:
>>>
>>> https://app.travis-ci.com/github/huth/qemu/jobs/593786529#L14411
>>>
>>> Everything was still fine a couple of days ago (commit fb7e799):
>>>
>>> https://app.travis-ci.com/github/huth/qemu/builds/259755664
>>>
>>> ... so it seems this is likely related to this pull request. Could
>>> you
>>> please have a look?
>>>
>>> Thanks,
>>> Thomas
>>>
>> I would expect this to be (temporarily) fixed by [1], but we
>> probably
>> don't set GITLAB_CI in Travis. Would it make sense to set it? It looks
>> as if this variable is currently used only to skip certain tests.
>> If not, then maybe split it into QEMU_CI, GITLAB_CI and TRAVIS_CI?
>> https://lists.gnu.org/archive/html/qemu-devel/2023-01/msg04438.html
>
> Ah, ok, so this test has issues in gitlab, too!
*sigh* yeah the test is flaky but this is a subtly different failure
mode. All the gitlab failures I saw where the test triggering the abort
rather than the assert catch we have here.
>
> For Travis, I think we should either check the CI or TRAVIS
> environment variables:
>
>
> https://docs.travis-ci.com/user/environment-variables/#default-environment-variables
>
> Thomas
--
Alex Bennée
Virtualisation Tech Lead @ Linaro
^ permalink raw reply [flat|nested] 20+ messages in thread
* Re: [PULL 0/5] tcg patch queue
2023-01-20 9:41 ` Thomas Huth
2023-01-20 10:50 ` Alex Bennée
2023-01-20 10:53 ` Ilya Leoshkevich
@ 2023-01-21 6:07 ` Richard Henderson
2 siblings, 0 replies; 20+ messages in thread
From: Richard Henderson @ 2023-01-21 6:07 UTC (permalink / raw)
To: Thomas Huth, qemu-devel, Ilya Leoshkevich; +Cc: peter.maydell
On 1/19/23 23:41, Thomas Huth wrote:
> On 16/01/2023 23.36, Richard Henderson wrote:
>> The following changes since commit fb7e7990342e59cf67dbd895c1a1e3fb1741df7a:
>>
>> tests/qtest/qom-test: Do not print tested properties by default (2023-01-16 15:00:57
>> +0000)
>>
>> are available in the Git repository at:
>>
>> https://gitlab.com/rth7680/qemu.git tags/pull-tcg-20230116
>>
>> for you to fetch changes up to 61710a7e23a63546da0071ea32adb96476fa5d07:
>>
>> accel/tcg: Split out cpu_exec_{setjmp,loop} (2023-01-16 10:14:12 -1000)
>>
>> ----------------------------------------------------------------
>> - Reorg cpu_tb_exec around setjmp.
>> - Use __attribute__((target)) for buffer_is_zero.
>> - Add perfmap and jitdump for perf support.
>>
>> ----------------------------------------------------------------
>> Ilya Leoshkevich (3):
>> linux-user: Clean up when exiting due to a signal
>> accel/tcg: Add debuginfo support
>> tcg: add perfmap and jitdump
>>
>> Richard Henderson (2):
>> util/bufferiszero: Use __attribute__((target)) for avx2/avx512
>> accel/tcg: Split out cpu_exec_{setjmp,loop}
>
> Hi Richard, hi Ilya,
>
> with the recent QEMU master branch (commit 701ed34), I'm now seeing failures in Travis:
>
> https://app.travis-ci.com/github/huth/qemu/jobs/593786529#L14411
>
> Everything was still fine a couple of days ago (commit fb7e799):
>
> https://app.travis-ci.com/github/huth/qemu/builds/259755664
>
> ... so it seems this is likely related to this pull request. Could you please have a look?
Thankfully our s390x.ci.qemu.org has the same version gcc installed, and I was able to
reproduce this. But only once -- it's irregular and very low frequency.
The code generated by gcc is correct and easy to inspect, since cpu_exec_setjmp is now
quite small:
00000000000f3250 <cpu_exec_setjmp.isra.0>:
f3250: eb 6f f0 30 00 24 stmg %r6,%r15,48(%r15)
f3256: a7 39 00 00 lghi %r3,0
f325a: e3 f0 ff 58 ff 71 lay %r15,-168(%r15)
// Save cpu to stack+160.
f3260: e3 20 f0 a0 00 24 stg %r2,160(%r15)
f3266: 41 20 20 f0 la %r2,240(%r2)
f326a: c0 e5 ff fb 10 eb brasl %r14,55440 <__sigsetjmp@plt>
f3270: ec 26 00 0d 00 7e cijne %r2,0,f328a <cpu_exec_setjmp.isra.0+0x3a>
// Reload cpu for cpu_exec_loop().
f3276: e3 20 f0 a0 00 04 lg %r2,160(%r15)
f327c: c0 e5 ff ff fb ee brasl %r14,f2a58 <cpu_exec_loop.isra.0>
f3282: eb 6f f0 d8 00 04 lmg %r6,%r15,216(%r15)
f3288: 07 fe br %r14
// Load tls pointer and current_cpu address.
f328a: b2 4f 00 10 ear %r1,%a0
f328e: c0 20 00 0a 35 9d larl %r2,239dc8 <current_cpu@@Base+0x239dc8>
f3294: eb 11 00 20 00 0d sllg %r1,%r1,32
f329a: e3 20 20 00 00 04 lg %r2,0(%r2)
f32a0: b2 4f 00 11 ear %r1,%a1
// Reload cpu for comparison
f32a4: e3 30 f0 a0 00 04 lg %r3,160(%r15)
// cpu == current_cpu
f32aa: e3 32 10 00 00 20 cg %r3,0(%r2,%r1)
f32b0: a7 84 00 12 je f32d4 <cpu_exec_setjmp.isra.0+0x84>
...
The only way I can imagine that this comparison fails is if we have corrupted the stack in
some way. I have not been able to induce failure under any sort of debugging, and I can't
imagine where irregular corruption would have come from.
r~
r~
^ permalink raw reply [flat|nested] 20+ messages in thread