Hi Alex, I hit the following warnings (with "./configure --enable-werror"):
/qemu/contrib/plugins/execlog.c: In function ‘registers_init’: /qemu/contrib/plugins/execlog.c:330:17: warning: ‘g_pattern_match_string’ is deprecated: Use 'g_pattern_spec_match_string' instead [-Wdeprecated-declarations] 330 | if (g_pattern_match_string(pat, rd->name) || | ^~ In file included from /usr/include/glib-2.0/glib.h:65, from /qemu/contrib/plugins/execlog.c:9: /usr/include/glib-2.0/glib/gpattern.h:55:15: note: declared here 55 | gboolean g_pattern_match_string (GPatternSpec *pspec, | ^~~~~~~~~~~~~~~~~~~~~~ /qemu/contrib/plugins/execlog.c:331:21: warning: ‘g_pattern_match_string’ is deprecated: Use 'g_pattern_spec_match_string' instead [-Wdeprecated-declarations] 331 | g_pattern_match_string(pat, rd_lower)) { | ^~~~~~~~~~~~~~~~~~~~~~ In file included from /usr/include/glib-2.0/glib.h:65, from /qemu/contrib/plugins/execlog.c:9: /usr/include/glib-2.0/glib/gpattern.h:55:15: note: declared here 55 | gboolean g_pattern_match_string (GPatternSpec *pspec, | ^~~~~~~~~~~~~~~~~~~~~~ /qemu/contrib/plugins/execlog.c:339:63: warning: passing argument 2 of ‘g_ptr_array_add’ discards ‘const’ qualifier from pointer target type [-Wdiscarded-qualifiers] 339 | g_ptr_array_add(all_reg_names, reg->name); | ~~~^~~~~~ In file included from /usr/include/glib-2.0/glib.h:31, from /qemu/contrib/plugins/execlog.c:9: /usr/include/glib-2.0/glib/garray.h:192:62: note: expected ‘gpointer’ {aka ‘void *’} but argument is of type ‘const char *’ 192 | gpointer data); | ~~~~~~~~~~~~~~~~~~^~~~ In addition, I checked my glic version: $ldd --version ldd (Ubuntu GLIBC 2.35-0ubuntu3.5) 2.35 I think it's v2.35. Are these three warning reports valid? I also noticed in target/arm/helper.c, there's another g_pattern_match_string() but I haven't met the warning. Regards, Zhao On Wed, Feb 28, 2024 at 11:56:58AM +0000, Alex Bennée wrote: > Date: Wed, 28 Feb 2024 11:56:58 +0000 > From: Alex Bennée <alex.ben...@linaro.org> > Subject: [PULL 26/29] contrib/plugins: extend execlog to track register > changes > X-Mailer: git-send-email 2.39.2 > > With the new plugin register API we can now track changes to register > values. Currently the implementation is fairly dumb which will slow > down if a large number of register values are being tracked. This > could be improved by only instrumenting instructions which mention > registers we are interested in tracking. > > Example usage: > > ./qemu-aarch64 -D plugin.log -d plugin \ > -cpu max,sve256=on \ > -plugin contrib/plugins/libexeclog.so,reg=sp,reg=z\* \ > ./tests/tcg/aarch64-linux-user/sha512-sve > > will display in the execlog any changes to the stack pointer (sp) and > the SVE Z registers. > > As testing registers every instruction will be quite a heavy operation > there is an additional flag which attempts to optimise the register > tracking by only instrumenting instructions which are likely to change > its value. This relies on the QEMU disassembler showing up the register > names in disassembly so is an explicit opt-in. > > Reviewed-by: Pierrick Bouvier <pierrick.bouv...@linaro.org> > Cc: Akihiko Odaki <akihiko.od...@daynix.com> > Based-On: <20231025093128.33116-19-akihiko.od...@daynix.com> > Signed-off-by: Alex Bennée <alex.ben...@linaro.org> > Message-Id: <20240227144335.1196131-27-alex.ben...@linaro.org> > > diff --git a/docs/devel/tcg-plugins.rst b/docs/devel/tcg-plugins.rst > index 81dcd43a612..fa7421279f5 100644 > --- a/docs/devel/tcg-plugins.rst > +++ b/docs/devel/tcg-plugins.rst > @@ -497,6 +497,22 @@ arguments if required:: > $ qemu-system-arm $(QEMU_ARGS) \ > -plugin ./contrib/plugins/libexeclog.so,ifilter=st1w,afilter=0x40001808 > -d plugin > > +This plugin can also dump registers when they change value. Specify the name > of the > +registers with multiple ``reg`` options. You can also use glob style > matching if you wish:: > + > + $ qemu-system-arm $(QEMU_ARGS) \ > + -plugin ./contrib/plugins/libexeclog.so,reg=\*_el2,reg=sp -d plugin > + > +Be aware that each additional register to check will slow down > +execution quite considerably. You can optimise the number of register > +checks done by using the rdisas option. This will only instrument > +instructions that mention the registers in question in disassembly. > +This is not foolproof as some instructions implicitly change > +instructions. You can use the ifilter to catch these cases: > + > + $ qemu-system-arm $(QEMU_ARGS) \ > + -plugin > ./contrib/plugins/libexeclog.so,ifilter=msr,ifilter=blr,reg=x30,reg=\*_el1,rdisas=on > + > - contrib/plugins/cache.c > > Cache modelling plugin that measures the performance of a given L1 cache > @@ -583,4 +599,3 @@ The following API is generated from the inline > documentation in > include the full kernel-doc annotations. > > .. kernel-doc:: include/qemu/qemu-plugin.h > - > diff --git a/contrib/plugins/execlog.c b/contrib/plugins/execlog.c > index f262e5555eb..a1dfd59ab71 100644 > --- a/contrib/plugins/execlog.c > +++ b/contrib/plugins/execlog.c > @@ -1,7 +1,7 @@ > /* > * Copyright (C) 2021, Alexandre Iooss <erdn...@crans.org> > * > - * Log instruction execution with memory access. > + * Log instruction execution with memory access and register changes > * > * License: GNU GPL, version 2 or later. > * See the COPYING file in the top-level directory. > @@ -15,29 +15,40 @@ > > #include <qemu-plugin.h> > > +typedef struct { > + struct qemu_plugin_register *handle; > + GByteArray *last; > + GByteArray *new; > + const char *name; > +} Register; > + > +typedef struct CPU { > + /* Store last executed instruction on each vCPU as a GString */ > + GString *last_exec; > + /* Ptr array of Register */ > + GPtrArray *registers; > +} CPU; > + > QEMU_PLUGIN_EXPORT int qemu_plugin_version = QEMU_PLUGIN_VERSION; > > -/* Store last executed instruction on each vCPU as a GString */ > -static GPtrArray *last_exec; > +static GArray *cpus; > static GRWLock expand_array_lock; > > static GPtrArray *imatches; > static GArray *amatches; > +static GPtrArray *rmatches; > +static bool disas_assist; > +static GMutex add_reg_name_lock; > +static GPtrArray *all_reg_names; > > -/* > - * Expand last_exec array. > - * > - * As we could have multiple threads trying to do this we need to > - * serialise the expansion under a lock. > - */ > -static void expand_last_exec(int cpu_index) > +static CPU *get_cpu(int vcpu_index) > { > - g_rw_lock_writer_lock(&expand_array_lock); > - while (cpu_index >= last_exec->len) { > - GString *s = g_string_new(NULL); > - g_ptr_array_add(last_exec, s); > - } > - g_rw_lock_writer_unlock(&expand_array_lock); > + CPU *c; > + g_rw_lock_reader_lock(&expand_array_lock); > + c = &g_array_index(cpus, CPU, vcpu_index); > + g_rw_lock_reader_unlock(&expand_array_lock); > + > + return c; > } > > /** > @@ -46,13 +57,10 @@ static void expand_last_exec(int cpu_index) > static void vcpu_mem(unsigned int cpu_index, qemu_plugin_meminfo_t info, > uint64_t vaddr, void *udata) > { > - GString *s; > + CPU *c = get_cpu(cpu_index); > + GString *s = c->last_exec; > > /* Find vCPU in array */ > - g_rw_lock_reader_lock(&expand_array_lock); > - g_assert(cpu_index < last_exec->len); > - s = g_ptr_array_index(last_exec, cpu_index); > - g_rw_lock_reader_unlock(&expand_array_lock); > > /* Indicate type of memory access */ > if (qemu_plugin_mem_is_store(info)) { > @@ -73,32 +81,91 @@ static void vcpu_mem(unsigned int cpu_index, > qemu_plugin_meminfo_t info, > } > > /** > - * Log instruction execution > + * Log instruction execution, outputting the last one. > + * > + * vcpu_insn_exec() is a copy and paste of vcpu_insn_exec_with_regs() > + * without the checking of register values when we've attempted to > + * optimise with disas_assist. > */ > -static void vcpu_insn_exec(unsigned int cpu_index, void *udata) > +static void insn_check_regs(CPU *cpu) > { > - GString *s; > + for (int n = 0; n < cpu->registers->len; n++) { > + Register *reg = cpu->registers->pdata[n]; > + int sz; > > - /* Find or create vCPU in array */ > - g_rw_lock_reader_lock(&expand_array_lock); > - if (cpu_index >= last_exec->len) { > - g_rw_lock_reader_unlock(&expand_array_lock); > - expand_last_exec(cpu_index); > - g_rw_lock_reader_lock(&expand_array_lock); > + g_byte_array_set_size(reg->new, 0); > + sz = qemu_plugin_read_register(reg->handle, reg->new); > + g_assert(sz == reg->last->len); > + > + if (memcmp(reg->last->data, reg->new->data, sz)) { > + GByteArray *temp = reg->last; > + g_string_append_printf(cpu->last_exec, ", %s -> 0x", reg->name); > + /* TODO: handle BE properly */ > + for (int i = sz; i >= 0; i--) { > + g_string_append_printf(cpu->last_exec, "%02x", > + reg->new->data[i]); > + } > + reg->last = reg->new; > + reg->new = temp; > + } > + } > +} > + > +/* Log last instruction while checking registers */ > +static void vcpu_insn_exec_with_regs(unsigned int cpu_index, void *udata) > +{ > + CPU *cpu = get_cpu(cpu_index); > + > + /* Print previous instruction in cache */ > + if (cpu->last_exec->len) { > + if (cpu->registers) { > + insn_check_regs(cpu); > + } > + > + qemu_plugin_outs(cpu->last_exec->str); > + qemu_plugin_outs("\n"); > + } > + > + /* Store new instruction in cache */ > + /* vcpu_mem will add memory access information to last_exec */ > + g_string_printf(cpu->last_exec, "%u, ", cpu_index); > + g_string_append(cpu->last_exec, (char *)udata); > +} > + > +/* Log last instruction while checking registers, ignore next */ > +static void vcpu_insn_exec_only_regs(unsigned int cpu_index, void *udata) > +{ > + CPU *cpu = get_cpu(cpu_index); > + > + /* Print previous instruction in cache */ > + if (cpu->last_exec->len) { > + if (cpu->registers) { > + insn_check_regs(cpu); > + } > + > + qemu_plugin_outs(cpu->last_exec->str); > + qemu_plugin_outs("\n"); > } > - s = g_ptr_array_index(last_exec, cpu_index); > - g_rw_lock_reader_unlock(&expand_array_lock); > + > + /* reset */ > + cpu->last_exec->len = 0; > +} > + > +/* Log last instruction without checking regs, setup next */ > +static void vcpu_insn_exec(unsigned int cpu_index, void *udata) > +{ > + CPU *cpu = get_cpu(cpu_index); > > /* Print previous instruction in cache */ > - if (s->len) { > - qemu_plugin_outs(s->str); > + if (cpu->last_exec->len) { > + qemu_plugin_outs(cpu->last_exec->str); > qemu_plugin_outs("\n"); > } > > /* Store new instruction in cache */ > /* vcpu_mem will add memory access information to last_exec */ > - g_string_printf(s, "%u, ", cpu_index); > - g_string_append(s, (char *)udata); > + g_string_printf(cpu->last_exec, "%u, ", cpu_index); > + g_string_append(cpu->last_exec, (char *)udata); > } > > /** > @@ -111,6 +178,8 @@ static void vcpu_tb_trans(qemu_plugin_id_t id, struct > qemu_plugin_tb *tb) > { > struct qemu_plugin_insn *insn; > bool skip = (imatches || amatches); > + bool check_regs_this = rmatches; > + bool check_regs_next = false; > > size_t n = qemu_plugin_tb_n_insns(tb); > for (size_t i = 0; i < n; i++) { > @@ -131,7 +200,8 @@ static void vcpu_tb_trans(qemu_plugin_id_t id, struct > qemu_plugin_tb *tb) > /* > * If we are filtering we better check out if we have any > * hits. The skip "latches" so we can track memory accesses > - * after the instruction we care about. > + * after the instruction we care about. Also enable register > + * checking on the next instruction. > */ > if (skip && imatches) { > int j; > @@ -139,6 +209,7 @@ static void vcpu_tb_trans(qemu_plugin_id_t id, struct > qemu_plugin_tb *tb) > char *m = g_ptr_array_index(imatches, j); > if (g_str_has_prefix(insn_disas, m)) { > skip = false; > + check_regs_next = rmatches; > } > } > } > @@ -153,8 +224,39 @@ static void vcpu_tb_trans(qemu_plugin_id_t id, struct > qemu_plugin_tb *tb) > } > } > > + /* > + * Check the disassembly to see if a register we care about > + * will be affected by this instruction. This relies on the > + * dissembler doing something sensible for the registers we > + * care about. > + */ > + if (disas_assist && rmatches) { > + check_regs_next = false; > + gchar *args = g_strstr_len(insn_disas, -1, " "); > + for (int n = 0; n < all_reg_names->len; n++) { > + gchar *reg = g_ptr_array_index(all_reg_names, n); > + if (g_strrstr(args, reg)) { > + check_regs_next = true; > + skip = false; > + } > + } > + } > + > + /* > + * We now have 3 choices: > + * > + * - Log insn > + * - Log insn while checking registers > + * - Don't log this insn but check if last insn changed registers > + */ > + > if (skip) { > - g_free(insn_disas); > + if (check_regs_this) { > + qemu_plugin_register_vcpu_insn_exec_cb(insn, > + > vcpu_insn_exec_only_regs, > + QEMU_PLUGIN_CB_R_REGS, > + NULL); > + } > } else { > uint32_t insn_opcode; > insn_opcode = *((uint32_t *)qemu_plugin_insn_data(insn)); > @@ -167,30 +269,124 @@ static void vcpu_tb_trans(qemu_plugin_id_t id, struct > qemu_plugin_tb *tb) > QEMU_PLUGIN_MEM_RW, NULL); > > /* Register callback on instruction */ > - qemu_plugin_register_vcpu_insn_exec_cb(insn, vcpu_insn_exec, > - QEMU_PLUGIN_CB_NO_REGS, > output); > + if (check_regs_this) { > + qemu_plugin_register_vcpu_insn_exec_cb( > + insn, vcpu_insn_exec_with_regs, > + QEMU_PLUGIN_CB_R_REGS, > + output); > + } else { > + qemu_plugin_register_vcpu_insn_exec_cb( > + insn, vcpu_insn_exec, > + QEMU_PLUGIN_CB_NO_REGS, > + output); > + } > > /* reset skip */ > skip = (imatches || amatches); > } > > + /* set regs for next */ > + if (disas_assist && rmatches) { > + check_regs_this = check_regs_next; > + } > + > + g_free(insn_disas); > } > } > > +static Register *init_vcpu_register(qemu_plugin_reg_descriptor *desc) > +{ > + Register *reg = g_new0(Register, 1); > + g_autofree gchar *lower = g_utf8_strdown(desc->name, -1); > + int r; > + > + reg->handle = desc->handle; > + reg->name = g_intern_string(lower); > + reg->last = g_byte_array_new(); > + reg->new = g_byte_array_new(); > + > + /* read the initial value */ > + r = qemu_plugin_read_register(reg->handle, reg->last); > + g_assert(r > 0); > + return reg; > +} > + > +static GPtrArray *registers_init(int vcpu_index) > +{ > + g_autoptr(GPtrArray) registers = g_ptr_array_new(); > + g_autoptr(GArray) reg_list = qemu_plugin_get_registers(); > + > + if (rmatches && reg_list->len) { > + /* > + * Go through each register in the complete list and > + * see if we want to track it. > + */ > + for (int r = 0; r < reg_list->len; r++) { > + qemu_plugin_reg_descriptor *rd = &g_array_index( > + reg_list, qemu_plugin_reg_descriptor, r); > + for (int p = 0; p < rmatches->len; p++) { > + g_autoptr(GPatternSpec) pat = > g_pattern_spec_new(rmatches->pdata[p]); > + g_autofree gchar *rd_lower = g_utf8_strdown(rd->name, -1); > + if (g_pattern_match_string(pat, rd->name) || > + g_pattern_match_string(pat, rd_lower)) { > + Register *reg = init_vcpu_register(rd); > + g_ptr_array_add(registers, reg); > + > + /* we need a list of regnames at TB translation time */ > + if (disas_assist) { > + g_mutex_lock(&add_reg_name_lock); > + if (!g_ptr_array_find(all_reg_names, reg->name, > NULL)) { > + g_ptr_array_add(all_reg_names, reg->name); > + } > + g_mutex_unlock(&add_reg_name_lock); > + } > + } > + } > + } > + } > + > + return registers->len ? g_steal_pointer(®isters) : NULL; > +} > + > +/* > + * Initialise a new vcpu/thread with: > + * - last_exec tracking data > + * - list of tracked registers > + * - initial value of registers > + * > + * As we could have multiple threads trying to do this we need to > + * serialise the expansion under a lock. > + */ > +static void vcpu_init(qemu_plugin_id_t id, unsigned int vcpu_index) > +{ > + CPU *c; > + > + g_rw_lock_writer_lock(&expand_array_lock); > + if (vcpu_index >= cpus->len) { > + g_array_set_size(cpus, vcpu_index + 1); > + } > + g_rw_lock_writer_unlock(&expand_array_lock); > + > + c = get_cpu(vcpu_index); > + c->last_exec = g_string_new(NULL); > + c->registers = registers_init(vcpu_index); > +} > + > /** > * On plugin exit, print last instruction in cache > */ > static void plugin_exit(qemu_plugin_id_t id, void *p) > { > guint i; > - GString *s; > - for (i = 0; i < last_exec->len; i++) { > - s = g_ptr_array_index(last_exec, i); > - if (s->str) { > - qemu_plugin_outs(s->str); > + g_rw_lock_reader_lock(&expand_array_lock); > + for (i = 0; i < cpus->len; i++) { > + CPU *c = get_cpu(i); > + if (c->last_exec && c->last_exec->str) { > + qemu_plugin_outs(c->last_exec->str); > qemu_plugin_outs("\n"); > } > } > + g_rw_lock_reader_unlock(&expand_array_lock); > } > > /* Add a match to the array of matches */ > @@ -212,6 +408,18 @@ static void parse_vaddr_match(char *match) > g_array_append_val(amatches, v); > } > > +/* > + * We have to wait until vCPUs are started before we can check the > + * patterns find anything. > + */ > +static void add_regpat(char *regpat) > +{ > + if (!rmatches) { > + rmatches = g_ptr_array_new(); > + } > + g_ptr_array_add(rmatches, g_strdup(regpat)); > +} > + > /** > * Install the plugin > */ > @@ -223,11 +431,8 @@ QEMU_PLUGIN_EXPORT int > qemu_plugin_install(qemu_plugin_id_t id, > * Initialize dynamic array to cache vCPU instruction. In user mode > * we don't know the size before emulation. > */ > - if (info->system_emulation) { > - last_exec = g_ptr_array_sized_new(info->system.max_vcpus); > - } else { > - last_exec = g_ptr_array_new(); > - } > + cpus = g_array_sized_new(true, true, sizeof(CPU), > + info->system_emulation ? info->system.max_vcpus > : 1); > > for (int i = 0; i < argc; i++) { > char *opt = argv[i]; > @@ -236,13 +441,22 @@ QEMU_PLUGIN_EXPORT int > qemu_plugin_install(qemu_plugin_id_t id, > parse_insn_match(tokens[1]); > } else if (g_strcmp0(tokens[0], "afilter") == 0) { > parse_vaddr_match(tokens[1]); > + } else if (g_strcmp0(tokens[0], "reg") == 0) { > + add_regpat(tokens[1]); > + } else if (g_strcmp0(tokens[0], "rdisas") == 0) { > + if (!qemu_plugin_bool_parse(tokens[0], tokens[1], > &disas_assist)) { > + fprintf(stderr, "boolean argument parsing failed: %s\n", > opt); > + return -1; > + } > + all_reg_names = g_ptr_array_new(); > } else { > fprintf(stderr, "option parsing failed: %s\n", opt); > return -1; > } > } > > - /* Register translation block and exit callbacks */ > + /* Register init, translation block and exit callbacks */ > + qemu_plugin_register_vcpu_init_cb(id, vcpu_init); > qemu_plugin_register_vcpu_tb_trans_cb(id, vcpu_tb_trans); > qemu_plugin_register_atexit_cb(id, plugin_exit, NULL); > > -- > 2.39.2 > >