Override kvm_emulate_insn formatting to use a disassembler to format the emulated instruction. If a disassembler (udis86) is not available, fall back to showing the instruction bytes in hex.
Signed-off-by: Avi Kivity <[email protected]> --- Note 1: on top of 'master' with 'trace-cmd-kvm' cherry-picked on top. Note 2: I get output of the form ... kvm_emulate_insn: 0:fffff800010527b5: mov $0x0, 0xfffe00b0CAN'T FIND FIELD "guest_rip" which leads me to believe there is a bug in trace_seq_printf when the input to %s is "". Makefile | 11 +++++- plugin_kvm.c | 111 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 121 insertions(+), 1 deletions(-) diff --git a/Makefile b/Makefile index 5282f94..fe34d1c 100644 --- a/Makefile +++ b/Makefile @@ -74,6 +74,14 @@ ifeq ($(shell sh -c "python-config --includes > /dev/null 2>&1 && echo y"), y) PYTHON_PY_INSTALL := event-viewer.install tracecmd.install tracecmdgui.install endif +# $(call test-build, snippet, ret) -> ret if snippet compiles +# -> empty otherwise +test-build = $(if $(shell $(CC) -o /dev/null -c -x c - > /dev/null 2>&1 \ + <<<'$1' && echo y), $2) + +# have udis86 disassembler library? +udis86-flags := $(call test-build,\#include <udis86.h>,-DHAVE_UDIS86 -ludis86) + ifeq ("$(origin O)", "command line") BUILD_OUTPUT := $(O) endif @@ -188,6 +196,7 @@ CFLAGS ?= -g -Wall # Append required CFLAGS override CFLAGS += $(CONFIG_FLAGS) $(INCLUDES) $(PLUGIN_DIR_SQ) +override CFLAGS += $(udis86-flags) ifeq ($(VERBOSE),1) Q = @@ -228,7 +237,7 @@ do_compile_plugin_obj = \ do_plugin_build = \ ($(print_plugin_build) \ - $(CC) -shared -nostartfiles -o $@ $<) + $(CC) $(CFLAGS) -shared -nostartfiles -o $@ $<) do_build_static_lib = \ ($(print_static_lib_build) \ diff --git a/plugin_kvm.c b/plugin_kvm.c index 7217e85..00cac5a 100644 --- a/plugin_kvm.c +++ b/plugin_kvm.c @@ -21,9 +21,68 @@ #include <stdio.h> #include <stdlib.h> #include <string.h> +#include <stdint.h> #include "parse-events.h" +#ifdef HAVE_UDIS86 + +#include <udis86.h> + +static ud_t ud; + +static void init_disassembler(void) +{ + ud_init(&ud); + ud_set_syntax(&ud, UD_SYN_ATT); +} + +static const char *disassemble(unsigned char *insn, int len, uint64_t rip, + int cr0_pe, int eflags_vm, + int cs_d, int cs_l) +{ + int mode; + + if (!cr0_pe) + mode = 16; + else if (eflags_vm) + mode = 16; + else if (cs_l) + mode = 64; + else if (cs_d) + mode = 32; + else + mode = 16; + + ud_set_pc(&ud, rip); + ud_set_mode(&ud, mode); + ud_set_input_buffer(&ud, insn, len); + ud_disassemble(&ud); + return ud_insn_asm(&ud); +} + +#else + +static void init_disassembler(void) +{ +} + +static const char *disassemble(unsigned char *insn, int len, uint64_t rip, + int cr0_pe, int eflags_vm, + int cs_d, int cs_l) +{ + static char out[15*3+1]; + int i; + + for (i = 0; i < len; ++i) + sprintf(out + i * 3, "%02x ", insn[i]); + out[len*3-1] = '\0'; + return out; +} + +#endif + + #define VMX_EXIT_REASONS \ _ER(EXCEPTION_NMI, 0) \ _ER(EXTERNAL_INTERRUPT, 1) \ @@ -99,6 +158,53 @@ static int kvm_exit_handler(struct trace_seq *s, struct record *record, return 0; } +#define KVM_EMUL_INSN_F_CR0_PE (1 << 0) +#define KVM_EMUL_INSN_F_EFL_VM (1 << 1) +#define KVM_EMUL_INSN_F_CS_D (1 << 2) +#define KVM_EMUL_INSN_F_CS_L (1 << 3) + +static int kvm_emulate_insn_handler(struct trace_seq *s, struct record *record, + struct event_format *event, void *context) +{ + unsigned long long rip, csbase, len, flags, failed; + int llen; + uint8_t *insn; + const char *disasm; + + if (pevent_get_field_val(s, event, "rip", record, &rip, 1) < 0) + return -1; + + if (pevent_get_field_val(s, event, "csbase", record, &csbase, 1) < 0) + return -1; + + if (pevent_get_field_val(s, event, "len", record, &len, 1) < 0) + return -1; + + if (pevent_get_field_val(s, event, "flags", record, &flags, 1) < 0) + return -1; + + if (pevent_get_field_val(s, event, "failed", record, &failed, 1) < 0) + return -1; + + insn = pevent_get_field_raw(s, event, "insn", record, &llen, 1); + if (!insn) + return -1; + + disasm = disassemble(insn, len, rip, + flags & KVM_EMUL_INSN_F_CR0_PE, + flags & KVM_EMUL_INSN_F_EFL_VM, + flags & KVM_EMUL_INSN_F_CS_D, + flags & KVM_EMUL_INSN_F_CS_L); + + trace_seq_printf(s, "%llx:%llx: %s%s", csbase, rip, disasm, + failed ? " FAIL" : ""); + + pevent_print_num_field(s, " rip %0xlx", event, "guest_rip", record, 1); + + return 0; +} + + static int kvm_nested_vmexit_inject_handler(struct trace_seq *s, struct record *record, struct event_format *event, void *context) { @@ -199,9 +305,14 @@ static int kvm_mmu_get_page_handler(struct trace_seq *s, struct record *record, int PEVENT_PLUGIN_LOADER(struct pevent *pevent) { + init_disassembler(); + pevent_register_event_handler(pevent, -1, "kvm", "kvm_exit", kvm_exit_handler, NULL); + pevent_register_event_handler(pevent, -1, "kvm", "kvm_emulate_insn", + kvm_emulate_insn_handler, NULL); + pevent_register_event_handler(pevent, -1, "kvm", "kvm_nested_vmexit", kvm_nested_vmexit_handler, NULL); -- 1.7.2.3 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
