qemu/plugins/api.c
Alex Bennée cfd405eae6 accel/tcg: allow plugin instrumentation to be disable via cflags
When icount is enabled and we recompile an MMIO access we end up
double counting the instruction execution. To avoid this we introduce
the CF_MEMI cflag which only allows memory instrumentation for the
next TB (which won't yet have been counted). As this is part of the
hashed compile flags we will only execute the generated TB while
coming out of a cpu_io_recompile.

While we are at it delete the old TODO. We might as well keep the
translation handy as it's likely you will repeatedly hit it on each
MMIO access.

Reported-by: Aaron Lindsay <aaron@os.amperecomputing.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Tested-by: Aaron Lindsay <aaron@os.amperecomputing.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210213130325.14781-21-alex.bennee@linaro.org>
2021-02-18 08:19:23 +00:00

377 lines
10 KiB
C

/*
* QEMU Plugin API
*
* This provides the API that is available to the plugins to interact
* with QEMU. We have to be careful not to expose internal details of
* how QEMU works so we abstract out things like translation and
* instructions to anonymous data types:
*
* qemu_plugin_tb
* qemu_plugin_insn
*
* Which can then be passed back into the API to do additional things.
* As such all the public functions in here are exported in
* qemu-plugin.h.
*
* The general life-cycle of a plugin is:
*
* - plugin is loaded, public qemu_plugin_install called
* - the install func registers callbacks for events
* - usually an atexit_cb is registered to dump info at the end
* - when a registered event occurs the plugin is called
* - some events pass additional info
* - during translation the plugin can decide to instrument any
* instruction
* - when QEMU exits all the registered atexit callbacks are called
*
* Copyright (C) 2017, Emilio G. Cota <cota@braap.org>
* Copyright (C) 2019, Linaro
*
* License: GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*
*/
#include "qemu/osdep.h"
#include "qemu/plugin.h"
#include "cpu.h"
#include "sysemu/sysemu.h"
#include "tcg/tcg.h"
#include "exec/exec-all.h"
#include "disas/disas.h"
#include "plugin.h"
#ifndef CONFIG_USER_ONLY
#include "qemu/plugin-memory.h"
#include "hw/boards.h"
#endif
#include "trace/mem.h"
/* Uninstall and Reset handlers */
void qemu_plugin_uninstall(qemu_plugin_id_t id, qemu_plugin_simple_cb_t cb)
{
plugin_reset_uninstall(id, cb, false);
}
void qemu_plugin_reset(qemu_plugin_id_t id, qemu_plugin_simple_cb_t cb)
{
plugin_reset_uninstall(id, cb, true);
}
/*
* Plugin Register Functions
*
* This allows the plugin to register callbacks for various events
* during the translation.
*/
void qemu_plugin_register_vcpu_init_cb(qemu_plugin_id_t id,
qemu_plugin_vcpu_simple_cb_t cb)
{
plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_INIT, cb);
}
void qemu_plugin_register_vcpu_exit_cb(qemu_plugin_id_t id,
qemu_plugin_vcpu_simple_cb_t cb)
{
plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_EXIT, cb);
}
void qemu_plugin_register_vcpu_tb_exec_cb(struct qemu_plugin_tb *tb,
qemu_plugin_vcpu_udata_cb_t cb,
enum qemu_plugin_cb_flags flags,
void *udata)
{
if (!tb->mem_only) {
plugin_register_dyn_cb__udata(&tb->cbs[PLUGIN_CB_REGULAR],
cb, flags, udata);
}
}
void qemu_plugin_register_vcpu_tb_exec_inline(struct qemu_plugin_tb *tb,
enum qemu_plugin_op op,
void *ptr, uint64_t imm)
{
if (!tb->mem_only) {
plugin_register_inline_op(&tb->cbs[PLUGIN_CB_INLINE], 0, op, ptr, imm);
}
}
void qemu_plugin_register_vcpu_insn_exec_cb(struct qemu_plugin_insn *insn,
qemu_plugin_vcpu_udata_cb_t cb,
enum qemu_plugin_cb_flags flags,
void *udata)
{
if (!insn->mem_only) {
plugin_register_dyn_cb__udata(&insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_REGULAR],
cb, flags, udata);
}
}
void qemu_plugin_register_vcpu_insn_exec_inline(struct qemu_plugin_insn *insn,
enum qemu_plugin_op op,
void *ptr, uint64_t imm)
{
if (!insn->mem_only) {
plugin_register_inline_op(&insn->cbs[PLUGIN_CB_INSN][PLUGIN_CB_INLINE],
0, op, ptr, imm);
}
}
/*
* We always plant memory instrumentation because they don't finalise until
* after the operation has complete.
*/
void qemu_plugin_register_vcpu_mem_cb(struct qemu_plugin_insn *insn,
qemu_plugin_vcpu_mem_cb_t cb,
enum qemu_plugin_cb_flags flags,
enum qemu_plugin_mem_rw rw,
void *udata)
{
plugin_register_vcpu_mem_cb(&insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_REGULAR],
cb, flags, rw, udata);
}
void qemu_plugin_register_vcpu_mem_inline(struct qemu_plugin_insn *insn,
enum qemu_plugin_mem_rw rw,
enum qemu_plugin_op op, void *ptr,
uint64_t imm)
{
plugin_register_inline_op(&insn->cbs[PLUGIN_CB_MEM][PLUGIN_CB_INLINE],
rw, op, ptr, imm);
}
void qemu_plugin_register_vcpu_tb_trans_cb(qemu_plugin_id_t id,
qemu_plugin_vcpu_tb_trans_cb_t cb)
{
plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_TB_TRANS, cb);
}
void qemu_plugin_register_vcpu_syscall_cb(qemu_plugin_id_t id,
qemu_plugin_vcpu_syscall_cb_t cb)
{
plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_SYSCALL, cb);
}
void
qemu_plugin_register_vcpu_syscall_ret_cb(qemu_plugin_id_t id,
qemu_plugin_vcpu_syscall_ret_cb_t cb)
{
plugin_register_cb(id, QEMU_PLUGIN_EV_VCPU_SYSCALL_RET, cb);
}
/*
* Plugin Queries
*
* These are queries that the plugin can make to gauge information
* from our opaque data types. We do not want to leak internal details
* here just information useful to the plugin.
*/
/*
* Translation block information:
*
* A plugin can query the virtual address of the start of the block
* and the number of instructions in it. It can also get access to
* each translated instruction.
*/
size_t qemu_plugin_tb_n_insns(const struct qemu_plugin_tb *tb)
{
return tb->n;
}
uint64_t qemu_plugin_tb_vaddr(const struct qemu_plugin_tb *tb)
{
return tb->vaddr;
}
struct qemu_plugin_insn *
qemu_plugin_tb_get_insn(const struct qemu_plugin_tb *tb, size_t idx)
{
struct qemu_plugin_insn *insn;
if (unlikely(idx >= tb->n)) {
return NULL;
}
insn = g_ptr_array_index(tb->insns, idx);
insn->mem_only = tb->mem_only;
return insn;
}
/*
* Instruction information
*
* These queries allow the plugin to retrieve information about each
* instruction being translated.
*/
const void *qemu_plugin_insn_data(const struct qemu_plugin_insn *insn)
{
return insn->data->data;
}
size_t qemu_plugin_insn_size(const struct qemu_plugin_insn *insn)
{
return insn->data->len;
}
uint64_t qemu_plugin_insn_vaddr(const struct qemu_plugin_insn *insn)
{
return insn->vaddr;
}
void *qemu_plugin_insn_haddr(const struct qemu_plugin_insn *insn)
{
return insn->haddr;
}
char *qemu_plugin_insn_disas(const struct qemu_plugin_insn *insn)
{
CPUState *cpu = current_cpu;
return plugin_disas(cpu, insn->vaddr, insn->data->len);
}
/*
* The memory queries allow the plugin to query information about a
* memory access.
*/
unsigned qemu_plugin_mem_size_shift(qemu_plugin_meminfo_t info)
{
return info & TRACE_MEM_SZ_SHIFT_MASK;
}
bool qemu_plugin_mem_is_sign_extended(qemu_plugin_meminfo_t info)
{
return !!(info & TRACE_MEM_SE);
}
bool qemu_plugin_mem_is_big_endian(qemu_plugin_meminfo_t info)
{
return !!(info & TRACE_MEM_BE);
}
bool qemu_plugin_mem_is_store(qemu_plugin_meminfo_t info)
{
return !!(info & TRACE_MEM_ST);
}
/*
* Virtual Memory queries
*/
#ifdef CONFIG_SOFTMMU
static __thread struct qemu_plugin_hwaddr hwaddr_info;
struct qemu_plugin_hwaddr *qemu_plugin_get_hwaddr(qemu_plugin_meminfo_t info,
uint64_t vaddr)
{
CPUState *cpu = current_cpu;
unsigned int mmu_idx = info >> TRACE_MEM_MMU_SHIFT;
hwaddr_info.is_store = info & TRACE_MEM_ST;
if (!tlb_plugin_lookup(cpu, vaddr, mmu_idx,
info & TRACE_MEM_ST, &hwaddr_info)) {
error_report("invalid use of qemu_plugin_get_hwaddr");
return NULL;
}
return &hwaddr_info;
}
#else
struct qemu_plugin_hwaddr *qemu_plugin_get_hwaddr(qemu_plugin_meminfo_t info,
uint64_t vaddr)
{
return NULL;
}
#endif
bool qemu_plugin_hwaddr_is_io(const struct qemu_plugin_hwaddr *haddr)
{
#ifdef CONFIG_SOFTMMU
return haddr->is_io;
#else
return false;
#endif
}
uint64_t qemu_plugin_hwaddr_device_offset(const struct qemu_plugin_hwaddr *haddr)
{
#ifdef CONFIG_SOFTMMU
if (haddr) {
if (!haddr->is_io) {
ram_addr_t ram_addr = qemu_ram_addr_from_host((void *) haddr->v.ram.hostaddr);
if (ram_addr == RAM_ADDR_INVALID) {
error_report("Bad ram pointer %"PRIx64"", haddr->v.ram.hostaddr);
abort();
}
return ram_addr;
} else {
return haddr->v.io.offset;
}
}
#endif
return 0;
}
const char *qemu_plugin_hwaddr_device_name(const struct qemu_plugin_hwaddr *h)
{
#ifdef CONFIG_SOFTMMU
if (h && h->is_io) {
MemoryRegionSection *mrs = h->v.io.section;
if (!mrs->mr->name) {
unsigned long maddr = 0xffffffff & (uintptr_t) mrs->mr;
g_autofree char *temp = g_strdup_printf("anon%08lx", maddr);
return g_intern_string(temp);
} else {
return g_intern_string(mrs->mr->name);
}
} else {
return g_intern_static_string("RAM");
}
#else
return g_intern_static_string("Invalid");
#endif
}
/*
* Queries to the number and potential maximum number of vCPUs there
* will be. This helps the plugin dimension per-vcpu arrays.
*/
#ifndef CONFIG_USER_ONLY
static MachineState * get_ms(void)
{
return MACHINE(qdev_get_machine());
}
#endif
int qemu_plugin_n_vcpus(void)
{
#ifdef CONFIG_USER_ONLY
return -1;
#else
return get_ms()->smp.cpus;
#endif
}
int qemu_plugin_n_max_vcpus(void)
{
#ifdef CONFIG_USER_ONLY
return -1;
#else
return get_ms()->smp.max_cpus;
#endif
}
/*
* Plugin output
*/
void qemu_plugin_outs(const char *string)
{
qemu_log_mask(CPU_LOG_PLUGIN, "%s", string);
}