plugins: conditional callbacks

Extend plugins API to support callback called with a given criteria
(evaluated inline).

Added functions:
- qemu_plugin_register_vcpu_tb_exec_cond_cb
- qemu_plugin_register_vcpu_insn_exec_cond_cb

They expect as parameter a condition, a qemu_plugin_u64_t (op1) and an
immediate (op2). Callback is called if op1 |cond| op2 is true.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Message-Id: <20240502211522.346467-6-pierrick.bouvier@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
[AJB: fix re-base conflict with tb_is_mem_only()]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20240514174253.694591-8-alex.bennee@linaro.org>
This commit is contained in:
Pierrick Bouvier 2024-05-14 18:42:49 +01:00 committed by Alex Bennée
parent a1c9bf2514
commit 7de77d3788
7 changed files with 213 additions and 0 deletions

View file

@ -132,6 +132,51 @@ static TCGv_ptr gen_plugin_u64_ptr(qemu_plugin_u64 entry)
return ptr;
}
static TCGCond plugin_cond_to_tcgcond(enum qemu_plugin_cond cond)
{
switch (cond) {
case QEMU_PLUGIN_COND_EQ:
return TCG_COND_EQ;
case QEMU_PLUGIN_COND_NE:
return TCG_COND_NE;
case QEMU_PLUGIN_COND_LT:
return TCG_COND_LTU;
case QEMU_PLUGIN_COND_LE:
return TCG_COND_LEU;
case QEMU_PLUGIN_COND_GT:
return TCG_COND_GTU;
case QEMU_PLUGIN_COND_GE:
return TCG_COND_GEU;
default:
/* ALWAYS and NEVER conditions should never reach */
g_assert_not_reached();
}
}
static void gen_udata_cond_cb(struct qemu_plugin_dyn_cb *cb)
{
TCGv_ptr ptr = gen_plugin_u64_ptr(cb->cond.entry);
TCGv_i32 cpu_index = tcg_temp_ebb_new_i32();
TCGv_i64 val = tcg_temp_ebb_new_i64();
TCGLabel *after_cb = gen_new_label();
/* Condition should be negated, as calling the cb is the "else" path */
TCGCond cond = tcg_invert_cond(plugin_cond_to_tcgcond(cb->cond.cond));
tcg_gen_ld_i64(val, ptr, 0);
tcg_gen_brcondi_i64(cond, val, cb->cond.imm, after_cb);
tcg_gen_ld_i32(cpu_index, tcg_env,
-offsetof(ArchCPU, env) + offsetof(CPUState, cpu_index));
tcg_gen_call2(cb->cond.f.vcpu_udata, cb->cond.info, NULL,
tcgv_i32_temp(cpu_index),
tcgv_ptr_temp(tcg_constant_ptr(cb->userp)));
gen_set_label(after_cb);
tcg_temp_free_i64(val);
tcg_temp_free_i32(cpu_index);
tcg_temp_free_ptr(ptr);
}
static void gen_inline_add_u64_cb(struct qemu_plugin_dyn_cb *cb)
{
TCGv_ptr ptr = gen_plugin_u64_ptr(cb->inline_insn.entry);
@ -177,6 +222,9 @@ static void inject_cb(struct qemu_plugin_dyn_cb *cb)
case PLUGIN_CB_REGULAR:
gen_udata_cb(cb);
break;
case PLUGIN_CB_COND:
gen_udata_cond_cb(cb);
break;
case PLUGIN_CB_INLINE_ADD_U64:
gen_inline_add_u64_cb(cb);
break;

View file

@ -68,6 +68,7 @@ union qemu_plugin_cb_sig {
enum plugin_dyn_cb_type {
PLUGIN_CB_REGULAR,
PLUGIN_CB_COND,
PLUGIN_CB_MEM_REGULAR,
PLUGIN_CB_INLINE_ADD_U64,
PLUGIN_CB_INLINE_STORE_U64,
@ -89,6 +90,13 @@ struct qemu_plugin_dyn_cb {
union qemu_plugin_cb_sig f;
TCGHelperInfo *info;
} regular;
struct {
union qemu_plugin_cb_sig f;
TCGHelperInfo *info;
qemu_plugin_u64 entry;
enum qemu_plugin_cond cond;
uint64_t imm;
} cond;
struct {
qemu_plugin_u64 entry;
enum qemu_plugin_op op;

View file

@ -262,6 +262,29 @@ enum qemu_plugin_mem_rw {
QEMU_PLUGIN_MEM_RW,
};
/**
* enum qemu_plugin_cond - condition to enable callback
*
* @QEMU_PLUGIN_COND_NEVER: false
* @QEMU_PLUGIN_COND_ALWAYS: true
* @QEMU_PLUGIN_COND_EQ: is equal?
* @QEMU_PLUGIN_COND_NE: is not equal?
* @QEMU_PLUGIN_COND_LT: is less than?
* @QEMU_PLUGIN_COND_LE: is less than or equal?
* @QEMU_PLUGIN_COND_GT: is greater than?
* @QEMU_PLUGIN_COND_GE: is greater than or equal?
*/
enum qemu_plugin_cond {
QEMU_PLUGIN_COND_NEVER,
QEMU_PLUGIN_COND_ALWAYS,
QEMU_PLUGIN_COND_EQ,
QEMU_PLUGIN_COND_NE,
QEMU_PLUGIN_COND_LT,
QEMU_PLUGIN_COND_LE,
QEMU_PLUGIN_COND_GT,
QEMU_PLUGIN_COND_GE,
};
/**
* typedef qemu_plugin_vcpu_tb_trans_cb_t - translation callback
* @id: unique plugin id
@ -301,6 +324,32 @@ void qemu_plugin_register_vcpu_tb_exec_cb(struct qemu_plugin_tb *tb,
enum qemu_plugin_cb_flags flags,
void *userdata);
/**
* qemu_plugin_register_vcpu_tb_exec_cond_cb() - register conditional callback
* @tb: the opaque qemu_plugin_tb handle for the translation
* @cb: callback function
* @cond: condition to enable callback
* @entry: first operand for condition
* @imm: second operand for condition
* @flags: does the plugin read or write the CPU's registers?
* @userdata: any plugin data to pass to the @cb?
*
* The @cb function is called when a translated unit executes if
* entry @cond imm is true.
* If condition is QEMU_PLUGIN_COND_ALWAYS, condition is never interpreted and
* this function is equivalent to qemu_plugin_register_vcpu_tb_exec_cb.
* If condition QEMU_PLUGIN_COND_NEVER, condition is never interpreted and
* callback is never installed.
*/
QEMU_PLUGIN_API
void qemu_plugin_register_vcpu_tb_exec_cond_cb(struct qemu_plugin_tb *tb,
qemu_plugin_vcpu_udata_cb_t cb,
enum qemu_plugin_cb_flags flags,
enum qemu_plugin_cond cond,
qemu_plugin_u64 entry,
uint64_t imm,
void *userdata);
/**
* enum qemu_plugin_op - describes an inline op
*
@ -344,6 +393,33 @@ void qemu_plugin_register_vcpu_insn_exec_cb(struct qemu_plugin_insn *insn,
enum qemu_plugin_cb_flags flags,
void *userdata);
/**
* qemu_plugin_register_vcpu_insn_exec_cond_cb() - conditional insn execution cb
* @insn: the opaque qemu_plugin_insn handle for an instruction
* @cb: callback function
* @flags: does the plugin read or write the CPU's registers?
* @cond: condition to enable callback
* @entry: first operand for condition
* @imm: second operand for condition
* @userdata: any plugin data to pass to the @cb?
*
* The @cb function is called when an instruction executes if
* entry @cond imm is true.
* If condition is QEMU_PLUGIN_COND_ALWAYS, condition is never interpreted and
* this function is equivalent to qemu_plugin_register_vcpu_insn_exec_cb.
* If condition QEMU_PLUGIN_COND_NEVER, condition is never interpreted and
* callback is never installed.
*/
QEMU_PLUGIN_API
void qemu_plugin_register_vcpu_insn_exec_cond_cb(
struct qemu_plugin_insn *insn,
qemu_plugin_vcpu_udata_cb_t cb,
enum qemu_plugin_cb_flags flags,
enum qemu_plugin_cond cond,
qemu_plugin_u64 entry,
uint64_t imm,
void *userdata);
/**
* qemu_plugin_register_vcpu_insn_exec_inline_per_vcpu() - insn exec inline op
* @insn: the opaque qemu_plugin_insn handle for an instruction

View file

@ -102,6 +102,25 @@ void qemu_plugin_register_vcpu_tb_exec_cb(struct qemu_plugin_tb *tb,
}
}
void qemu_plugin_register_vcpu_tb_exec_cond_cb(struct qemu_plugin_tb *tb,
qemu_plugin_vcpu_udata_cb_t cb,
enum qemu_plugin_cb_flags flags,
enum qemu_plugin_cond cond,
qemu_plugin_u64 entry,
uint64_t imm,
void *udata)
{
if (cond == QEMU_PLUGIN_COND_NEVER || tb_is_mem_only()) {
return;
}
if (cond == QEMU_PLUGIN_COND_ALWAYS) {
qemu_plugin_register_vcpu_tb_exec_cb(tb, cb, flags, udata);
return;
}
plugin_register_dyn_cond_cb__udata(&tb->cbs, cb, flags,
cond, entry, imm, udata);
}
void qemu_plugin_register_vcpu_tb_exec_inline_per_vcpu(
struct qemu_plugin_tb *tb,
enum qemu_plugin_op op,
@ -123,6 +142,26 @@ void qemu_plugin_register_vcpu_insn_exec_cb(struct qemu_plugin_insn *insn,
}
}
void qemu_plugin_register_vcpu_insn_exec_cond_cb(
struct qemu_plugin_insn *insn,
qemu_plugin_vcpu_udata_cb_t cb,
enum qemu_plugin_cb_flags flags,
enum qemu_plugin_cond cond,
qemu_plugin_u64 entry,
uint64_t imm,
void *udata)
{
if (cond == QEMU_PLUGIN_COND_NEVER || tb_is_mem_only()) {
return;
}
if (cond == QEMU_PLUGIN_COND_ALWAYS) {
qemu_plugin_register_vcpu_insn_exec_cb(insn, cb, flags, udata);
return;
}
plugin_register_dyn_cond_cb__udata(&insn->insn_cbs, cb, flags,
cond, entry, imm, udata);
}
void qemu_plugin_register_vcpu_insn_exec_inline_per_vcpu(
struct qemu_plugin_insn *insn,
enum qemu_plugin_op op,

View file

@ -371,6 +371,38 @@ void plugin_register_dyn_cb__udata(GArray **arr,
dyn_cb->regular.info = &info[flags];
}
void plugin_register_dyn_cond_cb__udata(GArray **arr,
qemu_plugin_vcpu_udata_cb_t cb,
enum qemu_plugin_cb_flags flags,
enum qemu_plugin_cond cond,
qemu_plugin_u64 entry,
uint64_t imm,
void *udata)
{
static TCGHelperInfo info[3] = {
[QEMU_PLUGIN_CB_NO_REGS].flags = TCG_CALL_NO_RWG,
[QEMU_PLUGIN_CB_R_REGS].flags = TCG_CALL_NO_WG,
/*
* Match qemu_plugin_vcpu_udata_cb_t:
* void (*)(uint32_t, void *)
*/
[0 ... 2].typemask = (dh_typemask(void, 0) |
dh_typemask(i32, 1) |
dh_typemask(ptr, 2))
};
struct qemu_plugin_dyn_cb *dyn_cb = plugin_get_dyn_cb(arr);
dyn_cb->userp = udata;
dyn_cb->type = PLUGIN_CB_COND;
dyn_cb->cond.f.vcpu_udata = cb;
dyn_cb->cond.cond = cond;
dyn_cb->cond.entry = entry;
dyn_cb->cond.imm = imm;
assert((unsigned)flags < ARRAY_SIZE(info));
dyn_cb->cond.info = &info[flags];
}
void plugin_register_vcpu_mem_cb(GArray **arr,
void *cb,
enum qemu_plugin_cb_flags flags,

View file

@ -93,6 +93,14 @@ plugin_register_dyn_cb__udata(GArray **arr,
qemu_plugin_vcpu_udata_cb_t cb,
enum qemu_plugin_cb_flags flags, void *udata);
void
plugin_register_dyn_cond_cb__udata(GArray **arr,
qemu_plugin_vcpu_udata_cb_t cb,
enum qemu_plugin_cb_flags flags,
enum qemu_plugin_cond cond,
qemu_plugin_u64 entry,
uint64_t imm,
void *udata);
void plugin_register_vcpu_mem_cb(GArray **arr,
void *cb,

View file

@ -27,6 +27,7 @@
qemu_plugin_register_vcpu_idle_cb;
qemu_plugin_register_vcpu_init_cb;
qemu_plugin_register_vcpu_insn_exec_cb;
qemu_plugin_register_vcpu_insn_exec_cond_cb;
qemu_plugin_register_vcpu_insn_exec_inline_per_vcpu;
qemu_plugin_register_vcpu_mem_cb;
qemu_plugin_register_vcpu_mem_inline_per_vcpu;
@ -34,6 +35,7 @@
qemu_plugin_register_vcpu_syscall_cb;
qemu_plugin_register_vcpu_syscall_ret_cb;
qemu_plugin_register_vcpu_tb_exec_cb;
qemu_plugin_register_vcpu_tb_exec_cond_cb;
qemu_plugin_register_vcpu_tb_exec_inline_per_vcpu;
qemu_plugin_register_vcpu_tb_trans_cb;
qemu_plugin_reset;