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authorPeter Maydell <peter.maydell@linaro.org>2017-04-10 15:01:15 +0100
committerPeter Maydell <peter.maydell@linaro.org>2017-04-10 15:01:15 +0100
commit0a49bfa1abaa7c7bea4505bef885a61fc910d055 (patch)
tree33ae0f96508d10f998b372491eeb963e9f9dca0d
parentad04d8cb2f8b5495109dee3d59fdb78403816a55 (diff)
parent982263ce714ffcc4c7c41a7b255bd29e093912fe (diff)
Merge remote-tracking branch 'remotes/stsquad/tags/pull-mttcg-fixups-for-rc2-100417-1' into staging
Final icount and misc MTTCG fixes for 2.9 Minor differences from: Message-Id: <20170405132503.32125-1-alex.bennee@linaro.org> - dropped new feature patches - last minute typo fix from Nikunj A Dadhania <nikunj@linux.vnet.ibm.com> # gpg: Signature made Mon 10 Apr 2017 11:38:10 BST # gpg: using RSA key 0xFBD0DB095A9E2A44 # gpg: Good signature from "Alex Bennée (Master Work Key) <alex.bennee@linaro.org>" # Primary key fingerprint: 6685 AE99 E751 67BC AFC8 DF35 FBD0 DB09 5A9E 2A44 * remotes/stsquad/tags/pull-mttcg-fixups-for-rc2-100417-1: replay: assert time only goes forward cpus: call cpu_update_icount on read cpu-exec: update icount after each TB_EXIT cpus: introduce cpu_update_icount helper cpus: don't credit executed instructions before they have run cpus: move icount preparation out of tcg_exec_cpu cpus: check cpu->running in cpu_get_icount_raw() cpus: remove icount handling from qemu_tcg_cpu_thread_fn target/i386/misc_helper: wrap BQL around another IRQ generator cpus: fix wrong define name scripts/qemugdb/mtree.py: fix up mtree dump Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
-rw-r--r--cpu-exec.c14
-rw-r--r--cpus.c111
-rw-r--r--include/qemu/timer.h1
-rw-r--r--include/qom/cpu.h1
-rw-r--r--replay/replay-internal.c4
-rw-r--r--replay/replay.c4
-rw-r--r--scripts/qemugdb/mtree.py12
-rw-r--r--target/i386/misc_helper.c3
8 files changed, 110 insertions, 40 deletions
diff --git a/cpu-exec.c b/cpu-exec.c
index 748cb66bca..63a56d0407 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -600,13 +600,13 @@ static inline void cpu_loop_exec_tb(CPUState *cpu, TranslationBlock *tb,
/* Instruction counter expired. */
assert(use_icount);
#ifndef CONFIG_USER_ONLY
- if (cpu->icount_extra) {
- /* Refill decrementer and continue execution. */
- cpu->icount_extra += insns_left;
- insns_left = MIN(0xffff, cpu->icount_extra);
- cpu->icount_extra -= insns_left;
- cpu->icount_decr.u16.low = insns_left;
- } else {
+ /* Ensure global icount has gone forward */
+ cpu_update_icount(cpu);
+ /* Refill decrementer and continue execution. */
+ insns_left = MIN(0xffff, cpu->icount_budget);
+ cpu->icount_decr.u16.low = insns_left;
+ cpu->icount_extra = cpu->icount_budget - insns_left;
+ if (!cpu->icount_extra) {
/* Execute any remaining instructions, then let the main loop
* handle the next event.
*/
diff --git a/cpus.c b/cpus.c
index 68fdbc40b9..740b8dc3f8 100644
--- a/cpus.c
+++ b/cpus.c
@@ -202,7 +202,7 @@ void qemu_tcg_configure(QemuOpts *opts, Error **errp)
} else if (use_icount) {
error_setg(errp, "No MTTCG when icount is enabled");
} else {
-#ifndef TARGET_SUPPORT_MTTCG
+#ifndef TARGET_SUPPORTS_MTTCG
error_report("Guest not yet converted to MTTCG - "
"you may get unexpected results");
#endif
@@ -223,20 +223,51 @@ void qemu_tcg_configure(QemuOpts *opts, Error **errp)
}
}
+/* The current number of executed instructions is based on what we
+ * originally budgeted minus the current state of the decrementing
+ * icount counters in extra/u16.low.
+ */
+static int64_t cpu_get_icount_executed(CPUState *cpu)
+{
+ return cpu->icount_budget - (cpu->icount_decr.u16.low + cpu->icount_extra);
+}
+
+/*
+ * Update the global shared timer_state.qemu_icount to take into
+ * account executed instructions. This is done by the TCG vCPU
+ * thread so the main-loop can see time has moved forward.
+ */
+void cpu_update_icount(CPUState *cpu)
+{
+ int64_t executed = cpu_get_icount_executed(cpu);
+ cpu->icount_budget -= executed;
+
+#ifdef CONFIG_ATOMIC64
+ atomic_set__nocheck(&timers_state.qemu_icount,
+ atomic_read__nocheck(&timers_state.qemu_icount) +
+ executed);
+#else /* FIXME: we need 64bit atomics to do this safely */
+ timers_state.qemu_icount += executed;
+#endif
+}
+
int64_t cpu_get_icount_raw(void)
{
- int64_t icount;
CPUState *cpu = current_cpu;
- icount = timers_state.qemu_icount;
- if (cpu) {
+ if (cpu && cpu->running) {
if (!cpu->can_do_io) {
fprintf(stderr, "Bad icount read\n");
exit(1);
}
- icount -= (cpu->icount_decr.u16.low + cpu->icount_extra);
+ /* Take into account what has run */
+ cpu_update_icount(cpu);
}
- return icount;
+#ifdef CONFIG_ATOMIC64
+ return atomic_read__nocheck(&timers_state.qemu_icount);
+#else /* FIXME: we need 64bit atomics to do this safely */
+ return timers_state.qemu_icount;
+#endif
}
/* Return the virtual CPU time, based on the instruction counter. */
@@ -1179,6 +1210,41 @@ static void handle_icount_deadline(void)
}
}
+static void prepare_icount_for_run(CPUState *cpu)
+{
+ if (use_icount) {
+ int insns_left;
+
+ /* These should always be cleared by process_icount_data after
+ * each vCPU execution. However u16.high can be raised
+ * asynchronously by cpu_exit/cpu_interrupt/tcg_handle_interrupt
+ */
+ g_assert(cpu->icount_decr.u16.low == 0);
+ g_assert(cpu->icount_extra == 0);
+
+ cpu->icount_budget = tcg_get_icount_limit();
+ insns_left = MIN(0xffff, cpu->icount_budget);
+ cpu->icount_decr.u16.low = insns_left;
+ cpu->icount_extra = cpu->icount_budget - insns_left;
+ }
+}
+
+static void process_icount_data(CPUState *cpu)
+{
+ if (use_icount) {
+ /* Account for executed instructions */
+ cpu_update_icount(cpu);
+
+ /* Reset the counters */
+ cpu->icount_decr.u16.low = 0;
+ cpu->icount_extra = 0;
+ cpu->icount_budget = 0;
+
+ replay_account_executed_instructions();
+ }
+}
+
+
static int tcg_cpu_exec(CPUState *cpu)
{
int ret;
@@ -1189,20 +1255,6 @@ static int tcg_cpu_exec(CPUState *cpu)
#ifdef CONFIG_PROFILER
ti = profile_getclock();
#endif
- if (use_icount) {
- int64_t count;
- int decr;
- timers_state.qemu_icount -= (cpu->icount_decr.u16.low
- + cpu->icount_extra);
- cpu->icount_decr.u16.low = 0;
- cpu->icount_extra = 0;
- count = tcg_get_icount_limit();
- timers_state.qemu_icount += count;
- decr = (count > 0xffff) ? 0xffff : count;
- count -= decr;
- cpu->icount_decr.u16.low = decr;
- cpu->icount_extra = count;
- }
qemu_mutex_unlock_iothread();
cpu_exec_start(cpu);
ret = cpu_exec(cpu);
@@ -1211,15 +1263,6 @@ static int tcg_cpu_exec(CPUState *cpu)
#ifdef CONFIG_PROFILER
tcg_time += profile_getclock() - ti;
#endif
- if (use_icount) {
- /* Fold pending instructions back into the
- instruction counter, and clear the interrupt flag. */
- timers_state.qemu_icount -= (cpu->icount_decr.u16.low
- + cpu->icount_extra);
- cpu->icount_decr.u32 = 0;
- cpu->icount_extra = 0;
- replay_account_executed_instructions();
- }
return ret;
}
@@ -1306,7 +1349,13 @@ static void *qemu_tcg_rr_cpu_thread_fn(void *arg)
if (cpu_can_run(cpu)) {
int r;
+
+ prepare_icount_for_run(cpu);
+
r = tcg_cpu_exec(cpu);
+
+ process_icount_data(cpu);
+
if (r == EXCP_DEBUG) {
cpu_handle_guest_debug(cpu);
break;
@@ -1392,6 +1441,8 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
{
CPUState *cpu = arg;
+ g_assert(!use_icount);
+
rcu_register_thread();
qemu_mutex_lock_iothread();
@@ -1434,8 +1485,6 @@ static void *qemu_tcg_cpu_thread_fn(void *arg)
}
}
- handle_icount_deadline();
-
atomic_mb_set(&cpu->exit_request, 0);
qemu_tcg_wait_io_event(cpu);
}
diff --git a/include/qemu/timer.h b/include/qemu/timer.h
index e1742f2f3d..8a1eb74839 100644
--- a/include/qemu/timer.h
+++ b/include/qemu/timer.h
@@ -869,6 +869,7 @@ int64_t cpu_get_icount_raw(void);
int64_t cpu_get_icount(void);
int64_t cpu_get_clock(void);
int64_t cpu_icount_to_ns(int64_t icount);
+void cpu_update_icount(CPUState *cpu);
/*******************************************/
/* host CPU ticks (if available) */
diff --git a/include/qom/cpu.h b/include/qom/cpu.h
index c3292efe1c..5d10359c8f 100644
--- a/include/qom/cpu.h
+++ b/include/qom/cpu.h
@@ -332,6 +332,7 @@ struct CPUState {
/* updates protected by BQL */
uint32_t interrupt_request;
int singlestep_enabled;
+ int64_t icount_budget;
int64_t icount_extra;
sigjmp_buf jmp_env;
diff --git a/replay/replay-internal.c b/replay/replay-internal.c
index bea7b4aa6b..fca8514012 100644
--- a/replay/replay-internal.c
+++ b/replay/replay-internal.c
@@ -195,6 +195,10 @@ void replay_save_instructions(void)
if (replay_file && replay_mode == REPLAY_MODE_RECORD) {
replay_mutex_lock();
int diff = (int)(replay_get_current_step() - replay_state.current_step);
+
+ /* Time can only go forward */
+ assert(diff >= 0);
+
if (diff > 0) {
replay_put_event(EVENT_INSTRUCTION);
replay_put_dword(diff);
diff --git a/replay/replay.c b/replay/replay.c
index 9e0724e756..f810628cac 100644
--- a/replay/replay.c
+++ b/replay/replay.c
@@ -84,6 +84,10 @@ void replay_account_executed_instructions(void)
if (replay_state.instructions_count > 0) {
int count = (int)(replay_get_current_step()
- replay_state.current_step);
+
+ /* Time can only go forward */
+ assert(count >= 0);
+
replay_state.instructions_count -= count;
replay_state.current_step += count;
if (replay_state.instructions_count == 0) {
diff --git a/scripts/qemugdb/mtree.py b/scripts/qemugdb/mtree.py
index cc8131c2e7..e6791b7885 100644
--- a/scripts/qemugdb/mtree.py
+++ b/scripts/qemugdb/mtree.py
@@ -21,7 +21,15 @@ def isnull(ptr):
return ptr == gdb.Value(0).cast(ptr.type)
def int128(p):
- return int(p['lo']) + (int(p['hi']) << 64)
+ '''Read an Int128 type to a python integer.
+
+ QEMU can be built with native Int128 support so we need to detect
+ if the value is a structure or the native type.
+ '''
+ if p.type.code == gdb.TYPE_CODE_STRUCT:
+ return int(p['lo']) + (int(p['hi']) << 64)
+ else:
+ return int(("%s" % p), 16)
class MtreeCommand(gdb.Command):
'''Display the memory tree hierarchy'''
@@ -69,7 +77,7 @@ class MtreeCommand(gdb.Command):
gdb.write('%s alias: %s@%016x (@ %s)\n' %
(' ' * level,
alias['name'].string(),
- ptr['alias_offset'],
+ int(ptr['alias_offset']),
alias,
),
gdb.STDOUT)
diff --git a/target/i386/misc_helper.c b/target/i386/misc_helper.c
index ca2ea09f54..628f64aad5 100644
--- a/target/i386/misc_helper.c
+++ b/target/i386/misc_helper.c
@@ -18,6 +18,7 @@
*/
#include "qemu/osdep.h"
+#include "qemu/main-loop.h"
#include "cpu.h"
#include "exec/helper-proto.h"
#include "exec/exec-all.h"
@@ -156,7 +157,9 @@ void helper_write_crN(CPUX86State *env, int reg, target_ulong t0)
break;
case 8:
if (!(env->hflags2 & HF2_VINTR_MASK)) {
+ qemu_mutex_lock_iothread();
cpu_set_apic_tpr(x86_env_get_cpu(env)->apic_state, t0);
+ qemu_mutex_unlock_iothread();
}
env->v_tpr = t0 & 0x0f;
break;