Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* Make checkpatch say 'qemu' instead of 'kernel' (Aleksandar)
* Fix PSE guests with emulated NPT (Alexander B. #1)
* Fix leak (Alexander B. #2)
* HVF fixes (Roman, Cameron)
* New Sapphire Rapids CPUID bits (Cathy)
* cpus.c and softmmu/ cleanups (Claudio)
* TAP driver tweaks (Daniel, Havard)
* object-add bugfix and testcases (Eric A.)
* Fix Coverity MIN_CONST and MAX_CONST (Eric B.)
* "info lapic" improvement (Jan)
* SSE fixes (Joseph)
* "-msg guest-name" option (Mario)
* support for AMD nested live migration (myself)
* Small i386 TCG fixes (myself)
* improved error reporting for Xen (myself)
* fix "-cpu host -overcommit cpu-pm=on" (myself)
* Add accel/Kconfig (Philippe)
* iscsi sense handling fixes (Yongji)
* Misc bugfixes

# gpg: Signature made Sat 11 Jul 2020 00:33:41 BST
# gpg:                using RSA key F13338574B662389866C7682BFFBD25F78C7AE83
# gpg:                issuer "pbonzini@redhat.com"
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* remotes/bonzini/tags/for-upstream: (47 commits)
  linux-headers: update again to 5.8
  apic: Report current_count via 'info lapic'
  scripts: improve message when TAP based tests fail
  target/i386: Enable TSX Suspend Load Address Tracking feature
  target/i386: Add SERIALIZE cpu feature
  softmmu/vl: Remove the check for colons in -accel parameters
  cpu-throttle: new module, extracted from cpus.c
  softmmu: move softmmu only files from root
  pc: fix leak in pc_system_flash_cleanup_unused
  cpus: Move CPU code from exec.c to cpus-common.c
  target/i386: Correct the warning message of Intel PT
  checkpatch: Change occurences of 'kernel' to 'qemu' in user messages
  iscsi: return -EIO when sense fields are meaningless
  iscsi: handle check condition status in retry loop
  target/i386: sev: fail query-sev-capabilities if QEMU cannot use SEV
  target/i386: sev: provide proper error reporting for query-sev-capabilities
  KVM: x86: believe what KVM says about WAITPKG
  target/i386: implement undocumented "smsw r32" behavior
  target/i386: remove gen_io_end
  Makefile: simplify MINIKCONF rules
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 122 insertions, 0 deletions

diff --git a/softmmu/cpu-throttle.c b/softmmu/cpu-throttle.c
new file mode 100644
index 0000000000..4e6b2818ca
--- /dev/null
+++ b/softmmu/cpu-throttle.c
@@ -0,0 +1,122 @@
+/*
+ * QEMU System Emulator
+ *
+ * Copyright (c) 2003-2008 Fabrice Bellard
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu-common.h"
+#include "qemu/thread.h"
+#include "hw/core/cpu.h"
+#include "qemu/main-loop.h"
+#include "sysemu/cpus.h"
+#include "sysemu/cpu-throttle.h"
+
+/* vcpu throttling controls */
+static QEMUTimer *throttle_timer;
+static unsigned int throttle_percentage;
+
+#define CPU_THROTTLE_PCT_MIN 1
+#define CPU_THROTTLE_PCT_MAX 99
+#define CPU_THROTTLE_TIMESLICE_NS 10000000
+
+static void cpu_throttle_thread(CPUState *cpu, run_on_cpu_data opaque)
+{
+    double pct;
+    double throttle_ratio;
+    int64_t sleeptime_ns, endtime_ns;
+
+    if (!cpu_throttle_get_percentage()) {
+        return;
+    }
+
+    pct = (double)cpu_throttle_get_percentage() / 100;
+    throttle_ratio = pct / (1 - pct);
+    /* Add 1ns to fix double's rounding error (like 0.9999999...) */
+    sleeptime_ns = (int64_t)(throttle_ratio * CPU_THROTTLE_TIMESLICE_NS + 1);
+    endtime_ns = qemu_clock_get_ns(QEMU_CLOCK_REALTIME) + sleeptime_ns;
+    while (sleeptime_ns > 0 && !cpu->stop) {
+        if (sleeptime_ns > SCALE_MS) {
+            qemu_cond_timedwait_iothread(cpu->halt_cond,
+                                         sleeptime_ns / SCALE_MS);
+        } else {
+            qemu_mutex_unlock_iothread();
+            g_usleep(sleeptime_ns / SCALE_US);
+            qemu_mutex_lock_iothread();
+        }
+        sleeptime_ns = endtime_ns - qemu_clock_get_ns(QEMU_CLOCK_REALTIME);
+    }
+    atomic_set(&cpu->throttle_thread_scheduled, 0);
+}
+
+static void cpu_throttle_timer_tick(void *opaque)
+{
+    CPUState *cpu;
+    double pct;
+
+    /* Stop the timer if needed */
+    if (!cpu_throttle_get_percentage()) {
+        return;
+    }
+    CPU_FOREACH(cpu) {
+        if (!atomic_xchg(&cpu->throttle_thread_scheduled, 1)) {
+            async_run_on_cpu(cpu, cpu_throttle_thread,
+                             RUN_ON_CPU_NULL);
+        }
+    }
+
+    pct = (double)cpu_throttle_get_percentage() / 100;
+    timer_mod(throttle_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL_RT) +
+                                   CPU_THROTTLE_TIMESLICE_NS / (1 - pct));
+}
+
+void cpu_throttle_set(int new_throttle_pct)
+{
+    /* Ensure throttle percentage is within valid range */
+    new_throttle_pct = MIN(new_throttle_pct, CPU_THROTTLE_PCT_MAX);
+    new_throttle_pct = MAX(new_throttle_pct, CPU_THROTTLE_PCT_MIN);
+
+    atomic_set(&throttle_percentage, new_throttle_pct);
+
+    timer_mod(throttle_timer, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL_RT) +
+                                       CPU_THROTTLE_TIMESLICE_NS);
+}
+
+void cpu_throttle_stop(void)
+{
+    atomic_set(&throttle_percentage, 0);
+}
+
+bool cpu_throttle_active(void)
+{
+    return (cpu_throttle_get_percentage() != 0);
+}
+
+int cpu_throttle_get_percentage(void)
+{
+    return atomic_read(&throttle_percentage);
+}
+
+void cpu_throttle_init(void)
+{
+    throttle_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL_RT,
+                                  cpu_throttle_timer_tick, NULL);
+}