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, 68 insertions, 0 deletions

diff --git a/include/sysemu/cpu-throttle.h b/include/sysemu/cpu-throttle.h
new file mode 100644
index 0000000000..d65bdef6d0
--- /dev/null
+++ b/include/sysemu/cpu-throttle.h
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2012 SUSE LINUX Products GmbH
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see
+ * <http://www.gnu.org/licenses/gpl-2.0.html>
+ */
+
+#ifndef SYSEMU_CPU_THROTTLE_H
+#define SYSEMU_CPU_THROTTLE_H
+
+#include "qemu/timer.h"
+
+/**
+ * cpu_throttle_init:
+ *
+ * Initialize the CPU throttling API.
+ */
+void cpu_throttle_init(void);
+
+/**
+ * cpu_throttle_set:
+ * @new_throttle_pct: Percent of sleep time. Valid range is 1 to 99.
+ *
+ * Throttles all vcpus by forcing them to sleep for the given percentage of
+ * time. A throttle_percentage of 25 corresponds to a 75% duty cycle roughly.
+ * (example: 10ms sleep for every 30ms awake).
+ *
+ * cpu_throttle_set can be called as needed to adjust new_throttle_pct.
+ * Once the throttling starts, it will remain in effect until cpu_throttle_stop
+ * is called.
+ */
+void cpu_throttle_set(int new_throttle_pct);
+
+/**
+ * cpu_throttle_stop:
+ *
+ * Stops the vcpu throttling started by cpu_throttle_set.
+ */
+void cpu_throttle_stop(void);
+
+/**
+ * cpu_throttle_active:
+ *
+ * Returns: %true if the vcpus are currently being throttled, %false otherwise.
+ */
+bool cpu_throttle_active(void);
+
+/**
+ * cpu_throttle_get_percentage:
+ *
+ * Returns the vcpu throttle percentage. See cpu_throttle_set for details.
+ *
+ * Returns: The throttle percentage in range 1 to 99.
+ */
+int cpu_throttle_get_percentage(void);
+
+#endif /* SYSEMU_CPU_THROTTLE_H */