From: Sean Christopherson <seanjc@google.com>
To: Kiryl Shutsemau <kas@kernel.org>,
Rick Edgecombe <rick.p.edgecombe@intel.com>,
Sean Christopherson <seanjc@google.com>,
Paolo Bonzini <pbonzini@redhat.com>,
"K. Y. Srinivasan" <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Wei Liu <wei.liu@kernel.org>, Dexuan Cui <decui@microsoft.com>,
Long Li <longli@microsoft.com>,
Ajay Kaher <ajay.kaher@broadcom.com>,
Alexey Makhalov <alexey.makhalov@broadcom.com>,
Jan Kiszka <jan.kiszka@siemens.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Juergen Gross <jgross@suse.com>,
Daniel Lezcano <daniel.lezcano@kernel.org>,
Thomas Gleixner <tglx@kernel.org>,
John Stultz <jstultz@google.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
Broadcom internal kernel review list
<bcm-kernel-feedback-list@broadcom.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Stephen Boyd <sboyd@kernel.org>,
Miroslav Lichvar <mlichvar@redhat.com>,
x86@kernel.org, linux-coco@lists.linux.dev, kvm@vger.kernel.org,
linux-hyperv@vger.kernel.org, virtualization@lists.linux.dev,
linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org,
Michael Kelley <mhklinux@outlook.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
Nikunj A Dadhania <nikunj@amd.com>,
David Woodhouse <dwmw@amazon.co.uk>,
David Woodhouse <dwmw2@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH v6 32/51] x86/kvmclock: Move sched_clock save/restore helpers up in kvmclock.c
Date: Thu, 6 Aug 2026 16:35:49 -0700 [thread overview]
Message-ID: <20260806233609.212337-33-seanjc@google.com> (raw)
In-Reply-To: <20260806233609.212337-1-seanjc@google.com>
Move kvmclock's sched_clock save/restore helper "up" so that they can
(eventually) be referenced by kvm_sched_clock_init().
No functional change intended.
Reviewed-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
arch/x86/kernel/kvmclock.c | 108 ++++++++++++++++++-------------------
1 file changed, 54 insertions(+), 54 deletions(-)
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 4bc0495f1f9e..07e875738c39 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -71,6 +71,25 @@ static int kvm_set_wallclock(const struct timespec64 *now)
return -ENODEV;
}
+static void kvm_register_clock(char *txt)
+{
+ struct pvclock_vsyscall_time_info *src = this_cpu_hvclock();
+ u64 pa;
+
+ if (!src)
+ return;
+
+ pa = slow_virt_to_phys(&src->pvti) | 0x01ULL;
+ wrmsrq(msr_kvm_system_time, pa);
+ pr_debug("kvm-clock: cpu %d, msr %llx, %s", smp_processor_id(), pa, txt);
+}
+
+static void kvmclock_disable(void)
+{
+ if (msr_kvm_system_time)
+ native_write_msr(msr_kvm_system_time, 0);
+}
+
static u64 kvm_clock_read(void)
{
u64 ret;
@@ -112,6 +131,30 @@ static noinstr u64 kvm_sched_clock_read(void)
return pvclock_clocksource_read_nowd(this_cpu_pvti()) - kvm_sched_clock_offset;
}
+static void kvm_save_sched_clock_state(void)
+{
+ /*
+ * Stop host writes to kvmclock immediately prior to suspend/hibernate.
+ * If the system is hibernating, then kvmclock will likely reside at a
+ * different physical address when the system awakens, and host writes
+ * to the old address prior to reconfiguring kvmclock would clobber
+ * random memory.
+ */
+ kvmclock_disable();
+}
+
+#ifdef CONFIG_SMP
+static void kvm_setup_secondary_clock(void)
+{
+ kvm_register_clock("secondary cpu clock");
+}
+#endif
+
+static void kvm_restore_sched_clock_state(void)
+{
+ kvm_register_clock("primary cpu clock, resume");
+}
+
static inline void kvm_sched_clock_init(bool stable)
{
kvm_sched_clock_offset = kvm_clock_read();
@@ -124,6 +167,17 @@ static inline void kvm_sched_clock_init(bool stable)
sizeof(((struct pvclock_vcpu_time_info *)NULL)->system_time));
}
+void kvmclock_cpu_action(enum kvm_guest_cpu_action action)
+{
+ /*
+ * Don't disable kvmclock on the BSP during suspend. If kvmclock is
+ * being used for sched_clock, then it needs to be kept alive until the
+ * last minute, and restored as quickly as possible after resume.
+ */
+ if (action != KVM_GUEST_BSP_SUSPEND)
+ kvmclock_disable();
+}
+
/*
* If we don't do that, there is the possibility that the guest
* will calibrate under heavy load - thus, getting a lower lpj -
@@ -183,60 +237,6 @@ static struct clocksource kvm_clock = {
.enable = kvm_cs_enable,
};
-static void kvm_register_clock(char *txt)
-{
- struct pvclock_vsyscall_time_info *src = this_cpu_hvclock();
- u64 pa;
-
- if (!src)
- return;
-
- pa = slow_virt_to_phys(&src->pvti) | 0x01ULL;
- wrmsrq(msr_kvm_system_time, pa);
- pr_debug("kvm-clock: cpu %d, msr %llx, %s", smp_processor_id(), pa, txt);
-}
-
-static void kvmclock_disable(void)
-{
- if (msr_kvm_system_time)
- native_write_msr(msr_kvm_system_time, 0);
-}
-
-static void kvm_save_sched_clock_state(void)
-{
- /*
- * Stop host writes to kvmclock immediately prior to suspend/hibernate.
- * If the system is hibernating, then kvmclock will likely reside at a
- * different physical address when the system awakens, and host writes
- * to the old address prior to reconfiguring kvmclock would clobber
- * random memory.
- */
- kvmclock_disable();
-}
-
-static void kvm_restore_sched_clock_state(void)
-{
- kvm_register_clock("primary cpu clock, resume");
-}
-
-void kvmclock_cpu_action(enum kvm_guest_cpu_action action)
-{
- /*
- * Don't disable kvmclock on the BSP during suspend. If kvmclock is
- * being used for sched_clock, then it needs to be kept alive until the
- * last minute, and restored as quickly as possible after resume.
- */
- if (action != KVM_GUEST_BSP_SUSPEND)
- kvmclock_disable();
-}
-
-#ifdef CONFIG_SMP
-static void kvm_setup_secondary_clock(void)
-{
- kvm_register_clock("secondary cpu clock");
-}
-#endif
-
static void __init kvmclock_init_mem(void)
{
unsigned long ncpus;
--
2.55.0.679.g6767b8d81c-goog
next prev parent reply other threads:[~2026-08-06 23:37 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-08-06 23:35 [PATCH v6 00/51] x86: Try to wrangle PV clocks vs. TSC Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 01/51] x86/apic: Provide helpers to set local APIC timer frequency in hz and khz Sean Christopherson
2026-08-08 10:36 ` David Woodhouse
2026-08-06 23:35 ` [PATCH v6 02/51] x86/apic: Add CONFIG_X86_LOCAL_APIC=n stubs for APIC timer frequency APIs Sean Christopherson
2026-08-08 10:37 ` David Woodhouse
2026-08-06 23:35 ` [PATCH v6 03/51] x86/tsc: Ensure that TSC recalibration doesn't run if TSC frequency is known Sean Christopherson
2026-08-06 23:55 ` sashiko-bot
2026-08-06 23:35 ` [PATCH v6 04/51] x86/tsc: Restrict recalibrate_cpu_khz() export to p4-clockmod and powernow-k7 Sean Christopherson
2026-08-08 14:39 ` David Woodhouse
2026-08-06 23:35 ` [PATCH v6 05/51] x86/sev: Mark TSC as reliable when configuring Secure TSC Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 06/51] x86/sev: Don't override CPU frequency calibration for SNP's " Sean Christopherson
2026-08-06 23:55 ` sashiko-bot
2026-08-08 14:48 ` David Woodhouse
2026-08-06 23:35 ` [PATCH v6 07/51] x86/sev: Move check for SNP Secure TSC support to tsc_early_init() Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 08/51] x86/sev: Shove SNP's secure/trusted TSC frequency directly into "calibration" Sean Christopherson
2026-08-08 14:50 ` David Woodhouse
2026-08-06 23:35 ` [PATCH v6 09/51] x86/tsc: Add a standalone helper for getting TSC info from CPUID.0x15 Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 10/51] x86/tdx: Force TSC frequency with CPUID-based info provided by the TDX-Module Sean Christopherson
2026-08-08 14:53 ` David Woodhouse
2026-08-10 14:30 ` Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 11/51] x86/tsc: Add dedicated hypervisor hooks for getting known TSC/CPU frequencies Sean Christopherson
2026-08-08 14:55 ` David Woodhouse
2026-08-06 23:35 ` [PATCH v6 12/51] x86/acrn: Register TSC/CPU frequency callbacks iff frequency is actually in CPUID Sean Christopherson
2026-08-08 14:57 ` David Woodhouse
2026-08-06 23:35 ` [PATCH v6 13/51] x86/acrn: Mark TSC frequency as known when using ACRN for calibration Sean Christopherson
2026-08-08 14:59 ` David Woodhouse
2026-08-10 13:56 ` Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 14/51] x86/tsc: Consolidate forcing of X86_FEATURE_TSC_KNOWN_FREQ for PV code Sean Christopherson
2026-08-08 15:00 ` David Woodhouse
2026-08-06 23:35 ` [PATCH v6 15/51] x86/tsc: Kill off x86_platform_ops.calibrate_{cpu,tsc}() hooks Sean Christopherson
2026-08-08 15:01 ` David Woodhouse
2026-08-06 23:35 ` [PATCH v6 16/51] x86/tsc: Rename pit_hpet_ptimer_calibrate_cpu() => native_calibrate_cpu_late() Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 17/51] x86/tsc: Fold native_calibrate_cpu() into recalibrate_cpu_khz() Sean Christopherson
2026-08-08 15:03 ` David Woodhouse
2026-08-06 23:35 ` [PATCH v6 18/51] x86/kvmclock: Rename kvm_get_tsc_khz() to kvmclock_get_tsc_khz() Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 19/51] x86/kvmclock: Drop dead check on TSC being unstable during kvmclock_init() Sean Christopherson
2026-08-08 15:05 ` David Woodhouse
2026-08-06 23:35 ` [PATCH v6 20/51] KVM: x86: Officially define CPUID 0x40000010 as PV Timing Info (TSC and Bus) Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 21/51] x86/kvm: Obtain TSC frequency from PV CPUID if present Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 22/51] x86/kvm: Mark TSC as reliable when it's constant and nonstop Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 23/51] x86/tsc: Add standalone helper for getting CPU frequency from CPUID Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 24/51] x86/kvm: Get CPU base frequency from CPUID when it's available Sean Christopherson
2026-08-07 0:04 ` sashiko-bot
2026-08-08 15:06 ` David Woodhouse
2026-08-06 23:35 ` [PATCH v6 25/51] clocksource: hyper-v: Register sched_clock save/restore iff it's necessary Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 26/51] clocksource: hyper-v: Drop wrappers to sched_clock save/restore helpers Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 27/51] clocksource: hyper-v: Don't save/restore TSC offset when using HV sched_clock Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 28/51] x86/kvmclock: Setup kvmclock for secondary CPUs iff CONFIG_SMP=y Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 29/51] x86/kvm: Don't disable kvmclock on BSP in syscore_suspend() Sean Christopherson
2026-08-07 0:04 ` sashiko-bot
2026-08-06 23:35 ` [PATCH v6 30/51] x86/paravirt: Remove unnecessary PARAVIRT=n stub for paravirt_set_sched_clock() Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 31/51] x86/paravirt: Move handling of unstable PV clocks into paravirt_set_sched_clock() Sean Christopherson
2026-08-06 23:35 ` Sean Christopherson [this message]
2026-08-06 23:35 ` [PATCH v6 33/51] x86/xen/time: NOP-ify x86_platform's sched_clock save/restore hooks Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 34/51] x86/vmware: NOP-ify save/restore hooks when using VMware's sched_clock Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 35/51] x86/tsc: WARN if TSC sched_clock save/restore used with PV sched_clock Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 36/51] x86/paravirt: Pass sched_clock save/restore helpers during registration Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 37/51] x86/kvmclock: Move kvm_sched_clock_init() down in kvmclock.c Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 38/51] x86/xen/time: Mark xen_setup_vsyscall_time_info() as __init Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 39/51] x86/pvclock: Mark setup helpers and related various as __init/__ro_after_init Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 40/51] x86/pvclock: WARN if pvclock's valid_flags are overwritten Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 41/51] x86/kvmclock: Refactor handling of PVCLOCK_TSC_STABLE_BIT during kvmclock_init() Sean Christopherson
2026-08-06 23:35 ` [PATCH v6 42/51] timekeeping: Resume clocksources before reading persistent clock Sean Christopherson
2026-08-06 23:36 ` [PATCH v6 43/51] x86/kvmclock: Hook clocksource.suspend/resume when kvmclock isn't sched_clock Sean Christopherson
2026-08-06 23:36 ` [PATCH v6 44/51] x86/kvmclock: WARN if wall clock is read while kvmclock is suspended Sean Christopherson
2026-08-06 23:36 ` [PATCH v6 45/51] x86/paravirt: Mark __paravirt_set_sched_clock() as __init Sean Christopherson
2026-08-06 23:36 ` [PATCH v6 46/51] x86/paravirt: Plumb a return code into __paravirt_set_sched_clock() Sean Christopherson
2026-08-06 23:36 ` [PATCH v6 47/51] x86/paravirt: Don't use a PV sched_clock in CoCo guests with trusted TSC Sean Christopherson
2026-08-06 23:36 ` [PATCH v6 48/51] x86/kvmclock: Use TSC for sched_clock if it's constant and non-stop Sean Christopherson
2026-08-06 23:36 ` [PATCH v6 49/51] x86/kvmclock: Plumb in AP-online and BSP-resume to kvmlock, for documentation Sean Christopherson
2026-08-06 23:36 ` [PATCH v6 50/51] x86/paravirt: Move using_native_sched_clock() stub into timer.h Sean Christopherson
2026-08-06 23:36 ` [PATCH v6 51/51] x86/kvm: Get local APIC bus frequency from PV CPUID Timing Info Sean Christopherson
2026-08-07 0:08 ` sashiko-bot
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