From: Sasha Levin <sashal@kernel.org>
To: stable@vger.kernel.org
Cc: Sean Christopherson <seanjc@google.com>,
Kai Huang <kai.huang@intel.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Sasha Levin <sashal@kernel.org>
Subject: [PATCH 7.2.y 7/9] KVM: x86: Expose several TSC helpers via x86.h for use by MSR code
Date: Fri, 11 Sep 2026 06:41:21 -0400 [thread overview]
Message-ID: <20260911104123.189614-7-sashal@kernel.org> (raw)
In-Reply-To: <20260911104123.189614-1-sashal@kernel.org>
From: Sean Christopherson <seanjc@google.com>
[ Upstream commit 9d13832ced63160ca67b6c72868b794cbcda556d ]
Begrudgingly move adjust_tsc_offset_{guest,host}() to x86.h as inlines,
and expose several other TSC helpers in anticipation of moving KVM's MSR
code to a dedicated msrs.c. Unfortunately for KVM, several MSRs that KVM
emulates can affect TSC state.
Opportunistically drop a superfluous local "tsc_offset" variable, whose
existence causes checkpatch to complain about lack of a blank line.
No functional change intended.
Reviewed-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260613000329.732085-14-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Stable-dep-of: e62392bf39eb ("KVM: x86: Disallow EFER.LME and EFER.LMA if long mode is not supported")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/kvm/x86.c | 22 +++-------------------
arch/x86/kvm/x86.h | 19 +++++++++++++++++++
2 files changed, 22 insertions(+), 19 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e78dd0c9a066e..7c31ec98ba723 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2639,7 +2639,7 @@ u64 kvm_scale_tsc(u64 tsc, u64 ratio)
return _tsc;
}
-static u64 kvm_compute_l1_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc)
+u64 kvm_compute_l1_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc)
{
u64 tsc;
@@ -2680,7 +2680,7 @@ u64 kvm_calc_nested_tsc_multiplier(u64 l1_multiplier, u64 l2_multiplier)
}
EXPORT_SYMBOL_FOR_KVM_INTERNAL(kvm_calc_nested_tsc_multiplier);
-static void kvm_vcpu_write_tsc_offset(struct kvm_vcpu *vcpu, u64 l1_offset)
+void kvm_vcpu_write_tsc_offset(struct kvm_vcpu *vcpu, u64 l1_offset)
{
if (vcpu->arch.guest_tsc_protected)
return;
@@ -2794,7 +2794,7 @@ static void __kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 offset, u64 tsc,
kvm_track_tsc_matching(vcpu, !matched);
}
-static void kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 *user_value)
+void kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 *user_value)
{
u64 data = user_value ? *user_value : 0;
struct kvm *kvm = vcpu->kvm;
@@ -2862,22 +2862,6 @@ static void kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 *user_value)
raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags);
}
-static inline void adjust_tsc_offset_guest(struct kvm_vcpu *vcpu,
- s64 adjustment)
-{
- u64 tsc_offset = vcpu->arch.l1_tsc_offset;
- kvm_vcpu_write_tsc_offset(vcpu, tsc_offset + adjustment);
-}
-
-static inline void adjust_tsc_offset_host(struct kvm_vcpu *vcpu, s64 adjustment)
-{
- if (vcpu->arch.l1_tsc_scaling_ratio != kvm_caps.default_tsc_scaling_ratio)
- WARN_ON(adjustment < 0);
- adjustment = kvm_scale_tsc((u64) adjustment,
- vcpu->arch.l1_tsc_scaling_ratio);
- adjust_tsc_offset_guest(vcpu, adjustment);
-}
-
#ifdef CONFIG_X86_64
static u64 read_tsc(void)
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index b7e0f554f804f..fe6ecd1efdb14 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -345,6 +345,25 @@ uint64_t kvm_get_wall_clock_epoch(struct kvm *kvm);
bool kvm_get_monotonic_and_clockread(s64 *kernel_ns, u64 *tsc_timestamp);
int kvm_guest_time_update(struct kvm_vcpu *v);
+void kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 *user_value);
+u64 kvm_compute_l1_tsc_offset(struct kvm_vcpu *vcpu, u64 target_tsc);
+void kvm_vcpu_write_tsc_offset(struct kvm_vcpu *vcpu, u64 l1_offset);
+
+static inline void adjust_tsc_offset_guest(struct kvm_vcpu *vcpu,
+ s64 adjustment)
+{
+ kvm_vcpu_write_tsc_offset(vcpu, vcpu->arch.l1_tsc_offset + adjustment);
+}
+
+static inline void adjust_tsc_offset_host(struct kvm_vcpu *vcpu, s64 adjustment)
+{
+ if (vcpu->arch.l1_tsc_scaling_ratio != kvm_caps.default_tsc_scaling_ratio)
+ WARN_ON(adjustment < 0);
+ adjustment = kvm_scale_tsc((u64) adjustment,
+ vcpu->arch.l1_tsc_scaling_ratio);
+ adjust_tsc_offset_guest(vcpu, adjustment);
+}
+
int kvm_read_guest_virt(struct kvm_vcpu *vcpu,
gva_t addr, void *val, unsigned int bytes,
struct x86_exception *exception);
--
2.53.0
next prev parent reply other threads:[~2026-09-11 10:41 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-09 10:32 FAILED: patch "[PATCH] KVM: x86: Disallow EFER.LME and EFER.LMA if long mode is not" failed to apply to 7.2-stable tree gregkh
2026-09-11 10:41 ` [PATCH 7.2.y 1/9] KVM: x86: Rename __{g,s}et_sregs2() => kvm_vcpu_ioctl_x86_{g,s}et_sregs2() Sasha Levin
2026-09-11 10:41 ` [PATCH 7.2.y 2/9] KVM: x86: Move kvm_caps and kvm_host_values to asm/kvm_host.h Sasha Levin
2026-09-11 10:41 ` [PATCH 7.2.y 3/9] KVM: x86: Swap the include order between x86.h and mmu.h Sasha Levin
2026-09-11 10:41 ` [PATCH 7.2.y 4/9] KVM: x86: Move eager_page_split to mmu.{c,h} Sasha Levin
2026-09-11 10:41 ` [PATCH 7.2.y 5/9] KVM: x86: Move kvm_{load,put}_guest_fpu() to fpu.h Sasha Levin
2026-09-11 10:41 ` [PATCH 7.2.y 6/9] KVM: x86: Extract get/set MSR (list) ioctl logic to helpers Sasha Levin
2026-09-11 10:41 ` Sasha Levin [this message]
2026-09-11 10:41 ` [PATCH 7.2.y 8/9] KVM: x86: Move the bulk of MSR specific code from x86.c to msrs.{c,h} Sasha Levin
2026-09-11 10:41 ` [PATCH 7.2.y 9/9] KVM: x86: Disallow EFER.LME and EFER.LMA if long mode is not supported Sasha Levin
2026-09-11 12:26 ` [PATCH 7.2.y 1/9] KVM: x86: Rename __{g,s}et_sregs2() => kvm_vcpu_ioctl_x86_{g,s}et_sregs2() Greg KH
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