linux-kernel - [PATCH 11/14] x86/paravirt: use common code for paravirt_steal

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Message-ID: <20250911063433.13783-12-jgross@suse.com>
Date: Thu, 11 Sep 2025 08:34:30 +0200
From: Juergen Gross <jgross@...e.com>
To: linux-kernel@...r.kernel.org,
	x86@...nel.org,
	virtualization@...ts.linux.dev
Cc: Juergen Gross <jgross@...e.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	Borislav Petkov <bp@...en8.de>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	Ajay Kaher <ajay.kaher@...adcom.com>,
	Alexey Makhalov <alexey.makhalov@...adcom.com>,
	Broadcom internal kernel review list <bcm-kernel-feedback-list@...adcom.com>,
	Boris Ostrovsky <boris.ostrovsky@...cle.com>,
	Stefano Stabellini <sstabellini@...nel.org>,
	Oleksandr Tyshchenko <oleksandr_tyshchenko@...m.com>,
	xen-devel@...ts.xenproject.org
Subject: [PATCH 11/14] x86/paravirt: use common code for paravirt_steal_clock()

Remove the arch specific variant of paravirt_steal_clock() and use
the common one instead.

With alol archs supporting Xen now having been switched to the common
variant, including paravirt.h can be dropped from drivers/xen/time.c.

Signed-off-by: Juergen Gross <jgross@...e.com>
---
 arch/x86/Kconfig                | 1 +
 arch/x86/include/asm/paravirt.h | 7 -------
 arch/x86/kernel/paravirt.c      | 6 ------
 arch/x86/xen/time.c             | 1 +
 drivers/xen/time.c              | 3 ---
 5 files changed, 2 insertions(+), 16 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 07bf67b849b7..0f8abf96cc39 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -784,6 +784,7 @@ if HYPERVISOR_GUEST
 config PARAVIRT
 	bool "Enable paravirtualization code"
 	depends on HAVE_STATIC_CALL
+	select HAVE_PV_STEAL_CLOCK_GEN
 	help
 	  This changes the kernel so it can modify itself when it is run
 	  under a hypervisor, potentially improving performance significantly
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 491cb7e037bf..37d7494ce146 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -21,10 +21,8 @@ struct mm_struct;
 #include <linux/static_call_types.h>
 #include <asm/frame.h>
 
-u64 dummy_steal_clock(int cpu);
 u64 dummy_sched_clock(void);
 
-DECLARE_STATIC_CALL(pv_steal_clock, dummy_steal_clock);
 DECLARE_STATIC_CALL(pv_sched_clock, dummy_sched_clock);
 
 void paravirt_set_sched_clock(u64 (*func)(void));
@@ -39,11 +37,6 @@ bool pv_is_native_spin_unlock(void);
 __visible bool __native_vcpu_is_preempted(long cpu);
 bool pv_is_native_vcpu_is_preempted(void);
 
-static inline u64 paravirt_steal_clock(int cpu)
-{
-	return static_call(pv_steal_clock)(cpu);
-}
-
 #ifdef CONFIG_PARAVIRT_SPINLOCKS
 void __init paravirt_set_cap(void);
 #endif
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index a3ba4747be1c..42991d471bf3 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -60,12 +60,6 @@ void __init native_pv_lock_init(void)
 		static_branch_enable(&virt_spin_lock_key);
 }
 
-static u64 native_steal_clock(int cpu)
-{
-	return 0;
-}
-
-DEFINE_STATIC_CALL(pv_steal_clock, native_steal_clock);
 DEFINE_STATIC_CALL(pv_sched_clock, native_sched_clock);
 
 void paravirt_set_sched_clock(u64 (*func)(void))
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 96521b1874ac..e4754b2fa900 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -16,6 +16,7 @@
 #include <linux/slab.h>
 #include <linux/pvclock_gtod.h>
 #include <linux/timekeeper_internal.h>
+#include <linux/sched/cputime.h>
 
 #include <asm/pvclock.h>
 #include <asm/xen/hypervisor.h>
diff --git a/drivers/xen/time.c b/drivers/xen/time.c
index 53b12f5ac465..0b18d8a5a2dd 100644
--- a/drivers/xen/time.c
+++ b/drivers/xen/time.c
@@ -10,9 +10,6 @@
 #include <linux/static_call.h>
 #include <linux/sched/cputime.h>
 
-#ifndef CONFIG_HAVE_PV_STEAL_CLOCK_GEN
-#include <asm/paravirt.h>
-#endif
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
 
-- 
2.51.0