Commit 9fe6a8c5 authored by Juergen Gross's avatar Juergen Gross
Browse files

x86/xen: remove deprecated xen_nopvspin boot parameter 



The xen_nopvspin boot parameter is deprecated since 2019. nopvspin
can be used instead.

Remove the xen_nopvspin boot parameter and replace the xen_pvspin
variable use cases with nopvspin.

This requires to move the nopvspin variable out of the .initdata
section, as it needs to be accessed for cpuhotplug, too.

Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Reviewed-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Message-ID: <20240710110139.22300-1-jgross@suse.com>
Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
parent bcea31e2

Documentation/admin-guide/kernel-parameters.txt

+0 −5
Original line number Diff line number Diff line
@@ -7439,11 +7439,6 @@ 
			access functions when running as Xen PV guest. The

			default value is controlled by CONFIG_XEN_PV_MSR_SAFE.



	xen_nopvspin	[X86,XEN,EARLY]

			Disables the qspinlock slowpath using Xen PV optimizations.

			This parameter is obsoleted by "nopvspin" parameter, which

			has equivalent effect for XEN platform.



	xen_nopv	[X86]

			Disables the PV optimizations forcing the HVM guest to

			run as generic HVM guest with no PV drivers.

arch/x86/xen/spinlock.c

+5 −15
Original line number Diff line number Diff line
@@ -18,7 +18,6 @@ 
static DEFINE_PER_CPU(int, lock_kicker_irq) = -1;

static DEFINE_PER_CPU(char *, irq_name);

static DEFINE_PER_CPU(atomic_t, xen_qlock_wait_nest);

static bool xen_pvspin = true;



static void xen_qlock_kick(int cpu)

{
@@ -68,7 +67,7 @@ void xen_init_lock_cpu(int cpu) 
	int irq;

	char *name;



	if (!xen_pvspin)

	if (nopvspin)

		return;



	WARN(per_cpu(lock_kicker_irq, cpu) >= 0, "spinlock on CPU%d exists on IRQ%d!\n",
@@ -95,7 +94,7 @@ void xen_uninit_lock_cpu(int cpu) 
{

	int irq;



	if (!xen_pvspin)

	if (nopvspin)

		return;



	kfree(per_cpu(irq_name, cpu));
@@ -125,10 +124,10 @@ PV_CALLEE_SAVE_REGS_THUNK(xen_vcpu_stolen); 
void __init xen_init_spinlocks(void)

{

	/*  Don't need to use pvqspinlock code if there is only 1 vCPU. */

	if (num_possible_cpus() == 1 || nopvspin)

		xen_pvspin = false;

	if (num_possible_cpus() == 1)

		nopvspin = true;



	if (!xen_pvspin) {

	if (nopvspin) {

		printk(KERN_DEBUG "xen: PV spinlocks disabled\n");

		static_branch_disable(&virt_spin_lock_key);

		return;
@@ -143,12 +142,3 @@ void __init xen_init_spinlocks(void) 
	pv_ops.lock.kick = xen_qlock_kick;

	pv_ops.lock.vcpu_is_preempted = PV_CALLEE_SAVE(xen_vcpu_stolen);

}
 


static __init int xen_parse_nopvspin(char *arg)

{

	pr_notice("\"xen_nopvspin\" is deprecated, please use \"nopvspin\" instead\n");

	xen_pvspin = false;

	return 0;

}

early_param("xen_nopvspin", xen_parse_nopvspin);

kernel/locking/qspinlock.c

+1 −1
Original line number Diff line number Diff line
@@ -583,7 +583,7 @@ EXPORT_SYMBOL(queued_spin_lock_slowpath); 
#include "qspinlock_paravirt.h"

#include "qspinlock.c"



bool nopvspin __initdata;

bool nopvspin;

static __init int parse_nopvspin(char *arg)

{

	nopvspin = true;