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	Older Xen versions (4.5 and before) might have problems migrating pv guests with MSR_IA32_SPEC_CTRL having a non-zero value. So before suspending zero that MSR and restore it after being resumed. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Jan Beulich <jbeulich@suse.com> Cc: stable@vger.kernel.org Cc: xen-devel@lists.xenproject.org Cc: boris.ostrovsky@oracle.com Link: https://lkml.kernel.org/r/20180226140818.4849-1-jgross@suse.com
		
			
				
	
	
		
			84 lines
		
	
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			84 lines
		
	
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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#include <linux/types.h>
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#include <linux/tick.h>
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#include <linux/percpu-defs.h>
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#include <xen/xen.h>
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#include <xen/interface/xen.h>
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#include <xen/grant_table.h>
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#include <xen/events.h>
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#include <asm/cpufeatures.h>
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#include <asm/msr-index.h>
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#include <asm/xen/hypercall.h>
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#include <asm/xen/page.h>
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#include <asm/fixmap.h>
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#include "xen-ops.h"
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#include "mmu.h"
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#include "pmu.h"
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static DEFINE_PER_CPU(u64, spec_ctrl);
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void xen_arch_pre_suspend(void)
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{
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	xen_save_time_memory_area();
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	if (xen_pv_domain())
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		xen_pv_pre_suspend();
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}
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void xen_arch_post_suspend(int cancelled)
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{
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	if (xen_pv_domain())
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		xen_pv_post_suspend(cancelled);
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	else
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		xen_hvm_post_suspend(cancelled);
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	xen_restore_time_memory_area();
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}
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static void xen_vcpu_notify_restore(void *data)
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{
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	if (xen_pv_domain() && boot_cpu_has(X86_FEATURE_SPEC_CTRL))
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		wrmsrl(MSR_IA32_SPEC_CTRL, this_cpu_read(spec_ctrl));
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	/* Boot processor notified via generic timekeeping_resume() */
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	if (smp_processor_id() == 0)
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		return;
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	tick_resume_local();
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}
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static void xen_vcpu_notify_suspend(void *data)
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{
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	u64 tmp;
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	tick_suspend_local();
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	if (xen_pv_domain() && boot_cpu_has(X86_FEATURE_SPEC_CTRL)) {
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		rdmsrl(MSR_IA32_SPEC_CTRL, tmp);
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		this_cpu_write(spec_ctrl, tmp);
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		wrmsrl(MSR_IA32_SPEC_CTRL, 0);
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	}
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}
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void xen_arch_resume(void)
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{
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	int cpu;
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	on_each_cpu(xen_vcpu_notify_restore, NULL, 1);
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	for_each_online_cpu(cpu)
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		xen_pmu_init(cpu);
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}
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void xen_arch_suspend(void)
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{
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	int cpu;
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	for_each_online_cpu(cpu)
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		xen_pmu_finish(cpu);
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	on_each_cpu(xen_vcpu_notify_suspend, NULL, 1);
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}
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