xen/x86: Do not call xen_init_time_ops() until shared_info is initialized (d162809f) · Commits · 戴 / test

Routines that are set by xen_init_time_ops() use shared_info's pvclock_vcpu_time_info area. This area is not properly available until shared_info is mapped in xen_setup_shared_info(). This became especially problematic due to commit ("x86/timers: Add simple udelay calibration") where we end up reading tsc_to_system_mul from xen_dummy_shared_info (i.e. getting zero value) and then trying to divide by it in pvclock_tsc_khz(). Signed-off-by:

Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by:

Juergen Gross <jgross@suse.com> Signed-off-by:

Juergen Gross <jgross@suse.com>

arch/x86/xen/enlighten_pv.c

+7 −2

Original line number	Diff line number	Diff line
		@@ -974,6 +974,13 @@ void xen_setup_shared_info(void)
		#endif

		xen_setup_mfn_list_list();

		/*
		* Now that shared info is set up we can start using routines that
		* point to pvclock area.
		*/
		if (system_state == SYSTEM_BOOTING)
		xen_init_time_ops();
		}

		/* This is called once we have the cpu_possible_mask */
		@@ -1272,8 +1279,6 @@ asmlinkage __visible void __init xen_start_kernel(void)
		x86_init.oem.arch_setup = xen_arch_setup;
		x86_init.oem.banner = xen_banner;

		xen_init_time_ops();

		/*
		* Set up some pagetable state before starting to set any ptes.
		*/

arch/x86/xen/time.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -406,7 +406,7 @@ static void __init xen_time_init(void)
		pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
		}

		void __init xen_init_time_ops(void)
		void __ref xen_init_time_ops(void)
		{
		pv_time_ops = xen_time_ops;

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