diff options
Diffstat (limited to 'arch/x86/xen/time.c')
| -rw-r--r-- | arch/x86/xen/time.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index befbdd8b17f0..4ec6c80f7687 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -547,6 +547,11 @@ static void xen_hvm_setup_cpu_clockevents(void) void __init xen_hvm_init_time_ops(void) { + static bool hvm_time_initialized; + + if (hvm_time_initialized) + return; + /* * vector callback is needed otherwise we cannot receive interrupts * on cpu > 0 and at this point we don't know how many cpus are @@ -556,7 +561,22 @@ void __init xen_hvm_init_time_ops(void) return; if (!xen_feature(XENFEAT_hvm_safe_pvclock)) { - pr_info("Xen doesn't support pvclock on HVM, disable pv timer"); + pr_info_once("Xen doesn't support pvclock on HVM, disable pv timer"); + return; + } + + /* + * Only MAX_VIRT_CPUS 'vcpu_info' are embedded inside 'shared_info'. + * The __this_cpu_read(xen_vcpu) is still NULL when Xen HVM guest + * boots on vcpu >= MAX_VIRT_CPUS (e.g., kexec), To access + * __this_cpu_read(xen_vcpu) via xen_clocksource_read() will panic. + * + * The xen_hvm_init_time_ops() should be called again later after + * __this_cpu_read(xen_vcpu) is available. + */ + if (!__this_cpu_read(xen_vcpu)) { + pr_info("Delay xen_init_time_common() as kernel is running on vcpu=%d\n", + xen_vcpu_nr(0)); return; } @@ -568,6 +588,8 @@ void __init xen_hvm_init_time_ops(void) x86_platform.calibrate_tsc = xen_tsc_khz; x86_platform.get_wallclock = xen_get_wallclock; x86_platform.set_wallclock = xen_set_wallclock; + + hvm_time_initialized = true; } #endif |