diff options
| -rw-r--r-- | arch/x86/xen/smp_hvm.c | 6 | ||||
| -rw-r--r-- | arch/x86/xen/time.c | 24 |
2 files changed, 29 insertions, 1 deletions
diff --git a/arch/x86/xen/smp_hvm.c b/arch/x86/xen/smp_hvm.c index 6ff3c887e0b9..b70afdff419c 100644 --- a/arch/x86/xen/smp_hvm.c +++ b/arch/x86/xen/smp_hvm.c @@ -20,6 +20,12 @@ static void __init xen_hvm_smp_prepare_boot_cpu(void) xen_vcpu_setup(0); /* + * Called again in case the kernel boots on vcpu >= MAX_VIRT_CPUS. + * Refer to comments in xen_hvm_init_time_ops(). + */ + xen_hvm_init_time_ops(); + + /* * The alternative logic (which patches the unlock/lock) runs before * the smp bootup up code is activated. Hence we need to set this up * the core kernel is being patched. Otherwise we will have only diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c index d9c945ee1100..9ef0a5cca96e 100644 --- a/arch/x86/xen/time.c +++ b/arch/x86/xen/time.c @@ -558,6 +558,11 @@ 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 @@ -567,7 +572,22 @@ 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; } @@ -577,6 +597,8 @@ void __init xen_hvm_init_time_ops(void) x86_cpuinit.setup_percpu_clockev = xen_hvm_setup_cpu_clockevents; x86_platform.set_wallclock = xen_set_wallclock; + + hvm_time_initialized = true; } #endif |