With the new Async PF code, some of our initiation code was moved to kvm.c. With that, code that was being issued conditional to kvmclock successful registration (primary cpu registering), started being issued unconditionally.
This patch proposes that we protect all registrations inside kvm_register_clock, re-using the kvmclock-enabled parameter for that. This fixes this specific bug, and should protect us from similar changes in the future. Signed-off-by: Glauber Costa <[email protected]> --- arch/x86/kernel/kvmclock.c | 12 ++++++++++-- 1 files changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index f98d3ea..fcdea34 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -130,6 +130,9 @@ int kvm_register_clock(char *txt) int cpu = smp_processor_id(); int low, high, ret; + if (!kvmclock) + return 0; + low = (int)__pa(&per_cpu(hv_clock, cpu)) | 1; high = ((u64)__pa(&per_cpu(hv_clock, cpu)) >> 32); ret = native_write_msr_safe(msr_kvm_system_time, low, high); @@ -182,14 +185,19 @@ void __init kvmclock_init(void) if (kvmclock && kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE2)) { msr_kvm_system_time = MSR_KVM_SYSTEM_TIME_NEW; msr_kvm_wall_clock = MSR_KVM_WALL_CLOCK_NEW; - } else if (!(kvmclock && kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE))) + } else if (!(kvmclock && kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE))) { + kvmclock = 0; return; + } printk(KERN_INFO "kvm-clock: Using msrs %x and %x", msr_kvm_system_time, msr_kvm_wall_clock); - if (kvm_register_clock("boot clock")) + if (kvm_register_clock("boot clock")) { + kvmclock = 0; return; + } + pv_time_ops.sched_clock = kvm_clock_read; x86_platform.calibrate_tsc = kvm_get_tsc_khz; x86_platform.get_wallclock = kvm_get_wallclock; -- 1.6.2.5 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
