> So something bothers me still about this bug. What you did correctly
> restores the old behavior - but it shouldn't be fixing a bug.
>
> The only reason you need to schedule an update for the KVM clock area is
> if a new VCPU has been created, you have an unstable TSC.. or something
> changes the VM's kvmclock offset.
>
> So this change could in fact be hiding an underlying bug - either an
> unstable TSC is not being properly reported, the KVM clock offset is
> being changed, we are missing a KVM clock update for secondary VCPUs -
> or something else we don't yet understand is going on.
>
> Nikola, can you try the patch below, which reverts your change and
> attempts to fix other possible sources of the problem, and see if it
> still reproduces?
with Your patch, 32b SMP guests boot fine as well, without it, they
don't, so if You consider this better fix, I can acknowledge it as
working :)
n.
>
> Thanks,
>
> Zach
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 58f517b..42618fb 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -2127,8 +2127,10 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
> if (check_tsc_unstable()) {
> kvm_x86_ops->adjust_tsc_offset(vcpu, -tsc_delta);
> vcpu->arch.tsc_catchup = 1;
> + kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
> }
> - kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
> + if (vcpu->cpu == -1)
> + kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
> if (vcpu->cpu != cpu)
> kvm_migrate_timers(vcpu);
> vcpu->cpu = cpu;
> @@ -3534,6 +3536,8 @@ long kvm_arch_vm_ioctl(struct file *filp,
> struct kvm_clock_data user_ns;
> u64 now_ns;
> s64 delta;
> + struct kvm_vcpu *vcpu;
> + int i;
>
> r = -EFAULT;
> if (copy_from_user(&user_ns, argp, sizeof(user_ns)))
> @@ -3549,6 +3553,8 @@ long kvm_arch_vm_ioctl(struct file *filp,
> delta = user_ns.clock - now_ns;
> local_irq_enable();
> kvm->arch.kvmclock_offset = delta;
> + kvm_for_each_vcpu(i, vcpu, kvm)
> + kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
> break;
> }
> case KVM_GET_CLOCK: {
--
-------------------------------------
Ing. Nikola CIPRICH
LinuxBox.cz, s.r.o.
28. rijna 168, 709 01 Ostrava
tel.: +420 596 603 142
fax: +420 596 621 273
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www.linuxbox.cz
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email servis: servis@xxxxxxxxxxx
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