Re: [nVMX] With 3.20.0-0.rc0.git5.1 on L0, booting L2 guest results in L1 *rebooting*

["Radim Krčmář" <rkrcmar@redhat.com>]

2015-02-22 16:46+0100, Kashyap Chamarthy:
> Radim,
> 
> I just tested with your patch[1] in this thread. I built a Fedora
> Kernel[2] with it, and installed (and booted into) it on both L0 and L1. 
> 
> Result: I don't have good news, I'm afraid: L1 *still* reboots when an
>         L2 guest is booted. And, L0 throws the stack trace that was
>         previously noted on this thread:

Thanks, I'm puzzled though ... isn't it possible that a wrong kernel
sneaked into grub?

> . . .
> [<   57.747345>] ------------[ cut here ]------------
> [<    0.004638>] WARNING: CPU: 5 PID: 50206 at arch/x86/kvm/vmx.c:8962 nested_vmx_vmexit+0x7ee/0x880 [kvm_intel]()
> [<    0.060404>] CPU: 5 PID: 50206 Comm: qemu-system-x86 Not tainted 3.18.7-200.fc21.x86_64 #1

This looks like a new backtrace, but the kernel is not [2].

> [  +0.006055]  [<ffffffff810992ea>] warn_slowpath_null+0x1a/0x20
> [  +0.005889]  [<ffffffffa02f00ee>] nested_vmx_vmexit+0x7ee/0x880 [kvm_intel]
> [  +0.007014]  [<ffffffffa02f05af>] ? vmx_handle_exit+0x1bf/0xaa0 [kvm_intel]
> [  +0.007015]  [<ffffffffa02f039c>] vmx_queue_exception+0xfc/0x150 [kvm_intel]
> [  +0.007130]  [<ffffffffa028cdfd>] kvm_arch_vcpu_ioctl_run+0xd9d/0x1290 [kvm]

(There is only one execution path and unless there is a race, it would
 be prevented by [1].)

> [  +0.007111]  [<ffffffffa0288528>] ? kvm_arch_vcpu_load+0x58/0x220 [kvm]
> [  +0.006670]  [<ffffffffa0274cbc>] kvm_vcpu_ioctl+0x32c/0x5c0 [kvm]
[...]
>   [1] http://article.gmane.org/gmane.comp.emulators.kvm.devel/132937
>   [2] http://koji.fedoraproject.org/koji/taskinfo?taskID=9004708