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: . . . [< 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]() [< 0.009903>] Modules linked in: vhost_net vhost macvtap macvlan xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defra g_ipv4 xt_conntrack nf_conntrack tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables kvm_intel coretemp iTCO_wdt kvm ipmi_devintf iTCO_vendor_support i7core_edac gpio_ich c rc32c_intel serio_raw edac_core ipmi_si dcdbas shpchp tpm_tis lpc_ich mfd_core tpm ipmi_msghandler wmi acpi_power_meter acpi_cpufreq nfsd auth_rpcgss nfs_acl lockd grace sunrpc mgag200 i2c_algo_bit drm_kms_helper ttm drm ata_generic megaraid_sas bnx2 pata_acpi [last unloaded: kvm_intel] [< 0.060404>] CPU: 5 PID: 50206 Comm: qemu-system-x86 Not tainted 3.18.7-200.fc21.x86_64 #1 [ +0.008220] Hardware name: Dell Inc. PowerEdge R910/0P658H, BIOS 2.8.2 10/25/2012 [ +0.007526] 0000000000000000 00000000a30d0ba3 ffff883f2489fc48 ffffffff8175e686 [ +0.007688] 0000000000000000 0000000000000000 ffff883f2489fc88 ffffffff810991d1 [ +0.007613] ffff883f2489fc98 ffff88bece1ba000 0000000000000000 0000000000000014 [ +0.007611] Call Trace: [ +0.002518] [<ffffffff8175e686>] dump_stack+0x46/0x58 [ +0.005202] [<ffffffff810991d1>] warn_slowpath_common+0x81/0xa0 [ +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] [ +0.007111] [<ffffffffa0288528>] ? kvm_arch_vcpu_load+0x58/0x220 [kvm] [ +0.006670] [<ffffffffa0274cbc>] kvm_vcpu_ioctl+0x32c/0x5c0 [kvm] [ +0.006236] [<ffffffff810d0f7b>] ? put_prev_entity+0x5b/0x400 [ +0.005887] [<ffffffff810cbb37>] ? set_next_entity+0x67/0x80 [ +0.005802] [<ffffffff810d4549>] ? pick_next_task_fair+0x6c9/0x8c0 [ +0.006324] [<ffffffff810126d6>] ? __switch_to+0x1d6/0x5f0 [ +0.005626] [<ffffffff8122a1c0>] do_vfs_ioctl+0x2d0/0x4b0 [ +0.005543] [<ffffffff81760764>] ? __schedule+0x2f4/0x8a0 [ +0.005537] [<ffffffff8122a421>] SyS_ioctl+0x81/0xa0 [ +0.005106] [<ffffffff81765429>] system_call_fastpath+0x12/0x17 [ +0.006056] ---[ end trace 646ed2360b84865c ]--- [ +7.000298] kvm [50179]: vcpu0 unhandled rdmsr: 0x1c9 [ +0.005061] kvm [50179]: vcpu0 unhandled rdmsr: 0x1a6 [ +0.005053] kvm [50179]: vcpu0 unhandled rdmsr: 0x3f6 . . . [1] http://article.gmane.org/gmane.comp.emulators.kvm.devel/132937 [2] http://koji.fedoraproject.org/koji/taskinfo?taskID=9004708 -- /kashyap -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html