https://bugzilla.kernel.org/show_bug.cgi?id=64801 Bug ID: 64801 Summary: Nested Virtualisation with KVM on Intel and AMD processors: L2 unreachable Product: Virtualization Version: unspecified Kernel Version: 3.12 Hardware: x86-64 OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: kvm Assignee: virtualization_kvm@xxxxxxxxxxxxxxxxxxxx Reporter: 2005@xxxxxxxxxxxxxxxxx Regression: No With the recent kernel version(s) it seems to be impossible to reach an L2 guest. The issues sometimes even render the L0 machine unusable, and hence could be considered relevant to system security. On three machines, the combination of KVM 1.2 and Linux 3.12 produces the following results when invoking the L2 VM: * Intel Core i5 680: register dump * Intel Core i7 M620: "nested_vmx_run: VMCS MSR_{LOAD,STORE} unsupported" * AMD Athlon X2 3800+: "skip emulated instructions" messages thrown over all host ttys On another machine, AMD Athlon II X2 240e which runs Linux 3.2.0 as host with KVM 1.1 and Linux 3.9.0 as guests, L2 can be reached. Booting the test setup from above with Linux 3.12 on all levels for comparing the results was not yet possible. The test setup consists of a minimal textmode VM which nests itself twice and contains some extra configuration for L0 for hardware support. Both SMP and single-core configurations seem to show the same behaviour. Kernel 3.12 host (L0) minimal configuration; may need tweaks depending on the hardware in use: http://serviceplatform.org/cgi-bin/gitweb.cgi?p=space-cloud;a=blob_plain;f=nestedcloud/kernel-boot/customkernel/nestedcloud.hostkernel.config;hb=master Kernel 3.12 guest (L1+L2) minimal configuration: https://gitorious.org/recvirt/recvirt/raw/2d4aeef70e53df7a2199256550515cd3bdbd4ecd:recvirt-basevm/kernel/recvirt.kvmkernel-smpfull.config Complete L0 test image (~800 MB) with extlinux as bootloader; may need root= and kvm_intel.nested=1 parameters, or PROMPT 1 in extlinux.conf; login is root, password is demo: http://141.76.41.201/recvirt/ -- You are receiving this mail because: You are watching the assignee of the bug. -- 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
