Commits
Nadav Har'El committed 8049d651e87
nEPT: Support LOAD_IA32_EFER entry/exit controls for L1 Recent KVM, since http://kerneltrap.org/mailarchive/linux-kvm/2010/5/2/6261577 switch the EFER MSR when EPT is used and the host and guest have different NX bits. So if we add support for nested EPT (L1 guest using EPT to run L2) and want to be able to run recent KVM as L1, we need to allow L1 to use this EFER switching feature. To do this EFER switching, KVM uses VM_ENTRY/EXIT_LOAD_IA32_EFER if available, and if it isn't, it uses the generic VM_ENTRY/EXIT_MSR_LOAD. This patch adds support for the former (the latter is still unsupported). Nested entry and exit emulation (prepare_vmcs_02 and load_vmcs12_host_state, respectively) already handled VM_ENTRY/EXIT_LOAD_IA32_EFER correctly. So all that's left to do in this patch is to properly advertise this feature to L1. Note that vmcs12's VM_ENTRY/EXIT_LOAD_IA32_EFER are emulated by L0, by using vmx_set_efer (which itself sets one of several vmcs02 fields), so we always support this feature, regardless of whether the host supports it. Reviewed-by: Orit Wasserman <owasserm@redhat.com> Signed-off-by: Nadav Har'El <nyh@il.ibm.com> Signed-off-by: Jun Nakajima <jun.nakajima@intel.com> Signed-off-by: Xinhao Xu <xinhao.xu@intel.com> Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com> Signed-off-by: Gleb Natapov <gleb@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>