https://bugzilla.kernel.org/show_bug.cgi?id=54461 Summary: nVMX: Downgrading nested VMX features from user-space Product: Virtualization Version: unspecified Platform: All OS/Version: Linux Tree: Mainline Status: NEW Severity: enhancement Priority: P1 Component: kvm AssignedTo: virtualization_kvm@xxxxxxxxxxxxxxxxxxxx ReportedBy: nyh@xxxxxxxxxxxxxxxxxxx Regression: No In nested SVM, the sub-features of SVM are all part of CPUID, so we already have a user-space interface (KVM_GET_SUPPORTED_CPUID/KVM_SET_CPUID2) to set a guest's features - which is, for example, useful for dictating a fixed set of features across different hosts. However, in nested VMX, the VMX sub-features offered or not to the guest are not in CPUID, but rather in MSRs, and currently the nested_vmx_setup_ctls_msrs() function determines their value - without any option for user space to control this. We need some sort of new KVM_SET_READONLY_MSRS ioctl for overriding (downgrading) nested_vmx_setup_ctls_msrs()'s decisions for a particular guest. -- Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email ------- 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
