On 8/29/2020 9:49 AM, Chenyi Qiang wrote:
On 8/29/2020 1:43 AM, Jim Mattson wrote:
On Fri, Aug 28, 2020 at 1:54 AM Chenyi Qiang <chenyi.qiang@xxxxxxxxx>
wrote:
KVM supports the nested VM_{EXIT, ENTRY}_LOAD_IA32_PERF_GLOBAL_CTRL and
VM_{ENTRY_LOAD, EXIT_CLEAR}_BNDCFGS, but they doesn't expose during
the setup of nested VMX controls MSR.
Aren't these features added conditionally in
nested_vmx_entry_exit_ctls_update() and
nested_vmx_pmu_entry_exit_ctls_update()?
Yes, but I assume vmcs_config.nested should reflect the global
capability of VMX MSR. KVM supports these two controls, so should be
exposed here.
No. I prefer to say they are removed conditionally in
nested_vmx_entry_exit_ctls_update() and
nested_vmx_pmu_entry_exit_ctls_update().
Userspace calls vmx_get_msr_feature() to query what KVM supports for
these VMX MSR. In vmx_get_msr_feature(), it returns the value of
vmcs_config.nested. As KVM supports these two bits, we should advertise
them in vmcs_config.nested and report to userspace.
