lkml.org 
[lkml]   [2020]   [Aug]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH 1/5] KVM: nVMX: Fix VMX controls MSRs setup when nested VMX enabled
    From
    Date
    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@intel.com>
    >> 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.

    \
     
     \ /
      Last update: 2020-08-29 04:53    [W:2.588 / U:0.056 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site