Re: [PATCH 00/14] KVM: nVMX: Use vmcs_config for setting up nested VMX MSRs
From: Maxim Levitsky
Date: Tue Jun 28 2022 - 05:08:18 EST
On Mon, 2022-06-27 at 18:04 +0200, Vitaly Kuznetsov wrote:
> Changes since RFC:
> - "KVM: VMX: Extend VMX controls macro shenanigans" PATCH added and the
> infrastructure is later used in other patches [Sean] PATCHes 1-3 added
> to support the change.
> - "KVM: VMX: Clear controls obsoleted by EPT at runtime, not setup" PATCH
> added [Sean].
> - Commit messages added.
>
> vmcs_config is a sanitized version of host VMX MSRs where some controls are
> filtered out (e.g. when Enlightened VMCS is enabled, some know bugs are
> discovered, some inconsistencies in controls are detected,...) but
> nested_vmx_setup_ctls_msrs() uses raw host MSRs instead. This may end up
> in exposing undesired controls to L1. Switch to using vmcs_config instead.
>
> Sean Christopherson (1):
> KVM: VMX: Clear controls obsoleted by EPT at runtime, not setup
>
> Vitaly Kuznetsov (13):
> KVM: VMX: Check VM_ENTRY_IA32E_MODE in setup_vmcs_config()
> KVM: VMX: Check CPU_BASED_{INTR,NMI}_WINDOW_EXITING in
> setup_vmcs_config()
> KVM: VMX: Tweak the special handling of SECONDARY_EXEC_ENCLS_EXITING
> in setup_vmcs_config()
> KVM: VMX: Extend VMX controls macro shenanigans
> KVM: VMX: Move CPU_BASED_CR8_{LOAD,STORE}_EXITING filtering out of
> setup_vmcs_config()
> KVM: VMX: Add missing VMEXIT controls to vmcs_config
> KVM: VMX: Add missing VMENTRY controls to vmcs_config
> KVM: VMX: Add missing CPU based VM execution controls to vmcs_config
> KVM: nVMX: Use sanitized allowed-1 bits for VMX control MSRs
> KVM: VMX: Store required-1 VMX controls in vmcs_config
> KVM: nVMX: Use sanitized required-1 bits for VMX control MSRs
> KVM: VMX: Cache MSR_IA32_VMX_MISC in vmcs_config
> KVM: nVMX: Use cached host MSR_IA32_VMX_MISC value for setting up
> nested MSR
>
> arch/x86/kvm/vmx/capabilities.h | 16 +--
> arch/x86/kvm/vmx/nested.c | 37 +++---
> arch/x86/kvm/vmx/nested.h | 2 +-
> arch/x86/kvm/vmx/vmx.c | 198 ++++++++++++++------------------
> arch/x86/kvm/vmx/vmx.h | 118 +++++++++++++++++++
> 5 files changed, 229 insertions(+), 142 deletions(-)
>
Sorry that I was a bit out of loop on this, so before I review it,
does this patch series solve the eVMCS issue we had alone,
or we still need the eVMCS version patch series as well?
Best regards,
Maxim Levitsky