On Wed, Nov 08, 2023 at 10:29:45AM -0800, Xin Li wrote: >Setup the global vmcs_config for FRED: >1) Add VM_ENTRY_LOAD_IA32_FRED to KVM_OPTIONAL_VMX_VM_ENTRY_CONTROLS to > have a FRED CPU load guest FRED MSRs from VMCS upon VM entry. >2) Add SECONDARY_VM_EXIT_SAVE_IA32_FRED to > KVM_OPTIONAL_VMX_SECONDARY_VM_EXIT_CONTROLS to have a FRED CPU save > guest FRED MSRs to VMCS during VM exit. >3) add SECONDARY_VM_EXIT_LOAD_IA32_FRED to > KVM_OPTIONAL_VMX_SECONDARY_VM_EXIT_CONTROLS to have a FRED CPU load > host FRED MSRs from VMCS during VM exit. > >Also add sanity checks to make sure FRED VM entry/exit controls can be >set on a FRED CPU. > >Tested-by: Shan Kang <shan.kang@xxxxxxxxx> >Signed-off-by: Xin Li <xin3.li@xxxxxxxxx> >--- > arch/x86/include/asm/vmx.h | 3 +++ > arch/x86/kvm/vmx/vmx.c | 19 ++++++++++++++++++- > arch/x86/kvm/vmx/vmx.h | 7 +++++-- > 3 files changed, 26 insertions(+), 3 deletions(-) > >diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h >index 4d4177ec802c..41796a733bc9 100644 >--- a/arch/x86/include/asm/vmx.h >+++ b/arch/x86/include/asm/vmx.h >@@ -106,6 +106,8 @@ > #define VM_EXIT_PT_CONCEAL_PIP 0x01000000 > #define VM_EXIT_CLEAR_IA32_RTIT_CTL 0x02000000 > #define VM_EXIT_ACTIVATE_SECONDARY_CONTROLS 0x80000000 >+#define SECONDARY_VM_EXIT_SAVE_IA32_FRED 0x00000001 >+#define SECONDARY_VM_EXIT_LOAD_IA32_FRED 0x00000002 > > #define VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR 0x00036dff > >@@ -119,6 +121,7 @@ > #define VM_ENTRY_LOAD_BNDCFGS 0x00010000 > #define VM_ENTRY_PT_CONCEAL_PIP 0x00020000 > #define VM_ENTRY_LOAD_IA32_RTIT_CTL 0x00040000 >+#define VM_ENTRY_LOAD_IA32_FRED 0x00800000 > > #define VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR 0x000011ff > >diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c >index df769207cbe0..9186f41974ab 100644 >--- a/arch/x86/kvm/vmx/vmx.c >+++ b/arch/x86/kvm/vmx/vmx.c >@@ -2694,10 +2694,27 @@ static int setup_vmcs_config(struct vmcs_config *vmcs_conf, > _vmexit_control &= ~x_ctrl; > } > >- if (_vmexit_control & VM_EXIT_ACTIVATE_SECONDARY_CONTROLS) >+ if (_vmexit_control & VM_EXIT_ACTIVATE_SECONDARY_CONTROLS) { > _secondary_vmexit_control = > adjust_vmx_controls64(KVM_OPTIONAL_VMX_SECONDARY_VM_EXIT_CONTROLS, > MSR_IA32_VMX_EXIT_CTLS2); >+ if (cpu_feature_enabled(X86_FEATURE_FRED) && >+ !(_secondary_vmexit_control & SECONDARY_VM_EXIT_SAVE_IA32_FRED && >+ _secondary_vmexit_control & SECONDARY_VM_EXIT_LOAD_IA32_FRED)) { >+ pr_warn_once("FRED enabled but no VMX VM-Exit {SAVE,LOAD}_IA32_FRED controls: %llx\n", >+ _secondary_vmexit_control); if there is no VM_EXIT_ACTIVATE_SECONDARY_CONTROLS, shouldn't we also emit this warning? >+ if (error_on_inconsistent_vmcs_config) >+ return -EIO; >+ } >+ } >+ >+ if (cpu_feature_enabled(X86_FEATURE_FRED) && >+ !(_vmentry_control & VM_ENTRY_LOAD_IA32_FRED)) { >+ pr_warn_once("FRED enabled but no VMX VM-Entry LOAD_IA32_FRED control: %x\n", >+ _vmentry_control); Can we just hide FRED from guests like what KVM does for other features which have similar dependencies? see vmx_set_cpu_caps().