On Fri, 2022-07-08 at 16:42 +0200, Vitaly Kuznetsov wrote: > Using raw host MSR values for setting up nested VMX control MSRs is > incorrect as some features need to disabled, e.g. when KVM runs as > a nested hypervisor on Hyper-V and uses Enlightened VMCS or when a > workaround for IA32_PERF_GLOBAL_CTRL is applied. For non-nested VMX, this > is done in setup_vmcs_config() and the result is stored in vmcs_config. > Use it for setting up allowed-1 bits in nested VMX MSRs too. > > Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx> > Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> > --- > arch/x86/kvm/vmx/nested.c | 30 ++++++++++++------------------ > arch/x86/kvm/vmx/nested.h | 2 +- > arch/x86/kvm/vmx/vmx.c | 5 ++--- > 3 files changed, 15 insertions(+), 22 deletions(-) > > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > index 09654d5c2144..3d386c663fac 100644 > --- a/arch/x86/kvm/vmx/nested.c > +++ b/arch/x86/kvm/vmx/nested.c > @@ -6565,8 +6565,10 @@ static u64 nested_vmx_calc_vmcs_enum_msr(void) > * bit in the high half is on if the corresponding bit in the control field > * may be on. See also vmx_control_verify(). > */ > -void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps) > +void nested_vmx_setup_ctls_msrs(struct vmcs_config *vmcs_conf, u32 ept_caps) > { > + struct nested_vmx_msrs *msrs = &vmcs_conf->nested; > + > /* > * Note that as a general rule, the high half of the MSRs (bits in > * the control fields which may be 1) should be initialized by the > @@ -6583,11 +6585,10 @@ void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps) > */ > > /* pin-based controls */ > - rdmsr(MSR_IA32_VMX_PINBASED_CTLS, > - msrs->pinbased_ctls_low, > - msrs->pinbased_ctls_high); > msrs->pinbased_ctls_low = > PIN_BASED_ALWAYSON_WITHOUT_TRUE_MSR; > + > + msrs->pinbased_ctls_high = vmcs_conf->pin_based_exec_ctrl; > msrs->pinbased_ctls_high &= > PIN_BASED_EXT_INTR_MASK | > PIN_BASED_NMI_EXITING | > @@ -6598,12 +6599,10 @@ void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps) > PIN_BASED_VMX_PREEMPTION_TIMER; > > /* exit controls */ > - rdmsr(MSR_IA32_VMX_EXIT_CTLS, > - msrs->exit_ctls_low, > - msrs->exit_ctls_high); > msrs->exit_ctls_low = > VM_EXIT_ALWAYSON_WITHOUT_TRUE_MSR; > > + msrs->exit_ctls_high = vmcs_conf->vmexit_ctrl; > msrs->exit_ctls_high &= > #ifdef CONFIG_X86_64 > VM_EXIT_HOST_ADDR_SPACE_SIZE | > @@ -6619,11 +6618,10 @@ void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps) > msrs->exit_ctls_low &= ~VM_EXIT_SAVE_DEBUG_CONTROLS; > > /* entry controls */ > - rdmsr(MSR_IA32_VMX_ENTRY_CTLS, > - msrs->entry_ctls_low, > - msrs->entry_ctls_high); > msrs->entry_ctls_low = > VM_ENTRY_ALWAYSON_WITHOUT_TRUE_MSR; > + > + msrs->entry_ctls_high = vmcs_conf->vmentry_ctrl; > msrs->entry_ctls_high &= > #ifdef CONFIG_X86_64 > VM_ENTRY_IA32E_MODE | > @@ -6637,11 +6635,10 @@ void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps) > msrs->entry_ctls_low &= ~VM_ENTRY_LOAD_DEBUG_CONTROLS; > > /* cpu-based controls */ > - rdmsr(MSR_IA32_VMX_PROCBASED_CTLS, > - msrs->procbased_ctls_low, > - msrs->procbased_ctls_high); > msrs->procbased_ctls_low = > CPU_BASED_ALWAYSON_WITHOUT_TRUE_MSR; > + > + msrs->procbased_ctls_high = vmcs_conf->cpu_based_exec_ctrl; > msrs->procbased_ctls_high &= > CPU_BASED_INTR_WINDOW_EXITING | > CPU_BASED_NMI_WINDOW_EXITING | CPU_BASED_USE_TSC_OFFSETTING | > @@ -6675,12 +6672,9 @@ void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps) > * depend on CPUID bits, they are added later by > * vmx_vcpu_after_set_cpuid. > */ > - if (msrs->procbased_ctls_high & CPU_BASED_ACTIVATE_SECONDARY_CONTROLS) > - rdmsr(MSR_IA32_VMX_PROCBASED_CTLS2, > - msrs->secondary_ctls_low, > - msrs->secondary_ctls_high); > - > msrs->secondary_ctls_low = 0; > + > + msrs->secondary_ctls_high = vmcs_conf->cpu_based_2nd_exec_ctrl; > msrs->secondary_ctls_high &= > SECONDARY_EXEC_DESC | > SECONDARY_EXEC_ENABLE_RDTSCP | > diff --git a/arch/x86/kvm/vmx/nested.h b/arch/x86/kvm/vmx/nested.h > index c92cea0b8ccc..fae047c6204b 100644 > --- a/arch/x86/kvm/vmx/nested.h > +++ b/arch/x86/kvm/vmx/nested.h > @@ -17,7 +17,7 @@ enum nvmx_vmentry_status { > }; > > void vmx_leave_nested(struct kvm_vcpu *vcpu); > -void nested_vmx_setup_ctls_msrs(struct nested_vmx_msrs *msrs, u32 ept_caps); > +void nested_vmx_setup_ctls_msrs(struct vmcs_config *vmcs_conf, u32 ept_caps); > void nested_vmx_hardware_unsetup(void); > __init int nested_vmx_hardware_setup(int (*exit_handlers[])(struct kvm_vcpu *)); > void nested_vmx_set_vmcs_shadowing_bitmap(void); > diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c > index e462e5b9c0a1..35285109856f 100644 > --- a/arch/x86/kvm/vmx/vmx.c > +++ b/arch/x86/kvm/vmx/vmx.c > @@ -7306,7 +7306,7 @@ static int __init vmx_check_processor_compat(void) > if (setup_vmcs_config(&vmcs_conf, &vmx_cap) < 0) > return -EIO; > if (nested) > - nested_vmx_setup_ctls_msrs(&vmcs_conf.nested, vmx_cap.ept); > + nested_vmx_setup_ctls_msrs(&vmcs_conf, vmx_cap.ept); > if (memcmp(&vmcs_config, &vmcs_conf, sizeof(struct vmcs_config)) != 0) { > printk(KERN_ERR "kvm: CPU %d feature inconsistency!\n", > smp_processor_id()); > @@ -8281,8 +8281,7 @@ static __init int hardware_setup(void) > setup_default_sgx_lepubkeyhash(); > > if (nested) { > - nested_vmx_setup_ctls_msrs(&vmcs_config.nested, > - vmx_capability.ept); > + nested_vmx_setup_ctls_msrs(&vmcs_config, vmx_capability.ept); > > r = nested_vmx_hardware_setup(kvm_vmx_exit_handlers); > if (r) Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx> Best regards, Maxim Levitsky