KVM: nVMX: Use sanitized allowed-1 bits for VMX control MSRs

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@google.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220830133737.1539624-32-vkuznets@redhat.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 9b26142..af807cc 100644 (file)
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -6568,8 +6568,10 @@ 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
@@ -6586,11 +6588,10 @@ 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 |
@@ -6601,12 +6602,10 @@ 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 |
@@ -6623,11 +6622,10 @@ 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 |
@@ -6641,11 +6639,10 @@ 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 |
@@ -6679,12 +6676,9 @@ 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 88b00a7..6312c95 100644 (file)
--- 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 c44bff5..e12e6e1 100644 (file)
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7400,7 +7400,7 @@ 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());
@@ -8355,8 +8355,7 @@ 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)