From 5870058d2be9b8d2e34604e7f67eb7522f554dd9 Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Wed, 15 Jun 2022 14:03:01 +0200 Subject: [PATCH 4/4] KVM: VMX: Support TSC scaling with enlightened VMCS Content-Type: text/plain Enlightened VMCS v1 now includes the required field for TSC scaling feature so SECONDARY_EXEC_TSC_SCALING doesn't need to be filtered out for KVM on Hyper-V case. Hyper-V on KVM is, however, trickier: to not break live migration to older KVMs which may not support the feature it needs to stay filtered out. Eventually, a new KVM capability indicating support for the new fields will need to be introduced. While on it, update the comment why VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL/ VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL are kept filtered out and add missing spaces in trace_kvm_nested_vmenter_failed() strings making the output ugly. Signed-off-by: Vitaly Kuznetsov --- arch/x86/kvm/vmx/evmcs.c | 8 +++++++- arch/x86/kvm/vmx/evmcs.h | 11 ++++------- 2 files changed, 11 insertions(+), 8 deletions(-) diff --git a/arch/x86/kvm/vmx/evmcs.c b/arch/x86/kvm/vmx/evmcs.c index 61a702a804f8..6ed4bb2e676e 100644 --- a/arch/x86/kvm/vmx/evmcs.c +++ b/arch/x86/kvm/vmx/evmcs.c @@ -385,7 +385,13 @@ void nested_evmcs_filter_control_msr(u32 msr_index, u64 *pdata) ctl_high &= ~EVMCS1_UNSUPPORTED_VMENTRY_CTRL; break; case MSR_IA32_VMX_PROCBASED_CTLS2: - ctl_high &= ~EVMCS1_UNSUPPORTED_2NDEXEC; + /* + * Initially, SECONDARY_EXEC_TSC_SCALING was filtered out as there was no + * TscMultiplier field defined in eVMCS. Keep the status quo to not break + * live migration. + */ + ctl_high &= ~(EVMCS1_UNSUPPORTED_2NDEXEC | + SECONDARY_EXEC_TSC_SCALING); break; case MSR_IA32_VMX_TRUE_PINBASED_CTLS: case MSR_IA32_VMX_PINBASED_CTLS: diff --git a/arch/x86/kvm/vmx/evmcs.h b/arch/x86/kvm/vmx/evmcs.h index 8d70f9aea94b..5fd9292be6bb 100644 --- a/arch/x86/kvm/vmx/evmcs.h +++ b/arch/x86/kvm/vmx/evmcs.h @@ -37,16 +37,14 @@ DECLARE_STATIC_KEY_FALSE(enable_evmcs); * EPTP_LIST_ADDRESS = 0x00002024, * VMREAD_BITMAP = 0x00002026, * VMWRITE_BITMAP = 0x00002028, - * - * TSC_MULTIPLIER = 0x00002032, * PLE_GAP = 0x00004020, * PLE_WINDOW = 0x00004022, * VMX_PREEMPTION_TIMER_VALUE = 0x0000482E, - * GUEST_IA32_PERF_GLOBAL_CTRL = 0x00002808, - * HOST_IA32_PERF_GLOBAL_CTRL = 0x00002c04, * - * Currently unsupported in KVM: - * GUEST_IA32_RTIT_CTL = 0x00002814, + * While GUEST_IA32_PERF_GLOBAL_CTRL and HOST_IA32_PERF_GLOBAL_CTRL + * are present in eVMCSv1, Windows 11 still has issues booting when + * VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL/VM_ENTRY_LOAD_IA32_PERF_GLOBAL_CTRL + * are exposed to it, keep them filtered out. */ #define EVMCS1_UNSUPPORTED_PINCTRL (PIN_BASED_POSTED_INTR | \ PIN_BASED_VMX_PREEMPTION_TIMER) @@ -57,7 +55,6 @@ DECLARE_STATIC_KEY_FALSE(enable_evmcs); SECONDARY_EXEC_ENABLE_PML | \ SECONDARY_EXEC_ENABLE_VMFUNC | \ SECONDARY_EXEC_SHADOW_VMCS | \ - SECONDARY_EXEC_TSC_SCALING | \ SECONDARY_EXEC_PAUSE_LOOP_EXITING) #define EVMCS1_UNSUPPORTED_VMEXIT_CTRL \ (VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL | \ -- 2.35.3