Do basic VMX/SVM support checks directly in vendor code instead of implementing them via kvm_x86_ops hooks. Beyond the superficial benefit of providing common messages, which isn't even clearly a net positive since vendor code can provide more precise/detailed messages, there's zero advantage to bouncing through common x86 code. Consolidating the checks will also simplify performing the checks across all CPUs (in a future patch). Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx> --- arch/x86/include/asm/kvm_host.h | 2 -- arch/x86/kvm/svm/svm.c | 38 +++++++++++++++------------------ arch/x86/kvm/vmx/vmx.c | 37 +++++++++++++++++--------------- arch/x86/kvm/x86.c | 11 ---------- 4 files changed, 37 insertions(+), 51 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 04a9ae66fb8d..d79aedf70908 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1729,8 +1729,6 @@ struct kvm_x86_nested_ops { }; struct kvm_x86_init_ops { - int (*cpu_has_kvm_support)(void); - int (*disabled_by_bios)(void); int (*check_processor_compatibility)(void); int (*hardware_setup)(void); unsigned int (*handle_intel_pt_intr)(void); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index ab53da3fbcd1..49ccef9fae81 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -519,21 +519,28 @@ static void svm_init_osvw(struct kvm_vcpu *vcpu) vcpu->arch.osvw.status |= 1; } -static int has_svm(void) +static bool kvm_is_svm_supported(void) { const char *msg; + u64 vm_cr; if (!cpu_has_svm(&msg)) { - printk(KERN_INFO "has_svm: %s\n", msg); - return 0; + pr_err("SVM not supported, %s\n", msg); + return false; } if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) { pr_info("KVM is unsupported when running as an SEV guest\n"); - return 0; + return false; } - return 1; + rdmsrl(MSR_VM_CR, vm_cr); + if (vm_cr & (1 << SVM_VM_CR_SVM_DISABLE)) { + pr_err("SVM disabled (by BIOS) in MSR_VM_CR\n"); + return false; + } + + return true; } void __svm_write_tsc_multiplier(u64 multiplier) @@ -572,10 +579,9 @@ static int svm_hardware_enable(void) if (efer & EFER_SVME) return -EBUSY; - if (!has_svm()) { - pr_err("%s: err EOPNOTSUPP on %d\n", __func__, me); + if (!kvm_is_svm_supported()) return -EINVAL; - } + sd = per_cpu_ptr(&svm_data, me); sd->asid_generation = 1; sd->max_asid = cpuid_ebx(SVM_CPUID_FUNC) - 1; @@ -4070,17 +4076,6 @@ static void svm_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, vmcb_mark_dirty(svm->vmcb, VMCB_CR); } -static int is_disabled(void) -{ - u64 vm_cr; - - rdmsrl(MSR_VM_CR, vm_cr); - if (vm_cr & (1 << SVM_VM_CR_SVM_DISABLE)) - return 1; - - return 0; -} - static void svm_patch_hypercall(struct kvm_vcpu *vcpu, unsigned char *hypercall) { @@ -5080,8 +5075,6 @@ static __init int svm_hardware_setup(void) static struct kvm_x86_init_ops svm_init_ops __initdata = { - .cpu_has_kvm_support = has_svm, - .disabled_by_bios = is_disabled, .hardware_setup = svm_hardware_setup, .check_processor_compatibility = svm_check_processor_compat, @@ -5095,6 +5088,9 @@ static int __init svm_init(void) __unused_size_checks(); + if (!kvm_is_svm_supported()) + return -EOPNOTSUPP; + r = kvm_x86_vendor_init(&svm_init_ops); if (r) return r; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 3f7d9f88b314..23b64bf4bfcf 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -2485,17 +2485,6 @@ static void vmx_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg) } } -static __init int cpu_has_kvm_support(void) -{ - return cpu_has_vmx(); -} - -static __init int vmx_disabled_by_bios(void) -{ - return !this_cpu_has(X86_FEATURE_MSR_IA32_FEAT_CTL) || - !this_cpu_has(X86_FEATURE_VMX); -} - static int kvm_cpu_vmxon(u64 vmxon_pointer) { u64 msr; @@ -7479,16 +7468,29 @@ static int vmx_vm_init(struct kvm *kvm) return 0; } +static bool __init kvm_is_vmx_supported(void) +{ + if (!cpu_has_vmx()) { + pr_err("CPU doesn't support VMX\n"); + return false; + } + + if (!this_cpu_has(X86_FEATURE_MSR_IA32_FEAT_CTL) || + !this_cpu_has(X86_FEATURE_VMX)) { + pr_err("VMX not enabled (by BIOS) in MSR_IA32_FEAT_CTL\n"); + return false; + } + + return true; +} + static int __init vmx_check_processor_compat(void) { struct vmcs_config vmcs_conf; struct vmx_capability vmx_cap; - if (!this_cpu_has(X86_FEATURE_MSR_IA32_FEAT_CTL) || - !this_cpu_has(X86_FEATURE_VMX)) { - pr_err("VMX is disabled on CPU %d\n", smp_processor_id()); + if (!kvm_is_vmx_supported()) return -EIO; - } if (setup_vmcs_config(&vmcs_conf, &vmx_cap) < 0) return -EIO; @@ -8499,8 +8501,6 @@ static __init int hardware_setup(void) } static struct kvm_x86_init_ops vmx_init_ops __initdata = { - .cpu_has_kvm_support = cpu_has_kvm_support, - .disabled_by_bios = vmx_disabled_by_bios, .check_processor_compatibility = vmx_check_processor_compat, .hardware_setup = hardware_setup, .handle_intel_pt_intr = NULL, @@ -8543,6 +8543,9 @@ static int __init vmx_init(void) { int r, cpu; + if (!kvm_is_vmx_supported()) + return -EOPNOTSUPP; + /* * Note, hv_init_evmcs() touches only VMX knobs, i.e. there's nothing * to unwind if a later step fails. diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 3d5455e08191..5551f3552f08 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9315,17 +9315,6 @@ static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops) return -EEXIST; } - if (!ops->cpu_has_kvm_support()) { - pr_err_ratelimited("no hardware support for '%s'\n", - ops->runtime_ops->name); - return -EOPNOTSUPP; - } - if (ops->disabled_by_bios()) { - pr_err_ratelimited("support for '%s' disabled by bios\n", - ops->runtime_ops->name); - return -EOPNOTSUPP; - } - /* * KVM explicitly assumes that the guest has an FPU and * FXSAVE/FXRSTOR. For example, the KVM_GET_FPU explicitly casts the -- 2.38.1.584.g0f3c55d4c2-goog