diff options
Diffstat (limited to 'arch/x86/kvm/svm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 50 |
1 files changed, 27 insertions, 23 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index adb3619a3c16..6dad89248312 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -115,13 +115,6 @@ static const struct svm_direct_access_msrs { { .index = MSR_INVALID, .always = false }, }; -/* enable NPT for AMD64 and X86 with PAE */ -#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE) -bool npt_enabled = true; -#else -bool npt_enabled; -#endif - /* * These 2 parameters are used to config the controls for Pause-Loop Exiting: * pause_filter_count: On processors that support Pause filtering(indicated @@ -170,9 +163,12 @@ module_param(pause_filter_count_shrink, ushort, 0444); static unsigned short pause_filter_count_max = KVM_SVM_DEFAULT_PLE_WINDOW_MAX; module_param(pause_filter_count_max, ushort, 0444); -/* allow nested paging (virtualized MMU) for all guests */ -static int npt = true; -module_param(npt, int, S_IRUGO); +/* + * Use nested page tables by default. Note, NPT may get forced off by + * svm_hardware_setup() if it's unsupported by hardware or the host kernel. + */ +bool npt_enabled = true; +module_param_named(npt, npt_enabled, bool, 0444); /* allow nested virtualization in KVM/SVM */ static int nested = true; @@ -926,9 +922,6 @@ static __init void svm_set_cpu_caps(void) if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) || boot_cpu_has(X86_FEATURE_AMD_SSBD)) kvm_cpu_cap_set(X86_FEATURE_VIRT_SSBD); - - /* Enable INVPCID feature */ - kvm_cpu_cap_check_and_set(X86_FEATURE_INVPCID); } static __init int svm_hardware_setup(void) @@ -991,10 +984,15 @@ static __init int svm_hardware_setup(void) goto err; } - if (!boot_cpu_has(X86_FEATURE_NPT)) + /* + * KVM's MMU doesn't support using 2-level paging for itself, and thus + * NPT isn't supported if the host is using 2-level paging since host + * CR4 is unchanged on VMRUN. + */ + if (!IS_ENABLED(CONFIG_X86_64) && !IS_ENABLED(CONFIG_X86_PAE)) npt_enabled = false; - if (npt_enabled && !npt) + if (!boot_cpu_has(X86_FEATURE_NPT)) npt_enabled = false; kvm_configure_mmu(npt_enabled, get_max_npt_level(), PG_LEVEL_1G); @@ -1103,12 +1101,12 @@ static u64 svm_write_l1_tsc_offset(struct kvm_vcpu *vcpu, u64 offset) static void svm_check_invpcid(struct vcpu_svm *svm) { /* - * Intercept INVPCID instruction only if shadow page table is - * enabled. Interception is not required with nested page table - * enabled. + * Intercept INVPCID if shadow paging is enabled to sync/free shadow + * roots, or if INVPCID is disabled in the guest to inject #UD. */ if (kvm_cpu_cap_has(X86_FEATURE_INVPCID)) { - if (!npt_enabled) + if (!npt_enabled || + !guest_cpuid_has(&svm->vcpu, X86_FEATURE_INVPCID)) svm_set_intercept(svm, INTERCEPT_INVPCID); else svm_clr_intercept(svm, INTERCEPT_INVPCID); @@ -1203,6 +1201,7 @@ static void init_vmcb(struct vcpu_svm *svm) init_sys_seg(&save->ldtr, SEG_TYPE_LDT); init_sys_seg(&save->tr, SEG_TYPE_BUSY_TSS16); + svm_set_cr4(&svm->vcpu, 0); svm_set_efer(&svm->vcpu, 0); save->dr6 = 0xffff0ff0; kvm_set_rflags(&svm->vcpu, X86_EFLAGS_FIXED); @@ -2214,15 +2213,20 @@ static int emulate_svm_instr(struct kvm_vcpu *vcpu, int opcode) [SVM_INSTR_VMSAVE] = vmsave_interception, }; struct vcpu_svm *svm = to_svm(vcpu); + int ret; if (is_guest_mode(vcpu)) { svm->vmcb->control.exit_code = guest_mode_exit_codes[opcode]; svm->vmcb->control.exit_info_1 = 0; svm->vmcb->control.exit_info_2 = 0; - return nested_svm_vmexit(svm); - } else - return svm_instr_handlers[opcode](svm); + /* Returns '1' or -errno on failure, '0' on success. */ + ret = nested_svm_vmexit(svm); + if (ret) + return ret; + return 1; + } + return svm_instr_handlers[opcode](svm); } /* @@ -4396,7 +4400,7 @@ static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, void *insn, int i * * This happens because CPU microcode reading instruction bytes * uses a special opcode which attempts to read data using CPL=0 - * priviledges. The microcode reads CS:RIP and if it hits a SMAP + * privileges. The microcode reads CS:RIP and if it hits a SMAP * fault, it gives up and returns no instruction bytes. * * Detection: |