diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 97 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 12 |
3 files changed, 53 insertions, 57 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index e8dcbc632cf8..6b15f27f49d0 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1777,6 +1777,7 @@ int kvm_pv_send_ipi(struct kvm *kvm, unsigned long ipi_bitmap_low, unsigned long icr, int op_64_bit); void kvm_define_user_return_msr(unsigned index, u32 msr); +int kvm_find_user_return_msr(u32 msr); int kvm_probe_user_return_msr(u32 msr); int kvm_set_user_return_msr(unsigned index, u64 val, u64 mask); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index adefedac0e3b..39506704be96 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -454,26 +454,7 @@ static inline void vmx_segment_cache_clear(struct vcpu_vmx *vmx) static unsigned long host_idt_base; -/* - * Though SYSCALL is only supported in 64-bit mode on Intel CPUs, kvm - * will emulate SYSCALL in legacy mode if the vendor string in guest - * CPUID.0:{EBX,ECX,EDX} is "AuthenticAMD" or "AMDisbetter!" To - * support this emulation, MSR_STAR is included in the list for i386, - * but is never loaded into hardware. MSR_CSTAR is also never loaded - * into hardware and is here purely for emulation purposes. - */ -static u32 vmx_uret_msrs_list[] = { -#ifdef CONFIG_X86_64 - MSR_SYSCALL_MASK, MSR_LSTAR, MSR_CSTAR, -#endif - MSR_EFER, MSR_TSC_AUX, MSR_STAR, - MSR_IA32_TSX_CTRL, -}; - -/* - * Number of user return MSRs that are actually supported in hardware. - * vmx_uret_msrs_list is modified when KVM is loaded to drop unsupported MSRs. - */ +/* Number of user return MSRs that are actually supported in hardware. */ static int vmx_nr_uret_msrs; #if IS_ENABLED(CONFIG_HYPERV) @@ -703,22 +684,11 @@ static bool is_valid_passthrough_msr(u32 msr) return r; } -static inline int __vmx_find_uret_msr(u32 msr) -{ - int i; - - for (i = 0; i < vmx_nr_uret_msrs; ++i) { - if (vmx_uret_msrs_list[i] == msr) - return i; - } - return -1; -} - struct vmx_uret_msr *vmx_find_uret_msr(struct vcpu_vmx *vmx, u32 msr) { int i; - i = __vmx_find_uret_msr(msr); + i = kvm_find_user_return_msr(msr); if (i >= 0) return &vmx->guest_uret_msrs[i]; return NULL; @@ -1086,7 +1056,7 @@ static bool update_transition_efer(struct vcpu_vmx *vmx) return false; } - i = __vmx_find_uret_msr(MSR_EFER); + i = kvm_find_user_return_msr(MSR_EFER); if (i < 0) return false; @@ -6922,6 +6892,7 @@ static void vmx_free_vcpu(struct kvm_vcpu *vcpu) static int vmx_create_vcpu(struct kvm_vcpu *vcpu) { + struct vmx_uret_msr *tsx_ctrl; struct vcpu_vmx *vmx; int i, cpu, err; @@ -6946,29 +6917,25 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu) for (i = 0; i < vmx_nr_uret_msrs; ++i) { vmx->guest_uret_msrs[i].data = 0; - - switch (vmx_uret_msrs_list[i]) { - case MSR_IA32_TSX_CTRL: - /* - * TSX_CTRL_CPUID_CLEAR is handled in the CPUID - * interception. Keep the host value unchanged to avoid - * changing CPUID bits under the host kernel's feet. - * - * hle=0, rtm=0, tsx_ctrl=1 can be found with some - * combinations of new kernel and old userspace. If - * those guests run on a tsx=off host, do allow guests - * to use TSX_CTRL, but do not change the value on the - * host so that TSX remains always disabled. - */ - if (boot_cpu_has(X86_FEATURE_RTM)) - vmx->guest_uret_msrs[i].mask = ~(u64)TSX_CTRL_CPUID_CLEAR; - else - vmx->guest_uret_msrs[i].mask = 0; - break; - default: - vmx->guest_uret_msrs[i].mask = -1ull; - break; - } + vmx->guest_uret_msrs[i].mask = -1ull; + } + tsx_ctrl = vmx_find_uret_msr(vmx, MSR_IA32_TSX_CTRL); + if (tsx_ctrl) { + /* + * TSX_CTRL_CPUID_CLEAR is handled in the CPUID interception. + * Keep the host value unchanged to avoid changing CPUID bits + * under the host kernel's feet. + * + * hle=0, rtm=0, tsx_ctrl=1 can be found with some combinations + * of new kernel and old userspace. If those guests run on a + * tsx=off host, do allow guests to use TSX_CTRL, but do not + * change the value on the host so that TSX remains always + * disabled. + */ + if (boot_cpu_has(X86_FEATURE_RTM)) + vmx->guest_uret_msrs[i].mask = ~(u64)TSX_CTRL_CPUID_CLEAR; + else + vmx->guest_uret_msrs[i].mask = 0; } err = alloc_loaded_vmcs(&vmx->vmcs01); @@ -7829,6 +7796,22 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = { static __init void vmx_setup_user_return_msrs(void) { + + /* + * Though SYSCALL is only supported in 64-bit mode on Intel CPUs, kvm + * will emulate SYSCALL in legacy mode if the vendor string in guest + * CPUID.0:{EBX,ECX,EDX} is "AuthenticAMD" or "AMDisbetter!" To + * support this emulation, MSR_STAR is included in the list for i386, + * but is never loaded into hardware. MSR_CSTAR is also never loaded + * into hardware and is here purely for emulation purposes. + */ + const u32 vmx_uret_msrs_list[] = { + #ifdef CONFIG_X86_64 + MSR_SYSCALL_MASK, MSR_LSTAR, MSR_CSTAR, + #endif + MSR_EFER, MSR_TSC_AUX, MSR_STAR, + MSR_IA32_TSX_CTRL, + }; u32 msr; int i; @@ -7841,7 +7824,7 @@ static __init void vmx_setup_user_return_msrs(void) continue; kvm_define_user_return_msr(vmx_nr_uret_msrs, msr); - vmx_uret_msrs_list[vmx_nr_uret_msrs++] = msr; + vmx_nr_uret_msrs++; } } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 0856636efc44..d514031ed25f 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -364,6 +364,18 @@ void kvm_define_user_return_msr(unsigned slot, u32 msr) } EXPORT_SYMBOL_GPL(kvm_define_user_return_msr); +int kvm_find_user_return_msr(u32 msr) +{ + int i; + + for (i = 0; i < user_return_msrs_global.nr; ++i) { + if (user_return_msrs_global.msrs[i] == msr) + return i; + } + return -1; +} +EXPORT_SYMBOL_GPL(kvm_find_user_return_msr); + static void kvm_user_return_msr_cpu_online(void) { unsigned int cpu = smp_processor_id(); |