diff options
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 15 | ||||
| -rw-r--r-- | arch/x86/kvm/vmx/vmx.c | 7 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 6 | ||||
| -rw-r--r-- | include/uapi/linux/kvm.h | 2 |
5 files changed, 31 insertions, 1 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 1df95f10c903..1bab87a444d7 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1263,7 +1263,7 @@ struct kvm_arch_async_pf { }; extern u64 __read_mostly host_efer; - +extern bool __read_mostly allow_smaller_maxphyaddr; extern struct kvm_x86_ops kvm_x86_ops; #define __KVM_HAVE_ARCH_VM_ALLOC diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 2371b1e40f39..783330d0e7b8 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -924,6 +924,21 @@ static __init int svm_hardware_setup(void) svm_set_cpu_caps(); + /* + * It seems that on AMD processors PTE's accessed bit is + * being set by the CPU hardware before the NPF vmexit. + * This is not expected behaviour and our tests fail because + * of it. + * A workaround here is to disable support for + * GUEST_MAXPHYADDR < HOST_MAXPHYADDR if NPT is enabled. + * In this case userspace can know if there is support using + * KVM_CAP_SMALLER_MAXPHYADDR extension and decide how to handle + * it + * If future AMD CPU models change the behaviour described above, + * this variable can be changed accordingly + */ + allow_smaller_maxphyaddr = !npt_enabled; + return 0; err: diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 962a78c7dde5..1bb59ae5016d 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -8309,6 +8309,13 @@ static int __init vmx_init(void) #endif vmx_check_vmcs12_offsets(); + /* + * Intel processors don't have problems with + * GUEST_MAXPHYADDR < HOST_MAXPHYADDR so enable + * it for VMX by default + */ + allow_smaller_maxphyaddr = true; + return 0; } module_init(vmx_init); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 35abe69aad28..95ef62922869 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -187,6 +187,9 @@ static struct kvm_shared_msrs __percpu *shared_msrs; u64 __read_mostly host_efer; EXPORT_SYMBOL_GPL(host_efer); +bool __read_mostly allow_smaller_maxphyaddr; +EXPORT_SYMBOL_GPL(allow_smaller_maxphyaddr); + static u64 __read_mostly host_xss; u64 __read_mostly supported_xss; EXPORT_SYMBOL_GPL(supported_xss); @@ -3574,6 +3577,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_HYPERV_ENLIGHTENED_VMCS: r = kvm_x86_ops.nested_ops->enable_evmcs != NULL; break; + case KVM_CAP_SMALLER_MAXPHYADDR: + r = (int) allow_smaller_maxphyaddr; + break; default: break; } diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index ff9b335620d0..2c73dcfb3dbb 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -1033,6 +1033,8 @@ struct kvm_ppc_resize_hpt { #define KVM_CAP_HALT_POLL 182 #define KVM_CAP_ASYNC_PF_INT 183 #define KVM_CAP_LAST_CPU 184 +#define KVM_CAP_SMALLER_MAXPHYADDR 185 + #ifdef KVM_CAP_IRQ_ROUTING |