diff options
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 31 |
1 files changed, 21 insertions, 10 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 76bce832cade..1b404e4d7dd8 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1394,16 +1394,24 @@ static u64 kvm_get_arch_capabilities(void) if (!boot_cpu_has_bug(X86_BUG_MDS)) data |= ARCH_CAP_MDS_NO; - /* - * On TAA affected systems: - * - nothing to do if TSX is disabled on the host. - * - we emulate TSX_CTRL if present on the host. - * This lets the guest use VERW to clear CPU buffers. - */ - if (!boot_cpu_has(X86_FEATURE_RTM)) - data &= ~(ARCH_CAP_TAA_NO | ARCH_CAP_TSX_CTRL_MSR); - else if (!boot_cpu_has_bug(X86_BUG_TAA)) + if (!boot_cpu_has(X86_FEATURE_RTM)) { + /* + * If RTM=0 because the kernel has disabled TSX, the host might + * have TAA_NO or TSX_CTRL. Clear TAA_NO (the guest sees RTM=0 + * and therefore knows that there cannot be TAA) but keep + * TSX_CTRL: some buggy userspaces leave it set on tsx=on hosts, + * and we want to allow migrating those guests to tsx=off hosts. + */ + data &= ~ARCH_CAP_TAA_NO; + } else if (!boot_cpu_has_bug(X86_BUG_TAA)) { data |= ARCH_CAP_TAA_NO; + } else { + /* + * Nothing to do here; we emulate TSX_CTRL if present on the + * host so the guest can choose between disabling TSX or + * using VERW to clear CPU buffers. + */ + } return data; } @@ -9616,6 +9624,8 @@ static bool kvm_is_valid_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs) */ if (!(sregs->cr4 & X86_CR4_PAE) || !(sregs->efer & EFER_LMA)) return false; + if (sregs->cr3 & vcpu->arch.cr3_lm_rsvd_bits) + return false; } else { /* * Not in 64-bit mode: EFER.LMA is clear and the code @@ -9993,6 +10003,7 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) fx_init(vcpu); vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); + vcpu->arch.cr3_lm_rsvd_bits = rsvd_bits(cpuid_maxphyaddr(vcpu), 63); vcpu->arch.pat = MSR_IA32_CR_PAT_DEFAULT; @@ -10494,7 +10505,7 @@ void __user * __x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa, return 0; old_npages = slot->npages; - hva = 0; + hva = slot->userspace_addr; } for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) { |