1 files changed, 14 insertions, 4 deletions

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9d1b5cd4d34c..20316c67b824 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -106,6 +106,8 @@ EXPORT_SYMBOL_GPL(kvm_max_guest_tsc_khz);
 static u32 tsc_tolerance_ppm = 250;
 module_param(tsc_tolerance_ppm, uint, S_IRUGO | S_IWUSR);
 
+static bool backwards_tsc_observed = false;
+
 #define KVM_NR_SHARED_MSRS 16
 
 struct kvm_shared_msrs_global {
@@ -280,7 +282,7 @@ int kvm_set_apic_base(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 }
 EXPORT_SYMBOL_GPL(kvm_set_apic_base);
 
-asmlinkage void kvm_spurious_fault(void)
+asmlinkage __visible void kvm_spurious_fault(void)
 {
         /* Fault while not rebooting.  We want the trace. */
         BUG();
@@ -652,6 +654,9 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
         if (!guest_cpuid_has_smep(vcpu) && (cr4 & X86_CR4_SMEP))
                 return 1;
 
+        if (!guest_cpuid_has_smap(vcpu) && (cr4 & X86_CR4_SMAP))
+                return 1;
+
         if (!guest_cpuid_has_fsgsbase(vcpu) && (cr4 & X86_CR4_FSGSBASE))
                 return 1;
 
@@ -680,6 +685,9 @@ int kvm_set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
             (!(cr4 & X86_CR4_PCIDE) && (old_cr4 & X86_CR4_PCIDE)))
                 kvm_mmu_reset_context(vcpu);
 
+        if ((cr4 ^ old_cr4) & X86_CR4_SMAP)
+                update_permission_bitmask(vcpu, vcpu->arch.walk_mmu, false);
+
         if ((cr4 ^ old_cr4) & X86_CR4_OSXSAVE)
                 kvm_update_cpuid(vcpu);
 
@@ -1117,7 +1125,6 @@ static inline u64 get_kernel_ns(void)
 {
         struct timespec ts;
 
-        WARN_ON(preemptible());
         ktime_get_ts(&ts);
         monotonic_to_bootbased(&ts);
         return timespec_to_ns(&ts);
@@ -1481,7 +1488,8 @@ static void pvclock_update_vm_gtod_copy(struct kvm *kvm)
                                         &ka->master_kernel_ns,
                                         &ka->master_cycle_now);
 
-        ka->use_master_clock = host_tsc_clocksource & vcpus_matched;
+        ka->use_master_clock = host_tsc_clocksource && vcpus_matched
+                                && !backwards_tsc_observed;
 
         if (ka->use_master_clock)
                 atomic_set(&kvm_guest_has_master_clock, 1);
@@ -4164,7 +4172,8 @@ static int vcpu_mmio_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva,
                 | (write ? PFERR_WRITE_MASK : 0);
 
         if (vcpu_match_mmio_gva(vcpu, gva)
-            && !permission_fault(vcpu->arch.walk_mmu, vcpu->arch.access, access)) {
+            && !permission_fault(vcpu, vcpu->arch.walk_mmu,
+                                 vcpu->arch.access, access)) {
                 *gpa = vcpu->arch.mmio_gfn << PAGE_SHIFT |
                                         (gva & (PAGE_SIZE - 1));
                 trace_vcpu_match_mmio(gva, *gpa, write, false);
@@ -6939,6 +6948,7 @@ int kvm_arch_hardware_enable(void *garbage)
          */
         if (backwards_tsc) {
                 u64 delta_cyc = max_tsc - local_tsc;
+                backwards_tsc_observed = true;
                 list_for_each_entry(kvm, &vm_list, vm_list) {
                         kvm_for_each_vcpu(i, vcpu, kvm) {
                                 vcpu->arch.tsc_offset_adjustment += delta_cyc;