]> git.kernelconcepts.de Git - karo-tx-linux.git/blobdiff - arch/x86/kvm/x86.c
KVM: Make EFER reads safe when EFER does not exist
[karo-tx-linux.git] / arch / x86 / kvm / x86.c
index 0d682fc6aeb333c382e6b9324105e2eb941bc545..662cf12d1db9436ea06e844ae7fce19219ba98d3 100644 (file)
@@ -752,6 +752,7 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, u32 msr, u64 *pdata)
        case MSR_IA32_MC0_MISC+8:
        case MSR_IA32_MC0_MISC+12:
        case MSR_IA32_MC0_MISC+16:
+       case MSR_IA32_MC0_MISC+20:
        case MSR_IA32_UCODE_REV:
        case MSR_IA32_EBL_CR_POWERON:
                data = 0;
@@ -982,9 +983,9 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 
 static int is_efer_nx(void)
 {
-       u64 efer;
+       unsigned long long efer = 0;
 
-       rdmsrl(MSR_EFER, efer);
+       rdmsrl_safe(MSR_EFER, &efer);
        return efer & EFER_NX;
 }
 
@@ -1303,28 +1304,33 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
        struct kvm_vcpu *vcpu = filp->private_data;
        void __user *argp = (void __user *)arg;
        int r;
+       struct kvm_lapic_state *lapic = NULL;
 
        switch (ioctl) {
        case KVM_GET_LAPIC: {
-               struct kvm_lapic_state lapic;
+               lapic = kzalloc(sizeof(struct kvm_lapic_state), GFP_KERNEL);
 
-               memset(&lapic, 0, sizeof lapic);
-               r = kvm_vcpu_ioctl_get_lapic(vcpu, &lapic);
+               r = -ENOMEM;
+               if (!lapic)
+                       goto out;
+               r = kvm_vcpu_ioctl_get_lapic(vcpu, lapic);
                if (r)
                        goto out;
                r = -EFAULT;
-               if (copy_to_user(argp, &lapic, sizeof lapic))
+               if (copy_to_user(argp, lapic, sizeof(struct kvm_lapic_state)))
                        goto out;
                r = 0;
                break;
        }
        case KVM_SET_LAPIC: {
-               struct kvm_lapic_state lapic;
-
+               lapic = kmalloc(sizeof(struct kvm_lapic_state), GFP_KERNEL);
+               r = -ENOMEM;
+               if (!lapic)
+                       goto out;
                r = -EFAULT;
-               if (copy_from_user(&lapic, argp, sizeof lapic))
+               if (copy_from_user(lapic, argp, sizeof(struct kvm_lapic_state)))
                        goto out;
-               r = kvm_vcpu_ioctl_set_lapic(vcpu, &lapic);;
+               r = kvm_vcpu_ioctl_set_lapic(vcpu, lapic);
                if (r)
                        goto out;
                r = 0;
@@ -1422,6 +1428,8 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
                r = -EINVAL;
        }
 out:
+       if (lapic)
+               kfree(lapic);
        return r;
 }
 
@@ -1630,6 +1638,15 @@ long kvm_arch_vm_ioctl(struct file *filp,
        struct kvm *kvm = filp->private_data;
        void __user *argp = (void __user *)arg;
        int r = -EINVAL;
+       /*
+        * This union makes it completely explicit to gcc-3.x
+        * that these two variables' stack usage should be
+        * combined, not added together.
+        */
+       union {
+               struct kvm_pit_state ps;
+               struct kvm_memory_alias alias;
+       } u;
 
        switch (ioctl) {
        case KVM_SET_TSS_ADDR:
@@ -1661,17 +1678,14 @@ long kvm_arch_vm_ioctl(struct file *filp,
        case KVM_GET_NR_MMU_PAGES:
                r = kvm_vm_ioctl_get_nr_mmu_pages(kvm);
                break;
-       case KVM_SET_MEMORY_ALIAS: {
-               struct kvm_memory_alias alias;
-
+       case KVM_SET_MEMORY_ALIAS:
                r = -EFAULT;
-               if (copy_from_user(&alias, argp, sizeof alias))
+               if (copy_from_user(&u.alias, argp, sizeof(struct kvm_memory_alias)))
                        goto out;
-               r = kvm_vm_ioctl_set_memory_alias(kvm, &alias);
+               r = kvm_vm_ioctl_set_memory_alias(kvm, &u.alias);
                if (r)
                        goto out;
                break;
-       }
        case KVM_CREATE_IRQCHIP:
                r = -ENOMEM;
                kvm->arch.vpic = kvm_create_pic(kvm);
@@ -1713,65 +1727,77 @@ long kvm_arch_vm_ioctl(struct file *filp,
        }
        case KVM_GET_IRQCHIP: {
                /* 0: PIC master, 1: PIC slave, 2: IOAPIC */
-               struct kvm_irqchip chip;
+               struct kvm_irqchip *chip = kmalloc(sizeof(*chip), GFP_KERNEL);
 
-               r = -EFAULT;
-               if (copy_from_user(&chip, argp, sizeof chip))
+               r = -ENOMEM;
+               if (!chip)
                        goto out;
+               r = -EFAULT;
+               if (copy_from_user(chip, argp, sizeof *chip))
+                       goto get_irqchip_out;
                r = -ENXIO;
                if (!irqchip_in_kernel(kvm))
-                       goto out;
-               r = kvm_vm_ioctl_get_irqchip(kvm, &chip);
+                       goto get_irqchip_out;
+               r = kvm_vm_ioctl_get_irqchip(kvm, chip);
                if (r)
-                       goto out;
+                       goto get_irqchip_out;
                r = -EFAULT;
-               if (copy_to_user(argp, &chip, sizeof chip))
-                       goto out;
+               if (copy_to_user(argp, chip, sizeof *chip))
+                       goto get_irqchip_out;
                r = 0;
+       get_irqchip_out:
+               kfree(chip);
+               if (r)
+                       goto out;
                break;
        }
        case KVM_SET_IRQCHIP: {
                /* 0: PIC master, 1: PIC slave, 2: IOAPIC */
-               struct kvm_irqchip chip;
+               struct kvm_irqchip *chip = kmalloc(sizeof(*chip), GFP_KERNEL);
 
-               r = -EFAULT;
-               if (copy_from_user(&chip, argp, sizeof chip))
+               r = -ENOMEM;
+               if (!chip)
                        goto out;
+               r = -EFAULT;
+               if (copy_from_user(chip, argp, sizeof *chip))
+                       goto set_irqchip_out;
                r = -ENXIO;
                if (!irqchip_in_kernel(kvm))
-                       goto out;
-               r = kvm_vm_ioctl_set_irqchip(kvm, &chip);
+                       goto set_irqchip_out;
+               r = kvm_vm_ioctl_set_irqchip(kvm, chip);
                if (r)
-                       goto out;
+                       goto set_irqchip_out;
                r = 0;
+       set_irqchip_out:
+               kfree(chip);
+               if (r)
+                       goto out;
                break;
        }
        case KVM_GET_PIT: {
-               struct kvm_pit_state ps;
                r = -EFAULT;
-               if (copy_from_user(&ps, argp, sizeof ps))
+               if (copy_from_user(&u.ps, argp, sizeof(struct kvm_pit_state)))
                        goto out;
                r = -ENXIO;
                if (!kvm->arch.vpit)
                        goto out;
-               r = kvm_vm_ioctl_get_pit(kvm, &ps);
+               r = kvm_vm_ioctl_get_pit(kvm, &u.ps);
                if (r)
                        goto out;
                r = -EFAULT;
-               if (copy_to_user(argp, &ps, sizeof ps))
+               if (copy_to_user(argp, &u.ps, sizeof(struct kvm_pit_state)))
                        goto out;
                r = 0;
                break;
        }
        case KVM_SET_PIT: {
-               struct kvm_pit_state ps;
                r = -EFAULT;
-               if (copy_from_user(&ps, argp, sizeof ps))
+               if (copy_from_user(&u.ps, argp, sizeof u.ps))
                        goto out;
                r = -ENXIO;
                if (!kvm->arch.vpit)
                        goto out;
-               r = kvm_vm_ioctl_set_pit(kvm, &ps);
+               r = kvm_vm_ioctl_set_pit(kvm, &u.ps);
                if (r)
                        goto out;
                r = 0;
@@ -2813,10 +2839,6 @@ static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
        down_read(&vcpu->kvm->slots_lock);
        vapic_enter(vcpu);
 
-preempted:
-       if (vcpu->guest_debug.enabled)
-               kvm_x86_ops->guest_debug_pre(vcpu);
-
 again:
        if (vcpu->requests)
                if (test_and_clear_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests))
@@ -2870,6 +2892,9 @@ again:
                goto out;
        }
 
+       if (vcpu->guest_debug.enabled)
+               kvm_x86_ops->guest_debug_pre(vcpu);
+
        vcpu->guest_mode = 1;
        /*
         * Make sure that guest_mode assignment won't happen after
@@ -2944,7 +2969,7 @@ out:
        if (r > 0) {
                kvm_resched(vcpu);
                down_read(&vcpu->kvm->slots_lock);
-               goto preempted;
+               goto again;
        }
 
        post_kvm_run_save(vcpu, kvm_run);
@@ -3294,11 +3319,33 @@ static int load_segment_descriptor_to_kvm_desct(struct kvm_vcpu *vcpu,
        return 0;
 }
 
+int kvm_load_realmode_segment(struct kvm_vcpu *vcpu, u16 selector, int seg)
+{
+       struct kvm_segment segvar = {
+               .base = selector << 4,
+               .limit = 0xffff,
+               .selector = selector,
+               .type = 3,
+               .present = 1,
+               .dpl = 3,
+               .db = 0,
+               .s = 1,
+               .l = 0,
+               .g = 0,
+               .avl = 0,
+               .unusable = 0,
+       };
+       kvm_x86_ops->set_segment(vcpu, &segvar, seg);
+       return 0;
+}
+
 int kvm_load_segment_descriptor(struct kvm_vcpu *vcpu, u16 selector,
                                int type_bits, int seg)
 {
        struct kvm_segment kvm_seg;
 
+       if (!(vcpu->arch.cr0 & X86_CR0_PE))
+               return kvm_load_realmode_segment(vcpu, selector, seg);
        if (load_segment_descriptor_to_kvm_desct(vcpu, selector, &kvm_seg))
                return 1;
        kvm_seg.type |= type_bits;
@@ -3981,7 +4028,7 @@ int kvm_arch_set_memory_region(struct kvm *kvm,
                        userspace_addr = do_mmap(NULL, 0,
                                                 npages * PAGE_SIZE,
                                                 PROT_READ | PROT_WRITE,
-                                                MAP_SHARED | MAP_ANONYMOUS,
+                                                MAP_PRIVATE | MAP_ANONYMOUS,
                                                 0);
                        up_write(&current->mm->mmap_sem);