4 files changed, 153 insertions, 119 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 41cc27de4d66..0d122bf889db 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -309,6 +309,7 @@ struct kvm {
         int busy;
         unsigned long rmap_overflow;
         struct list_head vm_list;
+        struct file *filp;
 };
 
 struct kvm_stat {
@@ -343,7 +344,7 @@ struct kvm_arch_ops {
         int (*vcpu_create)(struct kvm_vcpu *vcpu);
         void (*vcpu_free)(struct kvm_vcpu *vcpu);
 
-        struct kvm_vcpu *(*vcpu_load)(struct kvm_vcpu *vcpu);
+        void (*vcpu_load)(struct kvm_vcpu *vcpu);
         void (*vcpu_put)(struct kvm_vcpu *vcpu);
         void (*vcpu_decache)(struct kvm_vcpu *vcpu);
 
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 6fb36c80e3e8..a593d092d85b 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -96,6 +96,9 @@ struct segment_descriptor_64 {
 
 #endif
 
+static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
+                           unsigned long arg);
+
 static struct inode *kvmfs_inode(struct file_operations *fops)
 {
         int error = -ENOMEM;
@@ -246,24 +249,30 @@ int kvm_write_guest(struct kvm_vcpu *vcpu, gva_t addr, unsigned long size,
 }
 EXPORT_SYMBOL_GPL(kvm_write_guest);
 
-static int vcpu_slot(struct kvm_vcpu *vcpu)
+/*
+ * Switches to specified vcpu, until a matching vcpu_put()
+ */
+static void vcpu_load(struct kvm_vcpu *vcpu)
 {
-        return vcpu - vcpu->kvm->vcpus;
+        mutex_lock(&vcpu->mutex);
+        kvm_arch_ops->vcpu_load(vcpu);
 }
 
 /*
- * Switches to specified vcpu, until a matching vcpu_put()
+ * Switches to specified vcpu, until a matching vcpu_put(). Will return NULL
+ * if the slot is not populated.
  */
-static struct kvm_vcpu *vcpu_load(struct kvm *kvm, int vcpu_slot)
+static struct kvm_vcpu *vcpu_load_slot(struct kvm *kvm, int slot)
 {
-        struct kvm_vcpu *vcpu = &kvm->vcpus[vcpu_slot];
+        struct kvm_vcpu *vcpu = &kvm->vcpus[slot];
 
         mutex_lock(&vcpu->mutex);
-        if (unlikely(!vcpu->vmcs)) {
+        if (!vcpu->vmcs) {
                 mutex_unlock(&vcpu->mutex);
                 return NULL;
         }
-        return kvm_arch_ops->vcpu_load(vcpu);
+        kvm_arch_ops->vcpu_load(vcpu);
+        return vcpu;
 }
 
 static void vcpu_put(struct kvm_vcpu *vcpu)
@@ -336,9 +345,10 @@ static void kvm_free_physmem(struct kvm *kvm)
 
 static void kvm_free_vcpu(struct kvm_vcpu *vcpu)
 {
-        if (!vcpu_load(vcpu->kvm, vcpu_slot(vcpu)))
+        if (!vcpu->vmcs)
                 return;
 
+        vcpu_load(vcpu);
         kvm_mmu_destroy(vcpu);
         vcpu_put(vcpu);
         kvm_arch_ops->vcpu_free(vcpu);
@@ -725,7 +735,7 @@ raced:
         for (i = 0; i < KVM_MAX_VCPUS; ++i) {
                 struct kvm_vcpu *vcpu;
 
-                vcpu = vcpu_load(kvm, i);
+                vcpu = vcpu_load_slot(kvm, i);
                 if (!vcpu)
                         continue;
                 kvm_mmu_reset_context(vcpu);
@@ -791,8 +801,9 @@ static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
         if (any) {
                 cleared = 0;
                 for (i = 0; i < KVM_MAX_VCPUS; ++i) {
-                        struct kvm_vcpu *vcpu = vcpu_load(kvm, i);
+                        struct kvm_vcpu *vcpu;
 
+                        vcpu = vcpu_load_slot(kvm, i);
                         if (!vcpu)
                                 continue;
                         if (!cleared) {
@@ -1461,8 +1472,7 @@ void kvm_resched(struct kvm_vcpu *vcpu)
 {
         vcpu_put(vcpu);
         cond_resched();
-        /* Cannot fail -  no vcpu unplug yet. */
-        vcpu_load(vcpu->kvm, vcpu_slot(vcpu));
+        vcpu_load(vcpu);
 }
 EXPORT_SYMBOL_GPL(kvm_resched);
 
@@ -1484,17 +1494,11 @@ void save_msrs(struct vmx_msr_entry *e, int n)
 }
 EXPORT_SYMBOL_GPL(save_msrs);
 
-static int kvm_vm_ioctl_run(struct kvm *kvm, struct kvm_run *kvm_run)
+static int kvm_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
 {
-        struct kvm_vcpu *vcpu;
         int r;
 
-        if (!valid_vcpu(kvm_run->vcpu))
-                return -EINVAL;
-
-        vcpu = vcpu_load(kvm, kvm_run->vcpu);
-        if (!vcpu)
-                return -ENOENT;
+        vcpu_load(vcpu);
 
         /* re-sync apic's tpr */
         vcpu->cr8 = kvm_run->cr8;
@@ -1517,16 +1521,10 @@ static int kvm_vm_ioctl_run(struct kvm *kvm, struct kvm_run *kvm_run)
         return r;
 }
 
-static int kvm_vm_ioctl_get_regs(struct kvm *kvm, struct kvm_regs *regs)
+static int kvm_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu,
+                                   struct kvm_regs *regs)
 {
-        struct kvm_vcpu *vcpu;
-
-        if (!valid_vcpu(regs->vcpu))
-                return -EINVAL;
-
-        vcpu = vcpu_load(kvm, regs->vcpu);
-        if (!vcpu)
-                return -ENOENT;
+        vcpu_load(vcpu);
 
         kvm_arch_ops->cache_regs(vcpu);
 
@@ -1563,16 +1561,10 @@ static int kvm_vm_ioctl_get_regs(struct kvm *kvm, struct kvm_regs *regs)
         return 0;
 }
 
-static int kvm_vm_ioctl_set_regs(struct kvm *kvm, struct kvm_regs *regs)
+static int kvm_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu,
+                                   struct kvm_regs *regs)
 {
-        struct kvm_vcpu *vcpu;
-
-        if (!valid_vcpu(regs->vcpu))
-                return -EINVAL;
-
-        vcpu = vcpu_load(kvm, regs->vcpu);
-        if (!vcpu)
-                return -ENOENT;
+        vcpu_load(vcpu);
 
         vcpu->regs[VCPU_REGS_RAX] = regs->rax;
         vcpu->regs[VCPU_REGS_RBX] = regs->rbx;
@@ -1609,16 +1601,12 @@ static void get_segment(struct kvm_vcpu *vcpu,
         return kvm_arch_ops->get_segment(vcpu, var, seg);
 }
 
-static int kvm_vm_ioctl_get_sregs(struct kvm *kvm, struct kvm_sregs *sregs)
+static int kvm_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
+                                    struct kvm_sregs *sregs)
 {
-        struct kvm_vcpu *vcpu;
         struct descriptor_table dt;
 
-        if (!valid_vcpu(sregs->vcpu))
-                return -EINVAL;
-        vcpu = vcpu_load(kvm, sregs->vcpu);
-        if (!vcpu)
-                return -ENOENT;
+        vcpu_load(vcpu);
 
         get_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
         get_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
@@ -1660,18 +1648,14 @@ static void set_segment(struct kvm_vcpu *vcpu,
         return kvm_arch_ops->set_segment(vcpu, var, seg);
 }
 
-static int kvm_vm_ioctl_set_sregs(struct kvm *kvm, struct kvm_sregs *sregs)
+static int kvm_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
+                                    struct kvm_sregs *sregs)
 {
-        struct kvm_vcpu *vcpu;
         int mmu_reset_needed = 0;
         int i;
         struct descriptor_table dt;
 
-        if (!valid_vcpu(sregs->vcpu))
-                return -EINVAL;
-        vcpu = vcpu_load(kvm, sregs->vcpu);
-        if (!vcpu)
-                return -ENOENT;
+        vcpu_load(vcpu);
 
         set_segment(vcpu, &sregs->cs, VCPU_SREG_CS);
         set_segment(vcpu, &sregs->ds, VCPU_SREG_DS);
@@ -1777,20 +1761,14 @@ static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
  *
  * @return number of msrs set successfully.
  */
-static int __msr_io(struct kvm *kvm, struct kvm_msrs *msrs,
+static int __msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs *msrs,
                     struct kvm_msr_entry *entries,
                     int (*do_msr)(struct kvm_vcpu *vcpu,
                                   unsigned index, u64 *data))
 {
-        struct kvm_vcpu *vcpu;
         int i;
 
-        if (!valid_vcpu(msrs->vcpu))
-                return -EINVAL;
-
-        vcpu = vcpu_load(kvm, msrs->vcpu);
-        if (!vcpu)
-                return -ENOENT;
+        vcpu_load(vcpu);
 
         for (i = 0; i < msrs->nmsrs; ++i)
                 if (do_msr(vcpu, entries[i].index, &entries[i].data))
@@ -1806,7 +1784,7 @@ static int __msr_io(struct kvm *kvm, struct kvm_msrs *msrs,
  *
  * @return number of msrs set successfully.
  */
-static int msr_io(struct kvm *kvm, struct kvm_msrs __user *user_msrs,
+static int msr_io(struct kvm_vcpu *vcpu, struct kvm_msrs __user *user_msrs,
                   int (*do_msr)(struct kvm_vcpu *vcpu,
                                 unsigned index, u64 *data),
                   int writeback)
@@ -1834,7 +1812,7 @@ static int msr_io(struct kvm *kvm, struct kvm_msrs __user *user_msrs,
         if (copy_from_user(entries, user_msrs->entries, size))
                 goto out_free;
 
-        r = n = __msr_io(kvm, &msrs, entries, do_msr);
+        r = n = __msr_io(vcpu, &msrs, entries, do_msr);
         if (r < 0)
                 goto out_free;
 
@@ -1853,38 +1831,31 @@ out:
 /*
  * Translate a guest virtual address to a guest physical address.
  */
-static int kvm_vm_ioctl_translate(struct kvm *kvm, struct kvm_translation *tr)
+static int kvm_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
+                                    struct kvm_translation *tr)
 {
         unsigned long vaddr = tr->linear_address;
-        struct kvm_vcpu *vcpu;
         gpa_t gpa;
 
-        vcpu = vcpu_load(kvm, tr->vcpu);
-        if (!vcpu)
-                return -ENOENT;
-        spin_lock(&kvm->lock);
+        vcpu_load(vcpu);
+        spin_lock(&vcpu->kvm->lock);
         gpa = vcpu->mmu.gva_to_gpa(vcpu, vaddr);
         tr->physical_address = gpa;
         tr->valid = gpa != UNMAPPED_GVA;
         tr->writeable = 1;
         tr->usermode = 0;
-        spin_unlock(&kvm->lock);
+        spin_unlock(&vcpu->kvm->lock);
         vcpu_put(vcpu);
 
         return 0;
 }
 
-static int kvm_vm_ioctl_interrupt(struct kvm *kvm, struct kvm_interrupt *irq)
+static int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
+                                    struct kvm_interrupt *irq)
 {
-        struct kvm_vcpu *vcpu;
-
-        if (!valid_vcpu(irq->vcpu))
-                return -EINVAL;
         if (irq->irq < 0 || irq->irq >= 256)
                 return -EINVAL;
-        vcpu = vcpu_load(kvm, irq->vcpu);
-        if (!vcpu)
-                return -ENOENT;
+        vcpu_load(vcpu);
 
         set_bit(irq->irq, vcpu->irq_pending);
         set_bit(irq->irq / BITS_PER_LONG, &vcpu->irq_summary);
@@ -1894,17 +1865,12 @@ static int kvm_vm_ioctl_interrupt(struct kvm *kvm, struct kvm_interrupt *irq)
         return 0;
 }
 
-static int kvm_vm_ioctl_debug_guest(struct kvm *kvm,
-                                     struct kvm_debug_guest *dbg)
+static int kvm_vcpu_ioctl_debug_guest(struct kvm_vcpu *vcpu,
+                                      struct kvm_debug_guest *dbg)
 {
-        struct kvm_vcpu *vcpu;
         int r;
 
-        if (!valid_vcpu(dbg->vcpu))
-                return -EINVAL;
-        vcpu = vcpu_load(kvm, dbg->vcpu);
-        if (!vcpu)
-                return -ENOENT;
+        vcpu_load(vcpu);
 
         r = kvm_arch_ops->set_guest_debug(vcpu, dbg);
 
@@ -1913,6 +1879,59 @@ static int kvm_vm_ioctl_debug_guest(struct kvm *kvm,
         return r;
 }
 
+static int kvm_vcpu_release(struct inode *inode, struct file *filp)
+{
+        struct kvm_vcpu *vcpu = filp->private_data;
+
+        fput(vcpu->kvm->filp);
+        return 0;
+}
+
+static struct file_operations kvm_vcpu_fops = {
+        .release        = kvm_vcpu_release,
+        .unlocked_ioctl = kvm_vcpu_ioctl,
+        .compat_ioctl   = kvm_vcpu_ioctl,
+};
+
+/*
+ * Allocates an inode for the vcpu.
+ */
+static int create_vcpu_fd(struct kvm_vcpu *vcpu)
+{
+        int fd, r;
+        struct inode *inode;
+        struct file *file;
+
+        atomic_inc(&vcpu->kvm->filp->f_count);
+        inode = kvmfs_inode(&kvm_vcpu_fops);
+        if (IS_ERR(inode)) {
+                r = PTR_ERR(inode);
+                goto out1;
+        }
+
+        file = kvmfs_file(inode, vcpu);
+        if (IS_ERR(file)) {
+                r = PTR_ERR(file);
+                goto out2;
+        }
+
+        r = get_unused_fd();
+        if (r < 0)
+                goto out3;
+        fd = r;
+        fd_install(fd, file);
+
+        return fd;
+
+out3:
+        fput(file);
+out2:
+        iput(inode);
+out1:
+        fput(vcpu->kvm->filp);
+        return r;
+}
+
 /*
  * Creates some virtual cpus.  Good luck creating more than one.
  */
@@ -1955,7 +1974,11 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
         if (r < 0)
                 goto out_free_vcpus;
 
-        return 0;
+        r = create_vcpu_fd(vcpu);
+        if (r < 0)
+                goto out_free_vcpus;
+
+        return r;
 
 out_free_vcpus:
         kvm_free_vcpu(vcpu);
@@ -1964,26 +1987,21 @@ out:
         return r;
 }
 
-static long kvm_vm_ioctl(struct file *filp,
-                         unsigned int ioctl, unsigned long arg)
+static long kvm_vcpu_ioctl(struct file *filp,
+                           unsigned int ioctl, unsigned long arg)
 {
-        struct kvm *kvm = filp->private_data;
+        struct kvm_vcpu *vcpu = filp->private_data;
         void __user *argp = (void __user *)arg;
         int r = -EINVAL;
 
         switch (ioctl) {
-        case KVM_CREATE_VCPU:
-                r = kvm_vm_ioctl_create_vcpu(kvm, arg);
-                if (r)
-                        goto out;
-                break;
         case KVM_RUN: {
                 struct kvm_run kvm_run;
 
                 r = -EFAULT;
                 if (copy_from_user(&kvm_run, argp, sizeof kvm_run))
                         goto out;
-                r = kvm_vm_ioctl_run(kvm, &kvm_run);
+                r = kvm_vcpu_ioctl_run(vcpu, &kvm_run);
                 if (r < 0 &&  r != -EINTR)
                         goto out;
                 if (copy_to_user(argp, &kvm_run, sizeof kvm_run)) {
@@ -1995,10 +2013,8 @@ static long kvm_vm_ioctl(struct file *filp,
         case KVM_GET_REGS: {
                 struct kvm_regs kvm_regs;
 
-                r = -EFAULT;
-                if (copy_from_user(&kvm_regs, argp, sizeof kvm_regs))
-                        goto out;
-                r = kvm_vm_ioctl_get_regs(kvm, &kvm_regs);
+                memset(&kvm_regs, 0, sizeof kvm_regs);
+                r = kvm_vcpu_ioctl_get_regs(vcpu, &kvm_regs);
                 if (r)
                         goto out;
                 r = -EFAULT;
@@ -2013,7 +2029,7 @@ static long kvm_vm_ioctl(struct file *filp,
                 r = -EFAULT;
                 if (copy_from_user(&kvm_regs, argp, sizeof kvm_regs))
                         goto out;
-                r = kvm_vm_ioctl_set_regs(kvm, &kvm_regs);
+                r = kvm_vcpu_ioctl_set_regs(vcpu, &kvm_regs);
                 if (r)
                         goto out;
                 r = 0;
@@ -2022,10 +2038,8 @@ static long kvm_vm_ioctl(struct file *filp,
         case KVM_GET_SREGS: {
                 struct kvm_sregs kvm_sregs;
 
-                r = -EFAULT;
-                if (copy_from_user(&kvm_sregs, argp, sizeof kvm_sregs))
-                        goto out;
-                r = kvm_vm_ioctl_get_sregs(kvm, &kvm_sregs);
+                memset(&kvm_sregs, 0, sizeof kvm_sregs);
+                r = kvm_vcpu_ioctl_get_sregs(vcpu, &kvm_sregs);
                 if (r)
                         goto out;
                 r = -EFAULT;
@@ -2040,7 +2054,7 @@ static long kvm_vm_ioctl(struct file *filp,
                 r = -EFAULT;
                 if (copy_from_user(&kvm_sregs, argp, sizeof kvm_sregs))
                         goto out;
-                r = kvm_vm_ioctl_set_sregs(kvm, &kvm_sregs);
+                r = kvm_vcpu_ioctl_set_sregs(vcpu, &kvm_sregs);
                 if (r)
                         goto out;
                 r = 0;
@@ -2052,7 +2066,7 @@ static long kvm_vm_ioctl(struct file *filp,
                 r = -EFAULT;
                 if (copy_from_user(&tr, argp, sizeof tr))
                         goto out;
-                r = kvm_vm_ioctl_translate(kvm, &tr);
+                r = kvm_vcpu_ioctl_translate(vcpu, &tr);
                 if (r)
                         goto out;
                 r = -EFAULT;
@@ -2067,7 +2081,7 @@ static long kvm_vm_ioctl(struct file *filp,
                 r = -EFAULT;
                 if (copy_from_user(&irq, argp, sizeof irq))
                         goto out;
-                r = kvm_vm_ioctl_interrupt(kvm, &irq);
+                r = kvm_vcpu_ioctl_interrupt(vcpu, &irq);
                 if (r)
                         goto out;
                 r = 0;
@@ -2079,12 +2093,38 @@ static long kvm_vm_ioctl(struct file *filp,
                 r = -EFAULT;
                 if (copy_from_user(&dbg, argp, sizeof dbg))
                         goto out;
-                r = kvm_vm_ioctl_debug_guest(kvm, &dbg);
+                r = kvm_vcpu_ioctl_debug_guest(vcpu, &dbg);
                 if (r)
                         goto out;
                 r = 0;
                 break;
         }
+        case KVM_GET_MSRS:
+                r = msr_io(vcpu, argp, get_msr, 1);
+                break;
+        case KVM_SET_MSRS:
+                r = msr_io(vcpu, argp, do_set_msr, 0);
+                break;
+        default:
+                ;
+        }
+out:
+        return r;
+}
+
+static long kvm_vm_ioctl(struct file *filp,
+                           unsigned int ioctl, unsigned long arg)
+{
+        struct kvm *kvm = filp->private_data;
+        void __user *argp = (void __user *)arg;
+        int r = -EINVAL;
+
+        switch (ioctl) {
+        case KVM_CREATE_VCPU:
+                r = kvm_vm_ioctl_create_vcpu(kvm, arg);
+                if (r < 0)
+                        goto out;
+                break;
         case KVM_SET_MEMORY_REGION: {
                 struct kvm_memory_region kvm_mem;
 
@@ -2107,12 +2147,6 @@ static long kvm_vm_ioctl(struct file *filp,
                         goto out;
                 break;
         }
-        case KVM_GET_MSRS:
-                r = msr_io(kvm, argp, get_msr, 1);
-                break;
-        case KVM_SET_MSRS:
-                r = msr_io(kvm, argp, do_set_msr, 0);
-                break;
         default:
                 ;
         }
@@ -2182,6 +2216,7 @@ static int kvm_dev_ioctl_create_vm(void)
                 r = PTR_ERR(file);
                 goto out3;
         }
+        kvm->filp = file;
 
         r = get_unused_fd();
         if (r < 0)
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 5a200c0b4b48..3d8ea7ac2ecc 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -600,10 +600,9 @@ static void svm_free_vcpu(struct kvm_vcpu *vcpu)
         kfree(vcpu->svm);
 }
 
-static struct kvm_vcpu *svm_vcpu_load(struct kvm_vcpu *vcpu)
+static void svm_vcpu_load(struct kvm_vcpu *vcpu)
 {
         get_cpu();
-        return vcpu;
 }
 
 static void svm_vcpu_put(struct kvm_vcpu *vcpu)
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index ff956a6302ec..c07178e61122 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -204,7 +204,7 @@ static void vmcs_write64(unsigned long field, u64 value)
  * Switches to specified vcpu, until a matching vcpu_put(), but assumes
  * vcpu mutex is already taken.
  */
-static struct kvm_vcpu *vmx_vcpu_load(struct kvm_vcpu *vcpu)
+static void vmx_vcpu_load(struct kvm_vcpu *vcpu)
 {
         u64 phys_addr = __pa(vcpu->vmcs);
         int cpu;
@@ -242,7 +242,6 @@ static struct kvm_vcpu *vmx_vcpu_load(struct kvm_vcpu *vcpu)
                 rdmsrl(MSR_IA32_SYSENTER_ESP, sysenter_esp);
                 vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */
         }
-        return vcpu;
 }
 
 static void vmx_vcpu_put(struct kvm_vcpu *vcpu)