3 files changed, 83 insertions, 11 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index ec5b498945ae..3eaed4dafec7 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -408,6 +408,7 @@ struct kvm_memory_slot {
         struct page **phys_mem;
         unsigned long *rmap;
         unsigned long *dirty_bitmap;
+        int user_alloc; /* user allocated memory */
 };
 
 struct kvm {
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index a1983d2d5b8f..22b143feb66d 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -40,6 +40,7 @@
 #include <linux/anon_inodes.h>
 #include <linux/profile.h>
 #include <linux/kvm_para.h>
+#include <linux/pagemap.h>
 
 #include <asm/processor.h>
 #include <asm/msr.h>
@@ -300,19 +301,40 @@ static struct kvm *kvm_create_vm(void)
         return kvm;
 }
 
+static void kvm_free_userspace_physmem(struct kvm_memory_slot *free)
+{
+        int i;
+
+        for (i = 0; i < free->npages; ++i) {
+                if (free->phys_mem[i]) {
+                        if (!PageReserved(free->phys_mem[i]))
+                                SetPageDirty(free->phys_mem[i]);
+                        page_cache_release(free->phys_mem[i]);
+                }
+        }
+}
+
+static void kvm_free_kernel_physmem(struct kvm_memory_slot *free)
+{
+        int i;
+
+        for (i = 0; i < free->npages; ++i)
+                if (free->phys_mem[i])
+                        __free_page(free->phys_mem[i]);
+}
+
 /*
  * Free any memory in @free but not in @dont.
  */
 static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
                                   struct kvm_memory_slot *dont)
 {
-        int i;
-
         if (!dont || free->phys_mem != dont->phys_mem)
                 if (free->phys_mem) {
-                        for (i = 0; i < free->npages; ++i)
-                                if (free->phys_mem[i])
-                                        __free_page(free->phys_mem[i]);
+                        if (free->user_alloc)
+                                kvm_free_userspace_physmem(free);
+                        else
+                                kvm_free_kernel_physmem(free);
                         vfree(free->phys_mem);
                 }
         if (!dont || free->rmap != dont->rmap)
@@ -652,7 +674,9 @@ EXPORT_SYMBOL_GPL(fx_init);
  * Discontiguous memory is allowed, mostly for framebuffers.
  */
 static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
-                                          struct kvm_memory_region *mem)
+                                          struct
+                                          kvm_userspace_memory_region *mem,
+                                          int user_alloc)
 {
         int r;
         gfn_t base_gfn;
@@ -728,11 +752,27 @@ static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
 
                 memset(new.phys_mem, 0, npages * sizeof(struct page *));
                 memset(new.rmap, 0, npages * sizeof(*new.rmap));
-                for (i = 0; i < npages; ++i) {
-                        new.phys_mem[i] = alloc_page(GFP_HIGHUSER
-                                                     | __GFP_ZERO);
-                        if (!new.phys_mem[i])
+                if (user_alloc) {
+                        unsigned long pages_num;
+
+                        new.user_alloc = 1;
+                        down_read(&current->mm->mmap_sem);
+
+                        pages_num = get_user_pages(current, current->mm,
+                                                   mem->userspace_addr,
+                                                   npages, 1, 1, new.phys_mem,
+                                                   NULL);
+
+                        up_read(&current->mm->mmap_sem);
+                        if (pages_num != npages)
                                 goto out_unlock;
+                } else {
+                        for (i = 0; i < npages; ++i) {
+                                new.phys_mem[i] = alloc_page(GFP_HIGHUSER
+                                                             | __GFP_ZERO);
+                                if (!new.phys_mem[i])
+                                        goto out_unlock;
+                        }
                 }
         }
 
@@ -3108,11 +3148,29 @@ static long kvm_vm_ioctl(struct file *filp,
                 break;
         case KVM_SET_MEMORY_REGION: {
                 struct kvm_memory_region kvm_mem;
+                struct kvm_userspace_memory_region kvm_userspace_mem;
 
                 r = -EFAULT;
                 if (copy_from_user(&kvm_mem, argp, sizeof kvm_mem))
                         goto out;
-                r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_mem);
+                kvm_userspace_mem.slot = kvm_mem.slot;
+                kvm_userspace_mem.flags = kvm_mem.flags;
+                kvm_userspace_mem.guest_phys_addr = kvm_mem.guest_phys_addr;
+                kvm_userspace_mem.memory_size = kvm_mem.memory_size;
+                r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem, 0);
+                if (r)
+                        goto out;
+                break;
+        }
+        case KVM_SET_USER_MEMORY_REGION: {
+                struct kvm_userspace_memory_region kvm_userspace_mem;
+
+                r = -EFAULT;
+                if (copy_from_user(&kvm_userspace_mem, argp,
+                                                sizeof kvm_userspace_mem))
+                        goto out;
+
+                r = kvm_vm_ioctl_set_memory_region(kvm, &kvm_userspace_mem, 1);
                 if (r)
                         goto out;
                 break;
@@ -3332,6 +3390,7 @@ static long kvm_dev_ioctl(struct file *filp,
                 case KVM_CAP_IRQCHIP:
                 case KVM_CAP_HLT:
                 case KVM_CAP_MMU_SHADOW_CACHE_CONTROL:
+                case KVM_CAP_USER_MEMORY:
                         r = 1;
                         break;
                 default:
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index d2fd973d81fe..971f465e26fa 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -23,6 +23,15 @@ struct kvm_memory_region {
         __u64 memory_size; /* bytes */
 };
 
+/* for KVM_SET_USER_MEMORY_REGION */
+struct kvm_userspace_memory_region {
+        __u32 slot;
+        __u32 flags;
+        __u64 guest_phys_addr;
+        __u64 memory_size; /* bytes */
+        __u64 userspace_addr; /* start of the userspace allocated memory */
+};
+
 /* for kvm_memory_region::flags */
 #define KVM_MEM_LOG_DIRTY_PAGES  1UL
 
@@ -348,6 +357,7 @@ struct kvm_signal_mask {
 #define KVM_CAP_IRQCHIP   0
 #define KVM_CAP_HLT       1
 #define KVM_CAP_MMU_SHADOW_CACHE_CONTROL 2
+#define KVM_CAP_USER_MEMORY 3
 
 /*
  * ioctls for VM fds
@@ -355,6 +365,8 @@ struct kvm_signal_mask {
 #define KVM_SET_MEMORY_REGION     _IOW(KVMIO, 0x40, struct kvm_memory_region)
 #define KVM_SET_NR_MMU_PAGES      _IO(KVMIO, 0x44)
 #define KVM_GET_NR_MMU_PAGES      _IO(KVMIO, 0x45)
+#define KVM_SET_USER_MEMORY_REGION _IOW(KVMIO, 0x46,\
+                                        struct kvm_userspace_memory_region)
 /*
  * KVM_CREATE_VCPU receives as a parameter the vcpu slot, and returns
  * a vcpu fd.