4 files changed, 32 insertions, 5 deletions

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 08732d7b6d98..e210b218df44 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -411,6 +411,7 @@ struct kvm_arch{
 
         struct page *ept_identity_pagetable;
         bool ept_identity_pagetable_done;
+        gpa_t ept_identity_map_addr;
 
         unsigned long irq_sources_bitmap;
         unsigned long irq_states[KVM_IOAPIC_NUM_PINS];
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c6256b98f078..686e1abb6816 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1719,7 +1719,7 @@ static void vmx_set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
                 eptp = construct_eptp(cr3);
                 vmcs_write64(EPT_POINTER, eptp);
                 guest_cr3 = is_paging(vcpu) ? vcpu->arch.cr3 :
-                        VMX_EPT_IDENTITY_PAGETABLE_ADDR;
+                        vcpu->kvm->arch.ept_identity_map_addr;
         }
 
         vmx_flush_tlb(vcpu);
@@ -2122,7 +2122,7 @@ static int init_rmode_identity_map(struct kvm *kvm)
         if (likely(kvm->arch.ept_identity_pagetable_done))
                 return 1;
         ret = 0;
-        identity_map_pfn = VMX_EPT_IDENTITY_PAGETABLE_ADDR >> PAGE_SHIFT;
+        identity_map_pfn = kvm->arch.ept_identity_map_addr >> PAGE_SHIFT;
         r = kvm_clear_guest_page(kvm, identity_map_pfn, 0, PAGE_SIZE);
         if (r < 0)
                 goto out;
@@ -2191,14 +2191,15 @@ static int alloc_identity_pagetable(struct kvm *kvm)
                 goto out;
         kvm_userspace_mem.slot = IDENTITY_PAGETABLE_PRIVATE_MEMSLOT;
         kvm_userspace_mem.flags = 0;
-        kvm_userspace_mem.guest_phys_addr = VMX_EPT_IDENTITY_PAGETABLE_ADDR;
+        kvm_userspace_mem.guest_phys_addr =
+                kvm->arch.ept_identity_map_addr;
         kvm_userspace_mem.memory_size = PAGE_SIZE;
         r = __kvm_set_memory_region(kvm, &kvm_userspace_mem, 0);
         if (r)
                 goto out;
 
         kvm->arch.ept_identity_pagetable = gfn_to_page(kvm,
-                        VMX_EPT_IDENTITY_PAGETABLE_ADDR >> PAGE_SHIFT);
+                        kvm->arch.ept_identity_map_addr >> PAGE_SHIFT);
 out:
         up_write(&kvm->slots_lock);
         return r;
@@ -3814,9 +3815,13 @@ static struct kvm_vcpu *vmx_create_vcpu(struct kvm *kvm, unsigned int id)
                 if (alloc_apic_access_page(kvm) != 0)
                         goto free_vmcs;
 
-        if (enable_ept)
+        if (enable_ept) {
+                if (!kvm->arch.ept_identity_map_addr)
+                        kvm->arch.ept_identity_map_addr =
+                                VMX_EPT_IDENTITY_PAGETABLE_ADDR;
                 if (alloc_identity_pagetable(kvm) != 0)
                         goto free_vmcs;
+        }
 
         return &vmx->vcpu;
 
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c7ec0c921c01..f4cb1baaa04b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1206,6 +1206,7 @@ int kvm_dev_ioctl_check_extension(long ext)
         case KVM_CAP_IOEVENTFD:
         case KVM_CAP_PIT2:
         case KVM_CAP_PIT_STATE2:
+        case KVM_CAP_SET_IDENTITY_MAP_ADDR:
                 r = 1;
                 break;
         case KVM_CAP_COALESCED_MMIO:
@@ -1906,6 +1907,13 @@ static int kvm_vm_ioctl_set_tss_addr(struct kvm *kvm, unsigned long addr)
         return ret;
 }
 
+static int kvm_vm_ioctl_set_identity_map_addr(struct kvm *kvm,
+                                              u64 ident_addr)
+{
+        kvm->arch.ept_identity_map_addr = ident_addr;
+        return 0;
+}
+
 static int kvm_vm_ioctl_set_nr_mmu_pages(struct kvm *kvm,
                                           u32 kvm_nr_mmu_pages)
 {
@@ -2173,6 +2181,17 @@ long kvm_arch_vm_ioctl(struct file *filp,
                 if (r < 0)
                         goto out;
                 break;
+        case KVM_SET_IDENTITY_MAP_ADDR: {
+                u64 ident_addr;
+
+                r = -EFAULT;
+                if (copy_from_user(&ident_addr, argp, sizeof ident_addr))
+                        goto out;
+                r = kvm_vm_ioctl_set_identity_map_addr(kvm, ident_addr);
+                if (r < 0)
+                        goto out;
+                break;
+        }
         case KVM_SET_MEMORY_REGION: {
                 struct kvm_memory_region kvm_mem;
                 struct kvm_userspace_memory_region kvm_userspace_mem;
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 230a91aa61c9..f8f8900fc5ec 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -435,6 +435,7 @@ struct kvm_ioeventfd {
 #define KVM_CAP_PIT_STATE2 35
 #endif
 #define KVM_CAP_IOEVENTFD 36
+#define KVM_CAP_SET_IDENTITY_MAP_ADDR 37
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -512,6 +513,7 @@ struct kvm_irqfd {
 #define KVM_SET_USER_MEMORY_REGION _IOW(KVMIO, 0x46,\
                                         struct kvm_userspace_memory_region)
 #define KVM_SET_TSS_ADDR          _IO(KVMIO, 0x47)
+#define KVM_SET_IDENTITY_MAP_ADDR _IOW(KVMIO, 0x48, __u64)
 /* Device model IOC */
 #define KVM_CREATE_IRQCHIP        _IO(KVMIO,  0x60)
 #define KVM_IRQ_LINE              _IOW(KVMIO, 0x61, struct kvm_irq_level)