KVM: VMX: Introduce KVM_SET_IDENTITY_MAP_ADDR ioctl
Now KVM allow guest to modify guest's physical address of EPT's identity mapping page.
(change from v1, discard unnecessary check, change ioctl to accept parameter
address rather than value)
Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c6256b9..686e1ab 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -1719,7 +1719,7 @@
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 @@
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 @@
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 @@
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;