[Qemu-devel] [patch 3/3] kvm: allow qemu to set EPT identity mapping address

[Marcelo Tosatti <mtosatti@redhat.com>]

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From: Sheng Yang <sheng@linux.intel.com>

If we use larger BIOS image than current 256KB, we would need move reserved
TSS and EPT identity mapping pages. Currently TSS support this, but not
EPT.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Index: qemu-kvm/target-i386/kvm.c
===================================================================
--- qemu-kvm.orig/target-i386/kvm.c
+++ qemu-kvm/target-i386/kvm.c
@@ -341,6 +341,24 @@ static int kvm_has_msr_star(CPUState *en
     return 0;
 }
 
+static int kvm_init_identity_map_page(KVMState *s)
+{
+#ifdef KVM_CAP_SET_IDENTITY_MAP_ADDR
+    int ret;
+    uint64_t addr = 0xfffbc000;
+
+    if (!kvm_check_extension(s, KVM_CAP_SET_IDENTITY_MAP_ADDR))
+        return 0;
+
+    ret = kvm_vm_ioctl(s, KVM_SET_IDENTITY_MAP_ADDR, &addr);
+    if (ret < 0) {
+        fprintf(stderr, "kvm_set_identity_map_addr: %s\n", strerror(ret));
+        return ret;
+    }
+#endif
+    return 0;
+}
+
 int kvm_arch_init(KVMState *s, int smp_cpus)
 {
     int ret;
@@ -368,7 +386,11 @@ int kvm_arch_init(KVMState *s, int smp_c
         perror("e820_add_entry() table is full");
         exit(1);
     }
-    return kvm_vm_ioctl(s, KVM_SET_TSS_ADDR, 0xfffbd000);
+    ret = kvm_vm_ioctl(s, KVM_SET_TSS_ADDR, 0xfffbd000);
+    if (ret < 0)
+        return ret;
+
+    return kvm_init_identity_map_page(s);
 }
                     
 static void set_v8086_seg(struct kvm_segment *lhs, const SegmentCache *rhs)