x86/VT-x: Fix determination of EFER.LMA in vmcs_dump_vcpu()

The LMA setting comes from the entry controls.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Kevin Tian <kevin.tian@intel.com>
Release-acked-by: Juergen Gross <jgross@suse.com>

xen/arch/x86/hvm/vmx/vmcs.c

@@ -1788,7 +1788,10 @@ void vmcs_dump_vcpu(struct vcpu *v)
     vmentry_ctl = vmr32(VM_ENTRY_CONTROLS),
     vmexit_ctl = vmr32(VM_EXIT_CONTROLS);
     cr4 = vmr(GUEST_CR4);
-    efer = vmr(GUEST_EFER);
+
+    /* EFER.LMA is read as zero, and is loaded from vmentry_ctl on entry. */
+    BUILD_BUG_ON(VM_ENTRY_IA32E_MODE << 1 != EFER_LMA);
+    efer = vmr(GUEST_EFER) | ((vmentry_ctl & VM_ENTRY_IA32E_MODE) << 1);
 
     printk("*** Guest State ***\n");
     printk("CR0: actual=0x%016lx, shadow=0x%016lx, gh_mask=%016lx\n",