KVM: Use standard CR4 flags, tighten checking

On this machine (Intel), writing to the CR4 bits 0x00000800 and
0x00001000 cause a GPF.  The Intel manual is a little unclear, but
AFIACT they're reserved, too.

Also fix spelling of CR4_RESEVED_BITS.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index ebd93b4..f3e7818 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -764,7 +764,7 @@
 	if ((old & 5) != 5)
 		/* enable and lock */
 		wrmsrl(MSR_IA32_FEATURE_CONTROL, old | 5);
-	write_cr4(read_cr4() | CR4_VMXE); /* FIXME: not cpu hotplug safe */
+	write_cr4(read_cr4() | X86_CR4_VMXE); /* FIXME: not cpu hotplug safe */
 	asm volatile (ASM_VMX_VMXON_RAX : : "a"(&phys_addr), "m"(phys_addr)
 		      : "memory", "cc");
 }
@@ -879,8 +879,8 @@
 	flags |= (vcpu->rmode.save_iopl << IOPL_SHIFT);
 	vmcs_writel(GUEST_RFLAGS, flags);
 
-	vmcs_writel(GUEST_CR4, (vmcs_readl(GUEST_CR4) & ~CR4_VME_MASK) |
-			(vmcs_readl(CR4_READ_SHADOW) & CR4_VME_MASK));
+	vmcs_writel(GUEST_CR4, (vmcs_readl(GUEST_CR4) & ~X86_CR4_VME) |
+			(vmcs_readl(CR4_READ_SHADOW) & X86_CR4_VME));
 
 	update_exception_bitmap(vcpu);
 
@@ -937,7 +937,7 @@
 	flags |= IOPL_MASK | X86_EFLAGS_VM;
 
 	vmcs_writel(GUEST_RFLAGS, flags);
-	vmcs_writel(GUEST_CR4, vmcs_readl(GUEST_CR4) | CR4_VME_MASK);
+	vmcs_writel(GUEST_CR4, vmcs_readl(GUEST_CR4) | X86_CR4_VME);
 	update_exception_bitmap(vcpu);
 
 	vmcs_write16(GUEST_SS_SELECTOR, vmcs_readl(GUEST_SS_BASE) >> 4);