KVM: Increase mmu shadow cache to 1024 pages

This improves kbuild times by about 10%, bringing it within a respectable
25% of native.
Signed-off-by: NAvi Kivity <avi@qumranet.com>

drivers/kvm/kvm.h

@@ -54,7 +54,7 @@
 #define KVM_MAX_VCPUS 1
 #define KVM_ALIAS_SLOTS 4
 #define KVM_MEMORY_SLOTS 4
-#define KVM_NUM_MMU_PAGES 256
+#define KVM_NUM_MMU_PAGES 1024
 #define KVM_MIN_FREE_MMU_PAGES 5
 #define KVM_REFILL_PAGES 25
 #define KVM_MAX_CPUID_ENTRIES 40