KVM: Introduce gfn_to_index() which returns the index for a given level
This patch cleans up the code and removes the "(void)level;" warning
suppressor.
Note that we can also use this for PT_PAGE_TABLE_LEVEL to treat every
level uniformly later.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index ae76cc3..37e7f10 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -688,8 +688,7 @@
{
unsigned long idx;
- idx = (gfn >> KVM_HPAGE_GFN_SHIFT(level)) -
- (slot->base_gfn >> KVM_HPAGE_GFN_SHIFT(level));
+ idx = gfn_to_index(gfn, slot->base_gfn, level);
return &slot->lpage_info[level - 2][idx];
}
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 9698080..7a08496 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -681,6 +681,13 @@
return gfn_to_memslot(kvm, gfn)->id;
}
+static inline gfn_t gfn_to_index(gfn_t gfn, gfn_t base_gfn, int level)
+{
+ /* KVM_HPAGE_GFN_SHIFT(PT_PAGE_TABLE_LEVEL) must be 0. */
+ return (gfn >> KVM_HPAGE_GFN_SHIFT(level)) -
+ (base_gfn >> KVM_HPAGE_GFN_SHIFT(level));
+}
+
static inline unsigned long gfn_to_hva_memslot(struct kvm_memory_slot *slot,
gfn_t gfn)
{
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 470e305..415fe81 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -784,15 +784,10 @@
int lpages;
int level = i + 2;
- /* Avoid unused variable warning if no large pages */
- (void)level;
-
if (new.lpage_info[i])
continue;
- lpages = 1 + ((base_gfn + npages - 1)
- >> KVM_HPAGE_GFN_SHIFT(level));
- lpages -= base_gfn >> KVM_HPAGE_GFN_SHIFT(level);
+ lpages = gfn_to_index(base_gfn + npages - 1, base_gfn, level) + 1;
new.lpage_info[i] = vzalloc(lpages * sizeof(*new.lpage_info[i]));
