From fb03cb6f44236f4bef62a0dda8e025ff5ca51417 Mon Sep 17 00:00:00 2001
From: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Date: Wed, 8 Feb 2012 12:59:10 +0900
Subject: [PATCH] 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>
---
arch/x86/kvm/mmu.c | 3 +--
include/linux/kvm_host.h | 7 +++++++
virt/kvm/kvm_main.c | 7 +------
3 files changed, 9 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index ae76cc3392e1..37e7f100a0e0 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -688,8 +688,7 @@ static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn,
{
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 9698080c902b..7a08496b974a 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -681,6 +681,13 @@ static inline int memslot_id(struct kvm *kvm, gfn_t gfn)
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 470e30520fe8..415fe816fc15 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -784,15 +784,10 @@ int __kvm_set_memory_region(struct kvm *kvm,
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]));
--
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