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authorJoerg Roedel <joerg.roedel@amd.com>2010-07-01 16:00:11 +0200
committerAvi Kivity <avi@redhat.com>2010-08-01 10:47:30 +0300
commit828554136bbacae6e39fc31b9cd7e7c660ad7530 (patch)
tree4e2ec85ff33c9c1e7245e83ed8e4fa3791007ef7 /virt
parent95c87e2b4460a488ec7ce42f273893e410ab385a (diff)
downloadkernel-828554136bbacae6e39fc31b9cd7e7c660ad7530.tar.gz
KVM: Remove unnecessary divide operations
This patch converts unnecessary divide and modulo operations in the KVM large page related code into logical operations. This allows to convert gfn_t to u64 while not breaking 32 bit builds. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/kvm_main.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index ec2e3c6ac7ed..a60b6b053b6f 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -626,9 +626,9 @@ int __kvm_set_memory_region(struct kvm *kvm,
if (new.lpage_info[i])
continue;
- lpages = 1 + (base_gfn + npages - 1) /
- KVM_PAGES_PER_HPAGE(level);
- lpages -= base_gfn / KVM_PAGES_PER_HPAGE(level);
+ lpages = 1 + ((base_gfn + npages - 1)
+ >> KVM_HPAGE_GFN_SHIFT(level));
+ lpages -= base_gfn >> KVM_HPAGE_GFN_SHIFT(level);
new.lpage_info[i] = vmalloc(lpages * sizeof(*new.lpage_info[i]));
@@ -638,9 +638,9 @@ int __kvm_set_memory_region(struct kvm *kvm,
memset(new.lpage_info[i], 0,
lpages * sizeof(*new.lpage_info[i]));
- if (base_gfn % KVM_PAGES_PER_HPAGE(level))
+ if (base_gfn & (KVM_PAGES_PER_HPAGE(level) - 1))
new.lpage_info[i][0].write_count = 1;
- if ((base_gfn+npages) % KVM_PAGES_PER_HPAGE(level))
+ if ((base_gfn+npages) & (KVM_PAGES_PER_HPAGE(level) - 1))
new.lpage_info[i][lpages - 1].write_count = 1;
ugfn = new.userspace_addr >> PAGE_SHIFT;
/*