From patchwork Mon Jan 23 10:44:44 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [3/4] KVM: Introduce gfn_to_index() which returns the index for a given level Date: Mon, 23 Jan 2012 00:44:44 -0000 From: Takuya Yoshikawa X-Patchwork-Id: 137341 Message-Id: <20120123194444.800e8bfe.yoshikawa.takuya@oss.ntt.co.jp> To: avi@redhat.com, mtosatti@redhat.com Cc: kvm@vger.kernel.org, kvm-ppc@vger.kernel.org We can also use this for PT_PAGE_TABLE_LEVEL to treat every level uniformly. Signed-off-by: Takuya Yoshikawa --- arch/x86/kvm/mmu.c | 3 +-- include/linux/kvm_host.h | 7 +++++++ virt/kvm/kvm_main.c | 4 +--- 3 files changed, 9 insertions(+), 5 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 0e82d9d..12f5c99 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 eada8e6..06d4e41 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -656,6 +656,13 @@ 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 9f32bff..4f2574f 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -803,9 +803,7 @@ int __kvm_set_memory_region(struct kvm *kvm, 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]));