From 1755fbcc6666906cada43c1c839ca1fc6616d4a6 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Wed, 21 Nov 2007 14:44:45 +0200 Subject: [PATCH] KVM: MMU: Introduce gfn_to_gpa() Converting a frame number to an address is tricky since the data type changes size. Introduce a function to do it. This fixes an actual bug when accessing guest ptes. Signed-off-by: Avi Kivity --- drivers/kvm/kvm.h | 4 ++++ drivers/kvm/paging_tmpl.h | 4 ++-- 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h index 048849d97b35..eda82cded88e 100644 --- a/drivers/kvm/kvm.h +++ b/drivers/kvm/kvm.h @@ -499,6 +499,10 @@ static inline int memslot_id(struct kvm *kvm, struct kvm_memory_slot *slot) return slot - kvm->memslots; } +static inline gpa_t gfn_to_gpa(gfn_t gfn) +{ + return (gpa_t)gfn << PAGE_SHIFT; +} enum kvm_stat_kind { KVM_STAT_VM, diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h index a3da98bfd6a6..b24bc7c86078 100644 --- a/drivers/kvm/paging_tmpl.h +++ b/drivers/kvm/paging_tmpl.h @@ -110,7 +110,7 @@ static int FNAME(walk_addr)(struct guest_walker *walker, index = PT_INDEX(addr, walker->level); table_gfn = gpte_to_gfn(pte); - pte_gpa = table_gfn << PAGE_SHIFT; + pte_gpa = gfn_to_gpa(table_gfn); pte_gpa += index * sizeof(pt_element_t); walker->table_gfn[walker->level - 1] = table_gfn; pgprintk("%s: table_gfn[%d] %lx\n", __FUNCTION__, @@ -442,7 +442,7 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr) r = FNAME(walk_addr)(&walker, vcpu, vaddr, 0, 0, 0); if (r) { - gpa = (gpa_t)walker.gfn << PAGE_SHIFT; + gpa = gfn_to_gpa(walker.gfn); gpa |= vaddr & ~PAGE_MASK; }