KVM: Simply gfn_to_page()

[linux-block.git] / drivers / kvm / kvm_main.c

diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 33eade7e237c4072f57f4ff0f75f8d3a6607e504..a0ec5dda330547d983cd5548b18c423713a136ed 100644 (file)
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -420,12 +420,12 @@ static int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3)
        u64 pdpte;
        u64 *pdpt;
        int ret;
-       struct kvm_memory_slot *memslot;
+       struct page *page;
 
        spin_lock(&vcpu->kvm->lock);
-       memslot = gfn_to_memslot(vcpu->kvm, pdpt_gfn);
-       /* FIXME: !memslot - emulate? 0xff? */
-       pdpt = kmap_atomic(gfn_to_page(memslot, pdpt_gfn), KM_USER0);
+       page = gfn_to_page(vcpu->kvm, pdpt_gfn);
+       /* FIXME: !page - emulate? 0xff? */
+       pdpt = kmap_atomic(page, KM_USER0);
 
        ret = 1;
        for (i = 0; i < 4; ++i) {
@@ -861,6 +861,17 @@ struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn)
 }
 EXPORT_SYMBOL_GPL(gfn_to_memslot);
 
+struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn)
+{
+       struct kvm_memory_slot *slot;
+
+       slot = gfn_to_memslot(kvm, gfn);
+       if (!slot)
+               return NULL;
+       return slot->phys_mem[gfn - slot->base_gfn];
+}
+EXPORT_SYMBOL_GPL(gfn_to_page);
+
 void mark_page_dirty(struct kvm *kvm, gfn_t gfn)
 {
        int i;
@@ -899,20 +910,20 @@ static int emulator_read_std(unsigned long addr,
                unsigned offset = addr & (PAGE_SIZE-1);
                unsigned tocopy = min(bytes, (unsigned)PAGE_SIZE - offset);
                unsigned long pfn;
-               struct kvm_memory_slot *memslot;
-               void *page;
+               struct page *page;
+               void *page_virt;
 
                if (gpa == UNMAPPED_GVA)
                        return X86EMUL_PROPAGATE_FAULT;
                pfn = gpa >> PAGE_SHIFT;
-               memslot = gfn_to_memslot(vcpu->kvm, pfn);
-               if (!memslot)
+               page = gfn_to_page(vcpu->kvm, pfn);
+               if (!page)
                        return X86EMUL_UNHANDLEABLE;
-               page = kmap_atomic(gfn_to_page(memslot, pfn), KM_USER0);
+               page_virt = kmap_atomic(page, KM_USER0);
 
-               memcpy(data, page + offset, tocopy);
+               memcpy(data, page_virt + offset, tocopy);
 
-               kunmap_atomic(page, KM_USER0);
+               kunmap_atomic(page_virt, KM_USER0);
 
                bytes -= tocopy;
                data += tocopy;
@@ -963,16 +974,14 @@ static int emulator_read_emulated(unsigned long addr,
 static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
                               unsigned long val, int bytes)
 {
-       struct kvm_memory_slot *m;
        struct page *page;
        void *virt;
 
        if (((gpa + bytes - 1) >> PAGE_SHIFT) != (gpa >> PAGE_SHIFT))
                return 0;
-       m = gfn_to_memslot(vcpu->kvm, gpa >> PAGE_SHIFT);
-       if (!m)
+       page = gfn_to_page(vcpu->kvm, gpa >> PAGE_SHIFT);
+       if (!page)
                return 0;
-       page = gfn_to_page(m, gpa >> PAGE_SHIFT);
        kvm_mmu_pre_write(vcpu, gpa, bytes);
        mark_page_dirty(vcpu->kvm, gpa >> PAGE_SHIFT);
        virt = kmap_atomic(page, KM_USER0);
@@ -2516,15 +2525,11 @@ static struct page *kvm_vm_nopage(struct vm_area_struct *vma,
 {
        struct kvm *kvm = vma->vm_file->private_data;
        unsigned long pgoff;
-       struct kvm_memory_slot *slot;
        struct page *page;
 
        *type = VM_FAULT_MINOR;
        pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
-       slot = gfn_to_memslot(kvm, pgoff);
-       if (!slot)
-               return NOPAGE_SIGBUS;
-       page = gfn_to_page(slot, pgoff);
+       page = gfn_to_page(kvm, pgoff);
        if (!page)
                return NOPAGE_SIGBUS;
        get_page(page);