KVM: Introduce kvm_memory_slot::arch and move lpage_info into it

Some members of kvm_memory_slot are not used by every architecture.

This patch is the first step to make this difference clear by
introducing kvm_memory_slot::arch;  lpage_info is moved into it.

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>

2 files changed, 60 insertions, 1 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 37e7f100a0e0..ff053ca32303 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -689,7 +689,7 @@ static struct kvm_lpage_info *lpage_info_slot(gfn_t gfn,
         unsigned long idx;
 
         idx = gfn_to_index(gfn, slot->base_gfn, level);
-        return &slot->lpage_info[level - 2][idx];
+        return &slot->arch.lpage_info[level - 2][idx];
 }
 
 static void account_shadowed(struct kvm *kvm, gfn_t gfn)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 3df0b7a140b0..ca74c1dadf3a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6239,6 +6239,65 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
                 put_page(kvm->arch.ept_identity_pagetable);
 }
 
+void kvm_arch_free_memslot(struct kvm_memory_slot *free,
+                           struct kvm_memory_slot *dont)
+{
+        int i;
+
+        for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
+                if (!dont || free->arch.lpage_info[i] != dont->arch.lpage_info[i]) {
+                        vfree(free->arch.lpage_info[i]);
+                        free->arch.lpage_info[i] = NULL;
+                }
+        }
+}
+
+int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages)
+{
+        int i;
+
+        for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
+                unsigned long ugfn;
+                int lpages;
+                int level = i + 2;
+
+                lpages = gfn_to_index(slot->base_gfn + npages - 1,
+                                      slot->base_gfn, level) + 1;
+
+                slot->arch.lpage_info[i] =
+                        vzalloc(lpages * sizeof(*slot->arch.lpage_info[i]));
+                if (!slot->arch.lpage_info[i])
+                        goto out_free;
+
+                if (slot->base_gfn & (KVM_PAGES_PER_HPAGE(level) - 1))
+                        slot->arch.lpage_info[i][0].write_count = 1;
+                if ((slot->base_gfn + npages) & (KVM_PAGES_PER_HPAGE(level) - 1))
+                        slot->arch.lpage_info[i][lpages - 1].write_count = 1;
+                ugfn = slot->userspace_addr >> PAGE_SHIFT;
+                /*
+                 * If the gfn and userspace address are not aligned wrt each
+                 * other, or if explicitly asked to, disable large page
+                 * support for this slot
+                 */
+                if ((slot->base_gfn ^ ugfn) & (KVM_PAGES_PER_HPAGE(level) - 1) ||
+                    !kvm_largepages_enabled()) {
+                        unsigned long j;
+
+                        for (j = 0; j < lpages; ++j)
+                                slot->arch.lpage_info[i][j].write_count = 1;
+                }
+        }
+
+        return 0;
+
+out_free:
+        for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
+                vfree(slot->arch.lpage_info[i]);
+                slot->arch.lpage_info[i] = NULL;
+        }
+        return -ENOMEM;
+}
+
 int kvm_arch_prepare_memory_region(struct kvm *kvm,
                                 struct kvm_memory_slot *memslot,
                                 struct kvm_memory_slot old,