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>

11 files changed, 122 insertions, 68 deletions

diff --git a/arch/ia64/include/asm/kvm_host.h b/arch/ia64/include/asm/kvm_host.h
index 2689ee54a1c9..e35b3a84a40b 100644
--- a/arch/ia64/include/asm/kvm_host.h
+++ b/arch/ia64/include/asm/kvm_host.h
@@ -459,6 +459,9 @@ struct kvm_sal_data {
         unsigned long boot_gp;
 };
 
+struct kvm_arch_memory_slot {
+};
+
 struct kvm_arch {
         spinlock_t dirty_log_lock;
 
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 8ca7261e7b3d..d8ddbba6fe7d 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -1571,6 +1571,16 @@ int kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
         return VM_FAULT_SIGBUS;
 }
 
+void kvm_arch_free_memslot(struct kvm_memory_slot *free,
+                           struct kvm_memory_slot *dont)
+{
+}
+
+int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages)
+{
+        return 0;
+}
+
 int kvm_arch_prepare_memory_region(struct kvm *kvm,
                 struct kvm_memory_slot *memslot,
                 struct kvm_memory_slot old,
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 1843d5d2a3be..52eb9c1f4fe0 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -213,6 +213,9 @@ struct revmap_entry {
 #define KVMPPC_PAGE_WRITETHRU   HPTE_R_W        /* 0x40 */
 #define KVMPPC_GOT_PAGE         0x80
 
+struct kvm_arch_memory_slot {
+};
+
 struct kvm_arch {
 #ifdef CONFIG_KVM_BOOK3S_64_HV
         unsigned long hpt_virt;
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 0e21d155eea7..00d7e345b3fe 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -281,6 +281,16 @@ long kvm_arch_dev_ioctl(struct file *filp,
         return -EINVAL;
 }
 
+void kvm_arch_free_memslot(struct kvm_memory_slot *free,
+                           struct kvm_memory_slot *dont)
+{
+}
+
+int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages)
+{
+        return 0;
+}
+
 int kvm_arch_prepare_memory_region(struct kvm *kvm,
                                    struct kvm_memory_slot *memslot,
                                    struct kvm_memory_slot old,
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index e6304268ea28..7343872890a2 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -245,6 +245,9 @@ struct kvm_vm_stat {
         u32 remote_tlb_flush;
 };
 
+struct kvm_arch_memory_slot {
+};
+
 struct kvm_arch{
         struct sca_block *sca;
         debug_info_t *dbf;
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index cf3c0a91d046..17ad69d596fd 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -814,6 +814,16 @@ int kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
         return VM_FAULT_SIGBUS;
 }
 
+void kvm_arch_free_memslot(struct kvm_memory_slot *free,
+                           struct kvm_memory_slot *dont)
+{
+}
+
+int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages)
+{
+        return 0;
+}
+
 /* Section: memory related */
 int kvm_arch_prepare_memory_region(struct kvm *kvm,
                                    struct kvm_memory_slot *memslot,
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c24125cd0c63..74c9edf2bb18 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -483,6 +483,15 @@ struct kvm_vcpu_arch {
         } osvw;
 };
 
+struct kvm_lpage_info {
+        unsigned long rmap_pde;
+        int write_count;
+};
+
+struct kvm_arch_memory_slot {
+        struct kvm_lpage_info *lpage_info[KVM_NR_PAGE_SIZES - 1];
+};
+
 struct kvm_arch {
         unsigned int n_used_mmu_pages;
         unsigned int n_requested_mmu_pages;
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,
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 7a08496b974a..355e44555c39 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -171,11 +171,6 @@ static inline int kvm_vcpu_exiting_guest_mode(struct kvm_vcpu *vcpu)
  */
 #define KVM_MEM_MAX_NR_PAGES ((1UL << 31) - 1)
 
-struct kvm_lpage_info {
-        unsigned long rmap_pde;
-        int write_count;
-};
-
 struct kvm_memory_slot {
         gfn_t base_gfn;
         unsigned long npages;
@@ -184,7 +179,7 @@ struct kvm_memory_slot {
         unsigned long *dirty_bitmap;
         unsigned long *dirty_bitmap_head;
         unsigned long nr_dirty_pages;
-        struct kvm_lpage_info *lpage_info[KVM_NR_PAGE_SIZES - 1];
+        struct kvm_arch_memory_slot arch;
         unsigned long userspace_addr;
         int user_alloc;
         int id;
@@ -376,6 +371,9 @@ int kvm_set_memory_region(struct kvm *kvm,
 int __kvm_set_memory_region(struct kvm *kvm,
                             struct kvm_userspace_memory_region *mem,
                             int user_alloc);
+void kvm_arch_free_memslot(struct kvm_memory_slot *free,
+                           struct kvm_memory_slot *dont);
+int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages);
 int kvm_arch_prepare_memory_region(struct kvm *kvm,
                                 struct kvm_memory_slot *memslot,
                                 struct kvm_memory_slot old,
@@ -385,6 +383,7 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
                                 struct kvm_userspace_memory_region *mem,
                                 struct kvm_memory_slot old,
                                 int user_alloc);
+bool kvm_largepages_enabled(void);
 void kvm_disable_largepages(void);
 void kvm_arch_flush_shadow(struct kvm *kvm);
 
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index a30447c5eb4a..8340e0e62034 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -535,21 +535,13 @@ static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
 static void kvm_free_physmem_slot(struct kvm_memory_slot *free,
                                   struct kvm_memory_slot *dont)
 {
-        int i;
-
         if (!dont || free->rmap != dont->rmap)
                 vfree(free->rmap);
 
         if (!dont || free->dirty_bitmap != dont->dirty_bitmap)
                 kvm_destroy_dirty_bitmap(free);
 
-
-        for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
-                if (!dont || free->lpage_info[i] != dont->lpage_info[i]) {
-                        vfree(free->lpage_info[i]);
-                        free->lpage_info[i] = NULL;
-                }
-        }
+        kvm_arch_free_memslot(free, dont);
 
         free->npages = 0;
         free->rmap = NULL;
@@ -685,53 +677,6 @@ void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new)
         slots->generation++;
 }
 
-#ifndef CONFIG_S390
-static int create_lpage_info(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->lpage_info[i] = vzalloc(lpages * sizeof(*slot->lpage_info[i]));
-                if (!slot->lpage_info[i])
-                        goto out_free;
-
-                if (slot->base_gfn & (KVM_PAGES_PER_HPAGE(level) - 1))
-                        slot->lpage_info[i][0].write_count = 1;
-                if ((slot->base_gfn + npages) & (KVM_PAGES_PER_HPAGE(level) - 1))
-                        slot->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) ||
-                    !largepages_enabled) {
-                        unsigned long j;
-
-                        for (j = 0; j < lpages; ++j)
-                                slot->lpage_info[i][j].write_count = 1;
-                }
-        }
-
-        return 0;
-
-out_free:
-        for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i) {
-                vfree(slot->lpage_info[i]);
-                slot->lpage_info[i] = NULL;
-        }
-        return -ENOMEM;
-}
-#endif /* not defined CONFIG_S390 */
-
 /*
  * Allocate some memory and give it an address in the guest physical address
  * space.
@@ -819,10 +764,9 @@ int __kvm_set_memory_region(struct kvm *kvm,
                 new.rmap = vzalloc(npages * sizeof(*new.rmap));
                 if (!new.rmap)
                         goto out_free;
-
-                if (create_lpage_info(&new, npages))
-                        goto out_free;
 #endif /* not defined CONFIG_S390 */
+                if (kvm_arch_create_memslot(&new, npages))
+                        goto out_free;
         }
 
         /* Allocate page dirty bitmap if needed */
@@ -880,8 +824,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
         if (!npages) {
                 new.rmap = NULL;
                 new.dirty_bitmap = NULL;
-                for (i = 0; i < KVM_NR_PAGE_SIZES - 1; ++i)
-                        new.lpage_info[i] = NULL;
+                memset(&new.arch, 0, sizeof(new.arch));
         }
 
         update_memslots(slots, &new);
@@ -968,6 +911,11 @@ out:
         return r;
 }
 
+bool kvm_largepages_enabled(void)
+{
+        return largepages_enabled;
+}
+
 void kvm_disable_largepages(void)
 {
         largepages_enabled = false;