KVM: Fix memory slot management functions for guest smp

The memory slot management functions were oriented against vcpu 0, where
they should be kvm-wide.  This causes hangs starting X on guest smp.

Fix by making the functions (and resultant tail in the mmu) non-vcpu-specific.
Unfortunately this reduces the efficiency of the mmu object cache a bit.  We
may have to revisit this later.

Signed-off-by: Avi Kivity <avi@qumranet.com>

3 files changed, 52 insertions, 123 deletions

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 65ab268d4256..6636ae2ee3b5 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -535,8 +535,8 @@ int kvm_mmu_create(struct kvm_vcpu *vcpu);
 int kvm_mmu_setup(struct kvm_vcpu *vcpu);
 
 int kvm_mmu_reset_context(struct kvm_vcpu *vcpu);
-void kvm_mmu_slot_remove_write_access(struct kvm_vcpu *vcpu, int slot);
-void kvm_mmu_zap_all(struct kvm_vcpu *vcpu);
+void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot);
+void kvm_mmu_zap_all(struct kvm *kvm);
 
 hpa_t gpa_to_hpa(struct kvm_vcpu *vcpu, gpa_t gpa);
 #define HPA_MSB ((sizeof(hpa_t) * 8) - 1)
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 1b206f197c6b..05f0418f2195 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -238,23 +238,6 @@ static void vcpu_load(struct kvm_vcpu *vcpu)
         kvm_arch_ops->vcpu_load(vcpu);
 }
 
-/*
- * Switches to specified vcpu, until a matching vcpu_put(). Will return NULL
- * if the slot is not populated.
- */
-static struct kvm_vcpu *vcpu_load_slot(struct kvm *kvm, int slot)
-{
-        struct kvm_vcpu *vcpu = &kvm->vcpus[slot];
-
-        mutex_lock(&vcpu->mutex);
-        if (!vcpu->vmcs) {
-                mutex_unlock(&vcpu->mutex);
-                return NULL;
-        }
-        kvm_arch_ops->vcpu_load(vcpu);
-        return vcpu;
-}
-
 static void vcpu_put(struct kvm_vcpu *vcpu)
 {
         kvm_arch_ops->vcpu_put(vcpu);
@@ -663,13 +646,6 @@ void fx_init(struct kvm_vcpu *vcpu)
 }
 EXPORT_SYMBOL_GPL(fx_init);
 
-static void do_remove_write_access(struct kvm_vcpu *vcpu, int slot)
-{
-        spin_lock(&vcpu->kvm->lock);
-        kvm_mmu_slot_remove_write_access(vcpu, slot);
-        spin_unlock(&vcpu->kvm->lock);
-}
-
 /*
  * Allocate some memory and give it an address in the guest physical address
  * space.
@@ -792,19 +768,10 @@ raced:
         *memslot = new;
         ++kvm->memory_config_version;
 
-        spin_unlock(&kvm->lock);
-
-        for (i = 0; i < KVM_MAX_VCPUS; ++i) {
-                struct kvm_vcpu *vcpu;
+        kvm_mmu_slot_remove_write_access(kvm, mem->slot);
+        kvm_flush_remote_tlbs(kvm);
 
-                vcpu = vcpu_load_slot(kvm, i);
-                if (!vcpu)
-                        continue;
-                if (new.flags & KVM_MEM_LOG_DIRTY_PAGES)
-                        do_remove_write_access(vcpu, mem->slot);
-                kvm_mmu_reset_context(vcpu);
-                vcpu_put(vcpu);
-        }
+        spin_unlock(&kvm->lock);
 
         kvm_free_physmem_slot(&old, &new);
         return 0;
@@ -826,7 +793,6 @@ static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
         struct kvm_memory_slot *memslot;
         int r, i;
         int n;
-        int cleared;
         unsigned long any = 0;
 
         spin_lock(&kvm->lock);
@@ -855,23 +821,11 @@ static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
         if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
                 goto out;
 
-        if (any) {
-                cleared = 0;
-                for (i = 0; i < KVM_MAX_VCPUS; ++i) {
-                        struct kvm_vcpu *vcpu;
-
-                        vcpu = vcpu_load_slot(kvm, i);
-                        if (!vcpu)
-                                continue;
-                        if (!cleared) {
-                                do_remove_write_access(vcpu, log->slot);
-                                memset(memslot->dirty_bitmap, 0, n);
-                                cleared = 1;
-                        }
-                        kvm_arch_ops->tlb_flush(vcpu);
-                        vcpu_put(vcpu);
-                }
-        }
+        spin_lock(&kvm->lock);
+        kvm_mmu_slot_remove_write_access(kvm, log->slot);
+        kvm_flush_remote_tlbs(kvm);
+        memset(memslot->dirty_bitmap, 0, n);
+        spin_unlock(&kvm->lock);
 
         r = 0;
 
@@ -920,13 +874,9 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,
                         break;
         kvm->naliases = n;
 
-        spin_unlock(&kvm->lock);
+        kvm_mmu_zap_all(kvm);
 
-        vcpu_load(&kvm->vcpus[0]);
-        spin_lock(&kvm->lock);
-        kvm_mmu_zap_all(&kvm->vcpus[0]);
         spin_unlock(&kvm->lock);
-        vcpu_put(&kvm->vcpus[0]);
 
         return 0;
 
diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 1199d3f32ac3..48d28f1ff4a1 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -281,24 +281,15 @@ static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc,
         return p;
 }
 
-static void mmu_memory_cache_free(struct kvm_mmu_memory_cache *mc, void *obj)
-{
-        if (mc->nobjs < KVM_NR_MEM_OBJS)
-                mc->objects[mc->nobjs++] = obj;
-        else
-                kfree(obj);
-}
-
 static struct kvm_pte_chain *mmu_alloc_pte_chain(struct kvm_vcpu *vcpu)
 {
         return mmu_memory_cache_alloc(&vcpu->mmu_pte_chain_cache,
                                       sizeof(struct kvm_pte_chain));
 }
 
-static void mmu_free_pte_chain(struct kvm_vcpu *vcpu,
-                               struct kvm_pte_chain *pc)
+static void mmu_free_pte_chain(struct kvm_pte_chain *pc)
 {
-        mmu_memory_cache_free(&vcpu->mmu_pte_chain_cache, pc);
+        kfree(pc);
 }
 
 static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
@@ -307,10 +298,9 @@ static struct kvm_rmap_desc *mmu_alloc_rmap_desc(struct kvm_vcpu *vcpu)
                                       sizeof(struct kvm_rmap_desc));
 }
 
-static void mmu_free_rmap_desc(struct kvm_vcpu *vcpu,
-                               struct kvm_rmap_desc *rd)
+static void mmu_free_rmap_desc(struct kvm_rmap_desc *rd)
 {
-        mmu_memory_cache_free(&vcpu->mmu_rmap_desc_cache, rd);
+        kfree(rd);
 }
 
 /*
@@ -355,8 +345,7 @@ static void rmap_add(struct kvm_vcpu *vcpu, u64 *spte)
         }
 }
 
-static void rmap_desc_remove_entry(struct kvm_vcpu *vcpu,
-                                   struct page *page,
+static void rmap_desc_remove_entry(struct page *page,
                                    struct kvm_rmap_desc *desc,
                                    int i,
                                    struct kvm_rmap_desc *prev_desc)
@@ -376,10 +365,10 @@ static void rmap_desc_remove_entry(struct kvm_vcpu *vcpu,
                         prev_desc->more = desc->more;
                 else
                         set_page_private(page,(unsigned long)desc->more | 1);
-        mmu_free_rmap_desc(vcpu, desc);
+        mmu_free_rmap_desc(desc);
 }
 
-static void rmap_remove(struct kvm_vcpu *vcpu, u64 *spte)
+static void rmap_remove(u64 *spte)
 {
         struct page *page;
         struct kvm_rmap_desc *desc;
@@ -407,7 +396,7 @@ static void rmap_remove(struct kvm_vcpu *vcpu, u64 *spte)
                 while (desc) {
                         for (i = 0; i < RMAP_EXT && desc->shadow_ptes[i]; ++i)
                                 if (desc->shadow_ptes[i] == spte) {
-                                        rmap_desc_remove_entry(vcpu, page,
+                                        rmap_desc_remove_entry(page,
                                                                desc, i,
                                                                prev_desc);
                                         return;
@@ -442,7 +431,7 @@ static void rmap_write_protect(struct kvm_vcpu *vcpu, u64 gfn)
                 BUG_ON(!(*spte & PT_PRESENT_MASK));
                 BUG_ON(!(*spte & PT_WRITABLE_MASK));
                 rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
-                rmap_remove(vcpu, spte);
+                rmap_remove(spte);
                 set_shadow_pte(spte, *spte & ~PT_WRITABLE_MASK);
                 kvm_flush_remote_tlbs(vcpu->kvm);
         }
@@ -464,14 +453,14 @@ static int is_empty_shadow_page(u64 *spt)
 }
 #endif
 
-static void kvm_mmu_free_page(struct kvm_vcpu *vcpu,
+static void kvm_mmu_free_page(struct kvm *kvm,
                               struct kvm_mmu_page *page_head)
 {
         ASSERT(is_empty_shadow_page(page_head->spt));
         list_del(&page_head->link);
-        mmu_memory_cache_free(&vcpu->mmu_page_cache, page_head->spt);
-        mmu_memory_cache_free(&vcpu->mmu_page_header_cache, page_head);
-        ++vcpu->kvm->n_free_mmu_pages;
+        kfree(page_head->spt);
+        kfree(page_head);
+        ++kvm->n_free_mmu_pages;
 }
 
 static unsigned kvm_page_table_hashfn(gfn_t gfn)
@@ -537,8 +526,7 @@ static void mmu_page_add_parent_pte(struct kvm_vcpu *vcpu,
         pte_chain->parent_ptes[0] = parent_pte;
 }
 
-static void mmu_page_remove_parent_pte(struct kvm_vcpu *vcpu,
-                                       struct kvm_mmu_page *page,
+static void mmu_page_remove_parent_pte(struct kvm_mmu_page *page,
                                        u64 *parent_pte)
 {
         struct kvm_pte_chain *pte_chain;
@@ -565,7 +553,7 @@ static void mmu_page_remove_parent_pte(struct kvm_vcpu *vcpu,
                         pte_chain->parent_ptes[i] = NULL;
                         if (i == 0) {
                                 hlist_del(&pte_chain->link);
-                                mmu_free_pte_chain(vcpu, pte_chain);
+                                mmu_free_pte_chain(pte_chain);
                                 if (hlist_empty(&page->parent_ptes)) {
                                         page->multimapped = 0;
                                         page->parent_pte = NULL;
@@ -643,7 +631,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
         return page;
 }
 
-static void kvm_mmu_page_unlink_children(struct kvm_vcpu *vcpu,
+static void kvm_mmu_page_unlink_children(struct kvm *kvm,
                                          struct kvm_mmu_page *page)
 {
         unsigned i;
@@ -655,10 +643,10 @@ static void kvm_mmu_page_unlink_children(struct kvm_vcpu *vcpu,
         if (page->role.level == PT_PAGE_TABLE_LEVEL) {
                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i) {
                         if (pt[i] & PT_PRESENT_MASK)
-                                rmap_remove(vcpu, &pt[i]);
+                                rmap_remove(&pt[i]);
                         pt[i] = 0;
                 }
-                kvm_flush_remote_tlbs(vcpu->kvm);
+                kvm_flush_remote_tlbs(kvm);
                 return;
         }
 
@@ -669,19 +657,18 @@ static void kvm_mmu_page_unlink_children(struct kvm_vcpu *vcpu,
                 if (!(ent & PT_PRESENT_MASK))
                         continue;
                 ent &= PT64_BASE_ADDR_MASK;
-                mmu_page_remove_parent_pte(vcpu, page_header(ent), &pt[i]);
+                mmu_page_remove_parent_pte(page_header(ent), &pt[i]);
         }
-        kvm_flush_remote_tlbs(vcpu->kvm);
+        kvm_flush_remote_tlbs(kvm);
 }
 
-static void kvm_mmu_put_page(struct kvm_vcpu *vcpu,
-                             struct kvm_mmu_page *page,
+static void kvm_mmu_put_page(struct kvm_mmu_page *page,
                              u64 *parent_pte)
 {
-        mmu_page_remove_parent_pte(vcpu, page, parent_pte);
+        mmu_page_remove_parent_pte(page, parent_pte);
 }
 
-static void kvm_mmu_zap_page(struct kvm_vcpu *vcpu,
+static void kvm_mmu_zap_page(struct kvm *kvm,
                              struct kvm_mmu_page *page)
 {
         u64 *parent_pte;
@@ -697,15 +684,15 @@ static void kvm_mmu_zap_page(struct kvm_vcpu *vcpu,
                         parent_pte = chain->parent_ptes[0];
                 }
                 BUG_ON(!parent_pte);
-                kvm_mmu_put_page(vcpu, page, parent_pte);
+                kvm_mmu_put_page(page, parent_pte);
                 set_shadow_pte(parent_pte, 0);
         }
-        kvm_mmu_page_unlink_children(vcpu, page);
+        kvm_mmu_page_unlink_children(kvm, page);
         if (!page->root_count) {
                 hlist_del(&page->hash_link);
-                kvm_mmu_free_page(vcpu, page);
+                kvm_mmu_free_page(kvm, page);
         } else
-                list_move(&page->link, &vcpu->kvm->active_mmu_pages);
+                list_move(&page->link, &kvm->active_mmu_pages);
 }
 
 static int kvm_mmu_unprotect_page(struct kvm_vcpu *vcpu, gfn_t gfn)
@@ -724,7 +711,7 @@ static int kvm_mmu_unprotect_page(struct kvm_vcpu *vcpu, gfn_t gfn)
                 if (page->gfn == gfn && !page->role.metaphysical) {
                         pgprintk("%s: gfn %lx role %x\n", __FUNCTION__, gfn,
                                  page->role.word);
-                        kvm_mmu_zap_page(vcpu, page);
+                        kvm_mmu_zap_page(vcpu->kvm, page);
                         r = 1;
                 }
         return r;
@@ -737,7 +724,7 @@ static void mmu_unshadow(struct kvm_vcpu *vcpu, gfn_t gfn)
         while ((page = kvm_mmu_lookup_page(vcpu, gfn)) != NULL) {
                 pgprintk("%s: zap %lx %x\n",
                          __FUNCTION__, gfn, page->role.word);
-                kvm_mmu_zap_page(vcpu, page);
+                kvm_mmu_zap_page(vcpu->kvm, page);
         }
 }
 
@@ -1089,10 +1076,10 @@ static void mmu_pte_write_zap_pte(struct kvm_vcpu *vcpu,
         pte = *spte;
         if (is_present_pte(pte)) {
                 if (page->role.level == PT_PAGE_TABLE_LEVEL)
-                        rmap_remove(vcpu, spte);
+                        rmap_remove(spte);
                 else {
                         child = page_header(pte & PT64_BASE_ADDR_MASK);
-                        mmu_page_remove_parent_pte(vcpu, child, spte);
+                        mmu_page_remove_parent_pte(child, spte);
                 }
         }
         *spte = 0;
@@ -1161,7 +1148,7 @@ void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
                          */
                         pgprintk("misaligned: gpa %llx bytes %d role %x\n",
                                  gpa, bytes, page->role.word);
-                        kvm_mmu_zap_page(vcpu, page);
+                        kvm_mmu_zap_page(vcpu->kvm, page);
                         continue;
                 }
                 page_offset = offset;
@@ -1207,7 +1194,7 @@ void kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
 
                 page = container_of(vcpu->kvm->active_mmu_pages.prev,
                                     struct kvm_mmu_page, link);
-                kvm_mmu_zap_page(vcpu, page);
+                kvm_mmu_zap_page(vcpu->kvm, page);
         }
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_free_some_pages);
@@ -1219,7 +1206,7 @@ static void free_mmu_pages(struct kvm_vcpu *vcpu)
         while (!list_empty(&vcpu->kvm->active_mmu_pages)) {
                 page = container_of(vcpu->kvm->active_mmu_pages.next,
                                     struct kvm_mmu_page, link);
-                kvm_mmu_zap_page(vcpu, page);
+                kvm_mmu_zap_page(vcpu->kvm, page);
         }
         free_page((unsigned long)vcpu->mmu.pae_root);
 }
@@ -1277,9 +1264,8 @@ void kvm_mmu_destroy(struct kvm_vcpu *vcpu)
         mmu_free_memory_caches(vcpu);
 }
 
-void kvm_mmu_slot_remove_write_access(struct kvm_vcpu *vcpu, int slot)
+void kvm_mmu_slot_remove_write_access(struct kvm *kvm, int slot)
 {
-        struct kvm *kvm = vcpu->kvm;
         struct kvm_mmu_page *page;
 
         list_for_each_entry(page, &kvm->active_mmu_pages, link) {
@@ -1293,27 +1279,20 @@ void kvm_mmu_slot_remove_write_access(struct kvm_vcpu *vcpu, int slot)
                 for (i = 0; i < PT64_ENT_PER_PAGE; ++i)
                         /* avoid RMW */
                         if (pt[i] & PT_WRITABLE_MASK) {
-                                rmap_remove(vcpu, &pt[i]);
+                                rmap_remove(&pt[i]);
                                 pt[i] &= ~PT_WRITABLE_MASK;
                         }
         }
 }
 
-void kvm_mmu_zap_all(struct kvm_vcpu *vcpu)
+void kvm_mmu_zap_all(struct kvm *kvm)
 {
-        destroy_kvm_mmu(vcpu);
+        struct kvm_mmu_page *page, *node;
 
-        while (!list_empty(&vcpu->kvm->active_mmu_pages)) {
-                struct kvm_mmu_page *page;
-
-                page = container_of(vcpu->kvm->active_mmu_pages.next,
-                                    struct kvm_mmu_page, link);
-                kvm_mmu_zap_page(vcpu, page);
-        }
+        list_for_each_entry_safe(page, node, &kvm->active_mmu_pages, link)
+                kvm_mmu_zap_page(kvm, page);
 
-        mmu_free_memory_caches(vcpu);
-        kvm_flush_remote_tlbs(vcpu->kvm);
-        init_kvm_mmu(vcpu);
+        kvm_flush_remote_tlbs(kvm);
 }
 
 void kvm_mmu_module_exit(void)