1 files changed, 64 insertions, 73 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 89a49fb46a2..741373e8ca7 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -18,6 +18,7 @@
  */
 
 #include "mmu.h"
+#include "x86.h"
 #include "kvm_cache_regs.h"
 
 #include <linux/kvm_host.h>
@@ -29,6 +30,7 @@
 #include <linux/swap.h>
 #include <linux/hugetlb.h>
 #include <linux/compiler.h>
+#include <linux/srcu.h>
 
 #include <asm/page.h>
 #include <asm/cmpxchg.h>
@@ -136,16 +138,6 @@ module_param(oos_shadow, bool, 0644);
 #define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | PT_USER_MASK \
                         | PT64_NX_MASK)
 
-#define PFERR_PRESENT_MASK (1U << 0)
-#define PFERR_WRITE_MASK (1U << 1)
-#define PFERR_USER_MASK (1U << 2)
-#define PFERR_RSVD_MASK (1U << 3)
-#define PFERR_FETCH_MASK (1U << 4)
-
-#define PT_PDPE_LEVEL 3
-#define PT_DIRECTORY_LEVEL 2
-#define PT_PAGE_TABLE_LEVEL 1
-
 #define RMAP_EXT 4
 
 #define ACC_EXEC_MASK    1
@@ -153,6 +145,9 @@ module_param(oos_shadow, bool, 0644);
 #define ACC_USER_MASK    PT_USER_MASK
 #define ACC_ALL          (ACC_EXEC_MASK | ACC_WRITE_MASK | ACC_USER_MASK)
 
+#include <trace/events/kvm.h>
+
+#undef TRACE_INCLUDE_FILE
 #define CREATE_TRACE_POINTS
 #include "mmutrace.h"
 
@@ -229,7 +224,7 @@ EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);
 
 static int is_write_protection(struct kvm_vcpu *vcpu)
 {
-        return vcpu->arch.cr0 & X86_CR0_WP;
+        return kvm_read_cr0_bits(vcpu, X86_CR0_WP);
 }
 
 static int is_cpuid_PSE36(void)
@@ -239,7 +234,7 @@ static int is_cpuid_PSE36(void)
 
 static int is_nx(struct kvm_vcpu *vcpu)
 {
-        return vcpu->arch.shadow_efer & EFER_NX;
+        return vcpu->arch.efer & EFER_NX;
 }
 
 static int is_shadow_present_pte(u64 pte)
@@ -253,7 +248,7 @@ static int is_large_pte(u64 pte)
         return pte & PT_PAGE_SIZE_MASK;
 }
 
-static int is_writeble_pte(unsigned long pte)
+static int is_writable_pte(unsigned long pte)
 {
         return pte & PT_WRITABLE_MASK;
 }
@@ -470,24 +465,10 @@ static int has_wrprotected_page(struct kvm *kvm,
 
 static int host_mapping_level(struct kvm *kvm, gfn_t gfn)
 {
-        unsigned long page_size = PAGE_SIZE;
-        struct vm_area_struct *vma;
-        unsigned long addr;
+        unsigned long page_size;
         int i, ret = 0;
 
-        addr = gfn_to_hva(kvm, gfn);
-        if (kvm_is_error_hva(addr))
-                return PT_PAGE_TABLE_LEVEL;
-
-        down_read(&current->mm->mmap_sem);
-        vma = find_vma(current->mm, addr);
-        if (!vma)
-                goto out;
-
-        page_size = vma_kernel_pagesize(vma);
-
-out:
-        up_read(&current->mm->mmap_sem);
+        page_size = kvm_host_page_size(kvm, gfn);
 
         for (i = PT_PAGE_TABLE_LEVEL;
              i < (PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES); ++i) {
@@ -503,8 +484,7 @@ out:
 static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn)
 {
         struct kvm_memory_slot *slot;
-        int host_level;
-        int level = PT_PAGE_TABLE_LEVEL;
+        int host_level, level, max_level;
 
         slot = gfn_to_memslot(vcpu->kvm, large_gfn);
         if (slot && slot->dirty_bitmap)
@@ -515,7 +495,10 @@ static int mapping_level(struct kvm_vcpu *vcpu, gfn_t large_gfn)
         if (host_level == PT_PAGE_TABLE_LEVEL)
                 return host_level;
 
-        for (level = PT_DIRECTORY_LEVEL; level <= host_level; ++level)
+        max_level = kvm_x86_ops->get_lpage_level() < host_level ?
+                kvm_x86_ops->get_lpage_level() : host_level;
+
+        for (level = PT_DIRECTORY_LEVEL; level <= max_level; ++level)
                 if (has_wrprotected_page(vcpu->kvm, large_gfn, level))
                         break;
 
@@ -633,7 +616,7 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
         pfn = spte_to_pfn(*spte);
         if (*spte & shadow_accessed_mask)
                 kvm_set_pfn_accessed(pfn);
-        if (is_writeble_pte(*spte))
+        if (is_writable_pte(*spte))
                 kvm_set_pfn_dirty(pfn);
         rmapp = gfn_to_rmap(kvm, sp->gfns[spte - sp->spt], sp->role.level);
         if (!*rmapp) {
@@ -662,6 +645,7 @@ static void rmap_remove(struct kvm *kvm, u64 *spte)
                         prev_desc = desc;
                         desc = desc->more;
                 }
+                pr_err("rmap_remove: %p %llx many->many\n", spte, *spte);
                 BUG();
         }
 }
@@ -708,7 +692,7 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn)
                 BUG_ON(!spte);
                 BUG_ON(!(*spte & PT_PRESENT_MASK));
                 rmap_printk("rmap_write_protect: spte %p %llx\n", spte, *spte);
-                if (is_writeble_pte(*spte)) {
+                if (is_writable_pte(*spte)) {
                         __set_spte(spte, *spte & ~PT_WRITABLE_MASK);
                         write_protected = 1;
                 }
@@ -732,7 +716,7 @@ static int rmap_write_protect(struct kvm *kvm, u64 gfn)
                         BUG_ON(!(*spte & PT_PRESENT_MASK));
                         BUG_ON((*spte & (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK)) != (PT_PAGE_SIZE_MASK|PT_PRESENT_MASK));
                         pgprintk("rmap_write_protect(large): spte %p %llx %lld\n", spte, *spte, gfn);
-                        if (is_writeble_pte(*spte)) {
+                        if (is_writable_pte(*spte)) {
                                 rmap_remove(kvm, spte);
                                 --kvm->stat.lpages;
                                 __set_spte(spte, shadow_trap_nonpresent_pte);
@@ -787,7 +771,7 @@ static int kvm_set_pte_rmapp(struct kvm *kvm, unsigned long *rmapp,
 
                         new_spte &= ~PT_WRITABLE_MASK;
                         new_spte &= ~SPTE_HOST_WRITEABLE;
-                        if (is_writeble_pte(*spte))
+                        if (is_writable_pte(*spte))
                                 kvm_set_pfn_dirty(spte_to_pfn(*spte));
                         __set_spte(spte, new_spte);
                         spte = rmap_next(kvm, rmapp, spte);
@@ -805,35 +789,32 @@ static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
                                          unsigned long data))
 {
         int i, j;
+        int ret;
         int retval = 0;
+        struct kvm_memslots *slots;
 
-        /*
-         * If mmap_sem isn't taken, we can look the memslots with only
-         * the mmu_lock by skipping over the slots with userspace_addr == 0.
-         */
-        for (i = 0; i < kvm->nmemslots; i++) {
-                struct kvm_memory_slot *memslot = &kvm->memslots[i];
+        slots = rcu_dereference(kvm->memslots);
+
+        for (i = 0; i < slots->nmemslots; i++) {
+                struct kvm_memory_slot *memslot = &slots->memslots[i];
                 unsigned long start = memslot->userspace_addr;
                 unsigned long end;
 
-                /* mmu_lock protects userspace_addr */
-                if (!start)
-                        continue;
-
                 end = start + (memslot->npages << PAGE_SHIFT);
                 if (hva >= start && hva < end) {
                         gfn_t gfn_offset = (hva - start) >> PAGE_SHIFT;
 
-                        retval |= handler(kvm, &memslot->rmap[gfn_offset],
-                                          data);
+                        ret = handler(kvm, &memslot->rmap[gfn_offset], data);
 
                         for (j = 0; j < KVM_NR_PAGE_SIZES - 1; ++j) {
                                 int idx = gfn_offset;
                                 idx /= KVM_PAGES_PER_HPAGE(PT_DIRECTORY_LEVEL + j);
-                                retval |= handler(kvm,
+                                ret |= handler(kvm,
                                         &memslot->lpage_info[j][idx].rmap_pde,
                                         data);
                         }
+                        trace_kvm_age_page(hva, memslot, ret);
+                        retval |= ret;
                 }
         }
 
@@ -856,9 +837,15 @@ static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp,
         u64 *spte;
         int young = 0;
 
-        /* always return old for EPT */
+        /*
+         * Emulate the accessed bit for EPT, by checking if this page has
+         * an EPT mapping, and clearing it if it does. On the next access,
+         * a new EPT mapping will be established.
+         * This has some overhead, but not as much as the cost of swapping
+         * out actively used pages or breaking up actively used hugepages.
+         */
         if (!shadow_accessed_mask)
-                return 0;
+                return kvm_unmap_rmapp(kvm, rmapp, data);
 
         spte = rmap_next(kvm, rmapp, NULL);
         while (spte) {
@@ -1615,7 +1602,7 @@ static void mmu_unshadow(struct kvm *kvm, gfn_t gfn)
 
 static void page_header_update_slot(struct kvm *kvm, void *pte, gfn_t gfn)
 {
-        int slot = memslot_id(kvm, gfn_to_memslot(kvm, gfn));
+        int slot = memslot_id(kvm, gfn);
         struct kvm_mmu_page *sp = page_header(__pa(pte));
 
         __set_bit(slot, sp->slot_bitmap);
@@ -1639,7 +1626,7 @@ struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva)
 {
         struct page *page;
 
-        gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
+        gpa_t gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL);
 
         if (gpa == UNMAPPED_GVA)
                 return NULL;
@@ -1852,7 +1839,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
                  * is responsibility of mmu_get_page / kvm_sync_page.
                  * Same reasoning can be applied to dirty page accounting.
                  */
-                if (!can_unsync && is_writeble_pte(*sptep))
+                if (!can_unsync && is_writable_pte(*sptep))
                         goto set_pte;
 
                 if (mmu_need_write_protect(vcpu, gfn, can_unsync)) {
@@ -1860,7 +1847,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
                                  __func__, gfn);
                         ret = 1;
                         pte_access &= ~ACC_WRITE_MASK;
-                        if (is_writeble_pte(spte))
+                        if (is_writable_pte(spte))
                                 spte &= ~PT_WRITABLE_MASK;
                 }
         }
@@ -1881,7 +1868,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
                          bool reset_host_protection)
 {
         int was_rmapped = 0;
-        int was_writeble = is_writeble_pte(*sptep);
+        int was_writable = is_writable_pte(*sptep);
         int rmap_count;
 
         pgprintk("%s: spte %llx access %x write_fault %d"
@@ -1932,7 +1919,7 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
                 if (rmap_count > RMAP_RECYCLE_THRESHOLD)
                         rmap_recycle(vcpu, sptep, gfn);
         } else {
-                if (was_writeble)
+                if (was_writable)
                         kvm_release_pfn_dirty(pfn);
                 else
                         kvm_release_pfn_clean(pfn);
@@ -2162,8 +2149,11 @@ void kvm_mmu_sync_roots(struct kvm_vcpu *vcpu)
         spin_unlock(&vcpu->kvm->mmu_lock);
 }
 
-static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr)
+static gpa_t nonpaging_gva_to_gpa(struct kvm_vcpu *vcpu, gva_t vaddr,
+                                  u32 access, u32 *error)
 {
+        if (error)
+                *error = 0;
         return vaddr;
 }
 
@@ -2747,7 +2737,7 @@ int kvm_mmu_unprotect_page_virt(struct kvm_vcpu *vcpu, gva_t gva)
         if (tdp_enabled)
                 return 0;
 
-        gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, gva);
+        gpa = kvm_mmu_gva_to_gpa_read(vcpu, gva, NULL);
 
         spin_lock(&vcpu->kvm->mmu_lock);
         r = kvm_mmu_unprotect_page(vcpu->kvm, gpa >> PAGE_SHIFT);
@@ -2847,16 +2837,13 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
          */
         page = alloc_page(GFP_KERNEL | __GFP_DMA32);
         if (!page)
-                goto error_1;
+                return -ENOMEM;
+
         vcpu->arch.mmu.pae_root = page_address(page);
         for (i = 0; i < 4; ++i)
                 vcpu->arch.mmu.pae_root[i] = INVALID_PAGE;
 
         return 0;
-
-error_1:
-        free_mmu_pages(vcpu);
-        return -ENOMEM;
 }
 
 int kvm_mmu_create(struct kvm_vcpu *vcpu)
@@ -2936,10 +2923,9 @@ static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask)
         spin_lock(&kvm_lock);
 
         list_for_each_entry(kvm, &vm_list, vm_list) {
-                int npages;
+                int npages, idx;
 
-                if (!down_read_trylock(&kvm->slots_lock))
-                        continue;
+                idx = srcu_read_lock(&kvm->srcu);
                 spin_lock(&kvm->mmu_lock);
                 npages = kvm->arch.n_alloc_mmu_pages -
                          kvm->arch.n_free_mmu_pages;
@@ -2952,7 +2938,7 @@ static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask)
                 nr_to_scan--;
 
                 spin_unlock(&kvm->mmu_lock);
-                up_read(&kvm->slots_lock);
+                srcu_read_unlock(&kvm->srcu, idx);
         }
         if (kvm_freed)
                 list_move_tail(&kvm_freed->vm_list, &vm_list);
@@ -3019,9 +3005,11 @@ unsigned int kvm_mmu_calculate_mmu_pages(struct kvm *kvm)
         int i;
         unsigned int nr_mmu_pages;
         unsigned int  nr_pages = 0;
+        struct kvm_memslots *slots;
 
-        for (i = 0; i < kvm->nmemslots; i++)
-                nr_pages += kvm->memslots[i].npages;
+        slots = rcu_dereference(kvm->memslots);
+        for (i = 0; i < slots->nmemslots; i++)
+                nr_pages += slots->memslots[i].npages;
 
         nr_mmu_pages = nr_pages * KVM_PERMILLE_MMU_PAGES / 1000;
         nr_mmu_pages = max(nr_mmu_pages,
@@ -3246,7 +3234,7 @@ static void audit_mappings_page(struct kvm_vcpu *vcpu, u64 page_pte,
                 if (is_shadow_present_pte(ent) && !is_last_spte(ent, level))
                         audit_mappings_page(vcpu, ent, va, level - 1);
                 else {
-                        gpa_t gpa = vcpu->arch.mmu.gva_to_gpa(vcpu, va);
+                        gpa_t gpa = kvm_mmu_gva_to_gpa_read(vcpu, va, NULL);
                         gfn_t gfn = gpa >> PAGE_SHIFT;
                         pfn_t pfn = gfn_to_pfn(vcpu->kvm, gfn);
                         hpa_t hpa = (hpa_t)pfn << PAGE_SHIFT;
@@ -3291,10 +3279,12 @@ static void audit_mappings(struct kvm_vcpu *vcpu)
 static int count_rmaps(struct kvm_vcpu *vcpu)
 {
         int nmaps = 0;
-        int i, j, k;
+        int i, j, k, idx;
 
+        idx = srcu_read_lock(&kvm->srcu);
+        slots = rcu_dereference(kvm->memslots);
         for (i = 0; i < KVM_MEMORY_SLOTS; ++i) {
-                struct kvm_memory_slot *m = &vcpu->kvm->memslots[i];
+                struct kvm_memory_slot *m = &slots->memslots[i];
                 struct kvm_rmap_desc *d;
 
                 for (j = 0; j < m->npages; ++j) {
@@ -3317,6 +3307,7 @@ static int count_rmaps(struct kvm_vcpu *vcpu)
                         }
                 }
         }
+        srcu_read_unlock(&kvm->srcu, idx);
         return nmaps;
 }