Merge branch 'kvm-updates-2.6.27' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm

* 'kvm-updates-2.6.27' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm:
  KVM: s390: Fix kvm on IBM System z10
  KVM: Advertise synchronized mmu support to userspace
  KVM: Synchronize guest physical memory map to host virtual memory map
  KVM: Allow browsing memslots with mmu_lock
  KVM: Allow reading aliases with mmu_lock

3 files changed, 129 insertions, 7 deletions

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 2fa231923cf7..0bfe2bd305eb 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -653,6 +653,84 @@ static void rmap_write_protect(struct kvm *kvm, u64 gfn)
 	account_shadowed(kvm, gfn);
 }
 
+static int kvm_unmap_rmapp(struct kvm *kvm, unsigned long *rmapp)
+{
+	u64 *spte;
+	int need_tlb_flush = 0;
+
+	while ((spte = rmap_next(kvm, rmapp, NULL))) {
+		BUG_ON(!(*spte & PT_PRESENT_MASK));
+		rmap_printk("kvm_rmap_unmap_hva: spte %p %llx\n", spte, *spte);
+		rmap_remove(kvm, spte);
+		set_shadow_pte(spte, shadow_trap_nonpresent_pte);
+		need_tlb_flush = 1;
+	}
+	return need_tlb_flush;
+}
+
+static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
+			  int (*handler)(struct kvm *kvm, unsigned long *rmapp))
+{
+	int i;
+	int retval = 0;
+
+	/*
+	 * 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];
+		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]);
+			retval |= handler(kvm,
+					  &memslot->lpage_info[
+						  gfn_offset /
+						  KVM_PAGES_PER_HPAGE].rmap_pde);
+		}
+	}
+
+	return retval;
+}
+
+int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
+{
+	return kvm_handle_hva(kvm, hva, kvm_unmap_rmapp);
+}
+
+static int kvm_age_rmapp(struct kvm *kvm, unsigned long *rmapp)
+{
+	u64 *spte;
+	int young = 0;
+
+	spte = rmap_next(kvm, rmapp, NULL);
+	while (spte) {
+		int _young;
+		u64 _spte = *spte;
+		BUG_ON(!(_spte & PT_PRESENT_MASK));
+		_young = _spte & PT_ACCESSED_MASK;
+		if (_young) {
+			young = 1;
+			clear_bit(PT_ACCESSED_SHIFT, (unsigned long *)spte);
+		}
+		spte = rmap_next(kvm, rmapp, spte);
+	}
+	return young;
+}
+
+int kvm_age_hva(struct kvm *kvm, unsigned long hva)
+{
+	return kvm_handle_hva(kvm, hva, kvm_age_rmapp);
+}
+
 #ifdef MMU_DEBUG
 static int is_empty_shadow_page(u64 *spt)
 {
@@ -1203,6 +1281,7 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
 	int r;
 	int largepage = 0;
 	pfn_t pfn;
+	unsigned long mmu_seq;
 
 	down_read(&current->mm->mmap_sem);
 	if (is_largepage_backed(vcpu, gfn & ~(KVM_PAGES_PER_HPAGE-1))) {
@@ -1210,6 +1289,8 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
 		largepage = 1;
 	}
 
+	mmu_seq = vcpu->kvm->mmu_notifier_seq;
+	/* implicit mb(), we'll read before PT lock is unlocked */
 	pfn = gfn_to_pfn(vcpu->kvm, gfn);
 	up_read(&current->mm->mmap_sem);
 
@@ -1220,6 +1301,8 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
 	}
 
 	spin_lock(&vcpu->kvm->mmu_lock);
+	if (mmu_notifier_retry(vcpu, mmu_seq))
+		goto out_unlock;
 	kvm_mmu_free_some_pages(vcpu);
 	r = __direct_map(vcpu, v, write, largepage, gfn, pfn,
 			 PT32E_ROOT_LEVEL);
@@ -1227,6 +1310,11 @@ static int nonpaging_map(struct kvm_vcpu *vcpu, gva_t v, int write, gfn_t gfn)
 
 
 	return r;
+
+out_unlock:
+	spin_unlock(&vcpu->kvm->mmu_lock);
+	kvm_release_pfn_clean(pfn);
+	return 0;
 }
 
 
@@ -1345,6 +1433,7 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
 	int r;
 	int largepage = 0;
 	gfn_t gfn = gpa >> PAGE_SHIFT;
+	unsigned long mmu_seq;
 
 	ASSERT(vcpu);
 	ASSERT(VALID_PAGE(vcpu->arch.mmu.root_hpa));
@@ -1358,6 +1447,8 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
 		gfn &= ~(KVM_PAGES_PER_HPAGE-1);
 		largepage = 1;
 	}
+	mmu_seq = vcpu->kvm->mmu_notifier_seq;
+	/* implicit mb(), we'll read before PT lock is unlocked */
 	pfn = gfn_to_pfn(vcpu->kvm, gfn);
 	up_read(&current->mm->mmap_sem);
 	if (is_error_pfn(pfn)) {
@@ -1365,12 +1456,19 @@ static int tdp_page_fault(struct kvm_vcpu *vcpu, gva_t gpa,
 		return 1;
 	}
 	spin_lock(&vcpu->kvm->mmu_lock);
+	if (mmu_notifier_retry(vcpu, mmu_seq))
+		goto out_unlock;
 	kvm_mmu_free_some_pages(vcpu);
 	r = __direct_map(vcpu, gpa, error_code & PFERR_WRITE_MASK,
 			 largepage, gfn, pfn, kvm_x86_ops->get_tdp_level());
 	spin_unlock(&vcpu->kvm->mmu_lock);
 
 	return r;
+
+out_unlock:
+	spin_unlock(&vcpu->kvm->mmu_lock);
+	kvm_release_pfn_clean(pfn);
+	return 0;
 }
 
 static void nonpaging_free(struct kvm_vcpu *vcpu)
@@ -1670,6 +1768,8 @@ static void mmu_guess_page_from_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
 		gfn &= ~(KVM_PAGES_PER_HPAGE-1);
 		vcpu->arch.update_pte.largepage = 1;
 	}
+	vcpu->arch.update_pte.mmu_seq = vcpu->kvm->mmu_notifier_seq;
+	/* implicit mb(), we'll read before PT lock is unlocked */
 	pfn = gfn_to_pfn(vcpu->kvm, gfn);
 	up_read(&current->mm->mmap_sem);
 
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index 4d918220baeb..f72ac1fa35f0 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -263,6 +263,8 @@ static void FNAME(update_pte)(struct kvm_vcpu *vcpu, struct kvm_mmu_page *page,
 	pfn = vcpu->arch.update_pte.pfn;
 	if (is_error_pfn(pfn))
 		return;
+	if (mmu_notifier_retry(vcpu, vcpu->arch.update_pte.mmu_seq))
+		return;
 	kvm_get_pfn(pfn);
 	mmu_set_spte(vcpu, spte, page->role.access, pte_access, 0, 0,
 		     gpte & PT_DIRTY_MASK, NULL, largepage, gpte_to_gfn(gpte),
@@ -380,6 +382,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
 	int r;
 	pfn_t pfn;
 	int largepage = 0;
+	unsigned long mmu_seq;
 
 	pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code);
 	kvm_mmu_audit(vcpu, "pre page fault");
@@ -413,6 +416,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
 			largepage = 1;
 		}
 	}
+	mmu_seq = vcpu->kvm->mmu_notifier_seq;
+	/* implicit mb(), we'll read before PT lock is unlocked */
 	pfn = gfn_to_pfn(vcpu->kvm, walker.gfn);
 	up_read(&current->mm->mmap_sem);
 
@@ -424,6 +429,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
 	}
 
 	spin_lock(&vcpu->kvm->mmu_lock);
+	if (mmu_notifier_retry(vcpu, mmu_seq))
+		goto out_unlock;
 	kvm_mmu_free_some_pages(vcpu);
 	shadow_pte = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault,
 				  largepage, &write_pt, pfn);
@@ -439,6 +446,11 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr,
 	spin_unlock(&vcpu->kvm->mmu_lock);
 
 	return write_pt;
+
+out_unlock:
+	spin_unlock(&vcpu->kvm->mmu_lock);
+	kvm_release_pfn_clean(pfn);
+	return 0;
 }
 
 static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5916191420c7..0d682fc6aeb3 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -883,6 +883,7 @@ int kvm_dev_ioctl_check_extension(long ext)
 	case KVM_CAP_PIT:
 	case KVM_CAP_NOP_IO_DELAY:
 	case KVM_CAP_MP_STATE:
+	case KVM_CAP_SYNC_MMU:
 		r = 1;
 		break;
 	case KVM_CAP_COALESCED_MMIO:
@@ -1495,6 +1496,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,
 		goto out;
 
 	down_write(&kvm->slots_lock);
+	spin_lock(&kvm->mmu_lock);
 
 	p = &kvm->arch.aliases[alias->slot];
 	p->base_gfn = alias->guest_phys_addr >> PAGE_SHIFT;
@@ -1506,6 +1508,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,
 			break;
 	kvm->arch.naliases = n;
 
+	spin_unlock(&kvm->mmu_lock);
 	kvm_mmu_zap_all(kvm);
 
 	up_write(&kvm->slots_lock);
@@ -3972,16 +3975,23 @@ int kvm_arch_set_memory_region(struct kvm *kvm,
 	 */
 	if (!user_alloc) {
 		if (npages && !old.rmap) {
+			unsigned long userspace_addr;
+
 			down_write(&current->mm->mmap_sem);
-			memslot->userspace_addr = do_mmap(NULL, 0,
-						     npages * PAGE_SIZE,
-						     PROT_READ | PROT_WRITE,
-						     MAP_SHARED | MAP_ANONYMOUS,
-						     0);
+			userspace_addr = do_mmap(NULL, 0,
+						 npages * PAGE_SIZE,
+						 PROT_READ | PROT_WRITE,
+						 MAP_SHARED | MAP_ANONYMOUS,
+						 0);
 			up_write(&current->mm->mmap_sem);
 
-			if (IS_ERR((void *)memslot->userspace_addr))
-				return PTR_ERR((void *)memslot->userspace_addr);
+			if (IS_ERR((void *)userspace_addr))
+				return PTR_ERR((void *)userspace_addr);
+
+			/* set userspace_addr atomically for kvm_hva_to_rmapp */
+			spin_lock(&kvm->mmu_lock);
+			memslot->userspace_addr = userspace_addr;
+			spin_unlock(&kvm->mmu_lock);
 		} else {
 			if (!old.user_alloc && old.rmap) {
 				int ret;