1 files changed, 161 insertions, 5 deletions

diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c
index 386d4e42b8d3..f9810d2a267c 100644
--- a/arch/s390/kernel/uv.c
+++ b/arch/s390/kernel/uv.c
@@ -30,7 +30,7 @@ int __bootdata_preserved(prot_virt_host);
 EXPORT_SYMBOL(prot_virt_host);
 EXPORT_SYMBOL(uv_info);
 
-static int __init uv_init(unsigned long stor_base, unsigned long stor_len)
+static int __init uv_init(phys_addr_t stor_base, unsigned long stor_len)
 {
 	struct uv_cb_init uvcb = {
 		.header.cmd = UVC_CMD_INIT_UV,
@@ -49,12 +49,12 @@ static int __init uv_init(unsigned long stor_base, unsigned long stor_len)
 
 void __init setup_uv(void)
 {
-	unsigned long uv_stor_base;
+	void *uv_stor_base;
 
 	if (!is_prot_virt_host())
 		return;
 
-	uv_stor_base = (unsigned long)memblock_alloc_try_nid(
+	uv_stor_base = memblock_alloc_try_nid(
 		uv_info.uv_base_stor_len, SZ_1M, SZ_2G,
 		MEMBLOCK_ALLOC_ACCESSIBLE, NUMA_NO_NODE);
 	if (!uv_stor_base) {
@@ -63,8 +63,8 @@ void __init setup_uv(void)
 		goto fail;
 	}
 
-	if (uv_init(uv_stor_base, uv_info.uv_base_stor_len)) {
-		memblock_phys_free(uv_stor_base, uv_info.uv_base_stor_len);
+	if (uv_init(__pa(uv_stor_base), uv_info.uv_base_stor_len)) {
+		memblock_free(uv_stor_base, uv_info.uv_base_stor_len);
 		goto fail;
 	}
 
@@ -234,6 +234,32 @@ static int make_secure_pte(pte_t *ptep, unsigned long addr,
 	return uvcb->rc == 0x10a ? -ENXIO : -EINVAL;
 }
 
+/**
+ * should_export_before_import - Determine whether an export is needed
+ * before an import-like operation
+ * @uvcb: the Ultravisor control block of the UVC to be performed
+ * @mm: the mm of the process
+ *
+ * Returns whether an export is needed before every import-like operation.
+ * This is needed for shared pages, which don't trigger a secure storage
+ * exception when accessed from a different guest.
+ *
+ * Although considered as one, the Unpin Page UVC is not an actual import,
+ * so it is not affected.
+ *
+ * No export is needed also when there is only one protected VM, because the
+ * page cannot belong to the wrong VM in that case (there is no "other VM"
+ * it can belong to).
+ *
+ * Return: true if an export is needed before every import, otherwise false.
+ */
+static bool should_export_before_import(struct uv_cb_header *uvcb, struct mm_struct *mm)
+{
+	if (uvcb->cmd == UVC_CMD_UNPIN_PAGE_SHARED)
+		return false;
+	return atomic_read(&mm->context.protected_count) > 1;
+}
+
 /*
  * Requests the Ultravisor to make a page accessible to a guest.
  * If it's brought in the first time, it will be cleared. If
@@ -277,6 +303,8 @@ again:
 
 	lock_page(page);
 	ptep = get_locked_pte(gmap->mm, uaddr, &ptelock);
+	if (should_export_before_import(uvcb, gmap->mm))
+		uv_convert_from_secure(page_to_phys(page));
 	rc = make_secure_pte(ptep, uaddr, page, uvcb);
 	pte_unmap_unlock(ptep, ptelock);
 	unlock_page(page);
@@ -334,6 +362,61 @@ int gmap_convert_to_secure(struct gmap *gmap, unsigned long gaddr)
 }
 EXPORT_SYMBOL_GPL(gmap_convert_to_secure);
 
+/**
+ * gmap_destroy_page - Destroy a guest page.
+ * @gmap: the gmap of the guest
+ * @gaddr: the guest address to destroy
+ *
+ * An attempt will be made to destroy the given guest page. If the attempt
+ * fails, an attempt is made to export the page. If both attempts fail, an
+ * appropriate error is returned.
+ */
+int gmap_destroy_page(struct gmap *gmap, unsigned long gaddr)
+{
+	struct vm_area_struct *vma;
+	unsigned long uaddr;
+	struct page *page;
+	int rc;
+
+	rc = -EFAULT;
+	mmap_read_lock(gmap->mm);
+
+	uaddr = __gmap_translate(gmap, gaddr);
+	if (IS_ERR_VALUE(uaddr))
+		goto out;
+	vma = vma_lookup(gmap->mm, uaddr);
+	if (!vma)
+		goto out;
+	/*
+	 * Huge pages should not be able to become secure
+	 */
+	if (is_vm_hugetlb_page(vma))
+		goto out;
+
+	rc = 0;
+	/* we take an extra reference here */
+	page = follow_page(vma, uaddr, FOLL_WRITE | FOLL_GET);
+	if (IS_ERR_OR_NULL(page))
+		goto out;
+	rc = uv_destroy_owned_page(page_to_phys(page));
+	/*
+	 * Fault handlers can race; it is possible that two CPUs will fault
+	 * on the same secure page. One CPU can destroy the page, reboot,
+	 * re-enter secure mode and import it, while the second CPU was
+	 * stuck at the beginning of the handler. At some point the second
+	 * CPU will be able to progress, and it will not be able to destroy
+	 * the page. In that case we do not want to terminate the process,
+	 * we instead try to export the page.
+	 */
+	if (rc)
+		rc = uv_convert_owned_from_secure(page_to_phys(page));
+	put_page(page);
+out:
+	mmap_read_unlock(gmap->mm);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(gmap_destroy_page);
+
 /*
  * To be called with the page locked or with an extra reference! This will
  * prevent gmap_make_secure from touching the page concurrently. Having 2
@@ -392,6 +475,54 @@ static ssize_t uv_query_facilities(struct kobject *kobj,
 static struct kobj_attribute uv_query_facilities_attr =
 	__ATTR(facilities, 0444, uv_query_facilities, NULL);
 
+static ssize_t uv_query_supp_se_hdr_ver(struct kobject *kobj,
+					struct kobj_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%lx\n", uv_info.supp_se_hdr_ver);
+}
+
+static struct kobj_attribute uv_query_supp_se_hdr_ver_attr =
+	__ATTR(supp_se_hdr_ver, 0444, uv_query_supp_se_hdr_ver, NULL);
+
+static ssize_t uv_query_supp_se_hdr_pcf(struct kobject *kobj,
+					struct kobj_attribute *attr, char *buf)
+{
+	return sysfs_emit(buf, "%lx\n", uv_info.supp_se_hdr_pcf);
+}
+
+static struct kobj_attribute uv_query_supp_se_hdr_pcf_attr =
+	__ATTR(supp_se_hdr_pcf, 0444, uv_query_supp_se_hdr_pcf, NULL);
+
+static ssize_t uv_query_dump_cpu_len(struct kobject *kobj,
+				     struct kobj_attribute *attr, char *page)
+{
+	return scnprintf(page, PAGE_SIZE, "%lx\n",
+			uv_info.guest_cpu_stor_len);
+}
+
+static struct kobj_attribute uv_query_dump_cpu_len_attr =
+	__ATTR(uv_query_dump_cpu_len, 0444, uv_query_dump_cpu_len, NULL);
+
+static ssize_t uv_query_dump_storage_state_len(struct kobject *kobj,
+					       struct kobj_attribute *attr, char *page)
+{
+	return scnprintf(page, PAGE_SIZE, "%lx\n",
+			uv_info.conf_dump_storage_state_len);
+}
+
+static struct kobj_attribute uv_query_dump_storage_state_len_attr =
+	__ATTR(dump_storage_state_len, 0444, uv_query_dump_storage_state_len, NULL);
+
+static ssize_t uv_query_dump_finalize_len(struct kobject *kobj,
+					  struct kobj_attribute *attr, char *page)
+{
+	return scnprintf(page, PAGE_SIZE, "%lx\n",
+			uv_info.conf_dump_finalize_len);
+}
+
+static struct kobj_attribute uv_query_dump_finalize_len_attr =
+	__ATTR(dump_finalize_len, 0444, uv_query_dump_finalize_len, NULL);
+
 static ssize_t uv_query_feature_indications(struct kobject *kobj,
 					    struct kobj_attribute *attr, char *buf)
 {
@@ -431,12 +562,37 @@ static ssize_t uv_query_max_guest_addr(struct kobject *kobj,
 static struct kobj_attribute uv_query_max_guest_addr_attr =
 	__ATTR(max_address, 0444, uv_query_max_guest_addr, NULL);
 
+static ssize_t uv_query_supp_att_req_hdr_ver(struct kobject *kobj,
+					     struct kobj_attribute *attr, char *page)
+{
+	return scnprintf(page, PAGE_SIZE, "%lx\n", uv_info.supp_att_req_hdr_ver);
+}
+
+static struct kobj_attribute uv_query_supp_att_req_hdr_ver_attr =
+	__ATTR(supp_att_req_hdr_ver, 0444, uv_query_supp_att_req_hdr_ver, NULL);
+
+static ssize_t uv_query_supp_att_pflags(struct kobject *kobj,
+					struct kobj_attribute *attr, char *page)
+{
+	return scnprintf(page, PAGE_SIZE, "%lx\n", uv_info.supp_att_pflags);
+}
+
+static struct kobj_attribute uv_query_supp_att_pflags_attr =
+	__ATTR(supp_att_pflags, 0444, uv_query_supp_att_pflags, NULL);
+
 static struct attribute *uv_query_attrs[] = {
 	&uv_query_facilities_attr.attr,
 	&uv_query_feature_indications_attr.attr,
 	&uv_query_max_guest_cpus_attr.attr,
 	&uv_query_max_guest_vms_attr.attr,
 	&uv_query_max_guest_addr_attr.attr,
+	&uv_query_supp_se_hdr_ver_attr.attr,
+	&uv_query_supp_se_hdr_pcf_attr.attr,
+	&uv_query_dump_storage_state_len_attr.attr,
+	&uv_query_dump_finalize_len_attr.attr,
+	&uv_query_dump_cpu_len_attr.attr,
+	&uv_query_supp_att_req_hdr_ver_attr.attr,
+	&uv_query_supp_att_pflags_attr.attr,
 	NULL,
 };