s390: Add attestation query information

We have information about the supported attestation header version
and plaintext attestation flag bits.
Let's expose it via the sysfs files.
Signed-off-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Link: https://lore.kernel.org/lkml/20220601100245.3189993-1-seiden@linux.ibm.com/Signed-off-by: Janosch Frank <frankja@linux.ibm.com>

arch/s390/boot/uv.c

@@ -45,6 +45,8 @@ void uv_query_info(void)
 		uv_info.supp_se_hdr_pcf = uvcb.supp_se_hdr_pcf;
 		uv_info.conf_dump_storage_state_len = uvcb.conf_dump_storage_state_len;
 		uv_info.conf_dump_finalize_len = uvcb.conf_dump_finalize_len;
+		uv_info.supp_att_req_hdr_ver = uvcb.supp_att_req_hdr_ver;
+		uv_info.supp_att_pflags = uvcb.supp_att_pflags;
 	}
 
 #ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST

arch/s390/include/asm/uv.h

@@ -124,7 +124,10 @@ struct uv_cb_qui {
 	u64 reservedc0;				/* 0x00c0 */
 	u64 conf_dump_storage_state_len;	/* 0x00c8 */
 	u64 conf_dump_finalize_len;		/* 0x00d0 */
-	u8  reservedd8[256 - 216];		/* 0x00d8 */
+	u64 reservedd8;				/* 0x00d8 */
+	u64 supp_att_req_hdr_ver;		/* 0x00e0 */
+	u64 supp_att_pflags;			/* 0x00e8 */
+	u8 reservedf0[256 - 240];		/* 0x00f0 */
 } __packed __aligned(8);
 
 /* Initialize Ultravisor */
@@ -350,6 +353,8 @@ struct uv_info {
 	unsigned long supp_se_hdr_pcf;
 	unsigned long conf_dump_storage_state_len;
 	unsigned long conf_dump_finalize_len;
+	unsigned long supp_att_req_hdr_ver;
+	unsigned long supp_att_pflags;
 };
 
 extern struct uv_info uv_info;

arch/s390/kernel/uv.c

@@ -479,6 +479,24 @@ 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,
@@ -490,6 +508,8 @@ static struct attribute *uv_query_attrs[] = {
 	&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,
 };