@@ -36,6 +36,7 @@ void uv_query_info(void)
uv_info.max_sec_stor_addr = ALIGN(uvcb.max_guest_stor_addr, PAGE_SIZE);
uv_info.max_num_sec_conf = uvcb.max_num_sec_conf;
uv_info.max_guest_cpu_id = uvcb.max_guest_cpu_id;
+ uv_info.uv_feature_indications = uvcb.uv_feature_indications;
}
#ifdef CONFIG_PROTECTED_VIRTUALIZATION_GUEST
@@ -73,6 +73,10 @@ enum uv_cmds_inst {
BIT_UVC_CMD_UNPIN_PAGE_SHARED = 22,
};
+enum uv_feat_ind {
+ BIT_UV_FEAT_MISC = 0,
+};
+
struct uv_cb_header {
u16 len;
u16 cmd; /* Command Code */
@@ -97,7 +101,8 @@ struct uv_cb_qui {
u64 max_guest_stor_addr;
u8 reserved88[158 - 136];
u16 max_guest_cpu_id;
- u8 reserveda0[200 - 160];
+ u64 uv_feature_indications;
+ u8 reserveda0[200 - 168];
} __packed __aligned(8);
/* Initialize Ultravisor */
@@ -274,6 +279,7 @@ struct uv_info {
unsigned long max_sec_stor_addr;
unsigned int max_num_sec_conf;
unsigned short max_guest_cpu_id;
+ unsigned long uv_feature_indications;
};
extern struct uv_info uv_info;
@@ -364,6 +364,15 @@ static ssize_t uv_query_facilities(struc
static struct kobj_attribute uv_query_facilities_attr =
__ATTR(facilities, 0444, uv_query_facilities, NULL);
+static ssize_t uv_query_feature_indications(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ return sysfs_emit(buf, "%lx\n", uv_info.uv_feature_indications);
+}
+
+static struct kobj_attribute uv_query_feature_indications_attr =
+ __ATTR(feature_indications, 0444, uv_query_feature_indications, NULL);
+
static ssize_t uv_query_max_guest_cpus(struct kobject *kobj,
struct kobj_attribute *attr, char *page)
{
@@ -396,6 +405,7 @@ static struct kobj_attribute uv_query_ma
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,
@@ -791,6 +791,32 @@ void do_secure_storage_access(struct pt_
struct page *page;
int rc;
+ /*
+ * bit 61 tells us if the address is valid, if it's not we
+ * have a major problem and should stop the kernel or send a
+ * SIGSEGV to the process. Unfortunately bit 61 is not
+ * reliable without the misc UV feature so we need to check
+ * for that as well.
+ */
+ if (test_bit_inv(BIT_UV_FEAT_MISC, &uv_info.uv_feature_indications) &&
+ !test_bit_inv(61, ®s->int_parm_long)) {
+ /*
+ * When this happens, userspace did something that it
+ * was not supposed to do, e.g. branching into secure
+ * memory. Trigger a segmentation fault.
+ */
+ if (user_mode(regs)) {
+ send_sig(SIGSEGV, current, 0);
+ return;
+ }
+
+ /*
+ * The kernel should never run into this case and we
+ * have no way out of this situation.
+ */
+ panic("Unexpected PGM 0x3d with TEID bit 61=0");
+ }
+
switch (get_fault_type(regs)) {
case USER_FAULT:
mm = current->mm;