virt: Further improve detection of EC2 metal instances

Commit f90eea7
virt: Improve detection of EC2 metal instances

Added support for detecting EC2 metal instances via the product
name in DMI by testing for the ".metal" suffix.

Unfortunately this doesn't cover all cases, as there are going to be
instance types where ".metal" is not a suffix (ie, .metal-16xl,
.metal-32xl, ...)

This modifies the logic to also allow those new forms.

Signed-off-by: Benjamin Herrenschmidt <benh@amazon.com>

src/basic/virt.c

@@ -264,6 +264,7 @@ static Virtualization detect_vm_dmi(void) {
                          * so we fallback to using the product name which is less restricted
                          * to distinguish metal systems from virtualized instances */
                         _cleanup_free_ char *s = NULL;
+                        const char *e;
 
                         r = read_full_virtual_file("/sys/class/dmi/id/product_name", &s, NULL);
                         /* In EC2, virtualized is much more common than metal, so if for some reason
@@ -273,8 +274,9 @@ static Virtualization detect_vm_dmi(void) {
                                                 " assuming virtualized: %m");
                                 return VIRTUALIZATION_AMAZON;
                         }
-                        if (endswith(truncate_nl(s), ".metal")) {
-                                log_debug("DMI product name ends with '.metal', assuming no virtualization");
+                        e = strstrafter(truncate_nl(s), ".metal");
+                        if (e && IN_SET(*e, 0, '-')) {
+                                log_debug("DMI product name has '.metal', assuming no virtualization");
                                 return VIRTUALIZATION_NONE;
                         } else
                                 return VIRTUALIZATION_AMAZON;