On 4/10/25 07:57, Jan Beulich wrote:
On 08.04.2025 18:07, Alejandro Vallejo wrote:
--- a/xen/arch/x86/domain-builder/fdt.c
+++ b/xen/arch/x86/domain-builder/fdt.c
@@ -193,6 +193,25 @@ static int __init process_domain_node(
bd->domid = (domid_t)val;
printk(" domid: %d\n", bd->domid);
}
+ else if ( strncmp(prop_name, "mode", name_len) == 0 )
+ {
+ if ( fdt_prop_as_u32(prop, &bd->mode) != 0 )
+ {
+ printk(" failed processing mode for domain %s\n", name);
+ return -EINVAL;
+ }
+
+ printk(" mode: ");
+ if ( !(bd->mode & BUILD_MODE_PARAVIRT) )
+ {
+ if ( bd->mode & BUILD_MODE_ENABLE_DM )
+ printk("HVM\n");
+ else
+ printk("PVH\n");
+ }
+ else
+ printk("PV\n");
+ }
My prior questions here remain: What's the significance of
BUILD_MODE_ENABLE_DM when set alongside BUILD_MODE_PARAVIRT? What about
any of the other bits being set?
From boot-domain.h:
/* On | Off */
#define BUILD_MODE_PARAVIRT (1 << 0) /* PV | PVH/HVM */
#define BUILD_MODE_ENABLE_DM (1 << 1) /* HVM | PVH */
The logic says, if BUILD_MODE_PARAVIRT bit is not set, thus an HVM
domain, check if BUILD_MODE_ENABLE_DM has been set. This is determin if
the domain is what the toolstack differentiates as either an HVM or PVH
domain. As you should know, there is no case of a PV domain requiring a
backing device mode (DM) domain. IOW, BUILD_MODE_ENABLE_DM is only
relevant to an HVM domain.
v/r,
dps
