On Mon, Feb 09, 2026 at 05:02:26PM +0100, Alejandro Vallejo wrote: > On Mon Feb 9, 2026 at 3:40 PM CET, Roger Pau Monne wrote: > > If shadow paging has been compiled out short circuit the creation of HVM > > guests that attempt to use shadow paging at arch_sanitise_domain_config(). > > There's no need to further build the domain when creation is doomed to fail > > later on. > > > > Signed-off-by: Roger Pau Monné <[email protected]> > > --- > > xen/arch/x86/domain.c | 6 ++++++ > > 1 file changed, 6 insertions(+) > > > > diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c > > index 8b2f33f1a06c..8eb1509782ef 100644 > > --- a/xen/arch/x86/domain.c > > +++ b/xen/arch/x86/domain.c > > @@ -627,6 +627,12 @@ int arch_sanitise_domain_config(struct > > xen_domctl_createdomain *config) > > return -EINVAL; > > } > > > > + if ( hvm && !hap && !IS_ENABLED(CONFIG_SHADOW_PAGING) ) > > + { > > + dprintk(XENLOG_INFO, "Shadow paging requested but not > > available\n"); > > nit: s/requested/required/, maybe?
The wording matches the rest of the messages in arch_sanitise_domain_config(). I'm not saying that makes it correct, but if we word this differently we should also change the others IMO. > Also, with this in place can't we get rid of the panic in create_dom0() that > checks an identical condition? Hm, I would possibly leave that one, as I think it's clearer for the dom0 case. Otherwise someone using a build without HAP or shadow and attempting to boot in PVH mode will get a message saying: "Shadow paging requested but not available", which is IMO less clear than getting a "Neither HAP nor Shadow available for PVH domain" error message. Just my thinking, both checks achieve the same result, but the error message in the create_dom0() instance is more helpful in the context of dom0 creation. Thanks, Roger.
