[xen master] x86/hvm: short-circuit HVM shadow guest creation earlier

[patchbot@xxxxxxx]

commit ddd52db068bbeafc7e9ec1d20ae93cf64b44ebb2
Author:     Roger Pau Monne <roger.pau@xxxxxxxxxx>
AuthorDate: Mon Feb 9 15:38:15 2026 +0100
Commit:     Roger Pau Monne <roger.pau@xxxxxxxxxx>
CommitDate: Tue Feb 10 08:58:25 2026 +0100

    x86/hvm: short-circuit HVM shadow guest creation earlier
    
    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 <roger.pau@xxxxxxxxxx>
    Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Alejandro Vallejo <alejandro.garciavallejo@xxxxxxx>
---
 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 8b2f33f1a0..8eb1509782 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");
+        return -EINVAL;
+    }
+
     if ( !hvm )
         /*
          * It is only meaningful for XEN_DOMCTL_CDF_oos_off to be clear
--
generated by git-patchbot for /home/xen/git/xen.git#master