[PATCH] powerpc/pseries/vas: Ignore VAS update for DLPAR if copy/paste is not enabled

[Haren Myneni]

The hypervisor supports user-mode NX from Power10. pseries_vas_dlpar_cpu()
is called from lparcfg_write() to update VAS windows for DLPAR CPU event
and the kernel gets -ENOTSUPP for HCALLs if the user-mode NX is not
supported.

This patch ignores updating VAS capabilities and returns success if the
copy/paste feature is not enabled.

Fixes: 2147783d6bf0 ("powerpc/pseries: Use lparcfg to reconfig VAS windows for 
DLPAR CPU")
Signed-off-by: Haren Myneni <ha...@linux.ibm.com>
---
 arch/powerpc/platforms/pseries/vas.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/vas.c 
b/arch/powerpc/platforms/pseries/vas.c
index 559112312810..dc003849d2c5 100644
--- a/arch/powerpc/platforms/pseries/vas.c
+++ b/arch/powerpc/platforms/pseries/vas.c
@@ -856,6 +856,13 @@ int pseries_vas_dlpar_cpu(void)
 {
        int new_nr_creds, rc;
 
+       /*
+        * NX-GZIP is not enabled. Nothing to do for DLPAR event
+        */
+       if (!copypaste_feat)
+               return 0;
+
+
        rc = h_query_vas_capabilities(H_QUERY_VAS_CAPABILITIES,
                                      vascaps[VAS_GZIP_DEF_FEAT_TYPE].feat,
                                      (u64)virt_to_phys(&hv_cop_caps));
@@ -1012,6 +1019,7 @@ static int __init pseries_vas_init(void)
         * Linux supports user space COPY/PASTE only with Radix
         */
        if (!radix_enabled()) {
+               copypaste_feat = 0;
                pr_err("API is supported only with radix page tables\n");
                return -ENOTSUPP;
        }
-- 
2.26.3