iommu/amd-vi: fix checking for Invalidate All support in amd_iommu_resume()

The iommu local variable does not point to to a valid amd_iommu element
after the call to for_each_amd_iommu().  Instead check whether any IOMMU
on the system doesn't support Invalidate All in order to perform the
per-domain and per-device flushes.

Fixes: 9c46139de889 ('amd iommu: Support INVALIDATE_IOMMU_ALL command.')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
master commit: 5ecbb779748a56495f2c892f0610d57dd623c7cd
master date: 2023-06-13 14:41:32 +0200

diff --git a/xen/drivers/passthrough/amd/iommu_init.c b/xen/drivers/passthrough/amd/iommu_init.c
index 559a734bdaa56611dd794d65664071d55cb62fe7..ca791d4e54a731039a30599791b37f814d3ad911 100644 (file)
--- a/xen/drivers/passthrough/amd/iommu_init.c
+++ b/xen/drivers/passthrough/amd/iommu_init.c
@@ -1587,6 +1587,7 @@ void amd_iommu_crash_shutdown(void)
 void amd_iommu_resume(void)
 {
     struct amd_iommu *iommu;
+    bool invalidate_all = true;
 
     for_each_amd_iommu ( iommu )
     {
@@ -1596,10 +1597,12 @@ void amd_iommu_resume(void)
         */
         disable_iommu(iommu);
         enable_iommu(iommu);
+        if ( !iommu->features.flds.ia_sup )
+            invalidate_all = false;
     }
 
     /* flush all cache entries after iommu re-enabled */
-    if ( !iommu->features.flds.ia_sup )
+    if ( !invalidate_all )
     {
         invalidate_all_devices();
         invalidate_all_domain_pages();