iommu/amd: Check EFR[EPHSup] bit before enabling PPR

Check for EFR[EPHSup] bit before enabling PPR. This bit must be set
to enable PPR.

Reported-by: Borislav Petkov <bp@alien8.de>
Fixes: c4cb231 ("iommu/amd: Add support for enable/disable IOPF")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218900
Tested-by: Borislav Petkov <bp@alien8.de>
Tested-by: Jean-Christophe Guillain <jean-christophe@guillain.net>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Link: https://lore.kernel.org/r/20240530071118.10297-1-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd/amd_iommu.h

@@ -129,7 +129,8 @@ static inline int check_feature_gpt_level(void)
 static inline bool amd_iommu_gt_ppr_supported(void)
 {
 	return (check_feature(FEATURE_GT) &&
-		check_feature(FEATURE_PPR));
+		check_feature(FEATURE_PPR) &&
+		check_feature(FEATURE_EPHSUP));
 }
 
 static inline u64 iommu_virt_to_phys(void *vaddr)