iommu/vt-d: Set SRE bit only when hardware has SRS cap

SRS cap is the hardware cap telling if the hardware IOMMU can support
requests seeking supervisor privilege or not. SRE bit in scalable-mode
PASID table entry is treated as Reserved(0) for implementation not
supporting SRS cap.

Checking SRS cap before setting SRE bit can avoid the non-recoverable
fault of "Non-zero reserved field set in PASID Table Entry" caused by
setting SRE bit while there is no SRS cap support. The fault messages
look like below:

 DMAR: DRHD: handling fault status reg 2
 DMAR: [DMA Read NO_PASID] Request device [00:0d.0] fault addr 0x1154e1000
       [fault reason 0x5a]
       SM: Non-zero reserved field set in PASID Table Entry

Fixes: 6f7db75e1c46 ("iommu/vt-d: Add second level page table interface")
Cc: stable@vger.kernel.org
Signed-off-by: Tina Zhang <tina.zhang@intel.com>
Link: https://lore.kernel.org/r/20221115070346.1112273-1-tina.zhang@intel.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20221116051544.26540-3-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c
index c30ddac40ee5fc2d5ce79cc1353854959bf5a998..e13d7e5273e195cc0bc84019e650e4c7e7a5523c 100644 (file)
--- a/drivers/iommu/intel/pasid.c
+++ b/drivers/iommu/intel/pasid.c
@@ -642,7 +642,7 @@ int intel_pasid_setup_second_level(struct intel_iommu *iommu,
         * Since it is a second level only translation setup, we should
         * set SRE bit as well (addresses are expected to be GPAs).
         */
-       if (pasid != PASID_RID2PASID)
+       if (pasid != PASID_RID2PASID && ecap_srs(iommu->ecap))
                pasid_set_sre(pte);
        pasid_set_present(pte);
        spin_unlock(&iommu->lock);
@@ -685,7 +685,8 @@ int intel_pasid_setup_pass_through(struct intel_iommu *iommu,
         * We should set SRE bit as well since the addresses are expected
         * to be GPAs.
         */
-       pasid_set_sre(pte);
+       if (ecap_srs(iommu->ecap))
+               pasid_set_sre(pte);
        pasid_set_present(pte);
        spin_unlock(&iommu->lock);