According to VTD spec, a 256-bit descriptor will result in an invalid
descriptor error if submitted in an IQ that is setup to provide hardware
with 128-bit descriptors (IQA_REG.DW=0). Meanwhile, there are old inv desc
types (e.g. iotlb_inv_desc) that can be either 128bits or 256bits. If a
128-bit version of this descriptor is submitted into an IQ that is setup
to provide hardware with 256-bit descriptors will also result in an invalid
descriptor error.
The 2nd will be captured by the tail register update. So we only need to
focus on the 1st.
Because the reserved bit check between different types of invalidation desc
are common, so introduce a common function vtd_inv_desc_reserved_check()
to do all the checks and pass the differences as parameters.
With this change, need to replace error_report_once() call with error_report()
to catch different call sites. This isn't an issue as error_report_once()
here is mainly used to help debug guest error, but it only dumps once in
qemu life cycle and doesn't help much, we need error_report() instead.
Fixes: c0c1d35184 ("intel_iommu: add 256 bits qi_desc support")
Suggested-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Message-Id: <20241104125536.1236118-3-zhenzhong.duan@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
8e761fb61c