On 2025-11-10 02:32 PM, Alex Mastro wrote:
On Mon, Nov 10, 2025 at 10:03:54PM +0000, David Matlack wrote:
On 2025-11-10 01:10 PM, Alex Mastro wrote:
- hdr = vfio_iommu_info_cap_hdr(buf, VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE);
- if (!hdr)
goto free_buf;Is this to account for running on old versions of VFIO? Or are there some scenarios when VFIO can't report the list of IOVA ranges?
I wanted to avoid being overly assertive in this low-level helper function, mostly out of ignorance about where/in which system states this capability may not be reported.
Makes sense, but IIUC a failure here will eventually turn into an assertion failure in all callers that exist today. So there's currently no reason to plumb it up the stack.
For situations like this, I think we should err on asserting at the lower level helpers, and only propagating errors up as needed. That keeps all the happy-path callers simple, and those should be the majority of callers (if not all callers).