This series fixes handling MSI-X when device model is running in a stubdomain. The main part is to avoid accessing /dev/mem, which also fixes running dom0 with lockdown enabled.
It depends on a behavior change of Xen that was just comitted, and signaled with a feature flag. If Xen is too old (and XENFEAT_dm_msix_all_writes flag is not set), fallback to the old behavior. The other part is a fix to enforce read-only registers in the config space. This fixes MSI-X setup for iwlwifi Linux driver, as it happen to write to MSI-X capability id reg (as a workaround for some older device which has another register there). It should be no-op, but due to a bug in xen_pt code, it broke MSI-X detection. All those patches have been shipped in Qubes OS 4.2 already, and prove to fix the issue. See individual commit messages for details. Marek Marczykowski-Górecki (3): hw/xen/xen_pt: Save back data only for declared registers Update Xen's features.h header Do not access /dev/mem in MSI-X PCI passthrough on Xen hw/xen/xen_pt.c | 7 +- hw/xen/xen_pt_msi.c | 94 ++++++++++++++++++------------ include/hw/xen/interface/features.h | 17 +++++- 3 files changed, 82 insertions(+), 36 deletions(-) base-commit: 2358f1b60f73287fe606c7ff48043b4f9e1c2d0f -- git-series 0.9.1
