When /etc/quirks.d/65-iommu-amd.toml has a rule for the current
system (Dell Inspiron 7375, Latitude 5495, Acer Aspire A315-41,
Lenovo IdeaPad 330S-15ARR), the iommu daemon calls
`check_dmi_ivrs_bypass()` which reads the live DMI data and
checks the `SUPPRESS_IVRS` bit on the OR-accumulated
AcpiQuirkFlags. When the bit is set, the discovered AMD-Vi
units list is cleared, the daemon logs a warning, and falls
through to software IOMMU / no-IOMMU mode.
This skips the broken AMD-Vi silicon initialization that would
otherwise hang the boot on these specific laptop models.
Source: linux-7.1 drivers/iommu/amd/init.c (DMI matching
pattern, `acpi_ivrs` DMI table).
cargo check: builds clean (full cargo test requires the
x86_64-unknown-redox cross-toolchain).
vasilito
eaaa4a6412