On Thu, 17 Sep 2026 00:14:12 +0530, Manish Honap wrote: > under preserve_config, the _DSM. Gate the _DSM on preserve_config: x86 q35 > passes false as it does not use the accelerated SMMU, so it emits no _DSM > and its ACPI tables stay byte for byte what they were.
Confirmed: on 28e7aad522 plus the series bios-tables-test passes on x86_64 (q35/cxl and q35/acpihmat-genericx, the v1 failures, included), aarch64, riscv64 and loongarch64. accel=on is out of reach under TCG, so I forced preserve_config on virt locally and booted an arm64 guest (7.3-rc1 based, defconfig) with a cxl-type3 behind a cxl-rp. With this patch Linux keeps the firmware BARs and bridge window under the pxb-cxl; on 09/10 with the same hack it releases and reassigns them. No ACPI errors either way. Tested-by: Junjie Cao <[email protected]> 08/10 still says the x86 bridge "still emits the ``_DSM`` method, but its function 0 returns an empty support mask"; that was v1. Junjie
