I am working on aarch64/sbsa-ref machine so people can have virtual machine to test their OS against something reminding standards compliant system.
One of tools I use is BSA ACS (Base System Architecture - Architecture Compliance Suite) [1] written by Arm. It runs set of tests to check does system conforms to BSA specification. 1. https://github.com/ARM-software/bsa-acs SBSA-ref goes better and better, yet still we have some issues. One of them is test 822 ("Check Type 1 config header rules") which fails on each PCIe root port device: BDF 0x400 : SLT attribute mismatch: 0xFF020100 instead of 0x20100 BDF 0x500 : SLT attribute mismatch: 0xFF030300 instead of 0x30300 BDF 0x600 : SLT attribute mismatch: 0xFF040400 instead of 0x40400 I reported it as an issue [2] and got response that it may be QEMU fault. My pcie knowledge is not good enough to know where the problem is. 2. https://github.com/ARM-software/bsa-acs/issues/193 In the comment Gowtham Siddarth wrote:
Regarding the SLT (Secondary Latency Timer) register, the expected values align with the ACS specifications, registering as 0. However, a discrepancy arises in the register's attribute, intended to be set as Read-Only. Contrary to this intent, the bit field seems to function as> Read-Write. Ordinarily, when attempting to write to the register by configuring all bits to 1, the anticipated behaviour should involve rejecting the write operation, maintaining the value at 0 to uphold the register's designated Read-Only nature. However, in this scenario, the write action takes effect, leading to a transformation of the register's value to FFs. This anomaly could potentially stem from an issue within the emulator.
Does someone know where the problem may be? And how to fix it?
