On Fri, Jul 14, 2023 at 10:37 AM Stefan Berger <stef...@linux.ibm.com> wrote: > > > > On 7/14/23 13:29, Joelle van Dyne wrote: > > On Fri, Jul 14, 2023 at 9:19 AM Stefan Berger <stef...@linux.ibm.com> wrote: > >> > >> > >> > >> > >> I don't know whether we would want multiple devices. tpm_find() usage is > >> certainly not prepared for multiple devices. > > Sorry, "multiple TPM interfaces" here does not mean "at the same > > time". Will clarify the description. > > > >> > >> > >> Good for the consolidation. > >> > >> > >> Does moving the TIS to a different address help on aarch64? > > That was the first thing we tried and no it doesn't help. > > I would remove it if we don't have a known alternative address that makes it > work. If we do, I think we should document it in tpm.rst. "It" is referring to tpm-tis-device? Note that it does work fine with Linux VMs.
> > > >> > >> Can the size really be an option? I don't see it useful and if one gave > >> the wrong size it may break things. > > It was added for consistency (otherwise we have to determine the size > > by looking at the interface everywhere). Also, it is possible for the > > size to be larger than the constant. For example, Apple Silicon uses > > 16KiB page sizes and we may decide to force the device to be 16KiB > > aligned (not sure if this is needed yet while we still track down why > > the dual mapping was not working). In that case, we would need to > > inform the OS of the true region size to prevent any overlap issues. > > Both baseaddr and size should be provided only by the plug handler in > > the virt machine, otherwise things may break even if we get rid of > > size and have just an incorrect baseaddr. > > > >> > >> > >>