On 7/14/23 13:46, Joelle van Dyne wrote:
On Fri, Jul 14, 2023 at 10:43 AM Stefan Berger <stef...@linux.ibm.com> wrote:



On 7/14/23 13:39, Joelle van Dyne wrote:
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.

yes, tpm_tis_sysbus and I know it works with Liunux but I see this discussion 
here around Win 11 on aarch64. Why do we need to user another address than the 
standard address if for Win 11 on aarch64 it doesn't get it to work.
The standard address won't work for Linux either.

TPM TIS on standard address on ARM64 Virt machines = collision with
DRAM, will not instantiate

I thought that this was working with Linux on the aarch64 virt board as 
contributed by Eric Auger.

https://github.com/qemu/qemu/commit/fcaa204194e15ba24cd53087dd616aabbc29e64f

Also I had tested it to some extent: 
https://github.com/stefanberger/swtpm/issues/493#issuecomment-885221109



TPM TIS on SysBus with dynamically allocated address = works on Linux,
cannot start on Windows






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.





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