On 5/14/20 11:32 AM, Daniel Henrique Barboza wrote:
On 5/14/20 11:09 AM, Ján Tomko wrote:
On a Wednesday in 2020, Daniel Henrique Barboza wrote:
Aside from trivial XML parsing/format changes, this patch adds
additional rules for TPM device support to better accomodate
[...]
Any reason why you store them separately?
It seems they are treated the same in every place except when building
QEMU command line. Switching to a def->tpms array would better reflect
the XML. The Validate function would then check wheteher there's just
one copy of each device type.
It is an attempt to minimize the amount of changes needed. For example, making
a def->tpms array would impact all the code related to the 'emulator' TPM type,
in particular the files qemu_tpm.c and qemu_extdevice.c, that would need to
handle an array instead of the def->tpm pointer.
It is also an attempt of making it easier for any future "TPM Proxy" device
style to be added in the future. Instead of revisiting the logic inside each
def->tpms loop one would simply deal with the def->tpmproxy pointer directly.
And, in the case this is wrong and no one else cares about it, at the very
least we didn't change the design of all TPM devices because of one single
PPC64 specific model.
This is all up to debate, of course. If we we decide that changing to a def->tpms
array is worth the extra lines of code I'll make it happen in the v4.
I'm experimenting with the idea of def->tpms array and, aside from having to
change additional files, it's not as bad as I thought. What I'm doing here
to mitigate the changes in the 'emulator' backend code is to always assure that
the 'emulator' device, if present, will be always at def->tpms[0]. This
makes most changes in qemu_tpm.c and qemu_extdevice.c a replace of "def->tpm" to
"def->tpms[0]", instead of having to insert a for loop to interact with
the array.
This also has the benefit of not having to duplicate the handling of def->tpm
for the def->tpmproxy pointer, as Jano mentioned above.
Jano, what do you think about this idea of making def->tpms[0] always a non-proxy
device?
DHB
Thanks,
DHB
Jano
+ if (def->tpm) {
+ virReportError(VIR_ERR_XML_ERROR, "%s",
+ _("only a single TPM non-proxy device is supported"));
+ goto error;
+ }
+ def->tpm = g_steal_pointer(&dev);
+ }
+ }
}
VIR_FREE(nodes);
