Re: [libvirt] [PATCH 10/12] conf: Add support for choosing emulation of a TPM 2

On 05/23/2018 11:55 AM, Ján Tomko wrote: > On Tue, May 22, 2018 at 04:44:51PM -0400, Stefan Berger wrote: >> @@ -24941,6 +24963,9 @@ virDomainTPMDefFormat(virBufferPtr buf, >>     virBufferAsprintf(buf, "<backend type='%s'", >> virDomainTPMBackendTypeToString(def->type)); >> >> +    if (def->version == VIR_DOMAIN_TPM_VERSION_2) >> +        virBufferAddLit(buf, " version='2'"); >> + > > Any reason for not formatting version 1.2? > We should format implicit defaults in the XML if possible. Basically I did it because the previous default 1.2 didn't have it. So I though I'd keep it as is for 1.2 and only write out 2.

> >>     switch (def->type) { >>     case VIR_DOMAIN_TPM_TYPE_PASSTHROUGH: >>         virBufferAddLit(buf, ">\n"); > > Given that version 2 has to be requested in the XML and we don't try to > use it automatically, I'd suggest just dropping this function. We don't > need to parse another tool's --help output to make up for the removal > of parsing --help of qemu and qemu-img. swtpm doesn't have all the bells and whistles of QEMU that we would have a JSON interface to query the features from.

So if a bad command line parameter is passed to swtpm, it will dump the help screen. Here's the output I get from trying to run a VM with an attached TPM 2 but there's no TPM 2 support compiled into swtpm (basically because it was created from the master branch not from the preview branch): # virsh start testvm-tpm2 Error: Failed to start domain testvm-tpm2 error: internal error: Could not start 'swtpm'. exitstatus: 1, error: socket: unrecognized option '--tpm2' Usage: /usr/bin/swtpm socket [options] The following options are supported: -p|--port <port> : use the given port -f|--fd <fd>     : use the given socket file descriptor [...] I think a more controlled error message would be better basically stating 'Local swtpm installation does not support TPM 2'.

   Stefan > > Jano