Re: tpm-tis device for ARM virt

Hi All, I received a private bug report that starting a VM with swtpm device fails with qemu-system-aarch64. The VM config has <tpm model='tpm-tis'> <backend type='emulator' version='2.0'/> </tpm> QEMU reports the following error error: internal error: process exited while connecting to monitor: 2021-02-07T05:15:35.378927Z qemu-system-aarch64: -device tpm-tis,tpmdev=tpm-tpm0,id=tpm0: 'tpm-tis' is not a valid device model name Indeed it appears the device name is 'tpm-tis-device' [1][2] for ARM virt. The similar yet different device naming between x86 and ARM is unfortunate. IIUC, the devices are the same between the architectures, i.e. they both emulate a TPM device conforming to the TIS spec. If so, adding a 'tpm-tis-device' to virDomainTPMModel seems redundant. I assume the naming difference should be handled internally, e.g. something like the below patch to qemuBuildTPMDevStr? I can send a proper patch if this is an acceptable approach. Regards, Jim [1] https://qemu.readthedocs.io/en/latest/specs/tpm.html [2] https://github.com/qemu/qemu/commit/c294ac327ca99342b90bd3a83d2cef9b447afaa7 diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 92036d26c0..5154611ccd 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -9198,6 +9198,9 @@ qemuBuildTPMDevStr(const virDomainDef *def, g_auto(virBuffer) buf = VIR_BUFFER_INITIALIZER; const char *model = virDomainTPMModelTypeToString(tpm->model); + if (tpm->model == VIR_DOMAIN_TPM_MODEL_TIS && def->os.arch == VIR_ARCH_AARCH64) + model = "tpm-tis-device"; + virBufferAsprintf(&buf, "%s,tpmdev=tpm-%s,id=%s", model, tpm->info.alias, tpm->info.alias);