Re: [libvirt PATCH v3] qemu: tpm: do not update profile name for transient domains

[Stefan Berger <stefanb@xxxxxxxxxxxxx>]

On 12/11/24 3:46 AM, Ján Tomko wrote:
> If we do not have a persistent definition, there's no point in
> looking for it since we cannot store it.
>
> Also skip the update if the tpm device(s) in the persistent
> definition are different.
>
> This fixes the crash when starting a transient domain.
>
> https://issues.redhat.com/browse/RHEL-69774
>
> Fixes: d79542eec669eb9c449bb8228179e7a87e768017
> Signed-off-by: Ján Tomko <jtomko@xxxxxxxxxx>

Reviewed-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>

> ---
>   src/qemu/qemu_extdevice.c | 13 ++++++++++++-
>   src/qemu/qemu_tpm.c       |  2 +-
>   2 files changed, 13 insertions(+), 2 deletions(-)
>
> diff --git a/src/qemu/qemu_extdevice.c b/src/qemu/qemu_extdevice.c
> index a6f31f9773..954cb323a4 100644
> --- a/src/qemu/qemu_extdevice.c
> +++ b/src/qemu/qemu_extdevice.c
> @@ -190,7 +190,18 @@ qemuExtDevicesStart(virQEMUDriver *driver,
>   
>       for (i = 0; i < def->ntpms; i++) {
>           virDomainTPMDef *tpm = def->tpms[i];
> -        virDomainTPMDef *persistentTPMDef = persistentDef->tpms[i];
> +        virDomainTPMDef *persistentTPMDef = NULL;
> +
> +        if (persistentDef) {
> +            /* do not try to update the profile in the persistent definition
> +             * if the device does not match */
> +            if (persistentDef->ntpms == def->ntpms)
> +                persistentTPMDef = persistentDef->tpms[i];
> +            if (persistentTPMDef &&
> +                (persistentTPMDef->type != tpm->type ||
> +                 persistentTPMDef->model != tpm->model))
> +                persistentTPMDef = NULL;
> +        }
>   
>           if (tpm->type == VIR_DOMAIN_TPM_TYPE_EMULATOR &&
>               qemuExtTPMStart(driver, vm, tpm, persistentTPMDef,
> diff --git a/src/qemu/qemu_tpm.c b/src/qemu/qemu_tpm.c
> index f223dcb9ae..f5e0184e54 100644
> --- a/src/qemu/qemu_tpm.c
> +++ b/src/qemu/qemu_tpm.c
> @@ -773,7 +773,7 @@ qemuTPMEmulatorBuildCommand(virDomainTPMDef *tpm,
>                                   incomingMigration) < 0)
>           goto error;
>   
> -    if (run_setup && !incomingMigration &&
> +    if (run_setup && !incomingMigration && persistentTPMDef &&
>           qemuTPMEmulatorUpdateProfileName(&tpm->data.emulator, persistentTPMDef,
>                                            cfg, saveDef) < 0)
>           goto error;