Re: [PATCH v2 1/3] io/crypto: Move tls premature termination handling into QIO layer

[Fabiano Rosas <farosas@suse.de>]

Peter Xu <peterx@redhat.com> writes:

> QCryptoTLSSession allows TLS premature termination in two cases, one of the
> case is when the channel shutdown() is invoked on READ side.
>
> It's possible the shutdown() happened after the read thread blocked at
> gnutls_record_recv().  In this case, we should allow the premature
> termination to happen.
>
> The problem is by the time qcrypto_tls_session_read() was invoked,
> tioc->shutdown may not have been set, so this may instead be treated as an
> error if there is concurrent shutdown() calls.
>
> To allow the flag to reflect the latest status of tioc->shutdown, move the
> check upper into the QIOChannel level, so as to read the flag only after
> QEMU gets an GNUTLS_E_PREMATURE_TERMINATION.
>
> When at it, introduce qio_channel_tls_allow_premature_termination() helper
> to make the condition checks easier to read.
>
> This patch will fix a qemu qtest warning when running the preempt tls test,
> reporting premature termination:
>
> QTEST_QEMU_BINARY=./qemu-system-x86_64 ./tests/qtest/migration-test --full -r /x86_64/migration/postcopy/preempt/tls/psk
> ...
> qemu-kvm: Cannot read from TLS channel: The TLS connection was non-properly terminated.
> ...
>
> In this specific case, the error was set by postcopy_preempt_thread, which
> normally will be concurrently shutdown()ed by the main thread.
>
> Signed-off-by: Peter Xu <peterx@redhat.com>

Reviewed-by: Fabiano Rosas <farosas@suse.de>