Re: [PATCH v2 15/15] tests/qtest: enable tests for virtio-gpio

["Alex Bennée" <alex.bennee@linaro.org>]

Stefan Hajnoczi <stefanha@redhat.com> writes:

> [[PGP Signed Part:Undecided]]
> On Tue, May 24, 2022 at 04:40:56PM +0100, Alex Bennée wrote:
>> We don't have a virtio-gpio implementation in QEMU and only
>> support a vhost-user backend. The QEMU side of the code is minimal so
>> it should be enough to instantiate the device and pass some vhost-user
>> messages over the control socket. To do this we hook into the existing
>> vhost-user-test code and just add the bits required for gpio.
>> 
>> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
>> Cc: Viresh Kumar <viresh.kumar@linaro.org>
>> Cc: Paolo Bonzini <pbonzini@redhat.com>
>> Cc: Eric Auger <eric.auger@redhat.com>
>> Message-Id: <20220408155704.2777166-1-alex.bennee@linaro.org>
>> 
>> ---
>> v2
>>   - add more of the missing boilerplate
>>   - don't request LOG_SHMD
>>   - use get_features op
>>   - report VIRTIO_F_VERSION_1
>>   - more comments
>> ---
>>  tests/qtest/libqos/virtio-gpio.h |  35 +++++++
>>  tests/qtest/libqos/virtio-gpio.c | 171 +++++++++++++++++++++++++++++++
>>  tests/qtest/libqos/virtio.c      |   2 +-
>>  tests/qtest/vhost-user-test.c    |  66 ++++++++++++
>>  tests/qtest/libqos/meson.build   |   1 +
>>  5 files changed, 274 insertions(+), 1 deletion(-)
>>  create mode 100644 tests/qtest/libqos/virtio-gpio.h
>>  create mode 100644 tests/qtest/libqos/virtio-gpio.c
>> 
>> diff --git a/tests/qtest/libqos/virtio-gpio.h b/tests/qtest/libqos/virtio-gpio.h
>> new file mode 100644
>> index 0000000000..f11d41bd19
>> --- /dev/null
>> +++ b/tests/qtest/libqos/virtio-gpio.h
>> @@ -0,0 +1,35 @@
>> +/*
>> + * virtio-gpio structures
>> + *
>> + * Copyright (c) 2022 Linaro Ltd
>> + *
>> + * SPDX-License-Identifier: GPL-2.0-or-later
>> + */
>> +
>> +#ifndef TESTS_LIBQOS_VIRTIO_GPIO_H
>> +#define TESTS_LIBQOS_VIRTIO_GPIO_H
>> +
>> +#include "qgraph.h"
>> +#include "virtio.h"
>> +#include "virtio-pci.h"
>> +
>> +typedef struct QVhostUserGPIO QVhostUserGPIO;
>> +typedef struct QVhostUserGPIOPCI QVhostUserGPIOPCI;
>> +typedef struct QVhostUserGPIODevice QVhostUserGPIODevice;
>> +
>> +struct QVhostUserGPIO {
>> +    QVirtioDevice *vdev;
>> +    QVirtQueue **queues;
>> +};
>> +
>> +struct QVhostUserGPIOPCI {
>> +    QVirtioPCIDevice pci_vdev;
>> +    QVhostUserGPIO gpio;
>> +};
>> +
>> +struct QVhostUserGPIODevice {
>> +    QOSGraphObject obj;
>> +    QVhostUserGPIO gpio;
>> +};
>> +
>> +#endif
>> diff --git a/tests/qtest/libqos/virtio-gpio.c b/tests/qtest/libqos/virtio-gpio.c
>> new file mode 100644
>> index 0000000000..762aa6695b
>> --- /dev/null
>> +++ b/tests/qtest/libqos/virtio-gpio.c
>> @@ -0,0 +1,171 @@
>> +/*
>> + * virtio-gpio nodes for testing
>> + *
>> + * Copyright (c) 2022 Linaro Ltd
>> + *
>> + * SPDX-License-Identifier: GPL-2.0-or-later
>> + */
>> +
>> +#include "qemu/osdep.h"
>> +#include "standard-headers/linux/virtio_config.h"
>> +#include "../libqtest.h"
>> +#include "qemu/module.h"
>> +#include "qgraph.h"
>> +#include "virtio-gpio.h"
>> +
>> +static QGuestAllocator *alloc;
>> +
>> +static void virtio_gpio_cleanup(QVhostUserGPIO *gpio)
>> +{
>> +    QVirtioDevice *vdev = gpio->vdev;
>> +    int i;
>> +
>> +    for (i = 0; i < 2; i++) {
>> +        qvirtqueue_cleanup(vdev->bus, gpio->queues[i], alloc);
>> +    }
>> +    g_free(gpio->queues);
>> +}
>> +
>> +/*
>> + * This handles the VirtIO setup from the point of view of the driver
>> + * frontend and therefor doesn't present any vhost specific features
>> + * and in fact masks of the re-used bit.
>> + */
>> +static void virtio_gpio_setup(QVhostUserGPIO *gpio)
>> +{
>> +    QVirtioDevice *vdev = gpio->vdev;
>> +    uint64_t features;
>> +    int i;
>> +
>> +    features = qvirtio_get_features(vdev);
>> +    features &= ~QVIRTIO_F_BAD_FEATURE;
>
> This looks questionable. qvirtio_get_features() should return VIRTIO
> feature bits. Is QVIRTIO_F_BAD_FEATURE masked out here because
> qvirtio_get_features() is returning raw vhost-user feature bits instead
> and you want to get rid of VHOST_USER_F_PROTOCOL_FEATURES?

Well it's an invalid bit for the driver/frontend<->hw/backend path -
although maybe we should error if we saw it?

>
> [[End of PGP Signed Part]]


-- 
Alex Bennée