From: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
To: Cornelia Huck <cohuck@redhat.com>
Cc: linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, freude@de.ibm.com, schwidefsky@de.ibm.com,
heiko.carstens@de.ibm.com, borntraeger@de.ibm.com,
kwankhede@nvidia.com, bjsdjshi@linux.vnet.ibm.com,
pbonzini@redhat.com, alex.williamson@redhat.com,
pmorel@linux.vnet.ibm.com, alifm@linux.vnet.ibm.com,
mjrosato@linux.vnet.ibm.com, jjherne@linux.vnet.ibm.com,
thuth@redhat.com, pasic@linux.vnet.ibm.com, berrange@redhat.com,
fiuczy@linux.vnet.ibm.com, buendgen@de.ibm.com
Subject: Re: [PATCH v5 05/13] s390: vfio-ap: register matrix device with VFIO mdev framework
Date: Wed, 16 May 2018 08:48:57 -0400 [thread overview]
Message-ID: <e66a3d32-953d-2082-83f1-be84d8a5422a@linux.vnet.ibm.com> (raw)
In-Reply-To: <20180516124240.42dcd426.cohuck@redhat.com>
On 05/16/2018 06:42 AM, Cornelia Huck wrote:
> On Mon, 7 May 2018 11:11:44 -0400
> Tony Krowiak <akrowiak@linux.vnet.ibm.com> wrote:
>
>> Registers the matrix device created by the VFIO AP device
>> driver with the VFIO mediated device framework.
>> Registering the matrix device will create the sysfs
>> structures needed to create mediated matrix devices
>> each of which will be used to configure the AP matrix
>> for a guest and connect it to the VFIO AP device driver.
>>
>> Registering the matrix device with the VFIO mediated device
>> framework will create the following sysfs structures:
>>
>> /sys/devices/vfio_ap
>> ... [matrix]
>> ...... [mdev_supported_types]
>> ......... [vfio_ap-passthrough]
>> ............ create
>>
>> To create a mediated device for the AP matrix device, write a UUID
>> to the create file:
>>
>> uuidgen > create
>>
>> A symbolic link to the mediated device's directory will be created in the
>> devices subdirectory named after the generated $uuid:
>>
>> /sys/devices/vfio_ap
>> ... [matrix]
>> ...... [mdev_supported_types]
>> ......... [vfio_ap-passthrough]
>> ............ [devices]
>> ............... [$uuid]
>>
>> Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
>> ---
>> MAINTAINERS | 1 +
>> drivers/s390/crypto/Makefile | 2 +-
>> drivers/s390/crypto/vfio_ap_drv.c | 9 +++
>> drivers/s390/crypto/vfio_ap_ops.c | 106 +++++++++++++++++++++++++++++++++
>> drivers/s390/crypto/vfio_ap_private.h | 17 +++++
>> 5 files changed, 134 insertions(+), 1 deletions(-)
>> create mode 100644 drivers/s390/crypto/vfio_ap_ops.c
>
>> diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
>> new file mode 100644
>> index 0000000..d7d36fb
>> --- /dev/null
>> +++ b/drivers/s390/crypto/vfio_ap_ops.c
>> @@ -0,0 +1,106 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * Adjunct processor matrix VFIO device driver callbacks.
>> + *
>> + * Copyright IBM Corp. 2017
> Should be '2018' (also in some other files in this series; please
> double check.)
Gee, I thought I got all of these fixed. I must have a gremlin in my
laptop.
>
>> + * Author(s): Tony Krowiak <akrowiak@linux.vnet.ibm.com>
>> + *
>> + */
>> +#include <linux/string.h>
>> +#include <linux/vfio.h>
>> +#include <linux/device.h>
>> +#include <linux/list.h>
>> +#include <linux/ctype.h>
>> +
>> +#include "vfio_ap_private.h"
>> +
>> +#define VFOP_AP_MDEV_TYPE_HWVIRT "passthrough"
>> +#define VFIO_AP_MDEV_NAME_HWVIRT "VFIO AP Passthrough Device"
>> +
>> +static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
>> +{
>> + struct ap_matrix *ap_matrix = to_ap_matrix(mdev_parent_dev(mdev));
>> +
>> + ap_matrix->available_instances--;
> Shouldn't the code check whether available_instances is actually > 0?
It is my understanding that once the available_instances hits zero, the
mdev
framework will not allow any more mediated devices to be created, so the
value should always be greater than zero when this function is invoked.
I did an experiment to verify my understanding. I initialized the
available_instances
to 1. I was able to create 2 mediated devices. It seems that the
framework refuses to
create a mediated device only after the available_instances sysfs
attribute is a negative
number, so I have two choices: Initialize available_instances to one
less than desires;
add the check you suggested. I think I'll go with the latter.
>
>> +
>> + return 0;
>> +}
>> +
>> +static int vfio_ap_mdev_remove(struct mdev_device *mdev)
>> +{
>> + struct ap_matrix *ap_matrix = to_ap_matrix(mdev_parent_dev(mdev));
>> +
>> + ap_matrix->available_instances++;
>> +
>> + return 0;
>> +}
>> +
>> +static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf)
>> +{
>> + return sprintf(buf, "%s\n", VFIO_AP_MDEV_NAME_HWVIRT);
>> +}
>> +
>> +MDEV_TYPE_ATTR_RO(name);
>> +
>> +static ssize_t available_instances_show(struct kobject *kobj,
>> + struct device *dev, char *buf)
>> +{
>> + struct ap_matrix *ap_matrix;
>> +
>> + ap_matrix = to_ap_matrix(dev);
> Move this with the declaration?
>
>> +
>> + return sprintf(buf, "%d\n", ap_matrix->available_instances);
>> +}
>> +
>> +MDEV_TYPE_ATTR_RO(available_instances);
>> +
>> +static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
>> + char *buf)
>> +{
>> + return sprintf(buf, "%s\n", VFIO_DEVICE_API_AP_STRING);
>> +}
>> +
>> +MDEV_TYPE_ATTR_RO(device_api);
>> +
>> +static struct attribute *vfio_ap_mdev_type_attrs[] = {
>> + &mdev_type_attr_name.attr,
>> + &mdev_type_attr_device_api.attr,
>> + &mdev_type_attr_available_instances.attr,
>> + NULL,
>> +};
>> +
>> +static struct attribute_group vfio_ap_mdev_hwvirt_type_group = {
>> + .name = VFOP_AP_MDEV_TYPE_HWVIRT,
>> + .attrs = vfio_ap_mdev_type_attrs,
>> +};
>> +
>> +static struct attribute_group *vfio_ap_mdev_type_groups[] = {
>> + &vfio_ap_mdev_hwvirt_type_group,
>> + NULL,
>> +};
>> +
>> +static const struct mdev_parent_ops vfio_ap_matrix_ops = {
>> + .owner = THIS_MODULE,
>> + .supported_type_groups = vfio_ap_mdev_type_groups,
>> + .create = vfio_ap_mdev_create,
>> + .remove = vfio_ap_mdev_remove,
>> +};
>> +
>> +int vfio_ap_mdev_register(struct ap_matrix *ap_matrix)
>> +{
>> + int ret;
>> +
>> + ret = mdev_register_device(&ap_matrix->device, &vfio_ap_matrix_ops);
>> + if (ret)
>> + return ret;
>> +
>> + ap_matrix->available_instances = AP_MATRIX_MAX_AVAILABLE_INSTANCES;
>> +
>> + return 0;
>> +}
>> +
>> +void vfio_ap_mdev_unregister(struct ap_matrix *ap_matrix)
>> +{
>> + ap_matrix->available_instances--;
>> + mdev_unregister_device(&ap_matrix->device);
>> +}
>> diff --git a/drivers/s390/crypto/vfio_ap_private.h b/drivers/s390/crypto/vfio_ap_private.h
>> index cf23675..afd8dbc 100644
>> --- a/drivers/s390/crypto/vfio_ap_private.h
>> +++ b/drivers/s390/crypto/vfio_ap_private.h
>> @@ -10,14 +10,31 @@
>> #define _VFIO_AP_PRIVATE_H_
>>
>> #include <linux/types.h>
>> +#include <linux/device.h>
>> +#include <linux/mdev.h>
>>
>> #include "ap_bus.h"
>>
>> #define VFIO_AP_MODULE_NAME "vfio_ap"
>> #define VFIO_AP_DRV_NAME "vfio_ap"
>> +/**
>> + * There must be one mediated matrix device per guest. If every APQN is assigned
> One, or at most one? Or one for every guest using ap devices?
>
>> + * to a guest, then the maximum number of guests with a unique APQN assigned
>> + * would be 255 adapters x 255 domains = 72351 guests.
>> + */
>> +#define AP_MATRIX_MAX_AVAILABLE_INSTANCES 72351
>>
>> struct ap_matrix {
>> struct device device;
>> + int available_instances;
>> };
>>
>> +static inline struct ap_matrix *to_ap_matrix(struct device *dev)
>> +{
>> + return container_of(dev, struct ap_matrix, device);
>> +}
>> +
>> +extern int vfio_ap_mdev_register(struct ap_matrix *ap_matrix);
>> +extern void vfio_ap_mdev_unregister(struct ap_matrix *ap_matrix);
>> +
>> #endif /* _VFIO_AP_PRIVATE_H_ */
next prev parent reply other threads:[~2018-05-16 12:50 UTC|newest]
Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-07 15:11 [PATCH v5 00/13] s390: vfio-ap: guest dedicated crypto adapters Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 01/13] KVM: s390: Interface to test whether APXA installed Tony Krowiak
2018-05-16 10:21 ` Cornelia Huck
2018-05-16 10:45 ` Tony Krowiak
2018-05-17 9:11 ` Harald Freudenberger
2018-05-17 9:44 ` Cornelia Huck
2018-05-07 15:11 ` [PATCH v5 02/13] KVM: s390: refactor crypto initialization Tony Krowiak
2018-05-16 8:51 ` Pierre Morel
2018-05-16 11:14 ` Tony Krowiak
2018-05-16 12:17 ` Pierre Morel
2018-05-16 12:21 ` Cornelia Huck
2018-05-07 15:11 ` [PATCH v5 03/13] KVM: s390: CPU model support for AP virtualization Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 04/13] s390: vfio-ap: base implementation of VFIO AP device driver Tony Krowiak
2018-05-16 8:21 ` Pierre Morel
2018-05-16 11:29 ` Tony Krowiak
2018-05-16 11:45 ` Tony Krowiak
2018-06-07 8:57 ` Pierre Morel
2018-06-13 7:41 ` Pierre Morel
2018-06-13 7:48 ` Cornelia Huck
2018-06-13 10:54 ` Pierre Morel
2018-06-13 11:14 ` Cornelia Huck
2018-06-13 12:01 ` Pierre Morel
2018-06-13 12:12 ` Cornelia Huck
2018-06-13 12:16 ` Pierre Morel
2018-06-14 13:04 ` Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 05/13] s390: vfio-ap: register matrix device with VFIO mdev framework Tony Krowiak
2018-05-11 17:18 ` Halil Pasic
2018-05-14 19:42 ` Tony Krowiak
2018-05-15 14:17 ` Pierre Morel
2018-05-15 15:16 ` Tony Krowiak
2018-05-15 15:48 ` Halil Pasic
2018-05-15 16:11 ` Tony Krowiak
2018-05-17 7:44 ` Cornelia Huck
2018-05-21 15:13 ` Tony Krowiak
2018-05-22 8:19 ` Cornelia Huck
2018-05-22 21:41 ` Tony Krowiak
2018-05-16 10:42 ` Cornelia Huck
2018-05-16 12:48 ` Tony Krowiak [this message]
2018-05-16 12:58 ` Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 06/13] KVM: s390: interfaces to manage guest's AP matrix Tony Krowiak
2018-05-11 16:08 ` Halil Pasic
2018-05-16 14:29 ` Tony Krowiak
2018-05-16 14:41 ` Pierre Morel
2018-05-21 15:23 ` Tony Krowiak
2018-05-15 14:55 ` Pierre Morel
2018-05-15 16:07 ` Tony Krowiak
2018-05-16 7:48 ` Pierre Morel
2018-05-16 13:12 ` Tony Krowiak
2018-05-16 13:15 ` Pierre Morel
2018-05-16 13:48 ` Tony Krowiak
2018-05-18 8:55 ` Pierre Morel
2018-05-23 14:29 ` Tony Krowiak
2018-05-24 7:46 ` Pierre Morel
2018-05-07 15:11 ` [PATCH v5 07/13] s390: vfio-ap: sysfs interfaces to configure adapters Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 08/13] s390: vfio-ap: sysfs interfaces to configure domains Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 09/13] s390: vfio-ap: sysfs interfaces to configure control domains Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 10/13] s390: vfio-ap: sysfs interface to view matrix mdev matrix Tony Krowiak
2018-05-16 7:55 ` Pierre Morel
2018-05-23 14:38 ` Tony Krowiak
2018-05-24 9:10 ` Pierre Morel
2018-05-30 14:28 ` Tony Krowiak
2018-06-05 12:40 ` Pierre Morel
2018-06-06 14:24 ` Tony Krowiak
2018-06-06 15:10 ` Pierre Morel
2018-06-07 12:53 ` Tony Krowiak
2018-06-07 13:16 ` Halil Pasic
2018-06-07 14:33 ` Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 11/13] KVM: s390: implement mediated device open callback Tony Krowiak
2018-05-16 8:03 ` Pierre Morel
2018-05-23 14:45 ` Tony Krowiak
2018-05-24 9:08 ` Pierre Morel
2018-05-30 14:33 ` Tony Krowiak
2018-06-05 12:19 ` Pierre Morel
2018-06-06 14:28 ` Tony Krowiak
2018-06-06 16:08 ` Pierre Morel
2018-06-06 17:40 ` Pierre Morel
2018-06-07 13:54 ` Tony Krowiak
2018-06-07 15:20 ` Pierre Morel
2018-06-07 16:30 ` Tony Krowiak
2018-06-07 17:15 ` Pierre Morel
2018-06-08 21:59 ` Tony Krowiak
2018-06-11 9:23 ` Pierre Morel
2018-06-11 11:32 ` Halil Pasic
2018-06-11 11:49 ` Janosch Frank
2018-06-11 16:26 ` Tony Krowiak
2018-06-11 16:50 ` Halil Pasic
2018-06-11 16:54 ` Tony Krowiak
2018-06-11 12:50 ` Tony Krowiak
2018-06-11 12:56 ` Tony Krowiak
2018-06-07 13:52 ` Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 12/13] s390: vfio-ap: implement VFIO_DEVICE_GET_INFO ioctl Tony Krowiak
2018-05-07 15:11 ` [PATCH v5 13/13] s390: doc: detailed specifications for AP virtualization Tony Krowiak
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