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Merge branch 'vfio-ccw-for-martin' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/vfio-ccw into features 

Pull vfio-ccw branch to add the basic channel I/O passthrough
intrastructure based on vfio.

The focus is on supporting dasd-eckd(cu_type/dev_type = 0x3990/0x3390)
as the target device.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky 2017-03-31 13:01:46 +02:00
Родитель 485527ba57 1877888d0a
Коммит 6fb81d69d0
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2
Documentation/s390/00-INDEX
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@ -22,5 +22,7 @@ qeth.txt
- HiperSockets Bridge Port Support.
s390dbf.txt
- information on using the s390 debug feature.
vfio-ccw.txt
information on the vfio-ccw I/O subchannel driver.
zfcpdump.txt
- information on the s390 SCSI dump tool.

303
Documentation/s390/vfio-ccw.txt Normal file
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@ -0,0 +1,303 @@
vfio-ccw: the basic infrastructure
==================================
Introduction
------------
Here we describe the vfio support for I/O subchannel devices for
Linux/s390. Motivation for vfio-ccw is to passthrough subchannels to a
virtual machine, while vfio is the means.
Different than other hardware architectures, s390 has defined a unified
I/O access method, which is so called Channel I/O. It has its own access
patterns:
- Channel programs run asynchronously on a separate (co)processor.
- The channel subsystem will access any memory designated by the caller
in the channel program directly, i.e. there is no iommu involved.
Thus when we introduce vfio support for these devices, we realize it
with a mediated device (mdev) implementation. The vfio mdev will be
added to an iommu group, so as to make itself able to be managed by the
vfio framework. And we add read/write callbacks for special vfio I/O
regions to pass the channel programs from the mdev to its parent device
(the real I/O subchannel device) to do further address translation and
to perform I/O instructions.
This document does not intend to explain the s390 I/O architecture in
every detail. More information/reference could be found here:
- A good start to know Channel I/O in general:
https://en.wikipedia.org/wiki/Channel_I/O
- s390 architecture:
s390 Principles of Operation manual (IBM Form. No. SA22-7832)
- The existing Qemu code which implements a simple emulated channel
subsystem could also be a good reference. It makes it easier to follow
the flow.
qemu/hw/s390x/css.c
For vfio mediated device framework:
- Documentation/vfio-mediated-device.txt
Motivation of vfio-ccw
----------------------
Currently, a guest virtualized via qemu/kvm on s390 only sees
paravirtualized virtio devices via the "Virtio Over Channel I/O
(virtio-ccw)" transport. This makes virtio devices discoverable via
standard operating system algorithms for handling channel devices.
However this is not enough. On s390 for the majority of devices, which
use the standard Channel I/O based mechanism, we also need to provide
the functionality of passing through them to a Qemu virtual machine.
This includes devices that don't have a virtio counterpart (e.g. tape
drives) or that have specific characteristics which guests want to
exploit.
For passing a device to a guest, we want to use the same interface as
everybody else, namely vfio. Thus, we would like to introduce vfio
support for channel devices. And we would like to name this new vfio
device "vfio-ccw".
Access patterns of CCW devices
------------------------------
s390 architecture has implemented a so called channel subsystem, that
provides a unified view of the devices physically attached to the
systems. Though the s390 hardware platform knows about a huge variety of
different peripheral attachments like disk devices (aka. DASDs), tapes,
communication controllers, etc. They can all be accessed by a well
defined access method and they are presenting I/O completion a unified
way: I/O interruptions.
All I/O requires the use of channel command words (CCWs). A CCW is an
instruction to a specialized I/O channel processor. A channel program is
a sequence of CCWs which are executed by the I/O channel subsystem. To
issue a channel program to the channel subsystem, it is required to
build an operation request block (ORB), which can be used to point out
the format of the CCW and other control information to the system. The
operating system signals the I/O channel subsystem to begin executing
the channel program with a SSCH (start sub-channel) instruction. The
central processor is then free to proceed with non-I/O instructions
until interrupted. The I/O completion result is received by the
interrupt handler in the form of interrupt response block (IRB).
Back to vfio-ccw, in short:
- ORBs and channel programs are built in guest kernel (with guest
physical addresses).
- ORBs and channel programs are passed to the host kernel.
- Host kernel translates the guest physical addresses to real addresses
and starts the I/O with issuing a privileged Channel I/O instruction
(e.g SSCH).
- channel programs run asynchronously on a separate processor.
- I/O completion will be signaled to the host with I/O interruptions.
And it will be copied as IRB to user space to pass it back to the
guest.
Physical vfio ccw device and its child mdev
-------------------------------------------
As mentioned above, we realize vfio-ccw with a mdev implementation.
Channel I/O does not have IOMMU hardware support, so the physical
vfio-ccw device does not have an IOMMU level translation or isolation.
Sub-channel I/O instructions are all privileged instructions, When
handling the I/O instruction interception, vfio-ccw has the software
policing and translation how the channel program is programmed before
it gets sent to hardware.
Within this implementation, we have two drivers for two types of
devices:
- The vfio_ccw driver for the physical subchannel device.
This is an I/O subchannel driver for the real subchannel device. It
realizes a group of callbacks and registers to the mdev framework as a
parent (physical) device. As a consequence, mdev provides vfio_ccw a
generic interface (sysfs) to create mdev devices. A vfio mdev could be
created by vfio_ccw then and added to the mediated bus. It is the vfio
device that added to an IOMMU group and a vfio group.
vfio_ccw also provides an I/O region to accept channel program
request from user space and store I/O interrupt result for user
space to retrieve. To notify user space an I/O completion, it offers
an interface to setup an eventfd fd for asynchronous signaling.
- The vfio_mdev driver for the mediated vfio ccw device.
This is provided by the mdev framework. It is a vfio device driver for
the mdev that created by vfio_ccw.
It realize a group of vfio device driver callbacks, adds itself to a
vfio group, and registers itself to the mdev framework as a mdev
driver.
It uses a vfio iommu backend that uses the existing map and unmap
ioctls, but rather than programming them into an IOMMU for a device,
it simply stores the translations for use by later requests. This
means that a device programmed in a VM with guest physical addresses
can have the vfio kernel convert that address to process virtual
address, pin the page and program the hardware with the host physical
address in one step.
For a mdev, the vfio iommu backend will not pin the pages during the
VFIO_IOMMU_MAP_DMA ioctl. Mdev framework will only maintain a database
of the iova<->vaddr mappings in this operation. And they export a
vfio_pin_pages and a vfio_unpin_pages interfaces from the vfio iommu
backend for the physical devices to pin and unpin pages by demand.
Below is a high Level block diagram.
+-------------+
| |
| +---------+ | mdev_register_driver() +--------------+
| | Mdev | +<-----------------------+ |
| | bus | | | vfio_mdev.ko |
| | driver | +----------------------->+ |<-> VFIO user
| +---------+ | probe()/remove() +--------------+ APIs
| |
| MDEV CORE |
| MODULE |
| mdev.ko |
| +---------+ | mdev_register_device() +--------------+
| |Physical | +<-----------------------+ |
| | device | | | vfio_ccw.ko |<-> subchannel
| |interface| +----------------------->+ | device
| +---------+ | callback +--------------+
+-------------+
The process of how these work together.
1. vfio_ccw.ko drives the physical I/O subchannel, and registers the
physical device (with callbacks) to mdev framework.
When vfio_ccw probing the subchannel device, it registers device
pointer and callbacks to the mdev framework. Mdev related file nodes
under the device node in sysfs would be created for the subchannel
device, namely 'mdev_create', 'mdev_destroy' and
'mdev_supported_types'.
2. Create a mediated vfio ccw device.
Use the 'mdev_create' sysfs file, we need to manually create one (and
only one for our case) mediated device.
3. vfio_mdev.ko drives the mediated ccw device.
vfio_mdev is also the vfio device drvier. It will probe the mdev and
add it to an iommu_group and a vfio_group. Then we could pass through
the mdev to a guest.
vfio-ccw I/O region
-------------------
An I/O region is used to accept channel program request from user
space and store I/O interrupt result for user space to retrieve. The
defination of the region is:
struct ccw_io_region {
#define ORB_AREA_SIZE 12
__u8 orb_area[ORB_AREA_SIZE];
#define SCSW_AREA_SIZE 12
__u8 scsw_area[SCSW_AREA_SIZE];
#define IRB_AREA_SIZE 96
__u8 irb_area[IRB_AREA_SIZE];
__u32 ret_code;
} __packed;
While starting an I/O request, orb_area should be filled with the
guest ORB, and scsw_area should be filled with the SCSW of the Virtual
Subchannel.
irb_area stores the I/O result.
ret_code stores a return code for each access of the region.
vfio-ccw patches overview
-------------------------
For now, our patches are rebased on the latest mdev implementation.
vfio-ccw follows what vfio-pci did on the s390 paltform and uses
vfio-iommu-type1 as the vfio iommu backend. It's a good start to launch
the code review for vfio-ccw. Note that the implementation is far from
complete yet; but we'd like to get feedback for the general
architecture.
* CCW translation APIs
- Description:
These introduce a group of APIs (start with 'cp_') to do CCW
translation. The CCWs passed in by a user space program are
organized with their guest physical memory addresses. These APIs
will copy the CCWs into the kernel space, and assemble a runnable
kernel channel program by updating the guest physical addresses with
their corresponding host physical addresses.
- Patches:
vfio: ccw: introduce channel program interfaces
* vfio_ccw device driver
- Description:
The following patches utilizes the CCW translation APIs and introduce
vfio_ccw, which is the driver for the I/O subchannel devices you want
to pass through.
vfio_ccw implements the following vfio ioctls:
VFIO_DEVICE_GET_INFO
VFIO_DEVICE_GET_IRQ_INFO
VFIO_DEVICE_GET_REGION_INFO
VFIO_DEVICE_RESET
VFIO_DEVICE_SET_IRQS
This provides an I/O region, so that the user space program can pass a
channel program to the kernel, to do further CCW translation before
issuing them to a real device.
This also provides the SET_IRQ ioctl to setup an event notifier to
notify the user space program the I/O completion in an asynchronous
way.
- Patches:
vfio: ccw: basic implementation for vfio_ccw driver
vfio: ccw: introduce ccw_io_region
vfio: ccw: realize VFIO_DEVICE_GET_REGION_INFO ioctl
vfio: ccw: realize VFIO_DEVICE_RESET ioctl
vfio: ccw: realize VFIO_DEVICE_G(S)ET_IRQ_INFO ioctls
The user of vfio-ccw is not limited to Qemu, while Qemu is definitely a
good example to get understand how these patches work. Here is a little
bit more detail how an I/O request triggered by the Qemu guest will be
handled (without error handling).
Explanation:
Q1-Q7: Qemu side process.
K1-K5: Kernel side process.
Q1. Get I/O region info during initialization.
Q2. Setup event notifier and handler to handle I/O completion.
... ...
Q3. Intercept a ssch instruction.
Q4. Write the guest channel program and ORB to the I/O region.
K1. Copy from guest to kernel.
K2. Translate the guest channel program to a host kernel space
channel program, which becomes runnable for a real device.
K3. With the necessary information contained in the orb passed in
by Qemu, issue the ccwchain to the device.
K4. Return the ssch CC code.
Q5. Return the CC code to the guest.
... ...
K5. Interrupt handler gets the I/O result and write the result to
the I/O region.
K6. Signal Qemu to retrieve the result.
Q6. Get the signal and event handler reads out the result from the I/O
region.
Q7. Update the irb for the guest.
Limitations
-----------
The current vfio-ccw implementation focuses on supporting basic commands
needed to implement block device functionality (read/write) of DASD/ECKD
device only. Some commands may need special handling in the future, for
example, anything related to path grouping.
DASD is a kind of storage device. While ECKD is a data recording format.
More information for DASD and ECKD could be found here:
https://en.wikipedia.org/wiki/Direct-access_storage_device
https://en.wikipedia.org/wiki/Count_key_data
Together with the corresponding work in Qemu, we can bring the passed
through DASD/ECKD device online in a guest now and use it as a block
device.
Reference
---------
1. ESA/s390 Principles of Operation manual (IBM Form. No. SA22-7832)
2. ESA/390 Common I/O Device Commands manual (IBM Form. No. SA22-7204)
3. https://en.wikipedia.org/wiki/Channel_I/O
4. Documentation/s390/cds.txt
5. Documentation/vfio.txt
6. Documentation/vfio-mediated-device.txt

10
MAINTAINERS
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@ -10860,6 +10860,16 @@ W: http://www.ibm.com/developerworks/linux/linux390/
S: Supported
F: drivers/iommu/s390-iommu.c
S390 VFIO-CCW DRIVER
M: Cornelia Huck <cornelia.huck@de.ibm.com>
M: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
L: linux-s390@vger.kernel.org
L: kvm@vger.kernel.org
S: Supported
F: drivers/s390/cio/vfio_ccw*
F: Documentation/s390/vfio-ccw.txt
F: include/uapi/linux/vfio_ccw.h
S3C24XX SD/MMC Driver
M: Ben Dooks <ben-linux@fluff.org>
L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)

10
arch/s390/Kconfig
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@ -682,6 +682,16 @@ config EADM_SCH
To compile this driver as a module, choose M here: the
module will be called eadm_sch.
config VFIO_CCW
def_tristate n
prompt "Support for VFIO-CCW subchannels"
depends on S390_CCW_IOMMU && VFIO_MDEV
help
This driver allows usage of I/O subchannels via VFIO-CCW.
To compile this driver as a module, choose M here: the
module will be called vfio_ccw.
endmenu
menu "Dump support"

18
arch/s390/include/asm/cio.h
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@ -33,6 +33,24 @@ struct ccw1 {
__u32 cda;
} __attribute__ ((packed,aligned(8)));
/**
* struct ccw0 - channel command word
* @cmd_code: command code
* @cda: data address
* @flags: flags, like IDA addressing, etc.
* @reserved: will be ignored
* @count: byte count
*
* The format-0 ccw structure.
*/
struct ccw0 {
__u8 cmd_code;
__u32 cda : 24;
__u8 flags;
__u8 reserved;
__u16 count;
} __packed __aligned(8);
#define CCW_FLAG_DC 0x80
#define CCW_FLAG_CC 0x40
#define CCW_FLAG_SLI 0x20

1
arch/s390/include/asm/isc.h
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@ -16,6 +16,7 @@
#define CONSOLE_ISC 1 /* console I/O subchannel */
#define EADM_SCH_ISC 4 /* EADM subchannels */
#define CHSC_SCH_ISC 7 /* CHSC subchannels */
#define VFIO_CCW_ISC IO_SCH_ISC /* VFIO-CCW I/O subchannels */
/* Adapter interrupts. */
#define QDIO_AIRQ_ISC IO_SCH_ISC /* I/O subchannel in qdio mode */
#define PCI_ISC 2 /* PCI I/O subchannels */

8
drivers/iommu/Kconfig
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@ -327,6 +327,14 @@ config S390_IOMMU
help
Support for the IOMMU API for s390 PCI devices.
config S390_CCW_IOMMU
bool "S390 CCW IOMMU Support"
depends on S390 && CCW
select IOMMU_API
help
Enables bits of IOMMU API required by VFIO. The iommu_ops
is not implemented as it is not necessary for VFIO.
config MTK_IOMMU
bool "MTK IOMMU Support"
depends on ARM || ARM64

3
drivers/s390/cio/Makefile
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@ -17,3 +17,6 @@ obj-$(CONFIG_CCWGROUP) += ccwgroup.o
qdio-objs := qdio_main.o qdio_thinint.o qdio_debug.o qdio_setup.o
obj-$(CONFIG_QDIO) += qdio.o
vfio_ccw-objs += vfio_ccw_drv.o vfio_ccw_cp.o vfio_ccw_ops.o vfio_ccw_fsm.o
obj-$(CONFIG_VFIO_CCW) += vfio_ccw.o

69
drivers/s390/cio/cio.c
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@ -170,12 +170,14 @@ cio_start_key (struct subchannel *sch, /* subchannel structure */
return ccode;
}
}
EXPORT_SYMBOL_GPL(cio_start_key);
int
cio_start (struct subchannel *sch, struct ccw1 *cpa, __u8 lpm)
{
return cio_start_key(sch, cpa, lpm, PAGE_DEFAULT_KEY);
}
EXPORT_SYMBOL_GPL(cio_start);
/*
* resume suspended I/O operation
@ -208,6 +210,7 @@ cio_resume (struct subchannel *sch)
return -ENODEV;
}
}
EXPORT_SYMBOL_GPL(cio_resume);
/*
* halt I/O operation
@ -241,6 +244,7 @@ cio_halt(struct subchannel *sch)
return -ENODEV;
}
}
EXPORT_SYMBOL_GPL(cio_halt);
/*
* Clear I/O operation
@ -271,6 +275,7 @@ cio_clear(struct subchannel *sch)
return -ENODEV;
}
}
EXPORT_SYMBOL_GPL(cio_clear);
/*
* Function: cio_cancel
@ -308,7 +313,68 @@ cio_cancel (struct subchannel *sch)
return -ENODEV;
}
}
EXPORT_SYMBOL_GPL(cio_cancel);
/**
* cio_cancel_halt_clear - Cancel running I/O by performing cancel, halt
* and clear ordinally if subchannel is valid.
* @sch: subchannel on which to perform the cancel_halt_clear operation
* @iretry: the number of the times remained to retry the next operation
*
* This should be called repeatedly since halt/clear are asynchronous
* operations. We do one try with cio_cancel, three tries with cio_halt,
* 255 tries with cio_clear. The caller should initialize @iretry with
* the value 255 for its first call to this, and keep using the same
* @iretry in the subsequent calls until it gets a non -EBUSY return.
*
* Returns 0 if device now idle, -ENODEV for device not operational,
* -EBUSY if an interrupt is expected (either from halt/clear or from a
* status pending), and -EIO if out of retries.
*/
int cio_cancel_halt_clear(struct subchannel *sch, int *iretry)
{
int ret;
if (cio_update_schib(sch))
return -ENODEV;
if (!sch->schib.pmcw.ena)
/* Not operational -> done. */
return 0;
/* Stage 1: cancel io. */
if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_HALT_PEND) &&
!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
if (!scsw_is_tm(&sch->schib.scsw)) {
ret = cio_cancel(sch);
if (ret != -EINVAL)
return ret;
}
/*
* Cancel io unsuccessful or not applicable (transport mode).
* Continue with asynchronous instructions.
*/
*iretry = 3; /* 3 halt retries. */
}
/* Stage 2: halt io. */
if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
if (*iretry) {
*iretry -= 1;
ret = cio_halt(sch);
if (ret != -EBUSY)
return (ret == 0) ? -EBUSY : ret;
}
/* Halt io unsuccessful. */
*iretry = 255; /* 255 clear retries. */
}
/* Stage 3: clear io. */
if (*iretry) {
*iretry -= 1;
ret = cio_clear(sch);
return (ret == 0) ? -EBUSY : ret;
}
/* Function was unsuccessful */
return -EIO;
}
EXPORT_SYMBOL_GPL(cio_cancel_halt_clear);
static void cio_apply_config(struct subchannel *sch, struct schib *schib)
{
@ -382,6 +448,7 @@ int cio_commit_config(struct subchannel *sch)
}
return ret;
}
EXPORT_SYMBOL_GPL(cio_commit_config);
/**
* cio_update_schib - Perform stsch and update schib if subchannel is valid.
@ -987,6 +1054,7 @@ int cio_tm_start_key(struct subchannel *sch, struct tcw *tcw, u8 lpm, u8 key)
return cio_start_handle_notoper(sch, lpm);
}
}
EXPORT_SYMBOL_GPL(cio_tm_start_key);
/**
* cio_tm_intrg - perform interrogate function
@ -1012,3 +1080,4 @@ int cio_tm_intrg(struct subchannel *sch)
return -ENODEV;
}
}
EXPORT_SYMBOL_GPL(cio_tm_intrg);

1
drivers/s390/cio/cio.h
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@ -123,6 +123,7 @@ extern int cio_enable_subchannel(struct subchannel *, u32);
extern int cio_disable_subchannel (struct subchannel *);
extern int cio_cancel (struct subchannel *);
extern int cio_clear (struct subchannel *);
extern int cio_cancel_halt_clear(struct subchannel *, int *);
extern int cio_resume (struct subchannel *);
extern int cio_halt (struct subchannel *);
extern int cio_start (struct subchannel *, struct ccw1 *, __u8);

54
drivers/s390/cio/device_fsm.c
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@ -124,14 +124,6 @@ ccw_device_set_timeout(struct ccw_device *cdev, int expires)
add_timer(&cdev->private->timer);
}
/*
* Cancel running i/o. This is called repeatedly since halt/clear are
* asynchronous operations. We do one try with cio_cancel, two tries
* with cio_halt, 255 tries with cio_clear. If everythings fails panic.
* Returns 0 if device now idle, -ENODEV for device not operational and
* -EBUSY if an interrupt is expected (either from halt/clear or from a
* status pending).
*/
int
ccw_device_cancel_halt_clear(struct ccw_device *cdev)
{
@ -139,44 +131,14 @@ ccw_device_cancel_halt_clear(struct ccw_device *cdev)
int ret;
sch = to_subchannel(cdev->dev.parent);
if (cio_update_schib(sch))
return -ENODEV;
if (!sch->schib.pmcw.ena)
/* Not operational -> done. */
return 0;
/* Stage 1: cancel io. */
if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_HALT_PEND) &&
!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
if (!scsw_is_tm(&sch->schib.scsw)) {
ret = cio_cancel(sch);
if (ret != -EINVAL)
return ret;
}
/* cancel io unsuccessful or not applicable (transport mode).
* Continue with asynchronous instructions. */
cdev->private->iretry = 3; /* 3 halt retries. */
}
if (!(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_CLEAR_PEND)) {
/* Stage 2: halt io. */
if (cdev->private->iretry) {
cdev->private->iretry--;
ret = cio_halt(sch);
if (ret != -EBUSY)
return (ret == 0) ? -EBUSY : ret;
}
/* halt io unsuccessful. */
cdev->private->iretry = 255; /* 255 clear retries. */
}
/* Stage 3: clear io. */
if (cdev->private->iretry) {
cdev->private->iretry--;
ret = cio_clear (sch);
return (ret == 0) ? -EBUSY : ret;
}
/* Function was unsuccessful */
CIO_MSG_EVENT(0, "0.%x.%04x: could not stop I/O\n",
cdev->private->dev_id.ssid, cdev->private->dev_id.devno);
return -EIO;
ret = cio_cancel_halt_clear(sch, &cdev->private->iretry);
if (ret == -EIO)
CIO_MSG_EVENT(0, "0.%x.%04x: could not stop I/O\n",
cdev->private->dev_id.ssid,
cdev->private->dev_id.devno);
return ret;
}
void ccw_device_update_sense_data(struct ccw_device *cdev)

842
drivers/s390/cio/vfio_ccw_cp.c Normal file
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@ -0,0 +1,842 @@
/*
* channel program interfaces
*
* Copyright IBM Corp. 2017
*
* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
* Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
*/
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/iommu.h>
#include <linux/vfio.h>
#include <asm/idals.h>
#include "vfio_ccw_cp.h"
/*
* Max length for ccw chain.
* XXX: Limit to 256, need to check more?
*/
#define CCWCHAIN_LEN_MAX 256
struct pfn_array {
unsigned long pa_iova;
unsigned long *pa_iova_pfn;
unsigned long *pa_pfn;
int pa_nr;
};
struct pfn_array_table {
struct pfn_array *pat_pa;
int pat_nr;
};
struct ccwchain {
struct list_head next;
struct ccw1 *ch_ccw;
/* Guest physical address of the current chain. */
u64 ch_iova;
/* Count of the valid ccws in chain. */
int ch_len;
/* Pinned PAGEs for the original data. */
struct pfn_array_table *ch_pat;
};
/*
* pfn_array_pin() - pin user pages in memory
* @pa: pfn_array on which to perform the operation
* @mdev: the mediated device to perform pin/unpin operations
*
* Attempt to pin user pages in memory.
*
* Usage of pfn_array:
* @pa->pa_iova starting guest physical I/O address. Assigned by caller.
* @pa->pa_iova_pfn array that stores PFNs of the pages need to pin. Allocated
* by caller.
* @pa->pa_pfn array that receives PFNs of the pages pinned. Allocated by
* caller.
* @pa->pa_nr number of pages from @pa->pa_iova to pin. Assigned by
* caller.
* number of pages pinned. Assigned by callee.
*
* Returns:
* Number of pages pinned on success.
* If @pa->pa_nr is 0 or negative, returns 0.
* If no pages were pinned, returns -errno.
*/
static int pfn_array_pin(struct pfn_array *pa, struct device *mdev)
{
int i, ret;
if (pa->pa_nr <= 0) {
pa->pa_nr = 0;
return 0;
}
pa->pa_iova_pfn[0] = pa->pa_iova >> PAGE_SHIFT;
for (i = 1; i < pa->pa_nr; i++)
pa->pa_iova_pfn[i] = pa->pa_iova_pfn[i - 1] + 1;
ret = vfio_pin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr,
IOMMU_READ | IOMMU_WRITE, pa->pa_pfn);
if (ret > 0 && ret != pa->pa_nr) {
vfio_unpin_pages(mdev, pa->pa_iova_pfn, ret);
pa->pa_nr = 0;
return 0;
}
return ret;
}
/* Unpin the pages before releasing the memory. */
static void pfn_array_unpin_free(struct pfn_array *pa, struct device *mdev)
{
vfio_unpin_pages(mdev, pa->pa_iova_pfn, pa->pa_nr);
pa->pa_nr = 0;
kfree(pa->pa_iova_pfn);
}
/* Alloc memory for PFNs, then pin pages with them. */
static int pfn_array_alloc_pin(struct pfn_array *pa, struct device *mdev,
u64 iova, unsigned int len)
{
int ret = 0;
if (!len || pa->pa_nr)
return -EINVAL;
pa->pa_iova = iova;
pa->pa_nr = ((iova & ~PAGE_MASK) + len + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
if (!pa->pa_nr)
return -EINVAL;
pa->pa_iova_pfn = kcalloc(pa->pa_nr,
sizeof(*pa->pa_iova_pfn) +
sizeof(*pa->pa_pfn),
GFP_KERNEL);
if (unlikely(!pa->pa_iova_pfn))
return -ENOMEM;
pa->pa_pfn = pa->pa_iova_pfn + pa->pa_nr;
ret = pfn_array_pin(pa, mdev);
if (ret > 0)
return ret;
else if (!ret)
ret = -EINVAL;
kfree(pa->pa_iova_pfn);
return ret;
}
static int pfn_array_table_init(struct pfn_array_table *pat, int nr)
{
pat->pat_pa = kcalloc(nr, sizeof(*pat->pat_pa), GFP_KERNEL);
if (unlikely(ZERO_OR_NULL_PTR(pat->pat_pa))) {
pat->pat_nr = 0;
return -ENOMEM;
}
pat->pat_nr = nr;
return 0;
}
static void pfn_array_table_unpin_free(struct pfn_array_table *pat,
struct device *mdev)
{
int i;
for (i = 0; i < pat->pat_nr; i++)
pfn_array_unpin_free(pat->pat_pa + i, mdev);
if (pat->pat_nr) {
kfree(pat->pat_pa);
pat->pat_pa = NULL;
pat->pat_nr = 0;
}
}
static bool pfn_array_table_iova_pinned(struct pfn_array_table *pat,
unsigned long iova)
{
struct pfn_array *pa = pat->pat_pa;
unsigned long iova_pfn = iova >> PAGE_SHIFT;
int i, j;
for (i = 0; i < pat->pat_nr; i++, pa++)
for (j = 0; j < pa->pa_nr; j++)
if (pa->pa_iova_pfn[i] == iova_pfn)
return true;
return false;
}
/* Create the list idal words for a pfn_array_table. */
static inline void pfn_array_table_idal_create_words(
struct pfn_array_table *pat,
unsigned long *idaws)
{
struct pfn_array *pa;
int i, j, k;
/*
* Idal words (execept the first one) rely on the memory being 4k
* aligned. If a user virtual address is 4K aligned, then it's
* corresponding kernel physical address will also be 4K aligned. Thus
* there will be no problem here to simply use the phys to create an
* idaw.
*/
k = 0;
for (i = 0; i < pat->pat_nr; i++) {
pa = pat->pat_pa + i;
for (j = 0; j < pa->pa_nr; j++) {
idaws[k] = pa->pa_pfn[j] << PAGE_SHIFT;
if (k == 0)
idaws[k] += pa->pa_iova & (PAGE_SIZE - 1);
k++;
}
}
}
/*
* Within the domain (@mdev), copy @n bytes from a guest physical
* address (@iova) to a host physical address (@to).
*/
static long copy_from_iova(struct device *mdev,
void *to, u64 iova,
unsigned long n)
{
struct pfn_array pa = {0};
u64 from;
int i, ret;
unsigned long l, m;
ret = pfn_array_alloc_pin(&pa, mdev, iova, n);
if (ret <= 0)
return ret;
l = n;
for (i = 0; i < pa.pa_nr; i++) {
from = pa.pa_pfn[i] << PAGE_SHIFT;
m = PAGE_SIZE;
if (i == 0) {
from += iova & (PAGE_SIZE - 1);
m -= iova & (PAGE_SIZE - 1);
}
m = min(l, m);
memcpy(to + (n - l), (void *)from, m);
l -= m;
if (l == 0)
break;
}
pfn_array_unpin_free(&pa, mdev);
return l;
}
static long copy_ccw_from_iova(struct channel_program *cp,
struct ccw1 *to, u64 iova,
unsigned long len)
{
struct ccw0 ccw0;
struct ccw1 *pccw1;
int ret;
int i;
ret = copy_from_iova(cp->mdev, to, iova, len * sizeof(struct ccw1));
if (ret)
return ret;
if (!cp->orb.cmd.fmt) {
pccw1 = to;
for (i = 0; i < len; i++) {
ccw0 = *(struct ccw0 *)pccw1;
if ((pccw1->cmd_code & 0x0f) == CCW_CMD_TIC) {
pccw1->cmd_code = CCW_CMD_TIC;
pccw1->flags = 0;
pccw1->count = 0;
} else {
pccw1->cmd_code = ccw0.cmd_code;
pccw1->flags = ccw0.flags;
pccw1->count = ccw0.count;
}
pccw1->cda = ccw0.cda;
pccw1++;
}
}
return ret;
}
/*
* Helpers to operate ccwchain.
*/
#define ccw_is_test(_ccw) (((_ccw)->cmd_code & 0x0F) == 0)
#define ccw_is_noop(_ccw) ((_ccw)->cmd_code == CCW_CMD_NOOP)
#define ccw_is_tic(_ccw) ((_ccw)->cmd_code == CCW_CMD_TIC)
#define ccw_is_idal(_ccw) ((_ccw)->flags & CCW_FLAG_IDA)
#define ccw_is_chain(_ccw) ((_ccw)->flags & (CCW_FLAG_CC | CCW_FLAG_DC))
static struct ccwchain *ccwchain_alloc(struct channel_program *cp, int len)
{
struct ccwchain *chain;
void *data;
size_t size;
/* Make ccw address aligned to 8. */
size = ((sizeof(*chain) + 7L) & -8L) +
sizeof(*chain->ch_ccw) * len +
sizeof(*chain->ch_pat) * len;
chain = kzalloc(size, GFP_DMA | GFP_KERNEL);
if (!chain)
return NULL;
data = (u8 *)chain + ((sizeof(*chain) + 7L) & -8L);
chain->ch_ccw = (struct ccw1 *)data;
data = (u8 *)(chain->ch_ccw) + sizeof(*chain->ch_ccw) * len;
chain->ch_pat = (struct pfn_array_table *)data;
chain->ch_len = len;
list_add_tail(&chain->next, &cp->ccwchain_list);
return chain;
}
static void ccwchain_free(struct ccwchain *chain)
{
list_del(&chain->next);
kfree(chain);
}
/* Free resource for a ccw that allocated memory for its cda. */
static void ccwchain_cda_free(struct ccwchain *chain, int idx)
{
struct ccw1 *ccw = chain->ch_ccw + idx;
if (!ccw->count)
return;
kfree((void *)(u64)ccw->cda);
}
/* Unpin the pages then free the memory resources. */
static void cp_unpin_free(struct channel_program *cp)
{
struct ccwchain *chain, *temp;
int i;
list_for_each_entry_safe(chain, temp, &cp->ccwchain_list, next) {
for (i = 0; i < chain->ch_len; i++) {
pfn_array_table_unpin_free(chain->ch_pat + i,
cp->mdev);
ccwchain_cda_free(chain, i);
}
ccwchain_free(chain);
}
}
/**
* ccwchain_calc_length - calculate the length of the ccw chain.
* @iova: guest physical address of the target ccw chain
* @cp: channel_program on which to perform the operation
*
* This is the chain length not considering any TICs.
* You need to do a new round for each TIC target.
*
* Returns: the length of the ccw chain or -errno.
*/
static int ccwchain_calc_length(u64 iova, struct channel_program *cp)
{
struct ccw1 *ccw, *p;
int cnt;
/*
* Copy current chain from guest to host kernel.
* Currently the chain length is limited to CCWCHAIN_LEN_MAX (256).
* So copying 2K is enough (safe).
*/
p = ccw = kcalloc(CCWCHAIN_LEN_MAX, sizeof(*ccw), GFP_KERNEL);
if (!ccw)
return -ENOMEM;
cnt = copy_ccw_from_iova(cp, ccw, iova, CCWCHAIN_LEN_MAX);
if (cnt) {
kfree(ccw);
return cnt;
}
cnt = 0;
do {
cnt++;
if ((!ccw_is_chain(ccw)) && (!ccw_is_tic(ccw)))
break;
ccw++;
} while (cnt < CCWCHAIN_LEN_MAX + 1);
if (cnt == CCWCHAIN_LEN_MAX + 1)
cnt = -EINVAL;
kfree(p);
return cnt;
}
static int tic_target_chain_exists(struct ccw1 *tic, struct channel_program *cp)
{
struct ccwchain *chain;
u32 ccw_head, ccw_tail;
list_for_each_entry(chain, &cp->ccwchain_list, next) {
ccw_head = chain->ch_iova;
ccw_tail = ccw_head + (chain->ch_len - 1) * sizeof(struct ccw1);
if ((ccw_head <= tic->cda) && (tic->cda <= ccw_tail))
return 1;
}
return 0;
}
static int ccwchain_loop_tic(struct ccwchain *chain,
struct channel_program *cp);
static int ccwchain_handle_tic(struct ccw1 *tic, struct channel_program *cp)
{
struct ccwchain *chain;
int len, ret;
/* May transfer to an existing chain. */
if (tic_target_chain_exists(tic, cp))
return 0;
/* Get chain length. */
len = ccwchain_calc_length(tic->cda, cp);
if (len < 0)
return len;
/* Need alloc a new chain for this one. */
chain = ccwchain_alloc(cp, len);
if (!chain)
return -ENOMEM;
chain->ch_iova = tic->cda;
/* Copy the new chain from user. */
ret = copy_ccw_from_iova(cp, chain->ch_ccw, tic->cda, len);
if (ret) {
ccwchain_free(chain);
return ret;
}
/* Loop for tics on this new chain. */
return ccwchain_loop_tic(chain, cp);
}
/* Loop for TICs. */
static int ccwchain_loop_tic(struct ccwchain *chain, struct channel_program *cp)
{
struct ccw1 *tic;
int i, ret;
for (i = 0; i < chain->ch_len; i++) {
tic = chain->ch_ccw + i;
if (!ccw_is_tic(tic))
continue;
ret = ccwchain_handle_tic(tic, cp);
if (ret)
return ret;
}
return 0;
}
static int ccwchain_fetch_tic(struct ccwchain *chain,
int idx,
struct channel_program *cp)
{
struct ccw1 *ccw = chain->ch_ccw + idx;
struct ccwchain *iter;
u32 ccw_head, ccw_tail;
list_for_each_entry(iter, &cp->ccwchain_list, next) {
ccw_head = iter->ch_iova;
ccw_tail = ccw_head + (iter->ch_len - 1) * sizeof(struct ccw1);
if ((ccw_head <= ccw->cda) && (ccw->cda <= ccw_tail)) {
ccw->cda = (__u32) (addr_t) (iter->ch_ccw +
(ccw->cda - ccw_head));
return 0;
}
}
return -EFAULT;
}
static int ccwchain_fetch_direct(struct ccwchain *chain,
int idx,
struct channel_program *cp)
{
struct ccw1 *ccw;
struct pfn_array_table *pat;
unsigned long *idaws;
int idaw_nr;
ccw = chain->ch_ccw + idx;
/*
* Pin data page(s) in memory.
* The number of pages actually is the count of the idaws which will be
* needed when translating a direct ccw to a idal ccw.
*/
pat = chain->ch_pat + idx;
if (pfn_array_table_init(pat, 1))
return -ENOMEM;
idaw_nr = pfn_array_alloc_pin(pat->pat_pa, cp->mdev,
ccw->cda, ccw->count);
if (idaw_nr < 0)
return idaw_nr;
/* Translate this direct ccw to a idal ccw. */
idaws = kcalloc(idaw_nr, sizeof(*idaws), GFP_DMA | GFP_KERNEL);
if (!idaws) {
pfn_array_table_unpin_free(pat, cp->mdev);
return -ENOMEM;
}
ccw->cda = (__u32) virt_to_phys(idaws);
ccw->flags |= CCW_FLAG_IDA;
pfn_array_table_idal_create_words(pat, idaws);
return 0;
}
static int ccwchain_fetch_idal(struct ccwchain *chain,
int idx,
struct channel_program *cp)
{
struct ccw1 *ccw;
struct pfn_array_table *pat;
unsigned long *idaws;
u64 idaw_iova;
unsigned int idaw_nr, idaw_len;
int i, ret;
ccw = chain->ch_ccw + idx;
/* Calculate size of idaws. */
ret = copy_from_iova(cp->mdev, &idaw_iova, ccw->cda, sizeof(idaw_iova));
if (ret)
return ret;
idaw_nr = idal_nr_words((void *)(idaw_iova), ccw->count);
idaw_len = idaw_nr * sizeof(*idaws);
/* Pin data page(s) in memory. */
pat = chain->ch_pat + idx;
ret = pfn_array_table_init(pat, idaw_nr);
if (ret)
return ret;
/* Translate idal ccw to use new allocated idaws. */
idaws = kzalloc(idaw_len, GFP_DMA | GFP_KERNEL);
if (!idaws) {
ret = -ENOMEM;
goto out_unpin;
}
ret = copy_from_iova(cp->mdev, idaws, ccw->cda, idaw_len);
if (ret)
goto out_free_idaws;
ccw->cda = virt_to_phys(idaws);
for (i = 0; i < idaw_nr; i++) {
idaw_iova = *(idaws + i);
if (IS_ERR_VALUE(idaw_iova)) {
ret = -EFAULT;
goto out_free_idaws;
}
ret = pfn_array_alloc_pin(pat->pat_pa + i, cp->mdev,
idaw_iova, 1);
if (ret < 0)
goto out_free_idaws;
}
pfn_array_table_idal_create_words(pat, idaws);
return 0;
out_free_idaws:
kfree(idaws);
out_unpin:
pfn_array_table_unpin_free(pat, cp->mdev);
return ret;
}
/*
* Fetch one ccw.
* To reduce memory copy, we'll pin the cda page in memory,
* and to get rid of the cda 2G limitiaion of ccw1, we'll translate
* direct ccws to idal ccws.
*/
static int ccwchain_fetch_one(struct ccwchain *chain,
int idx,
struct channel_program *cp)
{
struct ccw1 *ccw = chain->ch_ccw + idx;
if (ccw_is_test(ccw) || ccw_is_noop(ccw))
return 0;
if (ccw_is_tic(ccw))
return ccwchain_fetch_tic(chain, idx, cp);
if (ccw_is_idal(ccw))
return ccwchain_fetch_idal(chain, idx, cp);
return ccwchain_fetch_direct(chain, idx, cp);
}
/**
* cp_init() - allocate ccwchains for a channel program.
* @cp: channel_program on which to perform the operation
* @mdev: the mediated device to perform pin/unpin operations
* @orb: control block for the channel program from the guest
*
* This creates one or more ccwchain(s), and copies the raw data of
* the target channel program from @orb->cmd.iova to the new ccwchain(s).
*
* Limitations:
* 1. Supports only prefetch enabled mode.
* 2. Supports idal(c64) ccw chaining.
* 3. Supports 4k idaw.
*
* Returns:
* %0 on success and a negative error value on failure.
*/
int cp_init(struct channel_program *cp, struct device *mdev, union orb *orb)
{
u64 iova = orb->cmd.cpa;
struct ccwchain *chain;
int len, ret;
/*
* XXX:
* Only support prefetch enable mode now.
* Only support 64bit addressing idal.
* Only support 4k IDAW.
*/
if (!orb->cmd.pfch || !orb->cmd.c64 || orb->cmd.i2k)
return -EOPNOTSUPP;
INIT_LIST_HEAD(&cp->ccwchain_list);
memcpy(&cp->orb, orb, sizeof(*orb));
cp->mdev = mdev;
/* Get chain length. */
len = ccwchain_calc_length(iova, cp);
if (len < 0)
return len;
/* Alloc mem for the head chain. */
chain = ccwchain_alloc(cp, len);
if (!chain)
return -ENOMEM;
chain->ch_iova = iova;
/* Copy the head chain from guest. */
ret = copy_ccw_from_iova(cp, chain->ch_ccw, iova, len);
if (ret) {
ccwchain_free(chain);
return ret;
}
/* Now loop for its TICs. */
ret = ccwchain_loop_tic(chain, cp);
if (ret)
cp_unpin_free(cp);
return ret;
}
/**
* cp_free() - free resources for channel program.
* @cp: channel_program on which to perform the operation
*
* This unpins the memory pages and frees the memory space occupied by
* @cp, which must have been returned by a previous call to cp_init().
* Otherwise, undefined behavior occurs.
*/
void cp_free(struct channel_program *cp)
{
cp_unpin_free(cp);
}
/**
* cp_prefetch() - translate a guest physical address channel program to
* a real-device runnable channel program.
* @cp: channel_program on which to perform the operation
*
* This function translates the guest-physical-address channel program
* and stores the result to ccwchain list. @cp must have been
* initialized by a previous call with cp_init(). Otherwise, undefined
* behavior occurs.
*
* The S/390 CCW Translation APIS (prefixed by 'cp_') are introduced
* as helpers to do ccw chain translation inside the kernel. Basically
* they accept a channel program issued by a virtual machine, and
* translate the channel program to a real-device runnable channel
* program.
*
* These APIs will copy the ccws into kernel-space buffers, and update
* the guest phsical addresses with their corresponding host physical
* addresses. Then channel I/O device drivers could issue the
* translated channel program to real devices to perform an I/O
* operation.
*
* These interfaces are designed to support translation only for
* channel programs, which are generated and formatted by a
* guest. Thus this will make it possible for things like VFIO to
* leverage the interfaces to passthrough a channel I/O mediated
* device in QEMU.
*
* We support direct ccw chaining by translating them to idal ccws.
*
* Returns:
* %0 on success and a negative error value on failure.
*/
int cp_prefetch(struct channel_program *cp)
{
struct ccwchain *chain;
int len, idx, ret;
list_for_each_entry(chain, &cp->ccwchain_list, next) {
len = chain->ch_len;
for (idx = 0; idx < len; idx++) {
ret = ccwchain_fetch_one(chain, idx, cp);
if (ret)
return ret;
}
}
return 0;
}
/**
* cp_get_orb() - get the orb of the channel program
* @cp: channel_program on which to perform the operation
* @intparm: new intparm for the returned orb
* @lpm: candidate value of the logical-path mask for the returned orb
*
* This function returns the address of the updated orb of the channel
* program. Channel I/O device drivers could use this orb to issue a
* ssch.
*/
union orb *cp_get_orb(struct channel_program *cp, u32 intparm, u8 lpm)
{
union orb *orb;
struct ccwchain *chain;
struct ccw1 *cpa;
orb = &cp->orb;
orb->cmd.intparm = intparm;
orb->cmd.fmt = 1;
orb->cmd.key = PAGE_DEFAULT_KEY >> 4;
if (orb->cmd.lpm == 0)
orb->cmd.lpm = lpm;
chain = list_first_entry(&cp->ccwchain_list, struct ccwchain, next);
cpa = chain->ch_ccw;
orb->cmd.cpa = (__u32) __pa(cpa);
return orb;
}
/**
* cp_update_scsw() - update scsw for a channel program.
* @cp: channel_program on which to perform the operation
* @scsw: I/O results of the channel program and also the target to be
* updated
*
* @scsw contains the I/O results of the channel program that pointed
* to by @cp. However what @scsw->cpa stores is a host physical
* address, which is meaningless for the guest, which is waiting for
* the I/O results.
*
* This function updates @scsw->cpa to its coressponding guest physical
* address.
*/
void cp_update_scsw(struct channel_program *cp, union scsw *scsw)
{
struct ccwchain *chain;
u32 cpa = scsw->cmd.cpa;
u32 ccw_head, ccw_tail;
/*
* LATER:
* For now, only update the cmd.cpa part. We may need to deal with
* other portions of the schib as well, even if we don't return them
* in the ioctl directly. Path status changes etc.
*/
list_for_each_entry(chain, &cp->ccwchain_list, next) {
ccw_head = (u32)(u64)chain->ch_ccw;
ccw_tail = (u32)(u64)(chain->ch_ccw + chain->ch_len - 1);
if ((ccw_head <= cpa) && (cpa <= ccw_tail)) {
/*
* (cpa - ccw_head) is the offset value of the host
* physical ccw to its chain head.
* Adding this value to the guest physical ccw chain
* head gets us the guest cpa.
*/
cpa = chain->ch_iova + (cpa - ccw_head);
break;
}
}
scsw->cmd.cpa = cpa;
}
/**
* cp_iova_pinned() - check if an iova is pinned for a ccw chain.
* @cmd: ccwchain command on which to perform the operation
* @iova: the iova to check
*
* If the @iova is currently pinned for the ccw chain, return true;
* else return false.
*/
bool cp_iova_pinned(struct channel_program *cp, u64 iova)
{
struct ccwchain *chain;
int i;
list_for_each_entry(chain, &cp->ccwchain_list, next) {
for (i = 0; i < chain->ch_len; i++)
if (pfn_array_table_iova_pinned(chain->ch_pat + i,
iova))
return true;
}
return false;
}

42
drivers/s390/cio/vfio_ccw_cp.h Normal file
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/*
* channel program interfaces
*
* Copyright IBM Corp. 2017
*
* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
* Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
*/
#ifndef _VFIO_CCW_CP_H_
#define _VFIO_CCW_CP_H_
#include <asm/cio.h>
#include <asm/scsw.h>
#include "orb.h"
/**
* struct channel_program - manage information for channel program
* @ccwchain_list: list head of ccwchains
* @orb: orb for the currently processed ssch request
* @mdev: the mediated device to perform page pinning/unpinning
*
* @ccwchain_list is the head of a ccwchain list, that contents the
* translated result of the guest channel program that pointed out by
* the iova parameter when calling cp_init.
*/
struct channel_program {
struct list_head ccwchain_list;
union orb orb;
struct device *mdev;
};
extern int cp_init(struct channel_program *cp, struct device *mdev,
union orb *orb);
extern void cp_free(struct channel_program *cp);
extern int cp_prefetch(struct channel_program *cp);
extern union orb *cp_get_orb(struct channel_program *cp, u32 intparm, u8 lpm);
extern void cp_update_scsw(struct channel_program *cp, union scsw *scsw);
extern bool cp_iova_pinned(struct channel_program *cp, u64 iova);
#endif

308
drivers/s390/cio/vfio_ccw_drv.c Normal file
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@ -0,0 +1,308 @@
/*
* VFIO based Physical Subchannel device driver
*
* Copyright IBM Corp. 2017
*
* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
* Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/uuid.h>
#include <linux/mdev.h>
#include <asm/isc.h>
#include "ioasm.h"
#include "css.h"
#include "vfio_ccw_private.h"
struct workqueue_struct *vfio_ccw_work_q;
/*
* Helpers
*/
int vfio_ccw_sch_quiesce(struct subchannel *sch)
{
struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
DECLARE_COMPLETION_ONSTACK(completion);
int iretry, ret = 0;
spin_lock_irq(sch->lock);
if (!sch->schib.pmcw.ena)
goto out_unlock;
ret = cio_disable_subchannel(sch);
if (ret != -EBUSY)
goto out_unlock;
do {
iretry = 255;
ret = cio_cancel_halt_clear(sch, &iretry);
while (ret == -EBUSY) {
/*
* Flush all I/O and wait for
* cancel/halt/clear completion.
*/
private->completion = &completion;
spin_unlock_irq(sch->lock);
wait_for_completion_timeout(&completion, 3*HZ);
spin_lock_irq(sch->lock);
private->completion = NULL;
flush_workqueue(vfio_ccw_work_q);
ret = cio_cancel_halt_clear(sch, &iretry);
};
ret = cio_disable_subchannel(sch);
} while (ret == -EBUSY);
out_unlock:
private->state = VFIO_CCW_STATE_NOT_OPER;
spin_unlock_irq(sch->lock);
return ret;
}
static void vfio_ccw_sch_io_todo(struct work_struct *work)
{
struct vfio_ccw_private *private;
struct subchannel *sch;
struct irb *irb;
private = container_of(work, struct vfio_ccw_private, io_work);
irb = &private->irb;
sch = private->sch;
if (scsw_is_solicited(&irb->scsw)) {
cp_update_scsw(&private->cp, &irb->scsw);
cp_free(&private->cp);
}
memcpy(private->io_region.irb_area, irb, sizeof(*irb));
if (private->io_trigger)
eventfd_signal(private->io_trigger, 1);
if (private->mdev)
private->state = VFIO_CCW_STATE_IDLE;
}
/*
* Sysfs interfaces
*/
static ssize_t chpids_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct subchannel *sch = to_subchannel(dev);
struct chsc_ssd_info *ssd = &sch->ssd_info;
ssize_t ret = 0;
int chp;
int mask;
for (chp = 0; chp < 8; chp++) {
mask = 0x80 >> chp;
if (ssd->path_mask & mask)
ret += sprintf(buf + ret, "%02x ", ssd->chpid[chp].id);
else
ret += sprintf(buf + ret, "00 ");
}
ret += sprintf(buf+ret, "\n");
return ret;
}
static ssize_t pimpampom_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct subchannel *sch = to_subchannel(dev);
struct pmcw *pmcw = &sch->schib.pmcw;
return sprintf(buf, "%02x %02x %02x\n",
pmcw->pim, pmcw->pam, pmcw->pom);
}
static DEVICE_ATTR(chpids, 0444, chpids_show, NULL);
static DEVICE_ATTR(pimpampom, 0444, pimpampom_show, NULL);
static struct attribute *vfio_subchannel_attrs[] = {
&dev_attr_chpids.attr,
&dev_attr_pimpampom.attr,
NULL,
};
static struct attribute_group vfio_subchannel_attr_group = {
.attrs = vfio_subchannel_attrs,
};
/*
* Css driver callbacks
*/
static void vfio_ccw_sch_irq(struct subchannel *sch)
{
struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
inc_irq_stat(IRQIO_CIO);
vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_INTERRUPT);
}
static int vfio_ccw_sch_probe(struct subchannel *sch)
{
struct pmcw *pmcw = &sch->schib.pmcw;
struct vfio_ccw_private *private;
int ret;
if (pmcw->qf) {
dev_warn(&sch->dev, "vfio: ccw: does not support QDIO: %s\n",
dev_name(&sch->dev));
return -ENODEV;
}
private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA);
if (!private)
return -ENOMEM;
private->sch = sch;
dev_set_drvdata(&sch->dev, private);
spin_lock_irq(sch->lock);
private->state = VFIO_CCW_STATE_NOT_OPER;
sch->isc = VFIO_CCW_ISC;
ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
spin_unlock_irq(sch->lock);
if (ret)
goto out_free;
ret = sysfs_create_group(&sch->dev.kobj, &vfio_subchannel_attr_group);
if (ret)
goto out_disable;
ret = vfio_ccw_mdev_reg(sch);
if (ret)
goto out_rm_group;
INIT_WORK(&private->io_work, vfio_ccw_sch_io_todo);
atomic_set(&private->avail, 1);
private->state = VFIO_CCW_STATE_STANDBY;
return 0;
out_rm_group:
sysfs_remove_group(&sch->dev.kobj, &vfio_subchannel_attr_group);
out_disable:
cio_disable_subchannel(sch);
out_free:
dev_set_drvdata(&sch->dev, NULL);
kfree(private);
return ret;
}
static int vfio_ccw_sch_remove(struct subchannel *sch)
{
struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
vfio_ccw_sch_quiesce(sch);
vfio_ccw_mdev_unreg(sch);
sysfs_remove_group(&sch->dev.kobj, &vfio_subchannel_attr_group);
dev_set_drvdata(&sch->dev, NULL);
kfree(private);
return 0;
}
static void vfio_ccw_sch_shutdown(struct subchannel *sch)
{
vfio_ccw_sch_quiesce(sch);
}
/**
* vfio_ccw_sch_event - process subchannel event
* @sch: subchannel
* @process: non-zero if function is called in process context
*
* An unspecified event occurred for this subchannel. Adjust data according
* to the current operational state of the subchannel. Return zero when the
* event has been handled sufficiently or -EAGAIN when this function should
* be called again in process context.
*/
static int vfio_ccw_sch_event(struct subchannel *sch, int process)
{
struct vfio_ccw_private *private = dev_get_drvdata(&sch->dev);
unsigned long flags;
spin_lock_irqsave(sch->lock, flags);
if (!device_is_registered(&sch->dev))
goto out_unlock;
if (work_pending(&sch->todo_work))
goto out_unlock;
if (cio_update_schib(sch)) {
vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_NOT_OPER);
goto out_unlock;
}
private = dev_get_drvdata(&sch->dev);
if (private->state == VFIO_CCW_STATE_NOT_OPER) {
private->state = private->mdev ? VFIO_CCW_STATE_IDLE :
VFIO_CCW_STATE_STANDBY;
}
out_unlock:
spin_unlock_irqrestore(sch->lock, flags);
return 0;
}
static struct css_device_id vfio_ccw_sch_ids[] = {
{ .match_flags = 0x1, .type = SUBCHANNEL_TYPE_IO, },
{ /* end of list */ },
};
MODULE_DEVICE_TABLE(css, vfio_ccw_sch_ids);
static struct css_driver vfio_ccw_sch_driver = {
.drv = {
.name = "vfio_ccw",
.owner = THIS_MODULE,
},
.subchannel_type = vfio_ccw_sch_ids,
.irq = vfio_ccw_sch_irq,
.probe = vfio_ccw_sch_probe,
.remove = vfio_ccw_sch_remove,
.shutdown = vfio_ccw_sch_shutdown,
.sch_event = vfio_ccw_sch_event,
};
static int __init vfio_ccw_sch_init(void)
{
int ret;
vfio_ccw_work_q = create_singlethread_workqueue("vfio-ccw");
if (!vfio_ccw_work_q)
return -ENOMEM;
isc_register(VFIO_CCW_ISC);
ret = css_driver_register(&vfio_ccw_sch_driver);
if (ret) {
isc_unregister(VFIO_CCW_ISC);
destroy_workqueue(vfio_ccw_work_q);
}
return ret;
}
static void __exit vfio_ccw_sch_exit(void)
{
css_driver_unregister(&vfio_ccw_sch_driver);
isc_unregister(VFIO_CCW_ISC);
destroy_workqueue(vfio_ccw_work_q);
}
module_init(vfio_ccw_sch_init);
module_exit(vfio_ccw_sch_exit);
MODULE_LICENSE("GPL v2");

207
drivers/s390/cio/vfio_ccw_fsm.c Normal file
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/*
* Finite state machine for vfio-ccw device handling
*
* Copyright IBM Corp. 2017
*
* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
*/
#include <linux/vfio.h>
#include <linux/mdev.h>
#include "ioasm.h"
#include "vfio_ccw_private.h"
static int fsm_io_helper(struct vfio_ccw_private *private)
{
struct subchannel *sch;
union orb *orb;
int ccode;
__u8 lpm;
unsigned long flags;
sch = private->sch;
spin_lock_irqsave(sch->lock, flags);
private->state = VFIO_CCW_STATE_BUSY;
spin_unlock_irqrestore(sch->lock, flags);
orb = cp_get_orb(&private->cp, (u32)(addr_t)sch, sch->lpm);
/* Issue "Start Subchannel" */
ccode = ssch(sch->schid, orb);
switch (ccode) {
case 0:
/*
* Initialize device status information
*/
sch->schib.scsw.cmd.actl |= SCSW_ACTL_START_PEND;
return 0;
case 1: /* Status pending */
case 2: /* Busy */
return -EBUSY;
case 3: /* Device/path not operational */
{
lpm = orb->cmd.lpm;
if (lpm != 0)
sch->lpm &= ~lpm;
else
sch->lpm = 0;
if (cio_update_schib(sch))
return -ENODEV;
return sch->lpm ? -EACCES : -ENODEV;
}
default:
return ccode;
}
}
static void fsm_notoper(struct vfio_ccw_private *private,
enum vfio_ccw_event event)
{
struct subchannel *sch = private->sch;
/*
* TODO:
* Probably we should send the machine check to the guest.
*/
css_sched_sch_todo(sch, SCH_TODO_UNREG);
private->state = VFIO_CCW_STATE_NOT_OPER;
}
/*
* No operation action.
*/
static void fsm_nop(struct vfio_ccw_private *private,
enum vfio_ccw_event event)
{
}
static void fsm_io_error(struct vfio_ccw_private *private,
enum vfio_ccw_event event)
{
pr_err("vfio-ccw: FSM: I/O request from state:%d\n", private->state);
private->io_region.ret_code = -EIO;
}
static void fsm_io_busy(struct vfio_ccw_private *private,
enum vfio_ccw_event event)
{
private->io_region.ret_code = -EBUSY;
}
static void fsm_disabled_irq(struct vfio_ccw_private *private,
enum vfio_ccw_event event)
{
struct subchannel *sch = private->sch;
/*
* An interrupt in a disabled state means a previous disable was not
* successful - should not happen, but we try to disable again.
*/
cio_disable_subchannel(sch);
}
/*
* Deal with the ccw command request from the userspace.
*/
static void fsm_io_request(struct vfio_ccw_private *private,
enum vfio_ccw_event event)
{
union orb *orb;
union scsw *scsw = &private->scsw;
struct ccw_io_region *io_region = &private->io_region;
struct mdev_device *mdev = private->mdev;
private->state = VFIO_CCW_STATE_BOXED;
memcpy(scsw, io_region->scsw_area, sizeof(*scsw));
if (scsw->cmd.fctl & SCSW_FCTL_START_FUNC) {
orb = (union orb *)io_region->orb_area;
io_region->ret_code = cp_init(&private->cp, mdev_dev(mdev),
orb);
if (io_region->ret_code)
goto err_out;
io_region->ret_code = cp_prefetch(&private->cp);
if (io_region->ret_code) {
cp_free(&private->cp);
goto err_out;
}
/* Start channel program and wait for I/O interrupt. */
io_region->ret_code = fsm_io_helper(private);
if (io_region->ret_code) {
cp_free(&private->cp);
goto err_out;
}
return;
} else if (scsw->cmd.fctl & SCSW_FCTL_HALT_FUNC) {
/* XXX: Handle halt. */
io_region->ret_code = -EOPNOTSUPP;
goto err_out;
} else if (scsw->cmd.fctl & SCSW_FCTL_CLEAR_FUNC) {
/* XXX: Handle clear. */
io_region->ret_code = -EOPNOTSUPP;
goto err_out;
}
err_out:
private->state = VFIO_CCW_STATE_IDLE;
}
/*
* Got an interrupt for a normal io (state busy).
*/
static void fsm_irq(struct vfio_ccw_private *private,
enum vfio_ccw_event event)
{
struct irb *irb;
if (!private)
return;
irb = this_cpu_ptr(&cio_irb);
memcpy(&private->irb, irb, sizeof(*irb));
queue_work(vfio_ccw_work_q, &private->io_work);
if (private->completion)
complete(private->completion);
}
/*
* Device statemachine
*/
fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS] = {
[VFIO_CCW_STATE_NOT_OPER] = {
[VFIO_CCW_EVENT_NOT_OPER] = fsm_nop,
[VFIO_CCW_EVENT_IO_REQ] = fsm_io_error,
[VFIO_CCW_EVENT_INTERRUPT] = fsm_disabled_irq,
},
[VFIO_CCW_STATE_STANDBY] = {
[VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper,
[VFIO_CCW_EVENT_IO_REQ] = fsm_io_error,
[VFIO_CCW_EVENT_INTERRUPT] = fsm_irq,
},
[VFIO_CCW_STATE_IDLE] = {
[VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper,
[VFIO_CCW_EVENT_IO_REQ] = fsm_io_request,
[VFIO_CCW_EVENT_INTERRUPT] = fsm_irq,
},
[VFIO_CCW_STATE_BOXED] = {
[VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper,
[VFIO_CCW_EVENT_IO_REQ] = fsm_io_busy,
[VFIO_CCW_EVENT_INTERRUPT] = fsm_irq,
},
[VFIO_CCW_STATE_BUSY] = {
[VFIO_CCW_EVENT_NOT_OPER] = fsm_notoper,
[VFIO_CCW_EVENT_IO_REQ] = fsm_io_busy,
[VFIO_CCW_EVENT_INTERRUPT] = fsm_irq,
},
};

447
drivers/s390/cio/vfio_ccw_ops.c Normal file
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@ -0,0 +1,447 @@
/*
* Physical device callbacks for vfio_ccw
*
* Copyright IBM Corp. 2017
*
* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
* Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
*/
#include <linux/vfio.h>
#include <linux/mdev.h>
#include "vfio_ccw_private.h"
static int vfio_ccw_mdev_reset(struct mdev_device *mdev)
{
struct vfio_ccw_private *private;
struct subchannel *sch;
int ret;
private = dev_get_drvdata(mdev_parent_dev(mdev));
if (!private)
return -ENODEV;
sch = private->sch;
/*
* TODO:
* In the cureent stage, some things like "no I/O running" and "no
* interrupt pending" are clear, but we are not sure what other state
* we need to care about.
* There are still a lot more instructions need to be handled. We
* should come back here later.
*/
ret = vfio_ccw_sch_quiesce(sch);
if (ret)
return ret;
ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
if (!ret)
private->state = VFIO_CCW_STATE_IDLE;
return ret;
}
static int vfio_ccw_mdev_notifier(struct notifier_block *nb,
unsigned long action,
void *data)
{
struct vfio_ccw_private *private =
container_of(nb, struct vfio_ccw_private, nb);
if (!private)
return NOTIFY_STOP;
/*
* Vendor drivers MUST unpin pages in response to an
* invalidation.
*/
if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {
struct vfio_iommu_type1_dma_unmap *unmap = data;
if (!cp_iova_pinned(&private->cp, unmap->iova))
return NOTIFY_OK;
if (vfio_ccw_mdev_reset(private->mdev))
return NOTIFY_BAD;
cp_free(&private->cp);
return NOTIFY_OK;
}
return NOTIFY_DONE;
}
static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf)
{
return sprintf(buf, "I/O subchannel (Non-QDIO)\n");
}
MDEV_TYPE_ATTR_RO(name);
static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
char *buf)
{
return sprintf(buf, "%s\n", VFIO_DEVICE_API_CCW_STRING);
}
MDEV_TYPE_ATTR_RO(device_api);
static ssize_t available_instances_show(struct kobject *kobj,
struct device *dev, char *buf)
{
struct vfio_ccw_private *private = dev_get_drvdata(dev);
return sprintf(buf, "%d\n", atomic_read(&private->avail));
}
MDEV_TYPE_ATTR_RO(available_instances);
static struct attribute *mdev_types_attrs[] = {
&mdev_type_attr_name.attr,
&mdev_type_attr_device_api.attr,
&mdev_type_attr_available_instances.attr,
NULL,
};
static struct attribute_group mdev_type_group = {
.name = "io",
.attrs = mdev_types_attrs,
};
struct attribute_group *mdev_type_groups[] = {
&mdev_type_group,
NULL,
};
static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
{
struct vfio_ccw_private *private =
dev_get_drvdata(mdev_parent_dev(mdev));
if (private->state == VFIO_CCW_STATE_NOT_OPER)
return -ENODEV;
if (atomic_dec_if_positive(&private->avail) < 0)
return -EPERM;
private->mdev = mdev;
private->state = VFIO_CCW_STATE_IDLE;
return 0;
}
static int vfio_ccw_mdev_remove(struct mdev_device *mdev)
{
struct vfio_ccw_private *private =
dev_get_drvdata(mdev_parent_dev(mdev));
int ret;
if (!private)
goto out;
if ((private->state == VFIO_CCW_STATE_NOT_OPER) ||
(private->state == VFIO_CCW_STATE_STANDBY))
goto out;
ret = vfio_ccw_mdev_reset(mdev);
if (ret)
return ret;
private->state = VFIO_CCW_STATE_STANDBY;
out:
private->mdev = NULL;
atomic_inc(&private->avail);
return 0;
}
static int vfio_ccw_mdev_open(struct mdev_device *mdev)
{
struct vfio_ccw_private *private =
dev_get_drvdata(mdev_parent_dev(mdev));
unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
private->nb.notifier_call = vfio_ccw_mdev_notifier;
return vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
&events, &private->nb);
}
void vfio_ccw_mdev_release(struct mdev_device *mdev)
{
struct vfio_ccw_private *private =
dev_get_drvdata(mdev_parent_dev(mdev));
vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
&private->nb);
}
static ssize_t vfio_ccw_mdev_read(struct mdev_device *mdev,
char __user *buf,
size_t count,
loff_t *ppos)
{
struct vfio_ccw_private *private;
struct ccw_io_region *region;
if (*ppos + count > sizeof(*region))
return -EINVAL;
private = dev_get_drvdata(mdev_parent_dev(mdev));
if (!private)
return -ENODEV;
region = &private->io_region;
if (copy_to_user(buf, (void *)region + *ppos, count))
return -EFAULT;
return count;
}
static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev,
const char __user *buf,
size_t count,
loff_t *ppos)
{
struct vfio_ccw_private *private;
struct ccw_io_region *region;
if (*ppos + count > sizeof(*region))
return -EINVAL;
private = dev_get_drvdata(mdev_parent_dev(mdev));
if (!private)
return -ENODEV;
if (private->state != VFIO_CCW_STATE_IDLE)
return -EACCES;
region = &private->io_region;
if (copy_from_user((void *)region + *ppos, buf, count))
return -EFAULT;
vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_IO_REQ);
if (region->ret_code != 0) {
private->state = VFIO_CCW_STATE_IDLE;
return region->ret_code;
}
return count;
}
static int vfio_ccw_mdev_get_device_info(struct vfio_device_info *info)
{
info->flags = VFIO_DEVICE_FLAGS_CCW | VFIO_DEVICE_FLAGS_RESET;
info->num_regions = VFIO_CCW_NUM_REGIONS;
info->num_irqs = VFIO_CCW_NUM_IRQS;
return 0;
}
static int vfio_ccw_mdev_get_region_info(struct vfio_region_info *info,
u16 *cap_type_id,
void **cap_type)
{
switch (info->index) {
case VFIO_CCW_CONFIG_REGION_INDEX:
info->offset = 0;
info->size = sizeof(struct ccw_io_region);
info->flags = VFIO_REGION_INFO_FLAG_READ
| VFIO_REGION_INFO_FLAG_WRITE;
return 0;
default:
return -EINVAL;
}
}
int vfio_ccw_mdev_get_irq_info(struct vfio_irq_info *info)
{
if (info->index != VFIO_CCW_IO_IRQ_INDEX)
return -EINVAL;
info->count = 1;
info->flags = VFIO_IRQ_INFO_EVENTFD;
return 0;
}
static int vfio_ccw_mdev_set_irqs(struct mdev_device *mdev,
uint32_t flags,
void __user *data)
{
struct vfio_ccw_private *private;
struct eventfd_ctx **ctx;
if (!(flags & VFIO_IRQ_SET_ACTION_TRIGGER))
return -EINVAL;
private = dev_get_drvdata(mdev_parent_dev(mdev));
if (!private)
return -ENODEV;
ctx = &private->io_trigger;
switch (flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
case VFIO_IRQ_SET_DATA_NONE:
{
if (*ctx)
eventfd_signal(*ctx, 1);
return 0;
}
case VFIO_IRQ_SET_DATA_BOOL:
{
uint8_t trigger;
if (get_user(trigger, (uint8_t __user *)data))
return -EFAULT;
if (trigger && *ctx)
eventfd_signal(*ctx, 1);
return 0;
}
case VFIO_IRQ_SET_DATA_EVENTFD:
{
int32_t fd;
if (get_user(fd, (int32_t __user *)data))
return -EFAULT;
if (fd == -1) {
if (*ctx)
eventfd_ctx_put(*ctx);
*ctx = NULL;
} else if (fd >= 0) {
struct eventfd_ctx *efdctx;
efdctx = eventfd_ctx_fdget(fd);
if (IS_ERR(efdctx))
return PTR_ERR(efdctx);
if (*ctx)
eventfd_ctx_put(*ctx);
*ctx = efdctx;
} else
return -EINVAL;
return 0;
}
default:
return -EINVAL;
}
}
static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
unsigned int cmd,
unsigned long arg)
{
int ret = 0;
unsigned long minsz;
switch (cmd) {
case VFIO_DEVICE_GET_INFO:
{
struct vfio_device_info info;
minsz = offsetofend(struct vfio_device_info, num_irqs);
if (copy_from_user(&info, (void __user *)arg, minsz))
return -EFAULT;
if (info.argsz < minsz)
return -EINVAL;
ret = vfio_ccw_mdev_get_device_info(&info);
if (ret)
return ret;
return copy_to_user((void __user *)arg, &info, minsz);
}
case VFIO_DEVICE_GET_REGION_INFO:
{
struct vfio_region_info info;
u16 cap_type_id = 0;
void *cap_type = NULL;
minsz = offsetofend(struct vfio_region_info, offset);
if (copy_from_user(&info, (void __user *)arg, minsz))
return -EFAULT;
if (info.argsz < minsz)
return -EINVAL;
ret = vfio_ccw_mdev_get_region_info(&info, &cap_type_id,
&cap_type);
if (ret)
return ret;
return copy_to_user((void __user *)arg, &info, minsz);
}
case VFIO_DEVICE_GET_IRQ_INFO:
{
struct vfio_irq_info info;
minsz = offsetofend(struct vfio_irq_info, count);
if (copy_from_user(&info, (void __user *)arg, minsz))
return -EFAULT;
if (info.argsz < minsz || info.index >= VFIO_CCW_NUM_IRQS)
return -EINVAL;
ret = vfio_ccw_mdev_get_irq_info(&info);
if (ret)
return ret;
if (info.count == -1)
return -EINVAL;
return copy_to_user((void __user *)arg, &info, minsz);
}
case VFIO_DEVICE_SET_IRQS:
{
struct vfio_irq_set hdr;
size_t data_size;
void __user *data;
minsz = offsetofend(struct vfio_irq_set, count);
if (copy_from_user(&hdr, (void __user *)arg, minsz))
return -EFAULT;
ret = vfio_set_irqs_validate_and_prepare(&hdr, 1,
VFIO_CCW_NUM_IRQS,
&data_size);
if (ret)
return ret;
data = (void __user *)(arg + minsz);
return vfio_ccw_mdev_set_irqs(mdev, hdr.flags, data);
}
case VFIO_DEVICE_RESET:
return vfio_ccw_mdev_reset(mdev);
default:
return -ENOTTY;
}
}
static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
.owner = THIS_MODULE,
.supported_type_groups = mdev_type_groups,
.create = vfio_ccw_mdev_create,
.remove = vfio_ccw_mdev_remove,
.open = vfio_ccw_mdev_open,
.release = vfio_ccw_mdev_release,
.read = vfio_ccw_mdev_read,
.write = vfio_ccw_mdev_write,
.ioctl = vfio_ccw_mdev_ioctl,
};
int vfio_ccw_mdev_reg(struct subchannel *sch)
{
return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
}
void vfio_ccw_mdev_unreg(struct subchannel *sch)
{
mdev_unregister_device(&sch->dev);
}

96
drivers/s390/cio/vfio_ccw_private.h Normal file
Просмотреть файл

@ -0,0 +1,96 @@
/*
* Private stuff for vfio_ccw driver
*
* Copyright IBM Corp. 2017
*
* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
* Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
*/
#ifndef _VFIO_CCW_PRIVATE_H_
#define _VFIO_CCW_PRIVATE_H_
#include <linux/completion.h>
#include <linux/eventfd.h>
#include <linux/workqueue.h>
#include <linux/vfio_ccw.h>
#include "css.h"
#include "vfio_ccw_cp.h"
/**
* struct vfio_ccw_private
* @sch: pointer to the subchannel
* @state: internal state of the device
* @completion: synchronization helper of the I/O completion
* @avail: available for creating a mediated device
* @mdev: pointer to the mediated device
* @nb: notifier for vfio events
* @io_region: MMIO region to input/output I/O arguments/results
* @cp: channel program for the current I/O operation
* @irb: irb info received from interrupt
* @scsw: scsw info
* @io_trigger: eventfd ctx for signaling userspace I/O results
* @io_work: work for deferral process of I/O handling
*/
struct vfio_ccw_private {
struct subchannel *sch;
int state;
struct completion *completion;
atomic_t avail;
struct mdev_device *mdev;
struct notifier_block nb;
struct ccw_io_region io_region;
struct channel_program cp;
struct irb irb;
union scsw scsw;
struct eventfd_ctx *io_trigger;
struct work_struct io_work;
} __aligned(8);
extern int vfio_ccw_mdev_reg(struct subchannel *sch);
extern void vfio_ccw_mdev_unreg(struct subchannel *sch);
extern int vfio_ccw_sch_quiesce(struct subchannel *sch);
/*
* States of the device statemachine.
*/
enum vfio_ccw_state {
VFIO_CCW_STATE_NOT_OPER,
VFIO_CCW_STATE_STANDBY,
VFIO_CCW_STATE_IDLE,
VFIO_CCW_STATE_BOXED,
VFIO_CCW_STATE_BUSY,
/* last element! */
NR_VFIO_CCW_STATES
};
/*
* Asynchronous events of the device statemachine.
*/
enum vfio_ccw_event {
VFIO_CCW_EVENT_NOT_OPER,
VFIO_CCW_EVENT_IO_REQ,
VFIO_CCW_EVENT_INTERRUPT,
/* last element! */
NR_VFIO_CCW_EVENTS
};
/*
* Action called through jumptable.
*/
typedef void (fsm_func_t)(struct vfio_ccw_private *, enum vfio_ccw_event);
extern fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS];
static inline void vfio_ccw_fsm_event(struct vfio_ccw_private *private,
int event)
{
vfio_ccw_jumptable[private->state][event](private, event);
}
extern struct workqueue_struct *vfio_ccw_work_q;
#endif

18
include/uapi/linux/vfio.h
Просмотреть файл

@ -198,6 +198,7 @@ struct vfio_device_info {
#define VFIO_DEVICE_FLAGS_PCI (1 << 1) /* vfio-pci device */
#define VFIO_DEVICE_FLAGS_PLATFORM (1 << 2) /* vfio-platform device */
#define VFIO_DEVICE_FLAGS_AMBA (1 << 3) /* vfio-amba device */
#define VFIO_DEVICE_FLAGS_CCW (1 << 4) /* vfio-ccw device */
__u32 num_regions; /* Max region index + 1 */
__u32 num_irqs; /* Max IRQ index + 1 */
};
@ -212,6 +213,7 @@ struct vfio_device_info {
#define VFIO_DEVICE_API_PCI_STRING "vfio-pci"
#define VFIO_DEVICE_API_PLATFORM_STRING "vfio-platform"
#define VFIO_DEVICE_API_AMBA_STRING "vfio-amba"
#define VFIO_DEVICE_API_CCW_STRING "vfio-ccw"
/**
* VFIO_DEVICE_GET_REGION_INFO - _IOWR(VFIO_TYPE, VFIO_BASE + 8,
@ -446,6 +448,22 @@ enum {
VFIO_PCI_NUM_IRQS
};
/*
* The vfio-ccw bus driver makes use of the following fixed region and
* IRQ index mapping. Unimplemented regions return a size of zero.
* Unimplemented IRQ types return a count of zero.
*/
enum {
VFIO_CCW_CONFIG_REGION_INDEX,
VFIO_CCW_NUM_REGIONS
};
enum {
VFIO_CCW_IO_IRQ_INDEX,
VFIO_CCW_NUM_IRQS
};
/**
* VFIO_DEVICE_GET_PCI_HOT_RESET_INFO - _IORW(VFIO_TYPE, VFIO_BASE + 12,
* struct vfio_pci_hot_reset_info)

24
include/uapi/linux/vfio_ccw.h Normal file
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@ -0,0 +1,24 @@
/*
* Interfaces for vfio-ccw
*
* Copyright IBM Corp. 2017
*
* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
*/
#ifndef _VFIO_CCW_H_
#define _VFIO_CCW_H_
#include <linux/types.h>
struct ccw_io_region {
#define ORB_AREA_SIZE 12
__u8 orb_area[ORB_AREA_SIZE];
#define SCSW_AREA_SIZE 12
__u8 scsw_area[SCSW_AREA_SIZE];
#define IRB_AREA_SIZE 96
__u8 irb_area[IRB_AREA_SIZE];
__u32 ret_code;
} __packed;
#endif