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nipung87awilliam
nipung87
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awilliam
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vfio/cdx: add interrupt support
Support the following ioctls for CDX devices: - VFIO_DEVICE_GET_IRQ_INFO - VFIO_DEVICE_SET_IRQS This allows user to set an eventfd for cdx device interrupts and trigger this interrupt eventfd from userspace. All CDX device interrupts are MSIs. The MSIs are allocated from the CDX-MSI domain. Signed-off-by: Nipun Gupta <[email protected]> Reviewed-by: Pieter Jansen van Vuuren <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alex Williamson <[email protected]>
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‎drivers/vfio/cdx/Makefile

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -5,4 +5,4 @@
55

66
obj-$(CONFIG_VFIO_CDX) += vfio-cdx.o
77

8-
vfio-cdx-objs := main.o
8+
vfio-cdx-objs := main.o intr.o

‎drivers/vfio/cdx/intr.c

Lines changed: 217 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,217 @@
1+
// SPDX-License-Identifier: GPL-2.0
2+
/*
3+
* Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
4+
*/
5+
6+
#include <linux/vfio.h>
7+
#include <linux/slab.h>
8+
#include <linux/types.h>
9+
#include <linux/eventfd.h>
10+
#include <linux/msi.h>
11+
#include <linux/interrupt.h>
12+
13+
#include "linux/cdx/cdx_bus.h"
14+
#include "private.h"
15+
16+
static irqreturn_t vfio_cdx_msihandler(int irq_no, void *arg)
17+
{
18+
struct eventfd_ctx *trigger = arg;
19+
20+
eventfd_signal(trigger);
21+
return IRQ_HANDLED;
22+
}
23+
24+
static int vfio_cdx_msi_enable(struct vfio_cdx_device *vdev, int nvec)
25+
{
26+
struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
27+
struct device *dev = vdev->vdev.dev;
28+
int msi_idx, ret;
29+
30+
vdev->cdx_irqs = kcalloc(nvec, sizeof(struct vfio_cdx_irq), GFP_KERNEL);
31+
if (!vdev->cdx_irqs)
32+
return -ENOMEM;
33+
34+
ret = cdx_enable_msi(cdx_dev);
35+
if (ret) {
36+
kfree(vdev->cdx_irqs);
37+
return ret;
38+
}
39+
40+
/* Allocate cdx MSIs */
41+
ret = msi_domain_alloc_irqs(dev, MSI_DEFAULT_DOMAIN, nvec);
42+
if (ret) {
43+
cdx_disable_msi(cdx_dev);
44+
kfree(vdev->cdx_irqs);
45+
return ret;
46+
}
47+
48+
for (msi_idx = 0; msi_idx < nvec; msi_idx++)
49+
vdev->cdx_irqs[msi_idx].irq_no = msi_get_virq(dev, msi_idx);
50+
51+
vdev->msi_count = nvec;
52+
vdev->config_msi = 1;
53+
54+
return 0;
55+
}
56+
57+
static int vfio_cdx_msi_set_vector_signal(struct vfio_cdx_device *vdev,
58+
int vector, int fd)
59+
{
60+
struct eventfd_ctx *trigger;
61+
int irq_no, ret;
62+
63+
if (vector < 0 || vector >= vdev->msi_count)
64+
return -EINVAL;
65+
66+
irq_no = vdev->cdx_irqs[vector].irq_no;
67+
68+
if (vdev->cdx_irqs[vector].trigger) {
69+
free_irq(irq_no, vdev->cdx_irqs[vector].trigger);
70+
kfree(vdev->cdx_irqs[vector].name);
71+
eventfd_ctx_put(vdev->cdx_irqs[vector].trigger);
72+
vdev->cdx_irqs[vector].trigger = NULL;
73+
}
74+
75+
if (fd < 0)
76+
return 0;
77+
78+
vdev->cdx_irqs[vector].name = kasprintf(GFP_KERNEL, "vfio-msi[%d](%s)",
79+
vector, dev_name(vdev->vdev.dev));
80+
if (!vdev->cdx_irqs[vector].name)
81+
return -ENOMEM;
82+
83+
trigger = eventfd_ctx_fdget(fd);
84+
if (IS_ERR(trigger)) {
85+
kfree(vdev->cdx_irqs[vector].name);
86+
return PTR_ERR(trigger);
87+
}
88+
89+
ret = request_irq(irq_no, vfio_cdx_msihandler, 0,
90+
vdev->cdx_irqs[vector].name, trigger);
91+
if (ret) {
92+
kfree(vdev->cdx_irqs[vector].name);
93+
eventfd_ctx_put(trigger);
94+
return ret;
95+
}
96+
97+
vdev->cdx_irqs[vector].trigger = trigger;
98+
99+
return 0;
100+
}
101+
102+
static int vfio_cdx_msi_set_block(struct vfio_cdx_device *vdev,
103+
unsigned int start, unsigned int count,
104+
int32_t *fds)
105+
{
106+
int i, j, ret = 0;
107+
108+
if (start >= vdev->msi_count || start + count > vdev->msi_count)
109+
return -EINVAL;
110+
111+
for (i = 0, j = start; i < count && !ret; i++, j++) {
112+
int fd = fds ? fds[i] : -1;
113+
114+
ret = vfio_cdx_msi_set_vector_signal(vdev, j, fd);
115+
}
116+
117+
if (ret) {
118+
for (--j; j >= (int)start; j--)
119+
vfio_cdx_msi_set_vector_signal(vdev, j, -1);
120+
}
121+
122+
return ret;
123+
}
124+
125+
static void vfio_cdx_msi_disable(struct vfio_cdx_device *vdev)
126+
{
127+
struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
128+
struct device *dev = vdev->vdev.dev;
129+
130+
vfio_cdx_msi_set_block(vdev, 0, vdev->msi_count, NULL);
131+
132+
if (!vdev->config_msi)
133+
return;
134+
135+
msi_domain_free_irqs_all(dev, MSI_DEFAULT_DOMAIN);
136+
cdx_disable_msi(cdx_dev);
137+
kfree(vdev->cdx_irqs);
138+
139+
vdev->cdx_irqs = NULL;
140+
vdev->msi_count = 0;
141+
vdev->config_msi = 0;
142+
}
143+
144+
static int vfio_cdx_set_msi_trigger(struct vfio_cdx_device *vdev,
145+
unsigned int index, unsigned int start,
146+
unsigned int count, u32 flags,
147+
void *data)
148+
{
149+
struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
150+
int i;
151+
152+
if (start + count > cdx_dev->num_msi)
153+
return -EINVAL;
154+
155+
if (!count && (flags & VFIO_IRQ_SET_DATA_NONE)) {
156+
vfio_cdx_msi_disable(vdev);
157+
return 0;
158+
}
159+
160+
if (flags & VFIO_IRQ_SET_DATA_EVENTFD) {
161+
s32 *fds = data;
162+
int ret;
163+
164+
if (vdev->config_msi)
165+
return vfio_cdx_msi_set_block(vdev, start, count,
166+
fds);
167+
ret = vfio_cdx_msi_enable(vdev, cdx_dev->num_msi);
168+
if (ret)
169+
return ret;
170+
171+
ret = vfio_cdx_msi_set_block(vdev, start, count, fds);
172+
if (ret)
173+
vfio_cdx_msi_disable(vdev);
174+
175+
return ret;
176+
}
177+
178+
for (i = start; i < start + count; i++) {
179+
if (!vdev->cdx_irqs[i].trigger)
180+
continue;
181+
if (flags & VFIO_IRQ_SET_DATA_NONE) {
182+
eventfd_signal(vdev->cdx_irqs[i].trigger);
183+
} else if (flags & VFIO_IRQ_SET_DATA_BOOL) {
184+
u8 *bools = data;
185+
186+
if (bools[i - start])
187+
eventfd_signal(vdev->cdx_irqs[i].trigger);
188+
}
189+
}
190+
191+
return 0;
192+
}
193+
194+
int vfio_cdx_set_irqs_ioctl(struct vfio_cdx_device *vdev,
195+
u32 flags, unsigned int index,
196+
unsigned int start, unsigned int count,
197+
void *data)
198+
{
199+
if (flags & VFIO_IRQ_SET_ACTION_TRIGGER)
200+
return vfio_cdx_set_msi_trigger(vdev, index, start,
201+
count, flags, data);
202+
else
203+
return -EINVAL;
204+
}
205+
206+
/* Free All IRQs for the given device */
207+
void vfio_cdx_irqs_cleanup(struct vfio_cdx_device *vdev)
208+
{
209+
/*
210+
* Device does not support any interrupt or the interrupts
211+
* were not configured
212+
*/
213+
if (!vdev->cdx_irqs)
214+
return;
215+
216+
vfio_cdx_set_msi_trigger(vdev, 0, 0, 0, VFIO_IRQ_SET_DATA_NONE, NULL);
217+
}

‎drivers/vfio/cdx/main.c

Lines changed: 62 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -61,6 +61,7 @@ static void vfio_cdx_close_device(struct vfio_device *core_vdev)
6161

6262
kfree(vdev->regions);
6363
cdx_dev_reset(core_vdev->dev);
64+
vfio_cdx_irqs_cleanup(vdev);
6465
}
6566

6667
static int vfio_cdx_bm_ctrl(struct vfio_device *core_vdev, u32 flags,
@@ -123,7 +124,7 @@ static int vfio_cdx_ioctl_get_info(struct vfio_cdx_device *vdev,
123124
info.flags |= VFIO_DEVICE_FLAGS_RESET;
124125

125126
info.num_regions = cdx_dev->res_count;
126-
info.num_irqs = 0;
127+
info.num_irqs = cdx_dev->num_msi ? 1 : 0;
127128

128129
return copy_to_user(arg, &info, minsz) ? -EFAULT : 0;
129130
}
@@ -152,6 +153,62 @@ static int vfio_cdx_ioctl_get_region_info(struct vfio_cdx_device *vdev,
152153
return copy_to_user(arg, &info, minsz) ? -EFAULT : 0;
153154
}
154155

156+
static int vfio_cdx_ioctl_get_irq_info(struct vfio_cdx_device *vdev,
157+
struct vfio_irq_info __user *arg)
158+
{
159+
unsigned long minsz = offsetofend(struct vfio_irq_info, count);
160+
struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
161+
struct vfio_irq_info info;
162+
163+
if (copy_from_user(&info, arg, minsz))
164+
return -EFAULT;
165+
166+
if (info.argsz < minsz)
167+
return -EINVAL;
168+
169+
if (info.index >= 1)
170+
return -EINVAL;
171+
172+
if (!cdx_dev->num_msi)
173+
return -EINVAL;
174+
175+
info.flags = VFIO_IRQ_INFO_EVENTFD | VFIO_IRQ_INFO_NORESIZE;
176+
info.count = cdx_dev->num_msi;
177+
178+
return copy_to_user(arg, &info, minsz) ? -EFAULT : 0;
179+
}
180+
181+
static int vfio_cdx_ioctl_set_irqs(struct vfio_cdx_device *vdev,
182+
struct vfio_irq_set __user *arg)
183+
{
184+
unsigned long minsz = offsetofend(struct vfio_irq_set, count);
185+
struct cdx_device *cdx_dev = to_cdx_device(vdev->vdev.dev);
186+
struct vfio_irq_set hdr;
187+
size_t data_size = 0;
188+
u8 *data = NULL;
189+
int ret = 0;
190+
191+
if (copy_from_user(&hdr, arg, minsz))
192+
return -EFAULT;
193+
194+
ret = vfio_set_irqs_validate_and_prepare(&hdr, cdx_dev->num_msi,
195+
1, &data_size);
196+
if (ret)
197+
return ret;
198+
199+
if (data_size) {
200+
data = memdup_user(arg->data, data_size);
201+
if (IS_ERR(data))
202+
return PTR_ERR(data);
203+
}
204+
205+
ret = vfio_cdx_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
206+
hdr.start, hdr.count, data);
207+
kfree(data);
208+
209+
return ret;
210+
}
211+
155212
static long vfio_cdx_ioctl(struct vfio_device *core_vdev,
156213
unsigned int cmd, unsigned long arg)
157214
{
@@ -164,6 +221,10 @@ static long vfio_cdx_ioctl(struct vfio_device *core_vdev,
164221
return vfio_cdx_ioctl_get_info(vdev, uarg);
165222
case VFIO_DEVICE_GET_REGION_INFO:
166223
return vfio_cdx_ioctl_get_region_info(vdev, uarg);
224+
case VFIO_DEVICE_GET_IRQ_INFO:
225+
return vfio_cdx_ioctl_get_irq_info(vdev, uarg);
226+
case VFIO_DEVICE_SET_IRQS:
227+
return vfio_cdx_ioctl_set_irqs(vdev, uarg);
167228
case VFIO_DEVICE_RESET:
168229
return cdx_dev_reset(core_vdev->dev);
169230
default:

‎drivers/vfio/cdx/private.h

Lines changed: 18 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -13,6 +13,14 @@ static inline u64 vfio_cdx_index_to_offset(u32 index)
1313
return ((u64)(index) << VFIO_CDX_OFFSET_SHIFT);
1414
}
1515

16+
struct vfio_cdx_irq {
17+
u32 flags;
18+
u32 count;
19+
int irq_no;
20+
struct eventfd_ctx *trigger;
21+
char *name;
22+
};
23+
1624
struct vfio_cdx_region {
1725
u32 flags;
1826
u32 type;
@@ -23,8 +31,18 @@ struct vfio_cdx_region {
2331
struct vfio_cdx_device {
2432
struct vfio_device vdev;
2533
struct vfio_cdx_region *regions;
34+
struct vfio_cdx_irq *cdx_irqs;
2635
u32 flags;
2736
#define BME_SUPPORT BIT(0)
37+
u32 msi_count;
38+
u8 config_msi;
2839
};
2940

41+
int vfio_cdx_set_irqs_ioctl(struct vfio_cdx_device *vdev,
42+
u32 flags, unsigned int index,
43+
unsigned int start, unsigned int count,
44+
void *data);
45+
46+
void vfio_cdx_irqs_cleanup(struct vfio_cdx_device *vdev);
47+
3048
#endif /* VFIO_CDX_PRIVATE_H */

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