Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
vfio/pci: rename and export range_intersect_range
range_intersect_range determines an overlap between two ranges. If an
overlap, the helper function returns the overlapping offset and size.
The VFIO PCI variant driver emulates the PCI config space BAR offset
registers. These offset may be accessed for read/write with a variety
of lengths including sub-word sizes from sub-word offsets. The driver
makes use of this helper function to read/write the targeted part of
the emulated register.
Make this a vfio_pci_core function, rename and export as GPL. Also
update references in virtio driver.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: Ankit Agrawal <ankita@nvidia.com>
Link: https://lore.kernel.org/r/20240220115055.23546-3-ankita@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
authored by
Ankit Agrawal
and committed by
Alex Williamson
30e920e1
4de676d4
+73
-46
+42
drivers/vfio/pci/vfio_pci_config.c
+42
drivers/vfio/pci/vfio_pci_config.c
···
1966
1966
1967
1967
return done;
1968
1968
}
1969
+
1970
+
/**
1971
+
* vfio_pci_core_range_intersect_range() - Determine overlap between a buffer
1972
+
* and register offset ranges.
1973
+
* @buf_start: start offset of the buffer
1974
+
* @buf_cnt: number of buffer bytes
1975
+
* @reg_start: start register offset
1976
+
* @reg_cnt: number of register bytes
1977
+
* @buf_offset: start offset of overlap in the buffer
1978
+
* @intersect_count: number of overlapping bytes
1979
+
* @register_offset: start offset of overlap in register
1980
+
*
1981
+
* Returns: true if there is overlap, false if not.
1982
+
* The overlap start and size is returned through function args.
1983
+
*/
1984
+
bool vfio_pci_core_range_intersect_range(loff_t buf_start, size_t buf_cnt,
1985
+
loff_t reg_start, size_t reg_cnt,
1986
+
loff_t *buf_offset,
1987
+
size_t *intersect_count,
1988
+
size_t *register_offset)
1989
+
{
1990
+
if (buf_start <= reg_start &&
1991
+
buf_start + buf_cnt > reg_start) {
1992
+
*buf_offset = reg_start - buf_start;
1993
+
*intersect_count = min_t(size_t, reg_cnt,
1994
+
buf_start + buf_cnt - reg_start);
1995
+
*register_offset = 0;
1996
+
return true;
1997
+
}
1998
+
1999
+
if (buf_start > reg_start &&
2000
+
buf_start < reg_start + reg_cnt) {
2001
+
*buf_offset = 0;
2002
+
*intersect_count = min_t(size_t, buf_cnt,
2003
+
reg_start + reg_cnt - buf_start);
2004
+
*register_offset = buf_start - reg_start;
2005
+
return true;
2006
+
}
2007
+
2008
+
return false;
2009
+
}
2010
+
EXPORT_SYMBOL_GPL(vfio_pci_core_range_intersect_range);
+26
-46
drivers/vfio/pci/virtio/main.c
+26
-46
drivers/vfio/pci/virtio/main.c
···
132
132
return ret ? ret : count;
133
133
}
134
134
135
-
static bool range_intersect_range(loff_t range1_start, size_t count1,
136
-
loff_t range2_start, size_t count2,
137
-
loff_t *start_offset,
138
-
size_t *intersect_count,
139
-
size_t *register_offset)
140
-
{
141
-
if (range1_start <= range2_start &&
142
-
range1_start + count1 > range2_start) {
143
-
*start_offset = range2_start - range1_start;
144
-
*intersect_count = min_t(size_t, count2,
145
-
range1_start + count1 - range2_start);
146
-
*register_offset = 0;
147
-
return true;
148
-
}
149
-
150
-
if (range1_start > range2_start &&
151
-
range1_start < range2_start + count2) {
152
-
*start_offset = 0;
153
-
*intersect_count = min_t(size_t, count1,
154
-
range2_start + count2 - range1_start);
155
-
*register_offset = range1_start - range2_start;
156
-
return true;
157
-
}
158
-
159
-
return false;
160
-
}
161
-
162
135
static ssize_t virtiovf_pci_read_config(struct vfio_device *core_vdev,
163
136
char __user *buf, size_t count,
164
137
loff_t *ppos)
···
151
178
if (ret < 0)
152
179
return ret;
153
180
154
-
if (range_intersect_range(pos, count, PCI_DEVICE_ID, sizeof(val16),
155
-
©_offset, ©_count, ®ister_offset)) {
181
+
if (vfio_pci_core_range_intersect_range(pos, count, PCI_DEVICE_ID,
182
+
sizeof(val16), ©_offset,
183
+
©_count, ®ister_offset)) {
156
184
val16 = cpu_to_le16(VIRTIO_TRANS_ID_NET);
157
185
if (copy_to_user(buf + copy_offset, (void *)&val16 + register_offset, copy_count))
158
186
return -EFAULT;
159
187
}
160
188
161
189
if ((le16_to_cpu(virtvdev->pci_cmd) & PCI_COMMAND_IO) &&
162
-
range_intersect_range(pos, count, PCI_COMMAND, sizeof(val16),
163
-
©_offset, ©_count, ®ister_offset)) {
190
+
vfio_pci_core_range_intersect_range(pos, count, PCI_COMMAND,
191
+
sizeof(val16), ©_offset,
192
+
©_count, ®ister_offset)) {
164
193
if (copy_from_user((void *)&val16 + register_offset, buf + copy_offset,
165
194
copy_count))
166
195
return -EFAULT;
···
172
197
return -EFAULT;
173
198
}
174
199
175
-
if (range_intersect_range(pos, count, PCI_REVISION_ID, sizeof(val8),
176
-
©_offset, ©_count, ®ister_offset)) {
200
+
if (vfio_pci_core_range_intersect_range(pos, count, PCI_REVISION_ID,
201
+
sizeof(val8), ©_offset,
202
+
©_count, ®ister_offset)) {
177
203
/* Transional needs to have revision 0 */
178
204
val8 = 0;
179
205
if (copy_to_user(buf + copy_offset, &val8, copy_count))
180
206
return -EFAULT;
181
207
}
182
208
183
-
if (range_intersect_range(pos, count, PCI_BASE_ADDRESS_0, sizeof(val32),
184
-
©_offset, ©_count, ®ister_offset)) {
209
+
if (vfio_pci_core_range_intersect_range(pos, count, PCI_BASE_ADDRESS_0,
210
+
sizeof(val32), ©_offset,
211
+
©_count, ®ister_offset)) {
185
212
u32 bar_mask = ~(virtvdev->bar0_virtual_buf_size - 1);
186
213
u32 pci_base_addr_0 = le32_to_cpu(virtvdev->pci_base_addr_0);
187
214
···
192
215
return -EFAULT;
193
216
}
194
217
195
-
if (range_intersect_range(pos, count, PCI_SUBSYSTEM_ID, sizeof(val16),
196
-
©_offset, ©_count, ®ister_offset)) {
218
+
if (vfio_pci_core_range_intersect_range(pos, count, PCI_SUBSYSTEM_ID,
219
+
sizeof(val16), ©_offset,
220
+
©_count, ®ister_offset)) {
197
221
/*
198
222
* Transitional devices use the PCI subsystem device id as
199
223
* virtio device id, same as legacy driver always did.
···
205
227
return -EFAULT;
206
228
}
207
229
208
-
if (range_intersect_range(pos, count, PCI_SUBSYSTEM_VENDOR_ID, sizeof(val16),
209
-
©_offset, ©_count, ®ister_offset)) {
230
+
if (vfio_pci_core_range_intersect_range(pos, count, PCI_SUBSYSTEM_VENDOR_ID,
231
+
sizeof(val16), ©_offset,
232
+
©_count, ®ister_offset)) {
210
233
val16 = cpu_to_le16(PCI_VENDOR_ID_REDHAT_QUMRANET);
211
234
if (copy_to_user(buf + copy_offset, (void *)&val16 + register_offset,
212
235
copy_count))
···
249
270
loff_t copy_offset;
250
271
size_t copy_count;
251
272
252
-
if (range_intersect_range(pos, count, PCI_COMMAND, sizeof(virtvdev->pci_cmd),
253
-
©_offset, ©_count,
254
-
®ister_offset)) {
273
+
if (vfio_pci_core_range_intersect_range(pos, count, PCI_COMMAND,
274
+
sizeof(virtvdev->pci_cmd),
275
+
©_offset, ©_count,
276
+
®ister_offset)) {
255
277
if (copy_from_user((void *)&virtvdev->pci_cmd + register_offset,
256
278
buf + copy_offset,
257
279
copy_count))
258
280
return -EFAULT;
259
281
}
260
282
261
-
if (range_intersect_range(pos, count, PCI_BASE_ADDRESS_0,
262
-
sizeof(virtvdev->pci_base_addr_0),
263
-
©_offset, ©_count,
264
-
®ister_offset)) {
283
+
if (vfio_pci_core_range_intersect_range(pos, count, PCI_BASE_ADDRESS_0,
284
+
sizeof(virtvdev->pci_base_addr_0),
285
+
©_offset, ©_count,
286
+
®ister_offset)) {
265
287
if (copy_from_user((void *)&virtvdev->pci_base_addr_0 + register_offset,
266
288
buf + copy_offset,
267
289
copy_count))
+5
include/linux/vfio_pci_core.h
+5
include/linux/vfio_pci_core.h
···
134
134
void __iomem *io, char __user *buf,
135
135
loff_t off, size_t count, size_t x_start,
136
136
size_t x_end, bool iswrite);
137
+
bool vfio_pci_core_range_intersect_range(loff_t buf_start, size_t buf_cnt,
138
+
loff_t reg_start, size_t reg_cnt,
139
+
loff_t *buf_offset,
140
+
size_t *intersect_count,
141
+
size_t *register_offset);
137
142
#define VFIO_IOWRITE_DECLATION(size) \
138
143
int vfio_pci_core_iowrite##size(struct vfio_pci_core_device *vdev, \
139
144
bool test_mem, u##size val, void __iomem *io);