xref: /openbmc/linux/drivers/gpu/drm/i915/gvt/cfg_space.c (revision f220d3eb)
1 /*
2  * Copyright(c) 2011-2016 Intel Corporation. All rights reserved.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21  * SOFTWARE.
22  *
23  * Authors:
24  *    Eddie Dong <eddie.dong@intel.com>
25  *    Jike Song <jike.song@intel.com>
26  *
27  * Contributors:
28  *    Zhi Wang <zhi.a.wang@intel.com>
29  *    Min He <min.he@intel.com>
30  *    Bing Niu <bing.niu@intel.com>
31  *
32  */
33 
34 #include "i915_drv.h"
35 #include "gvt.h"
36 
37 enum {
38 	INTEL_GVT_PCI_BAR_GTTMMIO = 0,
39 	INTEL_GVT_PCI_BAR_APERTURE,
40 	INTEL_GVT_PCI_BAR_PIO,
41 	INTEL_GVT_PCI_BAR_MAX,
42 };
43 
44 /* bitmap for writable bits (RW or RW1C bits, but cannot co-exist in one
45  * byte) byte by byte in standard pci configuration space. (not the full
46  * 256 bytes.)
47  */
48 static const u8 pci_cfg_space_rw_bmp[PCI_INTERRUPT_LINE + 4] = {
49 	[PCI_COMMAND]		= 0xff, 0x07,
50 	[PCI_STATUS]		= 0x00, 0xf9, /* the only one RW1C byte */
51 	[PCI_CACHE_LINE_SIZE]	= 0xff,
52 	[PCI_BASE_ADDRESS_0 ... PCI_CARDBUS_CIS - 1] = 0xff,
53 	[PCI_ROM_ADDRESS]	= 0x01, 0xf8, 0xff, 0xff,
54 	[PCI_INTERRUPT_LINE]	= 0xff,
55 };
56 
57 /**
58  * vgpu_pci_cfg_mem_write - write virtual cfg space memory
59  *
60  * Use this function to write virtual cfg space memory.
61  * For standard cfg space, only RW bits can be changed,
62  * and we emulates the RW1C behavior of PCI_STATUS register.
63  */
64 static void vgpu_pci_cfg_mem_write(struct intel_vgpu *vgpu, unsigned int off,
65 				   u8 *src, unsigned int bytes)
66 {
67 	u8 *cfg_base = vgpu_cfg_space(vgpu);
68 	u8 mask, new, old;
69 	int i = 0;
70 
71 	for (; i < bytes && (off + i < sizeof(pci_cfg_space_rw_bmp)); i++) {
72 		mask = pci_cfg_space_rw_bmp[off + i];
73 		old = cfg_base[off + i];
74 		new = src[i] & mask;
75 
76 		/**
77 		 * The PCI_STATUS high byte has RW1C bits, here
78 		 * emulates clear by writing 1 for these bits.
79 		 * Writing a 0b to RW1C bits has no effect.
80 		 */
81 		if (off + i == PCI_STATUS + 1)
82 			new = (~new & old) & mask;
83 
84 		cfg_base[off + i] = (old & ~mask) | new;
85 	}
86 
87 	/* For other configuration space directly copy as it is. */
88 	if (i < bytes)
89 		memcpy(cfg_base + off + i, src + i, bytes - i);
90 }
91 
92 /**
93  * intel_vgpu_emulate_cfg_read - emulate vGPU configuration space read
94  *
95  * Returns:
96  * Zero on success, negative error code if failed.
97  */
98 int intel_vgpu_emulate_cfg_read(struct intel_vgpu *vgpu, unsigned int offset,
99 	void *p_data, unsigned int bytes)
100 {
101 	if (WARN_ON(bytes > 4))
102 		return -EINVAL;
103 
104 	if (WARN_ON(offset + bytes > vgpu->gvt->device_info.cfg_space_size))
105 		return -EINVAL;
106 
107 	memcpy(p_data, vgpu_cfg_space(vgpu) + offset, bytes);
108 	return 0;
109 }
110 
111 static int map_aperture(struct intel_vgpu *vgpu, bool map)
112 {
113 	phys_addr_t aperture_pa = vgpu_aperture_pa_base(vgpu);
114 	unsigned long aperture_sz = vgpu_aperture_sz(vgpu);
115 	u64 first_gfn;
116 	u64 val;
117 	int ret;
118 
119 	if (map == vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_APERTURE].tracked)
120 		return 0;
121 
122 	val = vgpu_cfg_space(vgpu)[PCI_BASE_ADDRESS_2];
123 	if (val & PCI_BASE_ADDRESS_MEM_TYPE_64)
124 		val = *(u64 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_2);
125 	else
126 		val = *(u32 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_2);
127 
128 	first_gfn = (val + vgpu_aperture_offset(vgpu)) >> PAGE_SHIFT;
129 
130 	ret = intel_gvt_hypervisor_map_gfn_to_mfn(vgpu, first_gfn,
131 						  aperture_pa >> PAGE_SHIFT,
132 						  aperture_sz >> PAGE_SHIFT,
133 						  map);
134 	if (ret)
135 		return ret;
136 
137 	vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_APERTURE].tracked = map;
138 	return 0;
139 }
140 
141 static int trap_gttmmio(struct intel_vgpu *vgpu, bool trap)
142 {
143 	u64 start, end;
144 	u64 val;
145 	int ret;
146 
147 	if (trap == vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].tracked)
148 		return 0;
149 
150 	val = vgpu_cfg_space(vgpu)[PCI_BASE_ADDRESS_0];
151 	if (val & PCI_BASE_ADDRESS_MEM_TYPE_64)
152 		start = *(u64 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_0);
153 	else
154 		start = *(u32 *)(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_0);
155 
156 	start &= ~GENMASK(3, 0);
157 	end = start + vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].size - 1;
158 
159 	ret = intel_gvt_hypervisor_set_trap_area(vgpu, start, end, trap);
160 	if (ret)
161 		return ret;
162 
163 	vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].tracked = trap;
164 	return 0;
165 }
166 
167 static int emulate_pci_command_write(struct intel_vgpu *vgpu,
168 	unsigned int offset, void *p_data, unsigned int bytes)
169 {
170 	u8 old = vgpu_cfg_space(vgpu)[offset];
171 	u8 new = *(u8 *)p_data;
172 	u8 changed = old ^ new;
173 	int ret;
174 
175 	vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes);
176 	if (!(changed & PCI_COMMAND_MEMORY))
177 		return 0;
178 
179 	if (old & PCI_COMMAND_MEMORY) {
180 		ret = trap_gttmmio(vgpu, false);
181 		if (ret)
182 			return ret;
183 		ret = map_aperture(vgpu, false);
184 		if (ret)
185 			return ret;
186 	} else {
187 		ret = trap_gttmmio(vgpu, true);
188 		if (ret)
189 			return ret;
190 		ret = map_aperture(vgpu, true);
191 		if (ret)
192 			return ret;
193 	}
194 
195 	return 0;
196 }
197 
198 static int emulate_pci_rom_bar_write(struct intel_vgpu *vgpu,
199 	unsigned int offset, void *p_data, unsigned int bytes)
200 {
201 	u32 *pval = (u32 *)(vgpu_cfg_space(vgpu) + offset);
202 	u32 new = *(u32 *)(p_data);
203 
204 	if ((new & PCI_ROM_ADDRESS_MASK) == PCI_ROM_ADDRESS_MASK)
205 		/* We don't have rom, return size of 0. */
206 		*pval = 0;
207 	else
208 		vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes);
209 	return 0;
210 }
211 
212 static int emulate_pci_bar_write(struct intel_vgpu *vgpu, unsigned int offset,
213 	void *p_data, unsigned int bytes)
214 {
215 	u32 new = *(u32 *)(p_data);
216 	bool lo = IS_ALIGNED(offset, 8);
217 	u64 size;
218 	int ret = 0;
219 	bool mmio_enabled =
220 		vgpu_cfg_space(vgpu)[PCI_COMMAND] & PCI_COMMAND_MEMORY;
221 	struct intel_vgpu_pci_bar *bars = vgpu->cfg_space.bar;
222 
223 	/*
224 	 * Power-up software can determine how much address
225 	 * space the device requires by writing a value of
226 	 * all 1's to the register and then reading the value
227 	 * back. The device will return 0's in all don't-care
228 	 * address bits.
229 	 */
230 	if (new == 0xffffffff) {
231 		switch (offset) {
232 		case PCI_BASE_ADDRESS_0:
233 		case PCI_BASE_ADDRESS_1:
234 			size = ~(bars[INTEL_GVT_PCI_BAR_GTTMMIO].size -1);
235 			intel_vgpu_write_pci_bar(vgpu, offset,
236 						size >> (lo ? 0 : 32), lo);
237 			/*
238 			 * Untrap the BAR, since guest hasn't configured a
239 			 * valid GPA
240 			 */
241 			ret = trap_gttmmio(vgpu, false);
242 			break;
243 		case PCI_BASE_ADDRESS_2:
244 		case PCI_BASE_ADDRESS_3:
245 			size = ~(bars[INTEL_GVT_PCI_BAR_APERTURE].size -1);
246 			intel_vgpu_write_pci_bar(vgpu, offset,
247 						size >> (lo ? 0 : 32), lo);
248 			ret = map_aperture(vgpu, false);
249 			break;
250 		default:
251 			/* Unimplemented BARs */
252 			intel_vgpu_write_pci_bar(vgpu, offset, 0x0, false);
253 		}
254 	} else {
255 		switch (offset) {
256 		case PCI_BASE_ADDRESS_0:
257 		case PCI_BASE_ADDRESS_1:
258 			/*
259 			 * Untrap the old BAR first, since guest has
260 			 * re-configured the BAR
261 			 */
262 			trap_gttmmio(vgpu, false);
263 			intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
264 			ret = trap_gttmmio(vgpu, mmio_enabled);
265 			break;
266 		case PCI_BASE_ADDRESS_2:
267 		case PCI_BASE_ADDRESS_3:
268 			map_aperture(vgpu, false);
269 			intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
270 			ret = map_aperture(vgpu, mmio_enabled);
271 			break;
272 		default:
273 			intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
274 		}
275 	}
276 	return ret;
277 }
278 
279 /**
280  * intel_vgpu_emulate_cfg_read - emulate vGPU configuration space write
281  *
282  * Returns:
283  * Zero on success, negative error code if failed.
284  */
285 int intel_vgpu_emulate_cfg_write(struct intel_vgpu *vgpu, unsigned int offset,
286 	void *p_data, unsigned int bytes)
287 {
288 	int ret;
289 
290 	if (WARN_ON(bytes > 4))
291 		return -EINVAL;
292 
293 	if (WARN_ON(offset + bytes > vgpu->gvt->device_info.cfg_space_size))
294 		return -EINVAL;
295 
296 	/* First check if it's PCI_COMMAND */
297 	if (IS_ALIGNED(offset, 2) && offset == PCI_COMMAND) {
298 		if (WARN_ON(bytes > 2))
299 			return -EINVAL;
300 		return emulate_pci_command_write(vgpu, offset, p_data, bytes);
301 	}
302 
303 	switch (rounddown(offset, 4)) {
304 	case PCI_ROM_ADDRESS:
305 		if (WARN_ON(!IS_ALIGNED(offset, 4)))
306 			return -EINVAL;
307 		return emulate_pci_rom_bar_write(vgpu, offset, p_data, bytes);
308 
309 	case PCI_BASE_ADDRESS_0 ... PCI_BASE_ADDRESS_5:
310 		if (WARN_ON(!IS_ALIGNED(offset, 4)))
311 			return -EINVAL;
312 		return emulate_pci_bar_write(vgpu, offset, p_data, bytes);
313 
314 	case INTEL_GVT_PCI_SWSCI:
315 		if (WARN_ON(!IS_ALIGNED(offset, 4)))
316 			return -EINVAL;
317 		ret = intel_vgpu_emulate_opregion_request(vgpu, *(u32 *)p_data);
318 		if (ret)
319 			return ret;
320 		break;
321 
322 	case INTEL_GVT_PCI_OPREGION:
323 		if (WARN_ON(!IS_ALIGNED(offset, 4)))
324 			return -EINVAL;
325 		ret = intel_vgpu_opregion_base_write_handler(vgpu,
326 						   *(u32 *)p_data);
327 		if (ret)
328 			return ret;
329 
330 		vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes);
331 		break;
332 	default:
333 		vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes);
334 		break;
335 	}
336 	return 0;
337 }
338 
339 /**
340  * intel_vgpu_init_cfg_space - init vGPU configuration space when create vGPU
341  *
342  * @vgpu: a vGPU
343  * @primary: is the vGPU presented as primary
344  *
345  */
346 void intel_vgpu_init_cfg_space(struct intel_vgpu *vgpu,
347 			       bool primary)
348 {
349 	struct intel_gvt *gvt = vgpu->gvt;
350 	const struct intel_gvt_device_info *info = &gvt->device_info;
351 	u16 *gmch_ctl;
352 
353 	memcpy(vgpu_cfg_space(vgpu), gvt->firmware.cfg_space,
354 	       info->cfg_space_size);
355 
356 	if (!primary) {
357 		vgpu_cfg_space(vgpu)[PCI_CLASS_DEVICE] =
358 			INTEL_GVT_PCI_CLASS_VGA_OTHER;
359 		vgpu_cfg_space(vgpu)[PCI_CLASS_PROG] =
360 			INTEL_GVT_PCI_CLASS_VGA_OTHER;
361 	}
362 
363 	/* Show guest that there isn't any stolen memory.*/
364 	gmch_ctl = (u16 *)(vgpu_cfg_space(vgpu) + INTEL_GVT_PCI_GMCH_CONTROL);
365 	*gmch_ctl &= ~(BDW_GMCH_GMS_MASK << BDW_GMCH_GMS_SHIFT);
366 
367 	intel_vgpu_write_pci_bar(vgpu, PCI_BASE_ADDRESS_2,
368 				 gvt_aperture_pa_base(gvt), true);
369 
370 	vgpu_cfg_space(vgpu)[PCI_COMMAND] &= ~(PCI_COMMAND_IO
371 					     | PCI_COMMAND_MEMORY
372 					     | PCI_COMMAND_MASTER);
373 	/*
374 	 * Clear the bar upper 32bit and let guest to assign the new value
375 	 */
376 	memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_1, 0, 4);
377 	memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_3, 0, 4);
378 	memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_4, 0, 8);
379 	memset(vgpu_cfg_space(vgpu) + INTEL_GVT_PCI_OPREGION, 0, 4);
380 
381 	vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].size =
382 				pci_resource_len(gvt->dev_priv->drm.pdev, 0);
383 	vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_APERTURE].size =
384 				pci_resource_len(gvt->dev_priv->drm.pdev, 2);
385 
386 	memset(vgpu_cfg_space(vgpu) + PCI_ROM_ADDRESS, 0, 4);
387 }
388 
389 /**
390  * intel_vgpu_reset_cfg_space - reset vGPU configuration space
391  *
392  * @vgpu: a vGPU
393  *
394  */
395 void intel_vgpu_reset_cfg_space(struct intel_vgpu *vgpu)
396 {
397 	u8 cmd = vgpu_cfg_space(vgpu)[PCI_COMMAND];
398 	bool primary = vgpu_cfg_space(vgpu)[PCI_CLASS_DEVICE] !=
399 				INTEL_GVT_PCI_CLASS_VGA_OTHER;
400 
401 	if (cmd & PCI_COMMAND_MEMORY) {
402 		trap_gttmmio(vgpu, false);
403 		map_aperture(vgpu, false);
404 	}
405 
406 	/**
407 	 * Currently we only do such reset when vGPU is not
408 	 * owned by any VM, so we simply restore entire cfg
409 	 * space to default value.
410 	 */
411 	intel_vgpu_init_cfg_space(vgpu, primary);
412 }
413