xref: /openbmc/qemu/hw/xen/xen_pt_msi.c (revision f0513d2c)
1 /*
2  * Copyright (c) 2007, Intel Corporation.
3  *
4  * This work is licensed under the terms of the GNU GPL, version 2.  See
5  * the COPYING file in the top-level directory.
6  *
7  * Jiang Yunhong <yunhong.jiang@intel.com>
8  *
9  * This file implements direct PCI assignment to a HVM guest
10  */
11 
12 #include <sys/mman.h>
13 
14 #include "hw/xen/xen_backend.h"
15 #include "xen_pt.h"
16 #include "hw/i386/apic-msidef.h"
17 
18 
19 #define XEN_PT_AUTO_ASSIGN -1
20 
21 /* shift count for gflags */
22 #define XEN_PT_GFLAGS_SHIFT_DEST_ID        0
23 #define XEN_PT_GFLAGS_SHIFT_RH             8
24 #define XEN_PT_GFLAGS_SHIFT_DM             9
25 #define XEN_PT_GFLAGSSHIFT_DELIV_MODE     12
26 #define XEN_PT_GFLAGSSHIFT_TRG_MODE       15
27 
28 
29 /*
30  * Helpers
31  */
32 
33 static inline uint8_t msi_vector(uint32_t data)
34 {
35     return (data & MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
36 }
37 
38 static inline uint8_t msi_dest_id(uint32_t addr)
39 {
40     return (addr & MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
41 }
42 
43 static inline uint32_t msi_ext_dest_id(uint32_t addr_hi)
44 {
45     return addr_hi & 0xffffff00;
46 }
47 
48 static uint32_t msi_gflags(uint32_t data, uint64_t addr)
49 {
50     uint32_t result = 0;
51     int rh, dm, dest_id, deliv_mode, trig_mode;
52 
53     rh = (addr >> MSI_ADDR_REDIRECTION_SHIFT) & 0x1;
54     dm = (addr >> MSI_ADDR_DEST_MODE_SHIFT) & 0x1;
55     dest_id = msi_dest_id(addr);
56     deliv_mode = (data >> MSI_DATA_DELIVERY_MODE_SHIFT) & 0x7;
57     trig_mode = (data >> MSI_DATA_TRIGGER_SHIFT) & 0x1;
58 
59     result = dest_id | (rh << XEN_PT_GFLAGS_SHIFT_RH)
60         | (dm << XEN_PT_GFLAGS_SHIFT_DM)
61         | (deliv_mode << XEN_PT_GFLAGSSHIFT_DELIV_MODE)
62         | (trig_mode << XEN_PT_GFLAGSSHIFT_TRG_MODE);
63 
64     return result;
65 }
66 
67 static inline uint64_t msi_addr64(XenPTMSI *msi)
68 {
69     return (uint64_t)msi->addr_hi << 32 | msi->addr_lo;
70 }
71 
72 static int msi_msix_enable(XenPCIPassthroughState *s,
73                            uint32_t address,
74                            uint16_t flag,
75                            bool enable)
76 {
77     uint16_t val = 0;
78 
79     if (!address) {
80         return -1;
81     }
82 
83     xen_host_pci_get_word(&s->real_device, address, &val);
84     if (enable) {
85         val |= flag;
86     } else {
87         val &= ~flag;
88     }
89     xen_host_pci_set_word(&s->real_device, address, val);
90     return 0;
91 }
92 
93 static int msi_msix_setup(XenPCIPassthroughState *s,
94                           uint64_t addr,
95                           uint32_t data,
96                           int *ppirq,
97                           bool is_msix,
98                           int msix_entry,
99                           bool is_not_mapped)
100 {
101     uint8_t gvec = msi_vector(data);
102     int rc = 0;
103 
104     assert((!is_msix && msix_entry == 0) || is_msix);
105 
106     if (gvec == 0) {
107         /* if gvec is 0, the guest is asking for a particular pirq that
108          * is passed as dest_id */
109         *ppirq = msi_ext_dest_id(addr >> 32) | msi_dest_id(addr);
110         if (!*ppirq) {
111             /* this probably identifies an misconfiguration of the guest,
112              * try the emulated path */
113             *ppirq = XEN_PT_UNASSIGNED_PIRQ;
114         } else {
115             XEN_PT_LOG(&s->dev, "requested pirq %d for MSI%s"
116                        " (vec: %#x, entry: %#x)\n",
117                        *ppirq, is_msix ? "-X" : "", gvec, msix_entry);
118         }
119     }
120 
121     if (is_not_mapped) {
122         uint64_t table_base = 0;
123 
124         if (is_msix) {
125             table_base = s->msix->table_base;
126         }
127 
128         rc = xc_physdev_map_pirq_msi(xen_xc, xen_domid, XEN_PT_AUTO_ASSIGN,
129                                      ppirq, PCI_DEVFN(s->real_device.dev,
130                                                       s->real_device.func),
131                                      s->real_device.bus,
132                                      msix_entry, table_base);
133         if (rc) {
134             XEN_PT_ERR(&s->dev,
135                        "Mapping of MSI%s (rc: %i, vec: %#x, entry %#x)\n",
136                        is_msix ? "-X" : "", rc, gvec, msix_entry);
137             return rc;
138         }
139     }
140 
141     return 0;
142 }
143 static int msi_msix_update(XenPCIPassthroughState *s,
144                            uint64_t addr,
145                            uint32_t data,
146                            int pirq,
147                            bool is_msix,
148                            int msix_entry,
149                            int *old_pirq)
150 {
151     PCIDevice *d = &s->dev;
152     uint8_t gvec = msi_vector(data);
153     uint32_t gflags = msi_gflags(data, addr);
154     int rc = 0;
155     uint64_t table_addr = 0;
156 
157     XEN_PT_LOG(d, "Updating MSI%s with pirq %d gvec %#x gflags %#x"
158                " (entry: %#x)\n",
159                is_msix ? "-X" : "", pirq, gvec, gflags, msix_entry);
160 
161     if (is_msix) {
162         table_addr = s->msix->mmio_base_addr;
163     }
164 
165     rc = xc_domain_update_msi_irq(xen_xc, xen_domid, gvec,
166                                   pirq, gflags, table_addr);
167 
168     if (rc) {
169         XEN_PT_ERR(d, "Updating of MSI%s failed. (rc: %d)\n",
170                    is_msix ? "-X" : "", rc);
171 
172         if (xc_physdev_unmap_pirq(xen_xc, xen_domid, *old_pirq)) {
173             XEN_PT_ERR(d, "Unmapping of MSI%s pirq %d failed.\n",
174                        is_msix ? "-X" : "", *old_pirq);
175         }
176         *old_pirq = XEN_PT_UNASSIGNED_PIRQ;
177     }
178     return rc;
179 }
180 
181 static int msi_msix_disable(XenPCIPassthroughState *s,
182                             uint64_t addr,
183                             uint32_t data,
184                             int pirq,
185                             bool is_msix,
186                             bool is_binded)
187 {
188     PCIDevice *d = &s->dev;
189     uint8_t gvec = msi_vector(data);
190     uint32_t gflags = msi_gflags(data, addr);
191     int rc = 0;
192 
193     if (pirq == XEN_PT_UNASSIGNED_PIRQ) {
194         return 0;
195     }
196 
197     if (is_binded) {
198         XEN_PT_LOG(d, "Unbind MSI%s with pirq %d, gvec %#x\n",
199                    is_msix ? "-X" : "", pirq, gvec);
200         rc = xc_domain_unbind_msi_irq(xen_xc, xen_domid, gvec, pirq, gflags);
201         if (rc) {
202             XEN_PT_ERR(d, "Unbinding of MSI%s failed. (pirq: %d, gvec: %#x)\n",
203                        is_msix ? "-X" : "", pirq, gvec);
204             return rc;
205         }
206     }
207 
208     XEN_PT_LOG(d, "Unmap MSI%s pirq %d\n", is_msix ? "-X" : "", pirq);
209     rc = xc_physdev_unmap_pirq(xen_xc, xen_domid, pirq);
210     if (rc) {
211         XEN_PT_ERR(d, "Unmapping of MSI%s pirq %d failed. (rc: %i)\n",
212                    is_msix ? "-X" : "", pirq, rc);
213         return rc;
214     }
215 
216     return 0;
217 }
218 
219 /*
220  * MSI virtualization functions
221  */
222 
223 int xen_pt_msi_set_enable(XenPCIPassthroughState *s, bool enable)
224 {
225     XEN_PT_LOG(&s->dev, "%s MSI.\n", enable ? "enabling" : "disabling");
226 
227     if (!s->msi) {
228         return -1;
229     }
230 
231     return msi_msix_enable(s, s->msi->ctrl_offset, PCI_MSI_FLAGS_ENABLE,
232                            enable);
233 }
234 
235 /* setup physical msi, but don't enable it */
236 int xen_pt_msi_setup(XenPCIPassthroughState *s)
237 {
238     int pirq = XEN_PT_UNASSIGNED_PIRQ;
239     int rc = 0;
240     XenPTMSI *msi = s->msi;
241 
242     if (msi->initialized) {
243         XEN_PT_ERR(&s->dev,
244                    "Setup physical MSI when it has been properly initialized.\n");
245         return -1;
246     }
247 
248     rc = msi_msix_setup(s, msi_addr64(msi), msi->data, &pirq, false, 0, true);
249     if (rc) {
250         return rc;
251     }
252 
253     if (pirq < 0) {
254         XEN_PT_ERR(&s->dev, "Invalid pirq number: %d.\n", pirq);
255         return -1;
256     }
257 
258     msi->pirq = pirq;
259     XEN_PT_LOG(&s->dev, "MSI mapped with pirq %d.\n", pirq);
260 
261     return 0;
262 }
263 
264 int xen_pt_msi_update(XenPCIPassthroughState *s)
265 {
266     XenPTMSI *msi = s->msi;
267     return msi_msix_update(s, msi_addr64(msi), msi->data, msi->pirq,
268                            false, 0, &msi->pirq);
269 }
270 
271 void xen_pt_msi_disable(XenPCIPassthroughState *s)
272 {
273     XenPTMSI *msi = s->msi;
274 
275     if (!msi) {
276         return;
277     }
278 
279     xen_pt_msi_set_enable(s, false);
280 
281     msi_msix_disable(s, msi_addr64(msi), msi->data, msi->pirq, false,
282                      msi->initialized);
283 
284     /* clear msi info */
285     msi->flags = 0;
286     msi->mapped = false;
287     msi->pirq = XEN_PT_UNASSIGNED_PIRQ;
288 }
289 
290 /*
291  * MSI-X virtualization functions
292  */
293 
294 static int msix_set_enable(XenPCIPassthroughState *s, bool enabled)
295 {
296     XEN_PT_LOG(&s->dev, "%s MSI-X.\n", enabled ? "enabling" : "disabling");
297 
298     if (!s->msix) {
299         return -1;
300     }
301 
302     return msi_msix_enable(s, s->msix->ctrl_offset, PCI_MSIX_FLAGS_ENABLE,
303                            enabled);
304 }
305 
306 static int xen_pt_msix_update_one(XenPCIPassthroughState *s, int entry_nr)
307 {
308     XenPTMSIXEntry *entry = NULL;
309     int pirq;
310     int rc;
311 
312     if (entry_nr < 0 || entry_nr >= s->msix->total_entries) {
313         return -EINVAL;
314     }
315 
316     entry = &s->msix->msix_entry[entry_nr];
317 
318     if (!entry->updated) {
319         return 0;
320     }
321 
322     pirq = entry->pirq;
323 
324     rc = msi_msix_setup(s, entry->addr, entry->data, &pirq, true, entry_nr,
325                         entry->pirq == XEN_PT_UNASSIGNED_PIRQ);
326     if (rc) {
327         return rc;
328     }
329     if (entry->pirq == XEN_PT_UNASSIGNED_PIRQ) {
330         entry->pirq = pirq;
331     }
332 
333     rc = msi_msix_update(s, entry->addr, entry->data, pirq, true,
334                          entry_nr, &entry->pirq);
335 
336     if (!rc) {
337         entry->updated = false;
338     }
339 
340     return rc;
341 }
342 
343 int xen_pt_msix_update(XenPCIPassthroughState *s)
344 {
345     XenPTMSIX *msix = s->msix;
346     int i;
347 
348     for (i = 0; i < msix->total_entries; i++) {
349         xen_pt_msix_update_one(s, i);
350     }
351 
352     return 0;
353 }
354 
355 void xen_pt_msix_disable(XenPCIPassthroughState *s)
356 {
357     int i = 0;
358 
359     msix_set_enable(s, false);
360 
361     for (i = 0; i < s->msix->total_entries; i++) {
362         XenPTMSIXEntry *entry = &s->msix->msix_entry[i];
363 
364         msi_msix_disable(s, entry->addr, entry->data, entry->pirq, true, true);
365 
366         /* clear MSI-X info */
367         entry->pirq = XEN_PT_UNASSIGNED_PIRQ;
368         entry->updated = false;
369     }
370 }
371 
372 int xen_pt_msix_update_remap(XenPCIPassthroughState *s, int bar_index)
373 {
374     XenPTMSIXEntry *entry;
375     int i, ret;
376 
377     if (!(s->msix && s->msix->bar_index == bar_index)) {
378         return 0;
379     }
380 
381     for (i = 0; i < s->msix->total_entries; i++) {
382         entry = &s->msix->msix_entry[i];
383         if (entry->pirq != XEN_PT_UNASSIGNED_PIRQ) {
384             ret = xc_domain_unbind_pt_irq(xen_xc, xen_domid, entry->pirq,
385                                           PT_IRQ_TYPE_MSI, 0, 0, 0, 0);
386             if (ret) {
387                 XEN_PT_ERR(&s->dev, "unbind MSI-X entry %d failed\n",
388                            entry->pirq);
389             }
390             entry->updated = true;
391         }
392     }
393     return xen_pt_msix_update(s);
394 }
395 
396 static uint32_t get_entry_value(XenPTMSIXEntry *e, int offset)
397 {
398     switch (offset) {
399     case PCI_MSIX_ENTRY_LOWER_ADDR:
400         return e->addr & UINT32_MAX;
401     case PCI_MSIX_ENTRY_UPPER_ADDR:
402         return e->addr >> 32;
403     case PCI_MSIX_ENTRY_DATA:
404         return e->data;
405     case PCI_MSIX_ENTRY_VECTOR_CTRL:
406         return e->vector_ctrl;
407     default:
408         return 0;
409     }
410 }
411 
412 static void set_entry_value(XenPTMSIXEntry *e, int offset, uint32_t val)
413 {
414     switch (offset) {
415     case PCI_MSIX_ENTRY_LOWER_ADDR:
416         e->addr = (e->addr & ((uint64_t)UINT32_MAX << 32)) | val;
417         break;
418     case PCI_MSIX_ENTRY_UPPER_ADDR:
419         e->addr = (uint64_t)val << 32 | (e->addr & UINT32_MAX);
420         break;
421     case PCI_MSIX_ENTRY_DATA:
422         e->data = val;
423         break;
424     case PCI_MSIX_ENTRY_VECTOR_CTRL:
425         e->vector_ctrl = val;
426         break;
427     }
428 }
429 
430 static void pci_msix_write(void *opaque, hwaddr addr,
431                            uint64_t val, unsigned size)
432 {
433     XenPCIPassthroughState *s = opaque;
434     XenPTMSIX *msix = s->msix;
435     XenPTMSIXEntry *entry;
436     int entry_nr, offset;
437 
438     entry_nr = addr / PCI_MSIX_ENTRY_SIZE;
439     if (entry_nr < 0 || entry_nr >= msix->total_entries) {
440         XEN_PT_ERR(&s->dev, "asked MSI-X entry '%i' invalid!\n", entry_nr);
441         return;
442     }
443     entry = &msix->msix_entry[entry_nr];
444     offset = addr % PCI_MSIX_ENTRY_SIZE;
445 
446     if (offset != PCI_MSIX_ENTRY_VECTOR_CTRL) {
447         const volatile uint32_t *vec_ctrl;
448 
449         if (get_entry_value(entry, offset) == val) {
450             return;
451         }
452 
453         /*
454          * If Xen intercepts the mask bit access, entry->vec_ctrl may not be
455          * up-to-date. Read from hardware directly.
456          */
457         vec_ctrl = s->msix->phys_iomem_base + entry_nr * PCI_MSIX_ENTRY_SIZE
458             + PCI_MSIX_ENTRY_VECTOR_CTRL;
459 
460         if (msix->enabled && !(*vec_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT)) {
461             XEN_PT_ERR(&s->dev, "Can't update msix entry %d since MSI-X is"
462                        " already enabled.\n", entry_nr);
463             return;
464         }
465 
466         entry->updated = true;
467     }
468 
469     set_entry_value(entry, offset, val);
470 
471     if (offset == PCI_MSIX_ENTRY_VECTOR_CTRL) {
472         if (msix->enabled && !(val & PCI_MSIX_ENTRY_CTRL_MASKBIT)) {
473             xen_pt_msix_update_one(s, entry_nr);
474         }
475     }
476 }
477 
478 static uint64_t pci_msix_read(void *opaque, hwaddr addr,
479                               unsigned size)
480 {
481     XenPCIPassthroughState *s = opaque;
482     XenPTMSIX *msix = s->msix;
483     int entry_nr, offset;
484 
485     entry_nr = addr / PCI_MSIX_ENTRY_SIZE;
486     if (entry_nr < 0) {
487         XEN_PT_ERR(&s->dev, "asked MSI-X entry '%i' invalid!\n", entry_nr);
488         return 0;
489     }
490 
491     offset = addr % PCI_MSIX_ENTRY_SIZE;
492 
493     if (addr < msix->total_entries * PCI_MSIX_ENTRY_SIZE) {
494         return get_entry_value(&msix->msix_entry[entry_nr], offset);
495     } else {
496         /* Pending Bit Array (PBA) */
497         return *(uint32_t *)(msix->phys_iomem_base + addr);
498     }
499 }
500 
501 static const MemoryRegionOps pci_msix_ops = {
502     .read = pci_msix_read,
503     .write = pci_msix_write,
504     .endianness = DEVICE_NATIVE_ENDIAN,
505     .valid = {
506         .min_access_size = 4,
507         .max_access_size = 4,
508         .unaligned = false,
509     },
510 };
511 
512 int xen_pt_msix_init(XenPCIPassthroughState *s, uint32_t base)
513 {
514     uint8_t id = 0;
515     uint16_t control = 0;
516     uint32_t table_off = 0;
517     int i, total_entries, bar_index;
518     XenHostPCIDevice *hd = &s->real_device;
519     PCIDevice *d = &s->dev;
520     int fd = -1;
521     XenPTMSIX *msix = NULL;
522     int rc = 0;
523 
524     rc = xen_host_pci_get_byte(hd, base + PCI_CAP_LIST_ID, &id);
525     if (rc) {
526         return rc;
527     }
528 
529     if (id != PCI_CAP_ID_MSIX) {
530         XEN_PT_ERR(d, "Invalid id %#x base %#x\n", id, base);
531         return -1;
532     }
533 
534     xen_host_pci_get_word(hd, base + PCI_MSIX_FLAGS, &control);
535     total_entries = control & PCI_MSIX_FLAGS_QSIZE;
536     total_entries += 1;
537 
538     s->msix = g_malloc0(sizeof (XenPTMSIX)
539                         + total_entries * sizeof (XenPTMSIXEntry));
540     msix = s->msix;
541 
542     msix->total_entries = total_entries;
543     for (i = 0; i < total_entries; i++) {
544         msix->msix_entry[i].pirq = XEN_PT_UNASSIGNED_PIRQ;
545     }
546 
547     memory_region_init_io(&msix->mmio, &pci_msix_ops, s, "xen-pci-pt-msix",
548                           (total_entries * PCI_MSIX_ENTRY_SIZE
549                            + XC_PAGE_SIZE - 1)
550                           & XC_PAGE_MASK);
551 
552     xen_host_pci_get_long(hd, base + PCI_MSIX_TABLE, &table_off);
553     bar_index = msix->bar_index = table_off & PCI_MSIX_FLAGS_BIRMASK;
554     table_off = table_off & ~PCI_MSIX_FLAGS_BIRMASK;
555     msix->table_base = s->real_device.io_regions[bar_index].base_addr;
556     XEN_PT_LOG(d, "get MSI-X table BAR base 0x%"PRIx64"\n", msix->table_base);
557 
558     fd = open("/dev/mem", O_RDWR);
559     if (fd == -1) {
560         rc = -errno;
561         XEN_PT_ERR(d, "Can't open /dev/mem: %s\n", strerror(errno));
562         goto error_out;
563     }
564     XEN_PT_LOG(d, "table_off = %#x, total_entries = %d\n",
565                table_off, total_entries);
566     msix->table_offset_adjust = table_off & 0x0fff;
567     msix->phys_iomem_base =
568         mmap(NULL,
569              total_entries * PCI_MSIX_ENTRY_SIZE + msix->table_offset_adjust,
570              PROT_READ,
571              MAP_SHARED | MAP_LOCKED,
572              fd,
573              msix->table_base + table_off - msix->table_offset_adjust);
574     close(fd);
575     if (msix->phys_iomem_base == MAP_FAILED) {
576         rc = -errno;
577         XEN_PT_ERR(d, "Can't map physical MSI-X table: %s\n", strerror(errno));
578         goto error_out;
579     }
580     msix->phys_iomem_base = (char *)msix->phys_iomem_base
581         + msix->table_offset_adjust;
582 
583     XEN_PT_LOG(d, "mapping physical MSI-X table to %p\n",
584                msix->phys_iomem_base);
585 
586     memory_region_add_subregion_overlap(&s->bar[bar_index], table_off,
587                                         &msix->mmio,
588                                         2); /* Priority: pci default + 1 */
589 
590     return 0;
591 
592 error_out:
593     memory_region_destroy(&msix->mmio);
594     g_free(s->msix);
595     s->msix = NULL;
596     return rc;
597 }
598 
599 void xen_pt_msix_delete(XenPCIPassthroughState *s)
600 {
601     XenPTMSIX *msix = s->msix;
602 
603     if (!msix) {
604         return;
605     }
606 
607     /* unmap the MSI-X memory mapped register area */
608     if (msix->phys_iomem_base) {
609         XEN_PT_LOG(&s->dev, "unmapping physical MSI-X table from %p\n",
610                    msix->phys_iomem_base);
611         munmap(msix->phys_iomem_base, msix->total_entries * PCI_MSIX_ENTRY_SIZE
612                + msix->table_offset_adjust);
613     }
614 
615     memory_region_del_subregion(&s->bar[msix->bar_index], &msix->mmio);
616     memory_region_destroy(&msix->mmio);
617 
618     g_free(s->msix);
619     s->msix = NULL;
620 }
621