xref: /openbmc/qemu/hw/xen/xen_pt_msi.c (revision a719a27c)
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 &= ~PCI_MSI_FLAGS_ENABLE;
286     msi->initialized = false;
287     msi->mapped = false;
288     msi->pirq = XEN_PT_UNASSIGNED_PIRQ;
289 }
290 
291 /*
292  * MSI-X virtualization functions
293  */
294 
295 static int msix_set_enable(XenPCIPassthroughState *s, bool enabled)
296 {
297     XEN_PT_LOG(&s->dev, "%s MSI-X.\n", enabled ? "enabling" : "disabling");
298 
299     if (!s->msix) {
300         return -1;
301     }
302 
303     return msi_msix_enable(s, s->msix->ctrl_offset, PCI_MSIX_FLAGS_ENABLE,
304                            enabled);
305 }
306 
307 static int xen_pt_msix_update_one(XenPCIPassthroughState *s, int entry_nr)
308 {
309     XenPTMSIXEntry *entry = NULL;
310     int pirq;
311     int rc;
312 
313     if (entry_nr < 0 || entry_nr >= s->msix->total_entries) {
314         return -EINVAL;
315     }
316 
317     entry = &s->msix->msix_entry[entry_nr];
318 
319     if (!entry->updated) {
320         return 0;
321     }
322 
323     pirq = entry->pirq;
324 
325     rc = msi_msix_setup(s, entry->addr, entry->data, &pirq, true, entry_nr,
326                         entry->pirq == XEN_PT_UNASSIGNED_PIRQ);
327     if (rc) {
328         return rc;
329     }
330     if (entry->pirq == XEN_PT_UNASSIGNED_PIRQ) {
331         entry->pirq = pirq;
332     }
333 
334     rc = msi_msix_update(s, entry->addr, entry->data, pirq, true,
335                          entry_nr, &entry->pirq);
336 
337     if (!rc) {
338         entry->updated = false;
339     }
340 
341     return rc;
342 }
343 
344 int xen_pt_msix_update(XenPCIPassthroughState *s)
345 {
346     XenPTMSIX *msix = s->msix;
347     int i;
348 
349     for (i = 0; i < msix->total_entries; i++) {
350         xen_pt_msix_update_one(s, i);
351     }
352 
353     return 0;
354 }
355 
356 void xen_pt_msix_disable(XenPCIPassthroughState *s)
357 {
358     int i = 0;
359 
360     msix_set_enable(s, false);
361 
362     for (i = 0; i < s->msix->total_entries; i++) {
363         XenPTMSIXEntry *entry = &s->msix->msix_entry[i];
364 
365         msi_msix_disable(s, entry->addr, entry->data, entry->pirq, true, true);
366 
367         /* clear MSI-X info */
368         entry->pirq = XEN_PT_UNASSIGNED_PIRQ;
369         entry->updated = false;
370     }
371 }
372 
373 int xen_pt_msix_update_remap(XenPCIPassthroughState *s, int bar_index)
374 {
375     XenPTMSIXEntry *entry;
376     int i, ret;
377 
378     if (!(s->msix && s->msix->bar_index == bar_index)) {
379         return 0;
380     }
381 
382     for (i = 0; i < s->msix->total_entries; i++) {
383         entry = &s->msix->msix_entry[i];
384         if (entry->pirq != XEN_PT_UNASSIGNED_PIRQ) {
385             ret = xc_domain_unbind_pt_irq(xen_xc, xen_domid, entry->pirq,
386                                           PT_IRQ_TYPE_MSI, 0, 0, 0, 0);
387             if (ret) {
388                 XEN_PT_ERR(&s->dev, "unbind MSI-X entry %d failed\n",
389                            entry->pirq);
390             }
391             entry->updated = true;
392         }
393     }
394     return xen_pt_msix_update(s);
395 }
396 
397 static uint32_t get_entry_value(XenPTMSIXEntry *e, int offset)
398 {
399     switch (offset) {
400     case PCI_MSIX_ENTRY_LOWER_ADDR:
401         return e->addr & UINT32_MAX;
402     case PCI_MSIX_ENTRY_UPPER_ADDR:
403         return e->addr >> 32;
404     case PCI_MSIX_ENTRY_DATA:
405         return e->data;
406     case PCI_MSIX_ENTRY_VECTOR_CTRL:
407         return e->vector_ctrl;
408     default:
409         return 0;
410     }
411 }
412 
413 static void set_entry_value(XenPTMSIXEntry *e, int offset, uint32_t val)
414 {
415     switch (offset) {
416     case PCI_MSIX_ENTRY_LOWER_ADDR:
417         e->addr = (e->addr & ((uint64_t)UINT32_MAX << 32)) | val;
418         break;
419     case PCI_MSIX_ENTRY_UPPER_ADDR:
420         e->addr = (uint64_t)val << 32 | (e->addr & UINT32_MAX);
421         break;
422     case PCI_MSIX_ENTRY_DATA:
423         e->data = val;
424         break;
425     case PCI_MSIX_ENTRY_VECTOR_CTRL:
426         e->vector_ctrl = val;
427         break;
428     }
429 }
430 
431 static void pci_msix_write(void *opaque, hwaddr addr,
432                            uint64_t val, unsigned size)
433 {
434     XenPCIPassthroughState *s = opaque;
435     XenPTMSIX *msix = s->msix;
436     XenPTMSIXEntry *entry;
437     int entry_nr, offset;
438 
439     entry_nr = addr / PCI_MSIX_ENTRY_SIZE;
440     if (entry_nr < 0 || entry_nr >= msix->total_entries) {
441         XEN_PT_ERR(&s->dev, "asked MSI-X entry '%i' invalid!\n", entry_nr);
442         return;
443     }
444     entry = &msix->msix_entry[entry_nr];
445     offset = addr % PCI_MSIX_ENTRY_SIZE;
446 
447     if (offset != PCI_MSIX_ENTRY_VECTOR_CTRL) {
448         const volatile uint32_t *vec_ctrl;
449 
450         if (get_entry_value(entry, offset) == val
451             && entry->pirq != XEN_PT_UNASSIGNED_PIRQ) {
452             return;
453         }
454 
455         /*
456          * If Xen intercepts the mask bit access, entry->vec_ctrl may not be
457          * up-to-date. Read from hardware directly.
458          */
459         vec_ctrl = s->msix->phys_iomem_base + entry_nr * PCI_MSIX_ENTRY_SIZE
460             + PCI_MSIX_ENTRY_VECTOR_CTRL;
461 
462         if (msix->enabled && !(*vec_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT)) {
463             XEN_PT_ERR(&s->dev, "Can't update msix entry %d since MSI-X is"
464                        " already enabled.\n", entry_nr);
465             return;
466         }
467 
468         entry->updated = true;
469     }
470 
471     set_entry_value(entry, offset, val);
472 
473     if (offset == PCI_MSIX_ENTRY_VECTOR_CTRL) {
474         if (msix->enabled && !(val & PCI_MSIX_ENTRY_CTRL_MASKBIT)) {
475             xen_pt_msix_update_one(s, entry_nr);
476         }
477     }
478 }
479 
480 static uint64_t pci_msix_read(void *opaque, hwaddr addr,
481                               unsigned size)
482 {
483     XenPCIPassthroughState *s = opaque;
484     XenPTMSIX *msix = s->msix;
485     int entry_nr, offset;
486 
487     entry_nr = addr / PCI_MSIX_ENTRY_SIZE;
488     if (entry_nr < 0) {
489         XEN_PT_ERR(&s->dev, "asked MSI-X entry '%i' invalid!\n", entry_nr);
490         return 0;
491     }
492 
493     offset = addr % PCI_MSIX_ENTRY_SIZE;
494 
495     if (addr < msix->total_entries * PCI_MSIX_ENTRY_SIZE) {
496         return get_entry_value(&msix->msix_entry[entry_nr], offset);
497     } else {
498         /* Pending Bit Array (PBA) */
499         return *(uint32_t *)(msix->phys_iomem_base + addr);
500     }
501 }
502 
503 static const MemoryRegionOps pci_msix_ops = {
504     .read = pci_msix_read,
505     .write = pci_msix_write,
506     .endianness = DEVICE_NATIVE_ENDIAN,
507     .valid = {
508         .min_access_size = 4,
509         .max_access_size = 4,
510         .unaligned = false,
511     },
512 };
513 
514 int xen_pt_msix_init(XenPCIPassthroughState *s, uint32_t base)
515 {
516     uint8_t id = 0;
517     uint16_t control = 0;
518     uint32_t table_off = 0;
519     int i, total_entries, bar_index;
520     XenHostPCIDevice *hd = &s->real_device;
521     PCIDevice *d = &s->dev;
522     int fd = -1;
523     XenPTMSIX *msix = NULL;
524     int rc = 0;
525 
526     rc = xen_host_pci_get_byte(hd, base + PCI_CAP_LIST_ID, &id);
527     if (rc) {
528         return rc;
529     }
530 
531     if (id != PCI_CAP_ID_MSIX) {
532         XEN_PT_ERR(d, "Invalid id %#x base %#x\n", id, base);
533         return -1;
534     }
535 
536     xen_host_pci_get_word(hd, base + PCI_MSIX_FLAGS, &control);
537     total_entries = control & PCI_MSIX_FLAGS_QSIZE;
538     total_entries += 1;
539 
540     s->msix = g_malloc0(sizeof (XenPTMSIX)
541                         + total_entries * sizeof (XenPTMSIXEntry));
542     msix = s->msix;
543 
544     msix->total_entries = total_entries;
545     for (i = 0; i < total_entries; i++) {
546         msix->msix_entry[i].pirq = XEN_PT_UNASSIGNED_PIRQ;
547     }
548 
549     memory_region_init_io(&msix->mmio, OBJECT(s), &pci_msix_ops,
550                           s, "xen-pci-pt-msix",
551                           (total_entries * PCI_MSIX_ENTRY_SIZE
552                            + XC_PAGE_SIZE - 1)
553                           & XC_PAGE_MASK);
554 
555     xen_host_pci_get_long(hd, base + PCI_MSIX_TABLE, &table_off);
556     bar_index = msix->bar_index = table_off & PCI_MSIX_FLAGS_BIRMASK;
557     table_off = table_off & ~PCI_MSIX_FLAGS_BIRMASK;
558     msix->table_base = s->real_device.io_regions[bar_index].base_addr;
559     XEN_PT_LOG(d, "get MSI-X table BAR base 0x%"PRIx64"\n", msix->table_base);
560 
561     fd = open("/dev/mem", O_RDWR);
562     if (fd == -1) {
563         rc = -errno;
564         XEN_PT_ERR(d, "Can't open /dev/mem: %s\n", strerror(errno));
565         goto error_out;
566     }
567     XEN_PT_LOG(d, "table_off = %#x, total_entries = %d\n",
568                table_off, total_entries);
569     msix->table_offset_adjust = table_off & 0x0fff;
570     msix->phys_iomem_base =
571         mmap(NULL,
572              total_entries * PCI_MSIX_ENTRY_SIZE + msix->table_offset_adjust,
573              PROT_READ,
574              MAP_SHARED | MAP_LOCKED,
575              fd,
576              msix->table_base + table_off - msix->table_offset_adjust);
577     close(fd);
578     if (msix->phys_iomem_base == MAP_FAILED) {
579         rc = -errno;
580         XEN_PT_ERR(d, "Can't map physical MSI-X table: %s\n", strerror(errno));
581         goto error_out;
582     }
583     msix->phys_iomem_base = (char *)msix->phys_iomem_base
584         + msix->table_offset_adjust;
585 
586     XEN_PT_LOG(d, "mapping physical MSI-X table to %p\n",
587                msix->phys_iomem_base);
588 
589     memory_region_add_subregion_overlap(&s->bar[bar_index], table_off,
590                                         &msix->mmio,
591                                         2); /* Priority: pci default + 1 */
592 
593     return 0;
594 
595 error_out:
596     memory_region_destroy(&msix->mmio);
597     g_free(s->msix);
598     s->msix = NULL;
599     return rc;
600 }
601 
602 void xen_pt_msix_delete(XenPCIPassthroughState *s)
603 {
604     XenPTMSIX *msix = s->msix;
605 
606     if (!msix) {
607         return;
608     }
609 
610     /* unmap the MSI-X memory mapped register area */
611     if (msix->phys_iomem_base) {
612         XEN_PT_LOG(&s->dev, "unmapping physical MSI-X table from %p\n",
613                    msix->phys_iomem_base);
614         munmap(msix->phys_iomem_base, msix->total_entries * PCI_MSIX_ENTRY_SIZE
615                + msix->table_offset_adjust);
616     }
617 
618     memory_region_del_subregion(&s->bar[msix->bar_index], &msix->mmio);
619     memory_region_destroy(&msix->mmio);
620 
621     g_free(s->msix);
622     s->msix = NULL;
623 }
624