xref: /openbmc/qemu/hw/xen/xen_pt_msi.c (revision 0f550c5c)
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 "qemu/osdep.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 #define XEN_PT_GFLAGSSHIFT_UNMASKED       16
28 
29 #define latch(fld) latch[PCI_MSIX_ENTRY_##fld / sizeof(uint32_t)]
30 
31 /*
32  * Helpers
33  */
34 
35 static inline uint8_t msi_vector(uint32_t data)
36 {
37     return (data & MSI_DATA_VECTOR_MASK) >> MSI_DATA_VECTOR_SHIFT;
38 }
39 
40 static inline uint8_t msi_dest_id(uint32_t addr)
41 {
42     return (addr & MSI_ADDR_DEST_ID_MASK) >> MSI_ADDR_DEST_ID_SHIFT;
43 }
44 
45 static inline uint32_t msi_ext_dest_id(uint32_t addr_hi)
46 {
47     return addr_hi & 0xffffff00;
48 }
49 
50 static uint32_t msi_gflags(uint32_t data, uint64_t addr)
51 {
52     uint32_t result = 0;
53     int rh, dm, dest_id, deliv_mode, trig_mode;
54 
55     rh = (addr >> MSI_ADDR_REDIRECTION_SHIFT) & 0x1;
56     dm = (addr >> MSI_ADDR_DEST_MODE_SHIFT) & 0x1;
57     dest_id = msi_dest_id(addr);
58     deliv_mode = (data >> MSI_DATA_DELIVERY_MODE_SHIFT) & 0x7;
59     trig_mode = (data >> MSI_DATA_TRIGGER_SHIFT) & 0x1;
60 
61     result = dest_id | (rh << XEN_PT_GFLAGS_SHIFT_RH)
62         | (dm << XEN_PT_GFLAGS_SHIFT_DM)
63         | (deliv_mode << XEN_PT_GFLAGSSHIFT_DELIV_MODE)
64         | (trig_mode << XEN_PT_GFLAGSSHIFT_TRG_MODE);
65 
66     return result;
67 }
68 
69 static inline uint64_t msi_addr64(XenPTMSI *msi)
70 {
71     return (uint64_t)msi->addr_hi << 32 | msi->addr_lo;
72 }
73 
74 static int msi_msix_enable(XenPCIPassthroughState *s,
75                            uint32_t address,
76                            uint16_t flag,
77                            bool enable)
78 {
79     uint16_t val = 0;
80     int rc;
81 
82     if (!address) {
83         return -1;
84     }
85 
86     rc = xen_host_pci_get_word(&s->real_device, address, &val);
87     if (rc) {
88         XEN_PT_ERR(&s->dev, "Failed to read MSI/MSI-X register (0x%x), rc:%d\n",
89                    address, rc);
90         return rc;
91     }
92     if (enable) {
93         val |= flag;
94     } else {
95         val &= ~flag;
96     }
97     rc = xen_host_pci_set_word(&s->real_device, address, val);
98     if (rc) {
99         XEN_PT_ERR(&s->dev, "Failed to write MSI/MSI-X register (0x%x), rc:%d\n",
100                    address, rc);
101     }
102     return rc;
103 }
104 
105 static int msi_msix_setup(XenPCIPassthroughState *s,
106                           uint64_t addr,
107                           uint32_t data,
108                           int *ppirq,
109                           bool is_msix,
110                           int msix_entry,
111                           bool is_not_mapped)
112 {
113     uint8_t gvec = msi_vector(data);
114     int rc = 0;
115 
116     assert((!is_msix && msix_entry == 0) || is_msix);
117 
118     if (xen_is_pirq_msi(data)) {
119         *ppirq = msi_ext_dest_id(addr >> 32) | msi_dest_id(addr);
120         if (!*ppirq) {
121             /* this probably identifies an misconfiguration of the guest,
122              * try the emulated path */
123             *ppirq = XEN_PT_UNASSIGNED_PIRQ;
124         } else {
125             XEN_PT_LOG(&s->dev, "requested pirq %d for MSI%s"
126                        " (vec: %#x, entry: %#x)\n",
127                        *ppirq, is_msix ? "-X" : "", gvec, msix_entry);
128         }
129     }
130 
131     if (is_not_mapped) {
132         uint64_t table_base = 0;
133 
134         if (is_msix) {
135             table_base = s->msix->table_base;
136         }
137 
138         rc = xc_physdev_map_pirq_msi(xen_xc, xen_domid, XEN_PT_AUTO_ASSIGN,
139                                      ppirq, PCI_DEVFN(s->real_device.dev,
140                                                       s->real_device.func),
141                                      s->real_device.bus,
142                                      msix_entry, table_base);
143         if (rc) {
144             XEN_PT_ERR(&s->dev,
145                        "Mapping of MSI%s (err: %i, vec: %#x, entry %#x)\n",
146                        is_msix ? "-X" : "", errno, gvec, msix_entry);
147             return rc;
148         }
149     }
150 
151     return 0;
152 }
153 static int msi_msix_update(XenPCIPassthroughState *s,
154                            uint64_t addr,
155                            uint32_t data,
156                            int pirq,
157                            bool is_msix,
158                            int msix_entry,
159                            int *old_pirq,
160                            bool masked)
161 {
162     PCIDevice *d = &s->dev;
163     uint8_t gvec = msi_vector(data);
164     uint32_t gflags = msi_gflags(data, addr);
165     int rc = 0;
166     uint64_t table_addr = 0;
167 
168     XEN_PT_LOG(d, "Updating MSI%s with pirq %d gvec %#x gflags %#x"
169                " (entry: %#x)\n",
170                is_msix ? "-X" : "", pirq, gvec, gflags, msix_entry);
171 
172     if (is_msix) {
173         table_addr = s->msix->mmio_base_addr;
174     }
175 
176     gflags |= masked ? 0 : (1u << XEN_PT_GFLAGSSHIFT_UNMASKED);
177 
178     rc = xc_domain_update_msi_irq(xen_xc, xen_domid, gvec,
179                                   pirq, gflags, table_addr);
180 
181     if (rc) {
182         XEN_PT_ERR(d, "Updating of MSI%s failed. (err: %d)\n",
183                    is_msix ? "-X" : "", errno);
184 
185         if (xc_physdev_unmap_pirq(xen_xc, xen_domid, *old_pirq)) {
186             XEN_PT_ERR(d, "Unmapping of MSI%s pirq %d failed. (err: %d)\n",
187                        is_msix ? "-X" : "", *old_pirq, errno);
188         }
189         *old_pirq = XEN_PT_UNASSIGNED_PIRQ;
190     }
191     return rc;
192 }
193 
194 static int msi_msix_disable(XenPCIPassthroughState *s,
195                             uint64_t addr,
196                             uint32_t data,
197                             int pirq,
198                             bool is_msix,
199                             bool is_binded)
200 {
201     PCIDevice *d = &s->dev;
202     uint8_t gvec = msi_vector(data);
203     uint32_t gflags = msi_gflags(data, addr);
204     int rc = 0;
205 
206     if (pirq == XEN_PT_UNASSIGNED_PIRQ) {
207         return 0;
208     }
209 
210     if (is_binded) {
211         XEN_PT_LOG(d, "Unbind MSI%s with pirq %d, gvec %#x\n",
212                    is_msix ? "-X" : "", pirq, gvec);
213         rc = xc_domain_unbind_msi_irq(xen_xc, xen_domid, gvec, pirq, gflags);
214         if (rc) {
215             XEN_PT_ERR(d, "Unbinding of MSI%s failed. (err: %d, pirq: %d, gvec: %#x)\n",
216                        is_msix ? "-X" : "", errno, pirq, gvec);
217             return rc;
218         }
219     }
220 
221     XEN_PT_LOG(d, "Unmap MSI%s pirq %d\n", is_msix ? "-X" : "", pirq);
222     rc = xc_physdev_unmap_pirq(xen_xc, xen_domid, pirq);
223     if (rc) {
224         XEN_PT_ERR(d, "Unmapping of MSI%s pirq %d failed. (err: %i)\n",
225                    is_msix ? "-X" : "", pirq, errno);
226         return rc;
227     }
228 
229     return 0;
230 }
231 
232 /*
233  * MSI virtualization functions
234  */
235 
236 static int xen_pt_msi_set_enable(XenPCIPassthroughState *s, bool enable)
237 {
238     XEN_PT_LOG(&s->dev, "%s MSI.\n", enable ? "enabling" : "disabling");
239 
240     if (!s->msi) {
241         return -1;
242     }
243 
244     return msi_msix_enable(s, s->msi->ctrl_offset, PCI_MSI_FLAGS_ENABLE,
245                            enable);
246 }
247 
248 /* setup physical msi, but don't enable it */
249 int xen_pt_msi_setup(XenPCIPassthroughState *s)
250 {
251     int pirq = XEN_PT_UNASSIGNED_PIRQ;
252     int rc = 0;
253     XenPTMSI *msi = s->msi;
254 
255     if (msi->initialized) {
256         XEN_PT_ERR(&s->dev,
257                    "Setup physical MSI when it has been properly initialized.\n");
258         return -1;
259     }
260 
261     rc = msi_msix_setup(s, msi_addr64(msi), msi->data, &pirq, false, 0, true);
262     if (rc) {
263         return rc;
264     }
265 
266     if (pirq < 0) {
267         XEN_PT_ERR(&s->dev, "Invalid pirq number: %d.\n", pirq);
268         return -1;
269     }
270 
271     msi->pirq = pirq;
272     XEN_PT_LOG(&s->dev, "MSI mapped with pirq %d.\n", pirq);
273 
274     return 0;
275 }
276 
277 int xen_pt_msi_update(XenPCIPassthroughState *s)
278 {
279     XenPTMSI *msi = s->msi;
280 
281     /* Current MSI emulation in QEMU only supports 1 vector */
282     return msi_msix_update(s, msi_addr64(msi), msi->data, msi->pirq,
283                            false, 0, &msi->pirq, msi->mask & 1);
284 }
285 
286 void xen_pt_msi_disable(XenPCIPassthroughState *s)
287 {
288     XenPTMSI *msi = s->msi;
289 
290     if (!msi) {
291         return;
292     }
293 
294     (void)xen_pt_msi_set_enable(s, false);
295 
296     msi_msix_disable(s, msi_addr64(msi), msi->data, msi->pirq, false,
297                      msi->initialized);
298 
299     /* clear msi info */
300     msi->flags &= ~PCI_MSI_FLAGS_ENABLE;
301     msi->initialized = false;
302     msi->mapped = false;
303     msi->pirq = XEN_PT_UNASSIGNED_PIRQ;
304 }
305 
306 /*
307  * MSI-X virtualization functions
308  */
309 
310 static int msix_set_enable(XenPCIPassthroughState *s, bool enabled)
311 {
312     XEN_PT_LOG(&s->dev, "%s MSI-X.\n", enabled ? "enabling" : "disabling");
313 
314     if (!s->msix) {
315         return -1;
316     }
317 
318     return msi_msix_enable(s, s->msix->ctrl_offset, PCI_MSIX_FLAGS_ENABLE,
319                            enabled);
320 }
321 
322 static int xen_pt_msix_update_one(XenPCIPassthroughState *s, int entry_nr,
323                                   uint32_t vec_ctrl)
324 {
325     XenPTMSIXEntry *entry = NULL;
326     int pirq;
327     int rc;
328 
329     if (entry_nr < 0 || entry_nr >= s->msix->total_entries) {
330         return -EINVAL;
331     }
332 
333     entry = &s->msix->msix_entry[entry_nr];
334 
335     if (!entry->updated) {
336         return 0;
337     }
338 
339     pirq = entry->pirq;
340 
341     /*
342      * Update the entry addr and data to the latest values only when the
343      * entry is masked or they are all masked, as required by the spec.
344      * Addr and data changes while the MSI-X entry is unmasked get deferred
345      * until the next masked -> unmasked transition.
346      */
347     if (pirq == XEN_PT_UNASSIGNED_PIRQ || s->msix->maskall ||
348         (vec_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT)) {
349         entry->addr = entry->latch(LOWER_ADDR) |
350                       ((uint64_t)entry->latch(UPPER_ADDR) << 32);
351         entry->data = entry->latch(DATA);
352     }
353 
354     rc = msi_msix_setup(s, entry->addr, entry->data, &pirq, true, entry_nr,
355                         entry->pirq == XEN_PT_UNASSIGNED_PIRQ);
356     if (rc) {
357         return rc;
358     }
359     if (entry->pirq == XEN_PT_UNASSIGNED_PIRQ) {
360         entry->pirq = pirq;
361     }
362 
363     rc = msi_msix_update(s, entry->addr, entry->data, pirq, true,
364                          entry_nr, &entry->pirq,
365                          vec_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT);
366 
367     if (!rc) {
368         entry->updated = false;
369     }
370 
371     return rc;
372 }
373 
374 int xen_pt_msix_update(XenPCIPassthroughState *s)
375 {
376     XenPTMSIX *msix = s->msix;
377     int i;
378 
379     for (i = 0; i < msix->total_entries; i++) {
380         xen_pt_msix_update_one(s, i, msix->msix_entry[i].latch(VECTOR_CTRL));
381     }
382 
383     return 0;
384 }
385 
386 void xen_pt_msix_disable(XenPCIPassthroughState *s)
387 {
388     int i = 0;
389 
390     msix_set_enable(s, false);
391 
392     for (i = 0; i < s->msix->total_entries; i++) {
393         XenPTMSIXEntry *entry = &s->msix->msix_entry[i];
394 
395         msi_msix_disable(s, entry->addr, entry->data, entry->pirq, true, true);
396 
397         /* clear MSI-X info */
398         entry->pirq = XEN_PT_UNASSIGNED_PIRQ;
399         entry->updated = false;
400     }
401 }
402 
403 int xen_pt_msix_update_remap(XenPCIPassthroughState *s, int bar_index)
404 {
405     XenPTMSIXEntry *entry;
406     int i, ret;
407 
408     if (!(s->msix && s->msix->bar_index == bar_index)) {
409         return 0;
410     }
411 
412     for (i = 0; i < s->msix->total_entries; i++) {
413         entry = &s->msix->msix_entry[i];
414         if (entry->pirq != XEN_PT_UNASSIGNED_PIRQ) {
415             ret = xc_domain_unbind_pt_irq(xen_xc, xen_domid, entry->pirq,
416                                           PT_IRQ_TYPE_MSI, 0, 0, 0, 0);
417             if (ret) {
418                 XEN_PT_ERR(&s->dev, "unbind MSI-X entry %d failed (err: %d)\n",
419                            entry->pirq, errno);
420             }
421             entry->updated = true;
422         }
423     }
424     return xen_pt_msix_update(s);
425 }
426 
427 static uint32_t get_entry_value(XenPTMSIXEntry *e, int offset)
428 {
429     assert(!(offset % sizeof(*e->latch)));
430     return e->latch[offset / sizeof(*e->latch)];
431 }
432 
433 static void set_entry_value(XenPTMSIXEntry *e, int offset, uint32_t val)
434 {
435     assert(!(offset % sizeof(*e->latch)));
436     e->latch[offset / sizeof(*e->latch)] = val;
437 }
438 
439 static void pci_msix_write(void *opaque, hwaddr addr,
440                            uint64_t val, unsigned size)
441 {
442     XenPCIPassthroughState *s = opaque;
443     XenPTMSIX *msix = s->msix;
444     XenPTMSIXEntry *entry;
445     unsigned int entry_nr, offset;
446 
447     entry_nr = addr / PCI_MSIX_ENTRY_SIZE;
448     if (entry_nr >= msix->total_entries) {
449         return;
450     }
451     entry = &msix->msix_entry[entry_nr];
452     offset = addr % PCI_MSIX_ENTRY_SIZE;
453 
454     if (offset != PCI_MSIX_ENTRY_VECTOR_CTRL) {
455         if (get_entry_value(entry, offset) == val
456             && entry->pirq != XEN_PT_UNASSIGNED_PIRQ) {
457             return;
458         }
459 
460         entry->updated = true;
461     } else if (msix->enabled && entry->updated &&
462                !(val & PCI_MSIX_ENTRY_CTRL_MASKBIT)) {
463         const volatile uint32_t *vec_ctrl;
464 
465         /*
466          * If Xen intercepts the mask bit access, entry->vec_ctrl may not be
467          * up-to-date. Read from hardware directly.
468          */
469         vec_ctrl = s->msix->phys_iomem_base + entry_nr * PCI_MSIX_ENTRY_SIZE
470             + PCI_MSIX_ENTRY_VECTOR_CTRL;
471         xen_pt_msix_update_one(s, entry_nr, *vec_ctrl);
472     }
473 
474     set_entry_value(entry, offset, val);
475 }
476 
477 static uint64_t pci_msix_read(void *opaque, hwaddr addr,
478                               unsigned size)
479 {
480     XenPCIPassthroughState *s = opaque;
481     XenPTMSIX *msix = s->msix;
482     int entry_nr, offset;
483 
484     entry_nr = addr / PCI_MSIX_ENTRY_SIZE;
485     if (entry_nr < 0) {
486         XEN_PT_ERR(&s->dev, "asked MSI-X entry '%i' invalid!\n", entry_nr);
487         return 0;
488     }
489 
490     offset = addr % PCI_MSIX_ENTRY_SIZE;
491 
492     if (addr < msix->total_entries * PCI_MSIX_ENTRY_SIZE) {
493         return get_entry_value(&msix->msix_entry[entry_nr], offset);
494     } else {
495         /* Pending Bit Array (PBA) */
496         return *(uint32_t *)(msix->phys_iomem_base + addr);
497     }
498 }
499 
500 static bool pci_msix_accepts(void *opaque, hwaddr addr,
501                              unsigned size, bool is_write)
502 {
503     return !(addr & (size - 1));
504 }
505 
506 static const MemoryRegionOps pci_msix_ops = {
507     .read = pci_msix_read,
508     .write = pci_msix_write,
509     .endianness = DEVICE_NATIVE_ENDIAN,
510     .valid = {
511         .min_access_size = 4,
512         .max_access_size = 4,
513         .unaligned = false,
514         .accepts = pci_msix_accepts
515     },
516     .impl = {
517         .min_access_size = 4,
518         .max_access_size = 4,
519         .unaligned = false
520     }
521 };
522 
523 int xen_pt_msix_init(XenPCIPassthroughState *s, uint32_t base)
524 {
525     uint8_t id = 0;
526     uint16_t control = 0;
527     uint32_t table_off = 0;
528     int i, total_entries, bar_index;
529     XenHostPCIDevice *hd = &s->real_device;
530     PCIDevice *d = &s->dev;
531     int fd = -1;
532     XenPTMSIX *msix = NULL;
533     int rc = 0;
534 
535     rc = xen_host_pci_get_byte(hd, base + PCI_CAP_LIST_ID, &id);
536     if (rc) {
537         return rc;
538     }
539 
540     if (id != PCI_CAP_ID_MSIX) {
541         XEN_PT_ERR(d, "Invalid id %#x base %#x\n", id, base);
542         return -1;
543     }
544 
545     rc = xen_host_pci_get_word(hd, base + PCI_MSIX_FLAGS, &control);
546     if (rc) {
547         XEN_PT_ERR(d, "Failed to read PCI_MSIX_FLAGS field\n");
548         return rc;
549     }
550     total_entries = control & PCI_MSIX_FLAGS_QSIZE;
551     total_entries += 1;
552 
553     s->msix = g_malloc0(sizeof (XenPTMSIX)
554                         + total_entries * sizeof (XenPTMSIXEntry));
555     msix = s->msix;
556 
557     msix->total_entries = total_entries;
558     for (i = 0; i < total_entries; i++) {
559         msix->msix_entry[i].pirq = XEN_PT_UNASSIGNED_PIRQ;
560     }
561 
562     memory_region_init_io(&msix->mmio, OBJECT(s), &pci_msix_ops,
563                           s, "xen-pci-pt-msix",
564                           (total_entries * PCI_MSIX_ENTRY_SIZE
565                            + XC_PAGE_SIZE - 1)
566                           & XC_PAGE_MASK);
567 
568     rc = xen_host_pci_get_long(hd, base + PCI_MSIX_TABLE, &table_off);
569     if (rc) {
570         XEN_PT_ERR(d, "Failed to read PCI_MSIX_TABLE field\n");
571         goto error_out;
572     }
573     bar_index = msix->bar_index = table_off & PCI_MSIX_FLAGS_BIRMASK;
574     table_off = table_off & ~PCI_MSIX_FLAGS_BIRMASK;
575     msix->table_base = s->real_device.io_regions[bar_index].base_addr;
576     XEN_PT_LOG(d, "get MSI-X table BAR base 0x%"PRIx64"\n", msix->table_base);
577 
578     fd = open("/dev/mem", O_RDWR);
579     if (fd == -1) {
580         rc = -errno;
581         XEN_PT_ERR(d, "Can't open /dev/mem: %s\n", strerror(errno));
582         goto error_out;
583     }
584     XEN_PT_LOG(d, "table_off = %#x, total_entries = %d\n",
585                table_off, total_entries);
586     msix->table_offset_adjust = table_off & 0x0fff;
587     msix->phys_iomem_base =
588         mmap(NULL,
589              total_entries * PCI_MSIX_ENTRY_SIZE + msix->table_offset_adjust,
590              PROT_READ,
591              MAP_SHARED | MAP_LOCKED,
592              fd,
593              msix->table_base + table_off - msix->table_offset_adjust);
594     close(fd);
595     if (msix->phys_iomem_base == MAP_FAILED) {
596         rc = -errno;
597         XEN_PT_ERR(d, "Can't map physical MSI-X table: %s\n", strerror(errno));
598         goto error_out;
599     }
600     msix->phys_iomem_base = (char *)msix->phys_iomem_base
601         + msix->table_offset_adjust;
602 
603     XEN_PT_LOG(d, "mapping physical MSI-X table to %p\n",
604                msix->phys_iomem_base);
605 
606     memory_region_add_subregion_overlap(&s->bar[bar_index], table_off,
607                                         &msix->mmio,
608                                         2); /* Priority: pci default + 1 */
609 
610     return 0;
611 
612 error_out:
613     g_free(s->msix);
614     s->msix = NULL;
615     return rc;
616 }
617 
618 void xen_pt_msix_unmap(XenPCIPassthroughState *s)
619 {
620     XenPTMSIX *msix = s->msix;
621 
622     if (!msix) {
623         return;
624     }
625 
626     /* unmap the MSI-X memory mapped register area */
627     if (msix->phys_iomem_base) {
628         XEN_PT_LOG(&s->dev, "unmapping physical MSI-X table from %p\n",
629                    msix->phys_iomem_base);
630         munmap(msix->phys_iomem_base, msix->total_entries * PCI_MSIX_ENTRY_SIZE
631                + msix->table_offset_adjust);
632     }
633 
634     memory_region_del_subregion(&s->bar[msix->bar_index], &msix->mmio);
635 }
636 
637 void xen_pt_msix_delete(XenPCIPassthroughState *s)
638 {
639     XenPTMSIX *msix = s->msix;
640 
641     if (!msix) {
642         return;
643     }
644 
645     object_unparent(OBJECT(&msix->mmio));
646 
647     g_free(s->msix);
648     s->msix = NULL;
649 }
650