xref: /openbmc/qemu/hw/xen/xen_pt_msi.c (revision d38ea87a)
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 #include <sys/mman.h>
14 
15 #include "hw/xen/xen_backend.h"
16 #include "xen_pt.h"
17 #include "hw/i386/apic-msidef.h"
18 
19 
20 #define XEN_PT_AUTO_ASSIGN -1
21 
22 /* shift count for gflags */
23 #define XEN_PT_GFLAGS_SHIFT_DEST_ID        0
24 #define XEN_PT_GFLAGS_SHIFT_RH             8
25 #define XEN_PT_GFLAGS_SHIFT_DM             9
26 #define XEN_PT_GFLAGSSHIFT_DELIV_MODE     12
27 #define XEN_PT_GFLAGSSHIFT_TRG_MODE       15
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 (gvec == 0) {
119         /* if gvec is 0, the guest is asking for a particular pirq that
120          * is passed as dest_id */
121         *ppirq = msi_ext_dest_id(addr >> 32) | msi_dest_id(addr);
122         if (!*ppirq) {
123             /* this probably identifies an misconfiguration of the guest,
124              * try the emulated path */
125             *ppirq = XEN_PT_UNASSIGNED_PIRQ;
126         } else {
127             XEN_PT_LOG(&s->dev, "requested pirq %d for MSI%s"
128                        " (vec: %#x, entry: %#x)\n",
129                        *ppirq, is_msix ? "-X" : "", gvec, msix_entry);
130         }
131     }
132 
133     if (is_not_mapped) {
134         uint64_t table_base = 0;
135 
136         if (is_msix) {
137             table_base = s->msix->table_base;
138         }
139 
140         rc = xc_physdev_map_pirq_msi(xen_xc, xen_domid, XEN_PT_AUTO_ASSIGN,
141                                      ppirq, PCI_DEVFN(s->real_device.dev,
142                                                       s->real_device.func),
143                                      s->real_device.bus,
144                                      msix_entry, table_base);
145         if (rc) {
146             XEN_PT_ERR(&s->dev,
147                        "Mapping of MSI%s (err: %i, vec: %#x, entry %#x)\n",
148                        is_msix ? "-X" : "", errno, gvec, msix_entry);
149             return rc;
150         }
151     }
152 
153     return 0;
154 }
155 static int msi_msix_update(XenPCIPassthroughState *s,
156                            uint64_t addr,
157                            uint32_t data,
158                            int pirq,
159                            bool is_msix,
160                            int msix_entry,
161                            int *old_pirq)
162 {
163     PCIDevice *d = &s->dev;
164     uint8_t gvec = msi_vector(data);
165     uint32_t gflags = msi_gflags(data, addr);
166     int rc = 0;
167     uint64_t table_addr = 0;
168 
169     XEN_PT_LOG(d, "Updating MSI%s with pirq %d gvec %#x gflags %#x"
170                " (entry: %#x)\n",
171                is_msix ? "-X" : "", pirq, gvec, gflags, msix_entry);
172 
173     if (is_msix) {
174         table_addr = s->msix->mmio_base_addr;
175     }
176 
177     rc = xc_domain_update_msi_irq(xen_xc, xen_domid, gvec,
178                                   pirq, gflags, table_addr);
179 
180     if (rc) {
181         XEN_PT_ERR(d, "Updating of MSI%s failed. (err: %d)\n",
182                    is_msix ? "-X" : "", errno);
183 
184         if (xc_physdev_unmap_pirq(xen_xc, xen_domid, *old_pirq)) {
185             XEN_PT_ERR(d, "Unmapping of MSI%s pirq %d failed. (err: %d)\n",
186                        is_msix ? "-X" : "", *old_pirq, errno);
187         }
188         *old_pirq = XEN_PT_UNASSIGNED_PIRQ;
189     }
190     return rc;
191 }
192 
193 static int msi_msix_disable(XenPCIPassthroughState *s,
194                             uint64_t addr,
195                             uint32_t data,
196                             int pirq,
197                             bool is_msix,
198                             bool is_binded)
199 {
200     PCIDevice *d = &s->dev;
201     uint8_t gvec = msi_vector(data);
202     uint32_t gflags = msi_gflags(data, addr);
203     int rc = 0;
204 
205     if (pirq == XEN_PT_UNASSIGNED_PIRQ) {
206         return 0;
207     }
208 
209     if (is_binded) {
210         XEN_PT_LOG(d, "Unbind MSI%s with pirq %d, gvec %#x\n",
211                    is_msix ? "-X" : "", pirq, gvec);
212         rc = xc_domain_unbind_msi_irq(xen_xc, xen_domid, gvec, pirq, gflags);
213         if (rc) {
214             XEN_PT_ERR(d, "Unbinding of MSI%s failed. (err: %d, pirq: %d, gvec: %#x)\n",
215                        is_msix ? "-X" : "", errno, pirq, gvec);
216             return rc;
217         }
218     }
219 
220     XEN_PT_LOG(d, "Unmap MSI%s pirq %d\n", is_msix ? "-X" : "", pirq);
221     rc = xc_physdev_unmap_pirq(xen_xc, xen_domid, pirq);
222     if (rc) {
223         XEN_PT_ERR(d, "Unmapping of MSI%s pirq %d failed. (err: %i)\n",
224                    is_msix ? "-X" : "", pirq, errno);
225         return rc;
226     }
227 
228     return 0;
229 }
230 
231 /*
232  * MSI virtualization functions
233  */
234 
235 static int xen_pt_msi_set_enable(XenPCIPassthroughState *s, bool enable)
236 {
237     XEN_PT_LOG(&s->dev, "%s MSI.\n", enable ? "enabling" : "disabling");
238 
239     if (!s->msi) {
240         return -1;
241     }
242 
243     return msi_msix_enable(s, s->msi->ctrl_offset, PCI_MSI_FLAGS_ENABLE,
244                            enable);
245 }
246 
247 /* setup physical msi, but don't enable it */
248 int xen_pt_msi_setup(XenPCIPassthroughState *s)
249 {
250     int pirq = XEN_PT_UNASSIGNED_PIRQ;
251     int rc = 0;
252     XenPTMSI *msi = s->msi;
253 
254     if (msi->initialized) {
255         XEN_PT_ERR(&s->dev,
256                    "Setup physical MSI when it has been properly initialized.\n");
257         return -1;
258     }
259 
260     rc = msi_msix_setup(s, msi_addr64(msi), msi->data, &pirq, false, 0, true);
261     if (rc) {
262         return rc;
263     }
264 
265     if (pirq < 0) {
266         XEN_PT_ERR(&s->dev, "Invalid pirq number: %d.\n", pirq);
267         return -1;
268     }
269 
270     msi->pirq = pirq;
271     XEN_PT_LOG(&s->dev, "MSI mapped with pirq %d.\n", pirq);
272 
273     return 0;
274 }
275 
276 int xen_pt_msi_update(XenPCIPassthroughState *s)
277 {
278     XenPTMSI *msi = s->msi;
279     return msi_msix_update(s, msi_addr64(msi), msi->data, msi->pirq,
280                            false, 0, &msi->pirq);
281 }
282 
283 void xen_pt_msi_disable(XenPCIPassthroughState *s)
284 {
285     XenPTMSI *msi = s->msi;
286 
287     if (!msi) {
288         return;
289     }
290 
291     (void)xen_pt_msi_set_enable(s, false);
292 
293     msi_msix_disable(s, msi_addr64(msi), msi->data, msi->pirq, false,
294                      msi->initialized);
295 
296     /* clear msi info */
297     msi->flags &= ~PCI_MSI_FLAGS_ENABLE;
298     msi->initialized = false;
299     msi->mapped = false;
300     msi->pirq = XEN_PT_UNASSIGNED_PIRQ;
301 }
302 
303 /*
304  * MSI-X virtualization functions
305  */
306 
307 static int msix_set_enable(XenPCIPassthroughState *s, bool enabled)
308 {
309     XEN_PT_LOG(&s->dev, "%s MSI-X.\n", enabled ? "enabling" : "disabling");
310 
311     if (!s->msix) {
312         return -1;
313     }
314 
315     return msi_msix_enable(s, s->msix->ctrl_offset, PCI_MSIX_FLAGS_ENABLE,
316                            enabled);
317 }
318 
319 static int xen_pt_msix_update_one(XenPCIPassthroughState *s, int entry_nr,
320                                   uint32_t vec_ctrl)
321 {
322     XenPTMSIXEntry *entry = NULL;
323     int pirq;
324     int rc;
325 
326     if (entry_nr < 0 || entry_nr >= s->msix->total_entries) {
327         return -EINVAL;
328     }
329 
330     entry = &s->msix->msix_entry[entry_nr];
331 
332     if (!entry->updated) {
333         return 0;
334     }
335 
336     pirq = entry->pirq;
337 
338     /*
339      * Update the entry addr and data to the latest values only when the
340      * entry is masked or they are all masked, as required by the spec.
341      * Addr and data changes while the MSI-X entry is unmasked get deferred
342      * until the next masked -> unmasked transition.
343      */
344     if (pirq == XEN_PT_UNASSIGNED_PIRQ || s->msix->maskall ||
345         (vec_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT)) {
346         entry->addr = entry->latch(LOWER_ADDR) |
347                       ((uint64_t)entry->latch(UPPER_ADDR) << 32);
348         entry->data = entry->latch(DATA);
349     }
350 
351     rc = msi_msix_setup(s, entry->addr, entry->data, &pirq, true, entry_nr,
352                         entry->pirq == XEN_PT_UNASSIGNED_PIRQ);
353     if (rc) {
354         return rc;
355     }
356     if (entry->pirq == XEN_PT_UNASSIGNED_PIRQ) {
357         entry->pirq = pirq;
358     }
359 
360     rc = msi_msix_update(s, entry->addr, entry->data, pirq, true,
361                          entry_nr, &entry->pirq);
362 
363     if (!rc) {
364         entry->updated = false;
365     }
366 
367     return rc;
368 }
369 
370 int xen_pt_msix_update(XenPCIPassthroughState *s)
371 {
372     XenPTMSIX *msix = s->msix;
373     int i;
374 
375     for (i = 0; i < msix->total_entries; i++) {
376         xen_pt_msix_update_one(s, i, msix->msix_entry[i].latch(VECTOR_CTRL));
377     }
378 
379     return 0;
380 }
381 
382 void xen_pt_msix_disable(XenPCIPassthroughState *s)
383 {
384     int i = 0;
385 
386     msix_set_enable(s, false);
387 
388     for (i = 0; i < s->msix->total_entries; i++) {
389         XenPTMSIXEntry *entry = &s->msix->msix_entry[i];
390 
391         msi_msix_disable(s, entry->addr, entry->data, entry->pirq, true, true);
392 
393         /* clear MSI-X info */
394         entry->pirq = XEN_PT_UNASSIGNED_PIRQ;
395         entry->updated = false;
396     }
397 }
398 
399 int xen_pt_msix_update_remap(XenPCIPassthroughState *s, int bar_index)
400 {
401     XenPTMSIXEntry *entry;
402     int i, ret;
403 
404     if (!(s->msix && s->msix->bar_index == bar_index)) {
405         return 0;
406     }
407 
408     for (i = 0; i < s->msix->total_entries; i++) {
409         entry = &s->msix->msix_entry[i];
410         if (entry->pirq != XEN_PT_UNASSIGNED_PIRQ) {
411             ret = xc_domain_unbind_pt_irq(xen_xc, xen_domid, entry->pirq,
412                                           PT_IRQ_TYPE_MSI, 0, 0, 0, 0);
413             if (ret) {
414                 XEN_PT_ERR(&s->dev, "unbind MSI-X entry %d failed (err: %d)\n",
415                            entry->pirq, errno);
416             }
417             entry->updated = true;
418         }
419     }
420     return xen_pt_msix_update(s);
421 }
422 
423 static uint32_t get_entry_value(XenPTMSIXEntry *e, int offset)
424 {
425     assert(!(offset % sizeof(*e->latch)));
426     return e->latch[offset / sizeof(*e->latch)];
427 }
428 
429 static void set_entry_value(XenPTMSIXEntry *e, int offset, uint32_t val)
430 {
431     assert(!(offset % sizeof(*e->latch)));
432     e->latch[offset / sizeof(*e->latch)] = val;
433 }
434 
435 static void pci_msix_write(void *opaque, hwaddr addr,
436                            uint64_t val, unsigned size)
437 {
438     XenPCIPassthroughState *s = opaque;
439     XenPTMSIX *msix = s->msix;
440     XenPTMSIXEntry *entry;
441     unsigned int entry_nr, offset;
442 
443     entry_nr = addr / PCI_MSIX_ENTRY_SIZE;
444     if (entry_nr >= msix->total_entries) {
445         return;
446     }
447     entry = &msix->msix_entry[entry_nr];
448     offset = addr % PCI_MSIX_ENTRY_SIZE;
449 
450     if (offset != PCI_MSIX_ENTRY_VECTOR_CTRL) {
451         if (get_entry_value(entry, offset) == val
452             && entry->pirq != XEN_PT_UNASSIGNED_PIRQ) {
453             return;
454         }
455 
456         entry->updated = true;
457     } else if (msix->enabled && entry->updated &&
458                !(val & PCI_MSIX_ENTRY_CTRL_MASKBIT)) {
459         const volatile uint32_t *vec_ctrl;
460 
461         /*
462          * If Xen intercepts the mask bit access, entry->vec_ctrl may not be
463          * up-to-date. Read from hardware directly.
464          */
465         vec_ctrl = s->msix->phys_iomem_base + entry_nr * PCI_MSIX_ENTRY_SIZE
466             + PCI_MSIX_ENTRY_VECTOR_CTRL;
467         xen_pt_msix_update_one(s, entry_nr, *vec_ctrl);
468     }
469 
470     set_entry_value(entry, offset, val);
471 }
472 
473 static uint64_t pci_msix_read(void *opaque, hwaddr addr,
474                               unsigned size)
475 {
476     XenPCIPassthroughState *s = opaque;
477     XenPTMSIX *msix = s->msix;
478     int entry_nr, offset;
479 
480     entry_nr = addr / PCI_MSIX_ENTRY_SIZE;
481     if (entry_nr < 0) {
482         XEN_PT_ERR(&s->dev, "asked MSI-X entry '%i' invalid!\n", entry_nr);
483         return 0;
484     }
485 
486     offset = addr % PCI_MSIX_ENTRY_SIZE;
487 
488     if (addr < msix->total_entries * PCI_MSIX_ENTRY_SIZE) {
489         return get_entry_value(&msix->msix_entry[entry_nr], offset);
490     } else {
491         /* Pending Bit Array (PBA) */
492         return *(uint32_t *)(msix->phys_iomem_base + addr);
493     }
494 }
495 
496 static bool pci_msix_accepts(void *opaque, hwaddr addr,
497                              unsigned size, bool is_write)
498 {
499     return !(addr & (size - 1));
500 }
501 
502 static const MemoryRegionOps pci_msix_ops = {
503     .read = pci_msix_read,
504     .write = pci_msix_write,
505     .endianness = DEVICE_NATIVE_ENDIAN,
506     .valid = {
507         .min_access_size = 4,
508         .max_access_size = 4,
509         .unaligned = false,
510         .accepts = pci_msix_accepts
511     },
512     .impl = {
513         .min_access_size = 4,
514         .max_access_size = 4,
515         .unaligned = false
516     }
517 };
518 
519 int xen_pt_msix_init(XenPCIPassthroughState *s, uint32_t base)
520 {
521     uint8_t id = 0;
522     uint16_t control = 0;
523     uint32_t table_off = 0;
524     int i, total_entries, bar_index;
525     XenHostPCIDevice *hd = &s->real_device;
526     PCIDevice *d = &s->dev;
527     int fd = -1;
528     XenPTMSIX *msix = NULL;
529     int rc = 0;
530 
531     rc = xen_host_pci_get_byte(hd, base + PCI_CAP_LIST_ID, &id);
532     if (rc) {
533         return rc;
534     }
535 
536     if (id != PCI_CAP_ID_MSIX) {
537         XEN_PT_ERR(d, "Invalid id %#x base %#x\n", id, base);
538         return -1;
539     }
540 
541     xen_host_pci_get_word(hd, base + PCI_MSIX_FLAGS, &control);
542     total_entries = control & PCI_MSIX_FLAGS_QSIZE;
543     total_entries += 1;
544 
545     s->msix = g_malloc0(sizeof (XenPTMSIX)
546                         + total_entries * sizeof (XenPTMSIXEntry));
547     msix = s->msix;
548 
549     msix->total_entries = total_entries;
550     for (i = 0; i < total_entries; i++) {
551         msix->msix_entry[i].pirq = XEN_PT_UNASSIGNED_PIRQ;
552     }
553 
554     memory_region_init_io(&msix->mmio, OBJECT(s), &pci_msix_ops,
555                           s, "xen-pci-pt-msix",
556                           (total_entries * PCI_MSIX_ENTRY_SIZE
557                            + XC_PAGE_SIZE - 1)
558                           & XC_PAGE_MASK);
559 
560     xen_host_pci_get_long(hd, base + PCI_MSIX_TABLE, &table_off);
561     bar_index = msix->bar_index = table_off & PCI_MSIX_FLAGS_BIRMASK;
562     table_off = table_off & ~PCI_MSIX_FLAGS_BIRMASK;
563     msix->table_base = s->real_device.io_regions[bar_index].base_addr;
564     XEN_PT_LOG(d, "get MSI-X table BAR base 0x%"PRIx64"\n", msix->table_base);
565 
566     fd = open("/dev/mem", O_RDWR);
567     if (fd == -1) {
568         rc = -errno;
569         XEN_PT_ERR(d, "Can't open /dev/mem: %s\n", strerror(errno));
570         goto error_out;
571     }
572     XEN_PT_LOG(d, "table_off = %#x, total_entries = %d\n",
573                table_off, total_entries);
574     msix->table_offset_adjust = table_off & 0x0fff;
575     msix->phys_iomem_base =
576         mmap(NULL,
577              total_entries * PCI_MSIX_ENTRY_SIZE + msix->table_offset_adjust,
578              PROT_READ,
579              MAP_SHARED | MAP_LOCKED,
580              fd,
581              msix->table_base + table_off - msix->table_offset_adjust);
582     close(fd);
583     if (msix->phys_iomem_base == MAP_FAILED) {
584         rc = -errno;
585         XEN_PT_ERR(d, "Can't map physical MSI-X table: %s\n", strerror(errno));
586         goto error_out;
587     }
588     msix->phys_iomem_base = (char *)msix->phys_iomem_base
589         + msix->table_offset_adjust;
590 
591     XEN_PT_LOG(d, "mapping physical MSI-X table to %p\n",
592                msix->phys_iomem_base);
593 
594     memory_region_add_subregion_overlap(&s->bar[bar_index], table_off,
595                                         &msix->mmio,
596                                         2); /* Priority: pci default + 1 */
597 
598     return 0;
599 
600 error_out:
601     g_free(s->msix);
602     s->msix = NULL;
603     return rc;
604 }
605 
606 void xen_pt_msix_unmap(XenPCIPassthroughState *s)
607 {
608     XenPTMSIX *msix = s->msix;
609 
610     if (!msix) {
611         return;
612     }
613 
614     /* unmap the MSI-X memory mapped register area */
615     if (msix->phys_iomem_base) {
616         XEN_PT_LOG(&s->dev, "unmapping physical MSI-X table from %p\n",
617                    msix->phys_iomem_base);
618         munmap(msix->phys_iomem_base, msix->total_entries * PCI_MSIX_ENTRY_SIZE
619                + msix->table_offset_adjust);
620     }
621 
622     memory_region_del_subregion(&s->bar[msix->bar_index], &msix->mmio);
623 }
624 
625 void xen_pt_msix_delete(XenPCIPassthroughState *s)
626 {
627     XenPTMSIX *msix = s->msix;
628 
629     if (!msix) {
630         return;
631     }
632 
633     object_unparent(OBJECT(&msix->mmio));
634 
635     g_free(s->msix);
636     s->msix = NULL;
637 }
638