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Marc Zyngier
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irqchip/gic-v3-its: Add VLPI map/unmap operations
In order to let a VLPI being injected into a guest, the VLPI must be mapped using the VMAPTI command. When moved to a different vcpu, it must be moved with the VMOVI command. These commands are issued via the irq_set_vcpu_affinity method, making sure we unmap the corresponding host LPI first. The reverse is also done when the VLPI is unmapped from the guest. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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‎drivers/irqchip/irq-gic-v3-its.c

Lines changed: 247 additions & 3 deletions
Original file line numberDiff line numberDiff line change
@@ -115,11 +115,17 @@ struct event_lpi_map {
115115
u16 *col_map;
116116
irq_hw_number_t lpi_base;
117117
int nr_lpis;
118+
struct mutex vlpi_lock;
119+
struct its_vm *vm;
120+
struct its_vlpi_map *vlpi_maps;
121+
int nr_vlpis;
118122
};
119123

120124
/*
121-
* The ITS view of a device - belongs to an ITS, a collection, owns an
122-
* interrupt translation table, and a list of interrupts.
125+
* The ITS view of a device - belongs to an ITS, owns an interrupt
126+
* translation table, and a list of interrupts. If it some of its
127+
* LPIs are injected into a guest (GICv4), the event_map.vm field
128+
* indicates which one.
123129
*/
124130
struct its_device {
125131
struct list_head entry;
@@ -205,6 +211,21 @@ struct its_cmd_desc {
205211
struct {
206212
struct its_collection *col;
207213
} its_invall_cmd;
214+
215+
struct {
216+
struct its_vpe *vpe;
217+
struct its_device *dev;
218+
u32 virt_id;
219+
u32 event_id;
220+
bool db_enabled;
221+
} its_vmapti_cmd;
222+
223+
struct {
224+
struct its_vpe *vpe;
225+
struct its_device *dev;
226+
u32 event_id;
227+
bool db_enabled;
228+
} its_vmovi_cmd;
208229
};
209230
};
210231

@@ -221,6 +242,9 @@ struct its_cmd_block {
221242
typedef struct its_collection *(*its_cmd_builder_t)(struct its_cmd_block *,
222243
struct its_cmd_desc *);
223244

245+
typedef struct its_vpe *(*its_cmd_vbuilder_t)(struct its_cmd_block *,
246+
struct its_cmd_desc *);
247+
224248
static void its_mask_encode(u64 *raw_cmd, u64 val, int h, int l)
225249
{
226250
u64 mask = GENMASK_ULL(h, l);
@@ -273,6 +297,26 @@ static void its_encode_collection(struct its_cmd_block *cmd, u16 col)
273297
its_mask_encode(&cmd->raw_cmd[2], col, 15, 0);
274298
}
275299

300+
static void its_encode_vpeid(struct its_cmd_block *cmd, u16 vpeid)
301+
{
302+
its_mask_encode(&cmd->raw_cmd[1], vpeid, 47, 32);
303+
}
304+
305+
static void its_encode_virt_id(struct its_cmd_block *cmd, u32 virt_id)
306+
{
307+
its_mask_encode(&cmd->raw_cmd[2], virt_id, 31, 0);
308+
}
309+
310+
static void its_encode_db_phys_id(struct its_cmd_block *cmd, u32 db_phys_id)
311+
{
312+
its_mask_encode(&cmd->raw_cmd[2], db_phys_id, 63, 32);
313+
}
314+
315+
static void its_encode_db_valid(struct its_cmd_block *cmd, bool db_valid)
316+
{
317+
its_mask_encode(&cmd->raw_cmd[2], db_valid, 0, 0);
318+
}
319+
276320
static inline void its_fixup_cmd(struct its_cmd_block *cmd)
277321
{
278322
/* Let's fixup BE commands */
@@ -431,6 +475,50 @@ static struct its_collection *its_build_invall_cmd(struct its_cmd_block *cmd,
431475
return NULL;
432476
}
433477

478+
static struct its_vpe *its_build_vmapti_cmd(struct its_cmd_block *cmd,
479+
struct its_cmd_desc *desc)
480+
{
481+
u32 db;
482+
483+
if (desc->its_vmapti_cmd.db_enabled)
484+
db = desc->its_vmapti_cmd.vpe->vpe_db_lpi;
485+
else
486+
db = 1023;
487+
488+
its_encode_cmd(cmd, GITS_CMD_VMAPTI);
489+
its_encode_devid(cmd, desc->its_vmapti_cmd.dev->device_id);
490+
its_encode_vpeid(cmd, desc->its_vmapti_cmd.vpe->vpe_id);
491+
its_encode_event_id(cmd, desc->its_vmapti_cmd.event_id);
492+
its_encode_db_phys_id(cmd, db);
493+
its_encode_virt_id(cmd, desc->its_vmapti_cmd.virt_id);
494+
495+
its_fixup_cmd(cmd);
496+
497+
return desc->its_vmapti_cmd.vpe;
498+
}
499+
500+
static struct its_vpe *its_build_vmovi_cmd(struct its_cmd_block *cmd,
501+
struct its_cmd_desc *desc)
502+
{
503+
u32 db;
504+
505+
if (desc->its_vmovi_cmd.db_enabled)
506+
db = desc->its_vmovi_cmd.vpe->vpe_db_lpi;
507+
else
508+
db = 1023;
509+
510+
its_encode_cmd(cmd, GITS_CMD_VMOVI);
511+
its_encode_devid(cmd, desc->its_vmovi_cmd.dev->device_id);
512+
its_encode_vpeid(cmd, desc->its_vmovi_cmd.vpe->vpe_id);
513+
its_encode_event_id(cmd, desc->its_vmovi_cmd.event_id);
514+
its_encode_db_phys_id(cmd, db);
515+
its_encode_db_valid(cmd, true);
516+
517+
its_fixup_cmd(cmd);
518+
519+
return desc->its_vmovi_cmd.vpe;
520+
}
521+
434522
static u64 its_cmd_ptr_to_offset(struct its_node *its,
435523
struct its_cmd_block *ptr)
436524
{
@@ -582,6 +670,18 @@ static void its_build_sync_cmd(struct its_cmd_block *sync_cmd,
582670
static BUILD_SINGLE_CMD_FUNC(its_send_single_command, its_cmd_builder_t,
583671
struct its_collection, its_build_sync_cmd)
584672

673+
static void its_build_vsync_cmd(struct its_cmd_block *sync_cmd,
674+
struct its_vpe *sync_vpe)
675+
{
676+
its_encode_cmd(sync_cmd, GITS_CMD_VSYNC);
677+
its_encode_vpeid(sync_cmd, sync_vpe->vpe_id);
678+
679+
its_fixup_cmd(sync_cmd);
680+
}
681+
682+
static BUILD_SINGLE_CMD_FUNC(its_send_single_vcommand, its_cmd_vbuilder_t,
683+
struct its_vpe, its_build_vsync_cmd)
684+
585685
static void its_send_int(struct its_device *dev, u32 event_id)
586686
{
587687
struct its_cmd_desc desc;
@@ -675,6 +775,33 @@ static void its_send_invall(struct its_node *its, struct its_collection *col)
675775
its_send_single_command(its, its_build_invall_cmd, &desc);
676776
}
677777

778+
static void its_send_vmapti(struct its_device *dev, u32 id)
779+
{
780+
struct its_vlpi_map *map = &dev->event_map.vlpi_maps[id];
781+
struct its_cmd_desc desc;
782+
783+
desc.its_vmapti_cmd.vpe = map->vpe;
784+
desc.its_vmapti_cmd.dev = dev;
785+
desc.its_vmapti_cmd.virt_id = map->vintid;
786+
desc.its_vmapti_cmd.event_id = id;
787+
desc.its_vmapti_cmd.db_enabled = map->db_enabled;
788+
789+
its_send_single_vcommand(dev->its, its_build_vmapti_cmd, &desc);
790+
}
791+
792+
static void its_send_vmovi(struct its_device *dev, u32 id)
793+
{
794+
struct its_vlpi_map *map = &dev->event_map.vlpi_maps[id];
795+
struct its_cmd_desc desc;
796+
797+
desc.its_vmovi_cmd.vpe = map->vpe;
798+
desc.its_vmovi_cmd.dev = dev;
799+
desc.its_vmovi_cmd.event_id = id;
800+
desc.its_vmovi_cmd.db_enabled = map->db_enabled;
801+
802+
its_send_single_vcommand(dev->its, its_build_vmovi_cmd, &desc);
803+
}
804+
678805
/*
679806
* irqchip functions - assumes MSI, mostly.
680807
*/
@@ -787,19 +914,135 @@ static int its_irq_set_irqchip_state(struct irq_data *d,
787914
return 0;
788915
}
789916

917+
static int its_vlpi_map(struct irq_data *d, struct its_cmd_info *info)
918+
{
919+
struct its_device *its_dev = irq_data_get_irq_chip_data(d);
920+
u32 event = its_get_event_id(d);
921+
int ret = 0;
922+
923+
if (!info->map)
924+
return -EINVAL;
925+
926+
mutex_lock(&its_dev->event_map.vlpi_lock);
927+
928+
if (!its_dev->event_map.vm) {
929+
struct its_vlpi_map *maps;
930+
931+
maps = kzalloc(sizeof(*maps) * its_dev->event_map.nr_lpis,
932+
GFP_KERNEL);
933+
if (!maps) {
934+
ret = -ENOMEM;
935+
goto out;
936+
}
937+
938+
its_dev->event_map.vm = info->map->vm;
939+
its_dev->event_map.vlpi_maps = maps;
940+
} else if (its_dev->event_map.vm != info->map->vm) {
941+
ret = -EINVAL;
942+
goto out;
943+
}
944+
945+
/* Get our private copy of the mapping information */
946+
its_dev->event_map.vlpi_maps[event] = *info->map;
947+
948+
if (irqd_is_forwarded_to_vcpu(d)) {
949+
/* Already mapped, move it around */
950+
its_send_vmovi(its_dev, event);
951+
} else {
952+
/* Drop the physical mapping */
953+
its_send_discard(its_dev, event);
954+
955+
/* and install the virtual one */
956+
its_send_vmapti(its_dev, event);
957+
irqd_set_forwarded_to_vcpu(d);
958+
959+
/* Increment the number of VLPIs */
960+
its_dev->event_map.nr_vlpis++;
961+
}
962+
963+
out:
964+
mutex_unlock(&its_dev->event_map.vlpi_lock);
965+
return ret;
966+
}
967+
968+
static int its_vlpi_get(struct irq_data *d, struct its_cmd_info *info)
969+
{
970+
struct its_device *its_dev = irq_data_get_irq_chip_data(d);
971+
u32 event = its_get_event_id(d);
972+
int ret = 0;
973+
974+
mutex_lock(&its_dev->event_map.vlpi_lock);
975+
976+
if (!its_dev->event_map.vm ||
977+
!its_dev->event_map.vlpi_maps[event].vm) {
978+
ret = -EINVAL;
979+
goto out;
980+
}
981+
982+
/* Copy our mapping information to the incoming request */
983+
*info->map = its_dev->event_map.vlpi_maps[event];
984+
985+
out:
986+
mutex_unlock(&its_dev->event_map.vlpi_lock);
987+
return ret;
988+
}
989+
990+
static int its_vlpi_unmap(struct irq_data *d)
991+
{
992+
struct its_device *its_dev = irq_data_get_irq_chip_data(d);
993+
u32 event = its_get_event_id(d);
994+
int ret = 0;
995+
996+
mutex_lock(&its_dev->event_map.vlpi_lock);
997+
998+
if (!its_dev->event_map.vm || !irqd_is_forwarded_to_vcpu(d)) {
999+
ret = -EINVAL;
1000+
goto out;
1001+
}
1002+
1003+
/* Drop the virtual mapping */
1004+
its_send_discard(its_dev, event);
1005+
1006+
/* and restore the physical one */
1007+
irqd_clr_forwarded_to_vcpu(d);
1008+
its_send_mapti(its_dev, d->hwirq, event);
1009+
lpi_update_config(d, 0xff, (LPI_PROP_DEFAULT_PRIO |
1010+
LPI_PROP_ENABLED |
1011+
LPI_PROP_GROUP1));
1012+
1013+
/*
1014+
* Drop the refcount and make the device available again if
1015+
* this was the last VLPI.
1016+
*/
1017+
if (!--its_dev->event_map.nr_vlpis) {
1018+
its_dev->event_map.vm = NULL;
1019+
kfree(its_dev->event_map.vlpi_maps);
1020+
}
1021+
1022+
out:
1023+
mutex_unlock(&its_dev->event_map.vlpi_lock);
1024+
return ret;
1025+
}
1026+
7901027
static int its_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
7911028
{
7921029
struct its_device *its_dev = irq_data_get_irq_chip_data(d);
7931030
struct its_cmd_info *info = vcpu_info;
7941031

7951032
/* Need a v4 ITS */
796-
if (!its_dev->its->is_v4 || !info)
1033+
if (!its_dev->its->is_v4)
7971034
return -EINVAL;
7981035

1036+
/* Unmap request? */
1037+
if (!info)
1038+
return its_vlpi_unmap(d);
1039+
7991040
switch (info->cmd_type) {
8001041
case MAP_VLPI:
1042+
return its_vlpi_map(d, info);
8011043

8021044
case GET_VLPI:
1045+
return its_vlpi_get(d, info);
8031046

8041047
case PROP_UPDATE_VLPI:
8051048
case PROP_UPDATE_AND_INV_VLPI:
@@ -1518,6 +1761,7 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
15181761
dev->event_map.col_map = col_map;
15191762
dev->event_map.lpi_base = lpi_base;
15201763
dev->event_map.nr_lpis = nr_lpis;
1764+
mutex_init(&dev->event_map.vlpi_lock);
15211765
dev->device_id = dev_id;
15221766
INIT_LIST_HEAD(&dev->entry);
15231767

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