[PATCH v3 17/59] irqchip/gic-v3-its: Add VLPI map/unmap operations

Marc Zyngier
2017-07-31T17:26:10Z

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>
---
drivers/irqchip/irq-gic-v3-its.c | 250 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 247 insertions(+), 3 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 9ef4f161690a..ef31c3e58c01 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -115,11 +115,17 @@ struct event_lpi_map {
u16 *col_map;
irq_hw_number_t lpi_base;
int nr_lpis;
+ struct mutex vlpi_lock;
+ struct its_vm *vm;
+ struct its_vlpi_map *vlpi_maps;
+ int nr_vlpis;
};

/*
- * The ITS view of a device - belongs to an ITS, a collection, owns an
- * interrupt translation table, and a list of interrupts.
+ * The ITS view of a device - belongs to an ITS, owns an interrupt
+ * translation table, and a list of interrupts. If it some of its
+ * LPIs are injected into a guest (GICv4), the event_map.vm field
+ * indicates which one.
*/
struct its_device {
struct list_head entry;
@@ -205,6 +211,21 @@ struct its_cmd_desc {
struct {
struct its_collection *col;
} its_invall_cmd;
+
+ struct {
+ struct its_vpe *vpe;
+ struct its_device *dev;
+ u32 virt_id;
+ u32 event_id;
+ bool db_enabled;
+ } its_vmapti_cmd;
+
+ struct {
+ struct its_vpe *vpe;
+ struct its_device *dev;
+ u32 event_id;
+ bool db_enabled;
+ } its_vmovi_cmd;
};
};

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

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

+static void its_encode_vpeid(struct its_cmd_block *cmd, u16 vpeid)
+{
+ its_mask_encode(&cmd->raw_cmd[1], vpeid, 47, 32);
+}
+
+static void its_encode_virt_id(struct its_cmd_block *cmd, u32 virt_id)
+{
+ its_mask_encode(&cmd->raw_cmd[2], virt_id, 31, 0);
+}
+
+static void its_encode_db_phys_id(struct its_cmd_block *cmd, u32 db_phys_id)
+{
+ its_mask_encode(&cmd->raw_cmd[2], db_phys_id, 63, 32);
+}
+
+static void its_encode_db_valid(struct its_cmd_block *cmd, bool db_valid)
+{
+ its_mask_encode(&cmd->raw_cmd[2], db_valid, 0, 0);
+}
+
static inline void its_fixup_cmd(struct its_cmd_block *cmd)
{
/* Let's fixup BE commands */
@@ -431,6 +475,50 @@ static struct its_collection *its_build_invall_cmd(struct its_cmd_block *cmd,
return NULL;
}

+static struct its_vpe *its_build_vmapti_cmd(struct its_cmd_block *cmd,
+ struct its_cmd_desc *desc)
+{
+ u32 db;
+
+ if (desc->its_vmapti_cmd.db_enabled)
+ db = desc->its_vmapti_cmd.vpe->vpe_db_lpi;
+ else
+ db = 1023;
+
+ its_encode_cmd(cmd, GITS_CMD_VMAPTI);
+ its_encode_devid(cmd, desc->its_vmapti_cmd.dev->device_id);
+ its_encode_vpeid(cmd, desc->its_vmapti_cmd.vpe->vpe_id);
+ its_encode_event_id(cmd, desc->its_vmapti_cmd.event_id);
+ its_encode_db_phys_id(cmd, db);
+ its_encode_virt_id(cmd, desc->its_vmapti_cmd.virt_id);
+
+ its_fixup_cmd(cmd);
+
+ return desc->its_vmapti_cmd.vpe;
+}
+
+static struct its_vpe *its_build_vmovi_cmd(struct its_cmd_block *cmd,
+ struct its_cmd_desc *desc)
+{
+ u32 db;
+
+ if (desc->its_vmovi_cmd.db_enabled)
+ db = desc->its_vmovi_cmd.vpe->vpe_db_lpi;
+ else
+ db = 1023;
+
+ its_encode_cmd(cmd, GITS_CMD_VMOVI);
+ its_encode_devid(cmd, desc->its_vmovi_cmd.dev->device_id);
+ its_encode_vpeid(cmd, desc->its_vmovi_cmd.vpe->vpe_id);
+ its_encode_event_id(cmd, desc->its_vmovi_cmd.event_id);
+ its_encode_db_phys_id(cmd, db);
+ its_encode_db_valid(cmd, true);
+
+ its_fixup_cmd(cmd);
+
+ return desc->its_vmovi_cmd.vpe;
+}
+
static u64 its_cmd_ptr_to_offset(struct its_node *its,
struct its_cmd_block *ptr)
{
@@ -576,6 +664,18 @@ static void its_build_sync_cmd(struct its_cmd_block *sync_cmd,
static BUILD_SINGLE_CMD_FUNC(its_send_single_command, its_cmd_builder_t,
struct its_collection, its_build_sync_cmd)

+static void its_build_vsync_cmd(struct its_cmd_block *sync_cmd,
+ struct its_vpe *sync_vpe)
+{
+ its_encode_cmd(sync_cmd, GITS_CMD_VSYNC);
+ its_encode_vpeid(sync_cmd, sync_vpe->vpe_id);
+
+ its_fixup_cmd(sync_cmd);
+}
+
+static BUILD_SINGLE_CMD_FUNC(its_send_single_vcommand, its_cmd_vbuilder_t,
+ struct its_vpe, its_build_vsync_cmd)
+
static void its_send_int(struct its_device *dev, u32 event_id)
{
struct its_cmd_desc desc;
@@ -669,6 +769,33 @@ static void its_send_invall(struct its_node *its, struct its_collection *col)
its_send_single_command(its, its_build_invall_cmd, &desc);
}

+static void its_send_vmapti(struct its_device *dev, u32 id)
+{
+ struct its_vlpi_map *map = &dev->event_map.vlpi_maps[id];
+ struct its_cmd_desc desc;
+
+ desc.its_vmapti_cmd.vpe = map->vm->vpes[map->vpe_idx];
+ desc.its_vmapti_cmd.dev = dev;
+ desc.its_vmapti_cmd.virt_id = map->vintid;
+ desc.its_vmapti_cmd.event_id = id;
+ desc.its_vmapti_cmd.db_enabled = map->db_enabled;
+
+ its_send_single_vcommand(dev->its, its_build_vmapti_cmd, &desc);
+}
+
+static void its_send_vmovi(struct its_device *dev, u32 id)
+{
+ struct its_vlpi_map *map = &dev->event_map.vlpi_maps[id];
+ struct its_cmd_desc desc;
+
+ desc.its_vmovi_cmd.vpe = map->vm->vpes[map->vpe_idx];
+ desc.its_vmovi_cmd.dev = dev;
+ desc.its_vmovi_cmd.event_id = id;
+ desc.its_vmovi_cmd.db_enabled = map->db_enabled;
+
+ its_send_single_vcommand(dev->its, its_build_vmovi_cmd, &desc);
+}
+
/*
* irqchip functions - assumes MSI, mostly.
*/
@@ -781,19 +908,135 @@ static int its_irq_set_irqchip_state(struct irq_data *d,
return 0;
}

+static int its_vlpi_map(struct irq_data *d, struct its_cmd_info *info)
+{
+ struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+ u32 event = its_get_event_id(d);
+ int ret = 0;
+
+ if (!info->map)
+ return -EINVAL;
+
+ mutex_lock(&its_dev->event_map.vlpi_lock);
+
+ if (!its_dev->event_map.vm) {
+ struct its_vlpi_map *maps;
+
+ maps = kzalloc(sizeof(*maps) * its_dev->event_map.nr_lpis,
+ GFP_KERNEL);
+ if (!maps) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ its_dev->event_map.vm = info->map->vm;
+ its_dev->event_map.vlpi_maps = maps;
+ } else if (its_dev->event_map.vm != info->map->vm) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* Get our private copy of the mapping information */
+ its_dev->event_map.vlpi_maps[event] = *info->map;
+
+ if (irqd_is_forwarded_to_vcpu(d)) {
+ /* Already mapped, move it around */
+ its_send_vmovi(its_dev, event);
+ } else {
+ /* Drop the physical mapping */
+ its_send_discard(its_dev, event);
+
+ /* and install the virtual one */
+ its_send_vmapti(its_dev, event);
+ irqd_set_forwarded_to_vcpu(d);
+
+ /* Increment the number of VLPIs */
+ its_dev->event_map.nr_vlpis++;
+ }
+
+out:
+ mutex_unlock(&its_dev->event_map.vlpi_lock);
+ return ret;
+}
+
+static int its_vlpi_get(struct irq_data *d, struct its_cmd_info *info)
+{
+ struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+ u32 event = its_get_event_id(d);
+ int ret = 0;
+
+ mutex_lock(&its_dev->event_map.vlpi_lock);
+
+ if (!its_dev->event_map.vm ||
+ !its_dev->event_map.vlpi_maps[event].vm) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* Copy our mapping information to the incoming request */
+ *info->map = its_dev->event_map.vlpi_maps[event];
+
+out:
+ mutex_unlock(&its_dev->event_map.vlpi_lock);
+ return ret;
+}
+
+static int its_vlpi_unmap(struct irq_data *d)
+{
+ struct its_device *its_dev = irq_data_get_irq_chip_data(d);
+ u32 event = its_get_event_id(d);
+ int ret = 0;
+
+ mutex_lock(&its_dev->event_map.vlpi_lock);
+
+ if (!its_dev->event_map.vm || !irqd_is_forwarded_to_vcpu(d)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* Drop the virtual mapping */
+ its_send_discard(its_dev, event);
+
+ /* and restore the physical one */
+ irqd_clr_forwarded_to_vcpu(d);
+ its_send_mapti(its_dev, d->hwirq, event);
+ lpi_update_config(d, 0xff, (LPI_PROP_DEFAULT_PRIO |
+ LPI_PROP_ENABLED |
+ LPI_PROP_GROUP1));
+
+ /*
+ * Drop the refcount and make the device available again if
+ * this was the last VLPI.
+ */
+ if (!--its_dev->event_map.nr_vlpis) {
+ its_dev->event_map.vm = NULL;
+ kfree(its_dev->event_map.vlpi_maps);
+ }
+
+out:
+ mutex_unlock(&its_dev->event_map.vlpi_lock);
+ return ret;
+}
+
static int its_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu_info)
{
struct its_device *its_dev = irq_data_get_irq_chip_data(d);
struct its_cmd_info *info = vcpu_info;

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

+ /* Unmap request? */
+ if (!info)
+ return its_vlpi_unmap(d);
+
switch (info->cmd_type) {
case MAP_VLPI:
+ return its_vlpi_map(d, info);

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

case PROP_UPDATE_VLPI:
case PROP_UPDATE_AND_INV_VLPI:
@@ -1512,6 +1755,7 @@ static struct its_device *its_create_device(struct its_node *its, u32 dev_id,
dev->event_map.col_map = col_map;
dev->event_map.lpi_base = lpi_base;
dev->event_map.nr_lpis = nr_lpis;
+ mutex_init(&dev->event_map.vlpi_lock);
dev->device_id = dev_id;
INIT_LIST_HEAD(&dev->entry);

--
2.11.0