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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v9 19/28] ARM: vITS: handle MAPD command
The MAPD command maps a device by associating a memory region for
storing ITEs with a certain device ID. Since it features a valid bit,
MAPD also covers the "unmap" functionality, which we also cover here.
We store the given guest physical address in the device table, and, if
this command comes from Dom0, tell the host ITS driver about this new
mapping, so it can issue the corresponding host MAPD command and create
the required tables. We take care of rolling back actions should one
step fail.
Upon unmapping a device we make sure we clean up all associated
resources and release the memory again.
We use our existing guest memory access function to find the right ITT
entry and store the mapping there (in guest memory).
Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
xen/arch/arm/gic-v3-its.c | 18 +++++
xen/arch/arm/gic-v3-lpi.c | 18 +++++
xen/arch/arm/vgic-v3-its.c | 145 +++++++++++++++++++++++++++++++++++++++
xen/include/asm-arm/gic_v3_its.h | 5 ++
4 files changed, 186 insertions(+)
diff --git a/xen/arch/arm/gic-v3-its.c b/xen/arch/arm/gic-v3-its.c
index fd6a394..be4c3e0 100644
--- a/xen/arch/arm/gic-v3-its.c
+++ b/xen/arch/arm/gic-v3-its.c
@@ -869,6 +869,24 @@ struct pending_irq *gicv3_its_get_event_pending_irq(struct
domain *d,
return get_event_pending_irq(d, vdoorbell_address, vdevid, veventid, NULL);
}
+int gicv3_remove_guest_event(struct domain *d, paddr_t vdoorbell_address,
+ uint32_t vdevid, uint32_t veventid)
+{
+ uint32_t host_lpi = INVALID_LPI;
+
+ if ( !get_event_pending_irq(d, vdoorbell_address, vdevid, veventid,
+ &host_lpi) )
+ return -EINVAL;
+
+ if ( host_lpi == INVALID_LPI )
+ return -EINVAL;
+
+ gicv3_lpi_update_host_entry(host_lpi, d->domain_id,
+ INVALID_VCPU_ID, INVALID_LPI);
+
+ return 0;
+}
+
/* Scan the DT for any ITS nodes and create a list of host ITSes out of it. */
void gicv3_its_dt_init(const struct dt_device_node *node)
{
diff --git a/xen/arch/arm/gic-v3-lpi.c b/xen/arch/arm/gic-v3-lpi.c
index 44f6315..d427539 100644
--- a/xen/arch/arm/gic-v3-lpi.c
+++ b/xen/arch/arm/gic-v3-lpi.c
@@ -207,6 +207,24 @@ out:
irq_exit();
}
+void gicv3_lpi_update_host_entry(uint32_t host_lpi, int domain_id,
+ unsigned int vcpu_id, uint32_t virt_lpi)
+{
+ union host_lpi *hlpip, hlpi;
+
+ ASSERT(host_lpi >= LPI_OFFSET);
+
+ host_lpi -= LPI_OFFSET;
+
+ hlpip = &lpi_data.host_lpis[host_lpi / HOST_LPIS_PER_PAGE][host_lpi %
HOST_LPIS_PER_PAGE];
+
+ hlpi.virt_lpi = virt_lpi;
+ hlpi.dom_id = domain_id;
+ hlpi.vcpu_id = vcpu_id;
+
+ write_u64_atomic(&hlpip->data, hlpi.data);
+}
+
static int gicv3_lpi_allocate_pendtable(uint64_t *reg)
{
uint64_t val;
diff --git a/xen/arch/arm/vgic-v3-its.c b/xen/arch/arm/vgic-v3-its.c
index 8a200e9..731fe0c 100644
--- a/xen/arch/arm/vgic-v3-its.c
+++ b/xen/arch/arm/vgic-v3-its.c
@@ -175,6 +175,21 @@ static struct vcpu *get_vcpu_from_collection(struct
virt_its *its,
#define DEV_TABLE_ENTRY(addr, bits) \
(((addr) & GENMASK(51, 8)) | (((bits) - 1) & GENMASK(4, 0)))
+/* Set the address of an ITT for a given device ID. */
+static int its_set_itt_address(struct virt_its *its, uint32_t devid,
+ paddr_t itt_address, uint32_t nr_bits)
+{
+ paddr_t addr = get_baser_phys_addr(its->baser_dev);
+ dev_table_entry_t itt_entry = DEV_TABLE_ENTRY(itt_address, nr_bits);
+
+ if ( devid >= its->max_devices )
+ return -ENOENT;
+
+ return vgic_access_guest_memory(its->d,
+ addr + devid * sizeof(dev_table_entry_t),
+ &itt_entry, sizeof(itt_entry), true);
+}
+
/*
* Lookup the address of the Interrupt Translation Table associated with
* that device ID.
@@ -414,6 +429,133 @@ out_unlock:
return ret;
}
+/* Must be called with the ITS lock held. */
+static int its_discard_event(struct virt_its *its,
+ uint32_t vdevid, uint32_t vevid)
+{
+ struct pending_irq *p;
+ unsigned long flags;
+ struct vcpu *vcpu;
+ uint32_t vlpi;
+
+ ASSERT(spin_is_locked(&its->its_lock));
+
+ if ( !read_itte_locked(its, vdevid, vevid, &vcpu, &vlpi) )
+ return -ENOENT;
+
+ if ( vlpi == INVALID_LPI )
+ return -ENOENT;
+
+ /* Lock this VCPU's VGIC to make sure nobody is using the pending_irq. */
+ spin_lock_irqsave(&vcpu->arch.vgic.lock, flags);
+
+ /* Remove the pending_irq from the tree. */
+ write_lock(&its->d->arch.vgic.pend_lpi_tree_lock);
+ p = radix_tree_delete(&its->d->arch.vgic.pend_lpi_tree, vlpi);
+ write_unlock(&its->d->arch.vgic.pend_lpi_tree_lock);
+
+ if ( !p )
+ {
+ spin_unlock_irqrestore(&vcpu->arch.vgic.lock, flags);
+
+ return -ENOENT;
+ }
+
+ /* Cleanup the pending_irq and disconnect it from the LPI. */
+ list_del_init(&p->inflight);
+ list_del_init(&p->lr_queue);
+ vgic_init_pending_irq(p, INVALID_LPI);
+
+ spin_unlock_irqrestore(&vcpu->arch.vgic.lock, flags);
+
+ /* Remove the corresponding host LPI entry */
+ return gicv3_remove_guest_event(its->d, its->doorbell_address,
+ vdevid, vevid);
+}
+
+static int its_unmap_device(struct virt_its *its, uint32_t devid)
+{
+ dev_table_entry_t itt;
+ uint64_t evid;
+ int ret;
+
+ spin_lock(&its->its_lock);
+
+ ret = its_get_itt(its, devid, &itt);
+ if ( ret )
+ {
+ spin_unlock(&its->its_lock);
+ return ret;
+ }
+
+ /*
+ * For DomUs we need to check that the number of events per device
+ * is really limited, otherwise looping over all events can take too
+ * long for a guest. This ASSERT can then be removed if that is
+ * covered.
+ */
+ ASSERT(is_hardware_domain(its->d));
+
+ for ( evid = 0; evid < DEV_TABLE_ITT_SIZE(itt); evid++ )
+ /* Don't care about errors here, clean up as much as possible. */
+ its_discard_event(its, devid, evid);
+
+ spin_unlock(&its->its_lock);
+
+ return 0;
+}
+
+static int its_handle_mapd(struct virt_its *its, uint64_t *cmdptr)
+{
+ /* size and devid get validated by the functions called below. */
+ uint32_t devid = its_cmd_get_deviceid(cmdptr);
+ unsigned int size = its_cmd_get_size(cmdptr) + 1;
+ bool valid = its_cmd_get_validbit(cmdptr);
+ paddr_t itt_addr = its_cmd_get_ittaddr(cmdptr);
+ int ret;
+
+ /* Sanitize the number of events. */
+ if ( valid && (size > its->evid_bits) )
+ return -1;
+
+ if ( !valid )
+ /* Discard all events and remove pending LPIs. */
+ its_unmap_device(its, devid);
+
+ /*
+ * There is no easy and clean way for Xen to know the ITS device ID of a
+ * particular (PCI) device, so we have to rely on the guest telling
+ * us about it. For *now* we are just using the device ID *Dom0* uses,
+ * because the driver there has the actual knowledge.
+ * Eventually this will be replaced with a dedicated hypercall to
+ * announce pass-through of devices.
+ */
+ if ( is_hardware_domain(its->d) )
+ {
+
+ /*
+ * Dom0's ITSes are mapped 1:1, so both addresses are the same.
+ * Also the device IDs are equal.
+ */
+ ret = gicv3_its_map_guest_device(its->d, its->doorbell_address, devid,
+ its->doorbell_address, devid,
+ BIT(size), valid);
+ if ( ret && valid )
+ return ret;
+ }
+
+ spin_lock(&its->its_lock);
+
+ if ( valid )
+ ret = its_set_itt_address(its, devid, itt_addr, size);
+ else
+ ret = its_set_itt_address(its, devid, INVALID_PADDR, 1);
+
+ spin_unlock(&its->its_lock);
+
+ return ret;
+}
+
#define ITS_CMD_BUFFER_SIZE(baser) ((((baser) & 0xff) + 1) << 12)
#define ITS_CMD_OFFSET(reg) ((reg) & GENMASK(19, 5))
@@ -452,6 +594,9 @@ static int vgic_its_handle_cmds(struct domain *d, struct
virt_its *its)
case GITS_CMD_MAPC:
ret = its_handle_mapc(its, command);
break;
+ case GITS_CMD_MAPD:
+ ret = its_handle_mapd(its, command);
+ break;
case GITS_CMD_SYNC:
/* We handle ITS commands synchronously, so we ignore SYNC. */
break;
diff --git a/xen/include/asm-arm/gic_v3_its.h b/xen/include/asm-arm/gic_v3_its.h
index d162e89..6f94e65 100644
--- a/xen/include/asm-arm/gic_v3_its.h
+++ b/xen/include/asm-arm/gic_v3_its.h
@@ -173,6 +173,11 @@ struct pending_irq *gicv3_its_get_event_pending_irq(struct
domain *d,
paddr_t vdoorbell_address,
uint32_t vdevid,
uint32_t veventid);
+int gicv3_remove_guest_event(struct domain *d, paddr_t vdoorbell_address,
+ uint32_t vdevid, uint32_t veventid);
+void gicv3_lpi_update_host_entry(uint32_t host_lpi, int domain_id,
+ unsigned int vcpu_id, uint32_t virt_lpi);
+
#else
static inline void gicv3_its_dt_init(const struct dt_device_node *node)
--
2.9.0
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