[Xen-devel] [PATCH v7 29/34] ARM: vITS: handle MOVI command

[Andre Przywara <andre.przywara@xxxxxxx>]

The MOVI command moves the interrupt affinity from one redistributor
(read: VCPU) to another.
For now migration of "live" LPIs is not yet implemented, but we store
the changed affinity in the host LPI structure and in our virtual ITTE.

Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
 xen/arch/arm/gic-v3-its.c        | 24 ++++++++++++++++++++
 xen/arch/arm/gic-v3-lpi.c        | 15 +++++++++++++
 xen/arch/arm/vgic-v3-its.c       | 47 ++++++++++++++++++++++++++++++++++++++++
 xen/include/asm-arm/gic_v3_its.h |  4 ++++
 4 files changed, 90 insertions(+)

diff --git a/xen/arch/arm/gic-v3-its.c b/xen/arch/arm/gic-v3-its.c
index 793ad82..3d8197a 100644
--- a/xen/arch/arm/gic-v3-its.c
+++ b/xen/arch/arm/gic-v3-its.c
@@ -874,6 +874,30 @@ struct pending_irq *gicv3_assign_guest_event(struct domain 
*d,
     return pirq;
 }
 
+/* Changes the target VCPU for a given host LPI assigned to a domain. */
+int gicv3_lpi_change_vcpu(struct domain *d, paddr_t vdoorbell,
+                          uint32_t vdevid, uint32_t veventid,
+                          unsigned int vcpu_id)
+{
+    uint32_t host_lpi;
+    struct its_device *dev;
+
+    spin_lock(&d->arch.vgic.its_devices_lock);
+    dev = get_its_device(d, vdoorbell, vdevid);
+    if ( dev )
+        host_lpi = get_host_lpi(dev, veventid);
+    else
+        host_lpi = 0;
+    spin_unlock(&d->arch.vgic.its_devices_lock);
+
+    if ( !host_lpi )
+        return -ENOENT;
+
+    gicv3_lpi_update_host_vcpuid(host_lpi, vcpu_id);
+
+    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 19774d6..f127e64 100644
--- a/xen/arch/arm/gic-v3-lpi.c
+++ b/xen/arch/arm/gic-v3-lpi.c
@@ -220,6 +220,21 @@ void gicv3_lpi_update_host_entry(uint32_t host_lpi, int 
domain_id,
     write_u64_atomic(&hlpip->data, hlpi.data);
 }
 
+int gicv3_lpi_update_host_vcpuid(uint32_t host_lpi, unsigned int vcpu_id)
+{
+    union host_lpi *hlpip;
+
+    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];
+
+    write_u16_atomic(&hlpip->vcpu_id, vcpu_id);
+
+    return 0;
+}
+
 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 171e259..c5dc797 100644
--- a/xen/arch/arm/vgic-v3-its.c
+++ b/xen/arch/arm/vgic-v3-its.c
@@ -530,6 +530,47 @@ static int its_handle_mapti(struct virt_its *its, uint64_t 
*cmdptr)
     return 0;
 }
 
+static int its_handle_movi(struct virt_its *its, uint64_t *cmdptr)
+{
+    uint32_t devid = its_cmd_get_deviceid(cmdptr);
+    uint32_t eventid = its_cmd_get_id(cmdptr);
+    int collid = its_cmd_get_collection(cmdptr);
+    struct pending_irq *p;
+    struct vcpu *vcpu;
+    uint32_t vlpi;
+    int ret = -1;
+
+    spin_lock(&its->its_lock);
+    /* Check for a mapped LPI and get the LPI number. */
+    if ( !read_itte_locked(its, devid, eventid, &vcpu, &vlpi) )
+        goto out_unlock;
+
+    /* Check the new collection ID and get the new VCPU pointer */
+    vcpu = get_vcpu_from_collection(its, collid);
+    if ( !vcpu )
+        goto out_unlock;
+
+    /* Update our cached vcpu_id in the pending_irq. */
+    p = its->d->arch.vgic.handler->lpi_to_pending(its->d, vlpi);
+    p->lpi_vcpu_id = vcpu->vcpu_id;
+
+    /* Now store the new collection in the translation table. */
+    if ( !write_itte_locked(its, devid, eventid, collid, vlpi, &vcpu) )
+        goto out_unlock;
+
+    spin_unlock(&its->its_lock);
+
+    /* TODO: lookup currently-in-guest virtual IRQs and migrate them? */
+
+    return gicv3_lpi_change_vcpu(its->d, its->doorbell_address,
+                                 devid, eventid, vcpu->vcpu_id);
+
+out_unlock:
+    spin_unlock(&its->its_lock);
+
+    return ret;
+}
+
 #define ITS_CMD_BUFFER_SIZE(baser)      ((((baser) & 0xff) + 1) << 12)
 
 /*
@@ -575,6 +616,12 @@ static int vgic_its_handle_cmds(struct domain *d, struct 
virt_its *its)
         case GITS_CMD_MAPTI:
             ret = its_handle_mapti(its, command);
             break;
+        case GITS_CMD_MOVALL:
+            gdprintk(XENLOG_G_INFO, "ITS: ignoring MOVALL command\n");
+            break;
+        case GITS_CMD_MOVI:
+            ret = its_handle_movi(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 0be88ac..cd2b527 100644
--- a/xen/include/asm-arm/gic_v3_its.h
+++ b/xen/include/asm-arm/gic_v3_its.h
@@ -172,8 +172,12 @@ void gicv3_free_host_lpi_block(uint32_t first_lpi);
 struct pending_irq *gicv3_assign_guest_event(struct domain *d, paddr_t 
doorbell,
                                              uint32_t devid, uint32_t eventid,
                                              struct vcpu *v, uint32_t 
virt_lpi);
+int gicv3_lpi_change_vcpu(struct domain *d, paddr_t doorbell,
+                          uint32_t devid, uint32_t eventid,
+                          unsigned int vcpu_id);
 void gicv3_lpi_update_host_entry(uint32_t host_lpi, int domain_id,
                                  unsigned int vcpu_id, uint32_t virt_lpi);
+int gicv3_lpi_update_host_vcpuid(uint32_t host_lpi, unsigned int vcpu_id);
 
 #else
 
-- 
2.8.2


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