From: Eric Auger <eric.auger@xxxxxxxxxx>
When the GITS_BASER<n>.Valid gets cleared, the data structures in
guest RAM are not valid anymore. The device, collection
and LPI lists stored in the in-kernel ITS represent the same
information in some form of cache. So let's void the cache.
Reviewed-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
---
virt/kvm/arm/vgic/vgic-its.c | 22 ++++++++++++++++++----
1 file changed, 18 insertions(+), 4 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index d46256c07ba5..1732e08a4375 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -1431,7 +1431,7 @@ static void vgic_mmio_write_its_baser(struct kvm *kvm,
unsigned long val)
{
const struct vgic_its_abi *abi = vgic_its_get_abi(its);
- u64 entry_size, device_type;
+ u64 entry_size, table_type;
u64 reg, *regptr, clearbits = 0;
/* When GITS_CTLR.Enable is 1, we ignore write accesses. */
@@ -1442,12 +1442,12 @@ static void vgic_mmio_write_its_baser(struct kvm *kvm,
case 0:
regptr = &its->baser_device_table;
entry_size = abi->dte_esz;
- device_type = GITS_BASER_TYPE_DEVICE;
+ table_type = GITS_BASER_TYPE_DEVICE;
break;
case 1:
regptr = &its->baser_coll_table;
entry_size = abi->cte_esz;
- device_type = GITS_BASER_TYPE_COLLECTION;
+ table_type = GITS_BASER_TYPE_COLLECTION;
clearbits = GITS_BASER_INDIRECT;
break;
default:
@@ -1459,10 +1459,24 @@ static void vgic_mmio_write_its_baser(struct kvm *kvm,
reg &= ~clearbits;
reg |= (entry_size - 1) << GITS_BASER_ENTRY_SIZE_SHIFT;
- reg |= device_type << GITS_BASER_TYPE_SHIFT;
+ reg |= table_type << GITS_BASER_TYPE_SHIFT;
reg = vgic_sanitise_its_baser(reg);
*regptr = reg;
+
+ if (!(reg & GITS_BASER_VALID)) {
+ /* Take the its_lock to prevent a race with a save/restore */
+ mutex_lock(&its->its_lock);
+ switch (table_type) {
+ case GITS_BASER_TYPE_DEVICE:
+ vgic_its_free_device_list(kvm, its);
+ break;
+ case GITS_BASER_TYPE_COLLECTION:
+ vgic_its_free_collection_list(kvm, its);
+ break;
+ }
+ mutex_unlock(&its->its_lock);
+ }
}
static unsigned long vgic_mmio_read_its_ctlr(struct kvm *vcpu,
--
2.14.2
