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authorAndre Przywara <andre.przywara@arm.com>2016-08-16 17:51:06 +0100
committerChristoffer Dall <christoffer.dall@linaro.org>2016-08-16 19:27:22 +0200
commit286054a7a8674b256da16564d96772b88896eb35 (patch)
tree9fcbe7e37c7da2983b2c08fb5470ff5fd25d9673 /virt
parent505a19eec49ab36b314a05bc062749ebdfb0aa90 (diff)
downloadlinux-stericsson-286054a7a8674b256da16564d96772b88896eb35.tar.gz
KVM: arm64: ITS: avoid re-mapping LPIs
When a guest wants to map a device-ID/event-ID combination that is already mapped, we may end up in a situation where an LPI is never "put", thus never being freed. Since the GICv3 spec says that mapping an already mapped LPI is UNPREDICTABLE, lets just bail out early in this situation to avoid any potential leaks. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/arm/vgic/vgic-its.c27
1 files changed, 13 insertions, 14 deletions
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 9533080b47d3..4660a7d04eea 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -731,7 +731,7 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
u32 device_id = its_cmd_get_deviceid(its_cmd);
u32 event_id = its_cmd_get_id(its_cmd);
u32 coll_id = its_cmd_get_collection(its_cmd);
- struct its_itte *itte, *new_itte = NULL;
+ struct its_itte *itte;
struct its_device *device;
struct its_collection *collection, *new_coll = NULL;
int lpi_nr;
@@ -749,6 +749,10 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
lpi_nr >= max_lpis_propbaser(kvm->arch.vgic.propbaser))
return E_ITS_MAPTI_PHYSICALID_OOR;
+ /* If there is an existing mapping, behavior is UNPREDICTABLE. */
+ if (find_itte(its, device_id, event_id))
+ return 0;
+
collection = find_collection(its, coll_id);
if (!collection) {
int ret = vgic_its_alloc_collection(its, &collection, coll_id);
@@ -757,20 +761,16 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
new_coll = collection;
}
- itte = find_itte(its, device_id, event_id);
+ itte = kzalloc(sizeof(struct its_itte), GFP_KERNEL);
if (!itte) {
- itte = kzalloc(sizeof(struct its_itte), GFP_KERNEL);
- if (!itte) {
- if (new_coll)
- vgic_its_free_collection(its, coll_id);
- return -ENOMEM;
- }
-
- new_itte = itte;
- itte->event_id = event_id;
- list_add_tail(&itte->itte_list, &device->itt_head);
+ if (new_coll)
+ vgic_its_free_collection(its, coll_id);
+ return -ENOMEM;
}
+ itte->event_id = event_id;
+ list_add_tail(&itte->itte_list, &device->itt_head);
+
itte->collection = collection;
itte->lpi = lpi_nr;
@@ -778,8 +778,7 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
if (IS_ERR(irq)) {
if (new_coll)
vgic_its_free_collection(its, coll_id);
- if (new_itte)
- its_free_itte(kvm, new_itte);
+ its_free_itte(kvm, itte);
return PTR_ERR(irq);
}
itte->irq = irq;