From: Eric Auger <eric.auger@xxxxxxxxxx>
At the moment we don't properly check the GITS_BASER<n>.Valid
bit before saving the collection and device tables.
On vgic_its_save_collection_table() we use the GITS_BASER gpa
field whereas the Valid bit should be used.
On vgic_its_save_device_tables() there is no check. This can
cause various bugs, among which a subsequent fault when accessing
the table in guest memory.
Let's systematically check the Valid bit before doing anything.
We also uniformize the code between save and restore.
Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
Reviewed-by: Andre Przywara <andre.przywara@xxxxxxx>
Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Reviewed-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
---
virt/kvm/arm/vgic/vgic-its.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index e69ef7d27fde..547f12dc4d54 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -2067,11 +2067,12 @@ static int vgic_its_device_cmp(void *priv, struct list_head *a,
static int vgic_its_save_device_tables(struct vgic_its *its)
{
const struct vgic_its_abi *abi = vgic_its_get_abi(its);
+ u64 baser = its->baser_device_table;
struct its_device *dev;
int dte_esz = abi->dte_esz;
- u64 baser;
- baser = its->baser_device_table;
+ if (!(baser & GITS_BASER_VALID))
+ return 0;
list_sort(NULL, &its->device_list, vgic_its_device_cmp);
@@ -2215,17 +2216,17 @@ static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz)
static int vgic_its_save_collection_table(struct vgic_its *its)
{
const struct vgic_its_abi *abi = vgic_its_get_abi(its);
+ u64 baser = its->baser_coll_table;
+ gpa_t gpa = BASER_ADDRESS(baser);
struct its_collection *collection;
u64 val;
- gpa_t gpa;
size_t max_size, filled = 0;
int ret, cte_esz = abi->cte_esz;
- gpa = BASER_ADDRESS(its->baser_coll_table);
- if (!gpa)
+ if (!(baser & GITS_BASER_VALID))
return 0;
- max_size = GITS_BASER_NR_PAGES(its->baser_coll_table) * SZ_64K;
+ max_size = GITS_BASER_NR_PAGES(baser) * SZ_64K;
list_for_each_entry(collection, &its->collection_list, coll_list) {
ret = vgic_its_save_cte(its, collection, gpa, cte_esz);
@@ -2256,17 +2257,18 @@ static int vgic_its_save_collection_table(struct vgic_its *its)
static int vgic_its_restore_collection_table(struct vgic_its *its)
{
const struct vgic_its_abi *abi = vgic_its_get_abi(its);
+ u64 baser = its->baser_coll_table;
int cte_esz = abi->cte_esz;
size_t max_size, read = 0;
gpa_t gpa;
int ret;
- if (!(its->baser_coll_table & GITS_BASER_VALID))
+ if (!(baser & GITS_BASER_VALID))
return 0;
- gpa = BASER_ADDRESS(its->baser_coll_table);
+ gpa = BASER_ADDRESS(baser);
- max_size = GITS_BASER_NR_PAGES(its->baser_coll_table) * SZ_64K;
+ max_size = GITS_BASER_NR_PAGES(baser) * SZ_64K;
while (read < max_size) {
ret = vgic_its_restore_cte(its, gpa, cte_esz);
--
2.14.2
