Commit c2385eaa authored by Eric Auger's avatar Eric Auger Committed by Christoffer Dall
Browse files

KVM: arm/arm64: vgic-its: Check GITS_BASER Valid bit before saving tables 



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: default avatarEric Auger <eric.auger@redhat.com>
Reviewed-by: default avatarAndre Przywara <andre.przywara@arm.com>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
parent c9b51bb6

virt/kvm/arm/vgic/vgic-its.c

+11 −9
Original line number Original line Diff line number Diff line
@@ -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)

static int vgic_its_save_device_tables(struct vgic_its *its)

{

{

	const struct vgic_its_abi *abi = vgic_its_get_abi(its);

	const struct vgic_its_abi *abi = vgic_its_get_abi(its);

	u64 baser = its->baser_device_table;

	struct its_device *dev;

	struct its_device *dev;

	int dte_esz = abi->dte_esz;

	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);

	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)

static int vgic_its_save_collection_table(struct vgic_its *its)

{

{

	const struct vgic_its_abi *abi = vgic_its_get_abi(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;

	struct its_collection *collection;

	u64 val;

	u64 val;

	gpa_t gpa;

	size_t max_size, filled = 0;

	size_t max_size, filled = 0;

	int ret, cte_esz = abi->cte_esz;

	int ret, cte_esz = abi->cte_esz;





	gpa = BASER_ADDRESS(its->baser_coll_table);

	if (!(baser & GITS_BASER_VALID))

	if (!gpa)

		return 0;

		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) {

	list_for_each_entry(collection, &its->collection_list, coll_list) {

		ret = vgic_its_save_cte(its, collection, gpa, cte_esz);

		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)

static int vgic_its_restore_collection_table(struct vgic_its *its)

{

{

	const struct vgic_its_abi *abi = vgic_its_get_abi(its);

	const struct vgic_its_abi *abi = vgic_its_get_abi(its);

	u64 baser = its->baser_coll_table;

	int cte_esz = abi->cte_esz;

	int cte_esz = abi->cte_esz;

	size_t max_size, read = 0;

	size_t max_size, read = 0;

	gpa_t gpa;

	gpa_t gpa;

	int ret;

	int ret;





	if (!(its->baser_coll_table & GITS_BASER_VALID))

	if (!(baser & GITS_BASER_VALID))

		return 0;

		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) {

	while (read < max_size) {

		ret = vgic_its_restore_cte(its, gpa, cte_esz);

		ret = vgic_its_restore_cte(its, gpa, cte_esz);

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