On Thu, 21 Sep 2023 10:14:55 +0100,
Zenghui Yu <yuzenghui@xxxxxxxxxx> wrote:
>
> On 2023/9/21 2:17, Marc Zyngier wrote:
> > Since our emulated ITS advertises GITS_TYPER.PTA=0, the target
> > address associated to a collection is a PE number and not
> > an address. So far, so good. However, the PE number is what userspace
> > has provided given us (aka the vcpu_id), and not the internal vcpu
> > index.
> >
> > Make sure we consistently retrieve the vcpu by ID rather than
> > by index, adding a helper that deals with most of the cases.
> >
> > Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
>
> Looks good, with 2 more points:
>
> - Like patch#1, we should have a go at all
> 'target_addr >= kvm->online_vcpus' comparisons in vgic-its.c
> - There is still a remaining kvm_get_vcpu() in vgic_its_restore_ite()
> which needs to be fixed
Yup, well spotted. I have this additional hack which I plan to put on
top.
Thanks,
M.
diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c
index 4aadcd24f6f6..6ec9dd970cbb 100644
--- a/arch/arm64/kvm/vgic/vgic-its.c
+++ b/arch/arm64/kvm/vgic/vgic-its.c
@@ -1248,21 +1248,22 @@ static int vgic_its_cmd_handle_mapc(struct kvm *kvm, struct vgic_its *its,
u64 *its_cmd)
{
u16 coll_id;
- u32 target_addr;
struct its_collection *collection;
bool valid;
valid = its_cmd_get_validbit(its_cmd);
coll_id = its_cmd_get_collection(its_cmd);
- target_addr = its_cmd_get_target_addr(its_cmd);
-
- if (target_addr >= atomic_read(&kvm->online_vcpus))
- return E_ITS_MAPC_PROCNUM_OOR;
if (!valid) {
vgic_its_free_collection(its, coll_id);
vgic_its_invalidate_cache(kvm);
} else {
+ struct kvm_vcpu *vcpu;
+
+ vcpu = kvm_get_vcpu_by_id(kvm, its_cmd_get_target_addr(its_cmd));
+ if (!vcpu)
+ return E_ITS_MAPC_PROCNUM_OOR;
+
collection = find_collection(its, coll_id);
if (!collection) {
@@ -1276,9 +1277,9 @@ static int vgic_its_cmd_handle_mapc(struct kvm *kvm, struct vgic_its *its,
coll_id);
if (ret)
return ret;
- collection->target_addr = target_addr;
+ collection->target_addr = vcpu->vcpu_id;
} else {
- collection->target_addr = target_addr;
+ collection->target_addr = vcpu->vcpu_id;
update_affinity_collection(kvm, its, collection);
}
}
@@ -1405,24 +1406,21 @@ static int vgic_its_cmd_handle_invall(struct kvm *kvm, struct vgic_its *its,
static int vgic_its_cmd_handle_movall(struct kvm *kvm, struct vgic_its *its,
u64 *its_cmd)
{
- u32 target1_addr = its_cmd_get_target_addr(its_cmd);
- u32 target2_addr = its_cmd_mask_field(its_cmd, 3, 16, 32);
struct kvm_vcpu *vcpu1, *vcpu2;
struct vgic_irq *irq;
u32 *intids;
int irq_count, i;
- if (target1_addr >= atomic_read(&kvm->online_vcpus) ||
- target2_addr >= atomic_read(&kvm->online_vcpus))
+ /* We advertise GITS_TYPER.PTA==0, making the address the vcpu ID */
+ vcpu1 = kvm_get_vcpu_by_id(kvm, its_cmd_get_target_addr(its_cmd));
+ vcpu2 = kvm_get_vcpu_by_id(kvm, its_cmd_mask_field(its_cmd, 3, 16, 32));
+
+ if (!vcpu1 || !vcpu2)
return E_ITS_MOVALL_PROCNUM_OOR;
- if (target1_addr == target2_addr)
+ if (vcpu1 == vcpu2)
return 0;
- /* We advertise GITS_TYPER.PTA==0, making the address the vcpu ID */
- vcpu1 = kvm_get_vcpu_by_id(kvm, target1_addr);
- vcpu2 = kvm_get_vcpu_by_id(kvm, target2_addr);
-
irq_count = vgic_copy_lpi_list(kvm, vcpu1, &intids);
if (irq_count < 0)
return irq_count;
@@ -2265,7 +2263,7 @@ static int vgic_its_restore_ite(struct vgic_its *its, u32 event_id,
return PTR_ERR(ite);
if (its_is_collection_mapped(collection))
- vcpu = kvm_get_vcpu(kvm, collection->target_addr);
+ vcpu = kvm_get_vcpu_by_id(kvm, collection->target_addr);
irq = vgic_add_lpi(kvm, lpi_id, vcpu);
if (IS_ERR(irq)) {
@@ -2580,7 +2578,7 @@ static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz)
coll_id = val & KVM_ITS_CTE_ICID_MASK;
if (target_addr != COLLECTION_NOT_MAPPED &&
- target_addr >= atomic_read(&kvm->online_vcpus))
+ !kvm_get_vcpu_by_id(kvm, target_addr))
return -EINVAL;
collection = find_collection(its, coll_id);
--
Without deviation from the norm, progress is not possible.
