DISCARD command error occurs if any of the following apply:
- [ ... (those which we have already handled) ]
- The EventID for the device is mapped to a collection that
has not been mapped to an RDbase using MAPC.
Let's take the unmapped collection case into account and report
a DISCARD command error if it really happens.
Signed-off-by: Zenghui Yu <[email protected]>
---
virt/kvm/arm/vgic/vgic-its.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 17920d1b350a..d53d34a33e35 100644
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -839,9 +839,8 @@ static int vgic_its_cmd_handle_discard(struct kvm *kvm, struct vgic_its *its,
u32 event_id = its_cmd_get_id(its_cmd);
struct its_ite *ite;
-
ite = find_ite(its, device_id, event_id);
- if (ite && ite->collection) {
+ if (ite && its_is_collection_mapped(ite->collection)) {
/*
* Though the spec talks about removing the pending state, we
* don't bother here since we clear the ITTE anyway and the
--
2.19.1
Hi Zenghui,
On 12/25/19 2:30 PM, Zenghui Yu wrote:
> DISCARD command error occurs if any of the following apply:
>
> - [ ... (those which we have already handled) ]
nit: I would remove the above and simply say the discard is supposed to
fail if the collection is not mapped to any target redistributor. If an
ITE exists then the ite->collection is non NULL. What needs to be
checked is its_is_collection_mapped().
By the way update_affinity_collection() also tests ite->collection. I
think this is useless or do I miss something?
Reviewed-by: Eric Auger <[email protected]>
Thanks
Eric
> - The EventID for the device is mapped to a collection that
> has not been mapped to an RDbase using MAPC.
>
> Let's take the unmapped collection case into account and report
> a DISCARD command error if it really happens.
>
> Signed-off-by: Zenghui Yu <[email protected]>
> ---
> virt/kvm/arm/vgic/vgic-its.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index 17920d1b350a..d53d34a33e35 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -839,9 +839,8 @@ static int vgic_its_cmd_handle_discard(struct kvm *kvm, struct vgic_its *its,
> u32 event_id = its_cmd_get_id(its_cmd);
> struct its_ite *ite;
>
> -
> ite = find_ite(its, device_id, event_id);
> - if (ite && ite->collection) {
> + if (ite && its_is_collection_mapped(ite->collection)) {
> /*
> * Though the spec talks about removing the pending state, we
> * don't bother here since we clear the ITTE anyway and the
>
Hi Eric,
On 2020/1/10 16:37, Auger Eric wrote:
> Hi Zenghui,
>
> On 12/25/19 2:30 PM, Zenghui Yu wrote:
>> DISCARD command error occurs if any of the following apply:
>>
>> - [ ... (those which we have already handled) ]
> nit: I would remove the above and simply say the discard is supposed to
> fail if the collection is not mapped to any target redistributor. If an
> ITE exists then the ite->collection is non NULL.
I think this is not always true. Let's talk about the following scenario
(a bit insane, though):
1. First map a LPI to an unmapped Collection, then ite->collection is
non NULL and its target_addr is COLLECTION_NOT_MAPPED.
2. Then issue MAPC and unMAPC(V=0) commands on this Collection, the
ite->collection will be NULL, see vgic_its_free_collection().
Discard the LPI mapping after "1" or "2", we will both encounter the
unmapped collection command error.
> What needs to be checked is its_is_collection_mapped().
>
> By the way update_affinity_collection() also tests ite->collection. I
> think this is useless or do I miss something?
Yeah, I agree. We managed to invoke update_affinity_collection(,, coll),
ensure that the 'coll' can _not_ be NULL.
So '!ite->collection' is already a subcase of 'coll != ite->collection'.
We can safely get rid of it.
>
> Reviewed-by: Eric Auger <[email protected]>
>
Thanks for that. I'll change the commit message with your suggestion and
add your R-b in v2.
Thanks,
Zenghui
Hi Zenghui,
On 1/14/20 8:10 AM, Zenghui Yu wrote:
> Hi Eric,
>
> On 2020/1/10 16:37, Auger Eric wrote:
>> Hi Zenghui,
>>
>> On 12/25/19 2:30 PM, Zenghui Yu wrote:
>>> DISCARD command error occurs if any of the following apply:
>>>
>>> - [ ... (those which we have already handled) ]
>> nit: I would remove the above and simply say the discard is supposed to
>> fail if the collection is not mapped to any target redistributor. If an
>> ITE exists then the ite->collection is non NULL.
>
> I think this is not always true. Let's talk about the following scenario
> (a bit insane, though):
>
> 1. First map a LPI to an unmapped Collection, then ite->collection is
> non NULL and its target_addr is COLLECTION_NOT_MAPPED.
>
> 2. Then issue MAPC and unMAPC(V=0) commands on this Collection, the
> ite->collection will be NULL, see vgic_its_free_collection().
You're right I missed that case.
>
> Discard the LPI mapping after "1" or "2", we will both encounter the
> unmapped collection command error.
>
>> What needs to be checked is its_is_collection_mapped().
>>
>> By the way update_affinity_collection() also tests ite->collection. I
>> think this is useless or do I miss something?
>
> Yeah, I agree. We managed to invoke update_affinity_collection(,, coll),
> ensure that the 'coll' can _not_ be NULL.
> So '!ite->collection' is already a subcase of 'coll != ite->collection'.
> We can safely get rid of it.
OK. But that's not for the (wrong) reason I mentioned above. So it is a
minor cleanup and you may just leave it as is and just focus on this fix.
Thanks
Eric
>
>>
>> Reviewed-by: Eric Auger <[email protected]>
>>
>
> Thanks for that. I'll change the commit message with your suggestion and
> add your R-b in v2.
>
>
> Thanks,
> Zenghui
>
>
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