From: Auger Eric <eric.auger@redhat.com>
To: Zenghui Yu <yuzenghui@huawei.com>,
eric.auger.pro@gmail.com, maz@kernel.org,
linux-kernel@vger.kernel.org, kvmarm@lists.cs.columbia.edu
Subject: Re: [PATCH] KVM: arm/arm64: vgic-its: Fix restoration of unmapped collections
Date: Fri, 13 Dec 2019 12:06:36 +0100 [thread overview]
Message-ID: <604a28ab-3a4a-4b9f-a9fa-719edc915d0d@redhat.com> (raw)
In-Reply-To: <d36b75e7-bd83-e501-3bd4-76bf0489c5ce@huawei.com>
Hi Zenghui,
On 12/13/19 11:53 AM, Zenghui Yu wrote:
> Hi Eric,
>
> On 2019/12/13 17:42, Eric Auger wrote:
>> Saving/restoring an unmapped collection is a valid scenario. For
>> example this happens if a MAPTI command was sent, featuring an
>> unmapped collection. At the moment the CTE fails to be restored.
>> Only compare against the number of online vcpus if the rdist
>> base is set.
>
> Have you actually seen a problem and this patch fixed it?
It is not with a linux guest but with kvm-unit-test.
To be honest,
> I'm surprised to find that we can map a LPI to an unmapped collection ;)
> (and prevent it to be delivered to vcpu with an INT_UNMAPPED_INTERRUPT
> error, until someone had actually mapped the collection).
> After a quick glance of spec (MAPTI), just as you said, this is valid.
>
> If Marc has no objection to this fix, please add
>
> Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Thank you for the review.
Eric
>
>
> Thanks,
> Zenghui
>
>>
>> Cc: stable@vger.kernel.org # v4.11+
>> Fixes: ea1ad53e1e31a ("KVM: arm64: vgic-its: Collection table
>> save/restore")
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>> ---
>> virt/kvm/arm/vgic/vgic-its.c | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
>> index 98c7360d9fb7..17920d1b350a 100644
>> --- a/virt/kvm/arm/vgic/vgic-its.c
>> +++ b/virt/kvm/arm/vgic/vgic-its.c
>> @@ -2475,7 +2475,8 @@ static int vgic_its_restore_cte(struct vgic_its
>> *its, gpa_t gpa, int esz)
>> target_addr = (u32)(val >> KVM_ITS_CTE_RDBASE_SHIFT);
>> coll_id = val & KVM_ITS_CTE_ICID_MASK;
>> - if (target_addr >= atomic_read(&kvm->online_vcpus))
>> + if (target_addr != COLLECTION_NOT_MAPPED &&
>> + target_addr >= atomic_read(&kvm->online_vcpus))
>> return -EINVAL;
>> collection = find_collection(its, coll_id);
>>
>
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next prev parent reply other threads:[~2019-12-13 21:13 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-13 9:42 [PATCH] KVM: arm/arm64: vgic-its: Fix restoration of unmapped collections Eric Auger
2019-12-13 10:43 ` Marc Zyngier
2019-12-13 10:55 ` Auger Eric
2019-12-13 10:53 ` Zenghui Yu
2019-12-13 11:06 ` Auger Eric [this message]
2019-12-13 11:28 ` Marc Zyngier
2019-12-13 14:22 ` Zenghui Yu
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