From: Paolo Bonzini <pbonzini@redhat.com>
To: Zhenyu Ye <yezhenyu2@huawei.com>
Cc: gleb@redhat.com, kvm@vger.kernel.org, "S. Tsirkin,
Michael" <mst@redhat.com>,
linux-kernel@vger.kernel.org, ghaskins@novell.com,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [Question] the check of ioeventfd collision in kvm_*assign_ioeventfd_idx
Date: Thu, 30 Jul 2020 20:03:28 +0200 [thread overview]
Message-ID: <CABgObfbFXYodCeGWSnKw0j_n2-QLxpnD_Uyc5r-_ApXv=x+qmw@mail.gmail.com> (raw)
In-Reply-To: <bbece68b-fb39-d599-9ba7-a8ee8be16525@huawei.com>
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Yes, I think it's not needed. Probably the deassign check can be turned
into an assertion?
Paolo
Il gio 30 lug 2020, 16:36 Zhenyu Ye <yezhenyu2@huawei.com> ha scritto:
> Hi all,
>
> There are checks of ioeventfd collision in both kvm_assign_ioeventfd_idx()
> and kvm_deassign_ioeventfd_idx(), however, with different logic.
>
> In kvm_assign_ioeventfd_idx(), this is done by ioeventfd_check_collision():
> ---8<---
> if (_p->bus_idx == p->bus_idx &&
> _p->addr == p->addr &&
> (!_p->length || !p->length ||
> (_p->length == p->length &&
> (_p->wildcard || p->wildcard ||
> _p->datamatch == p->datamatch))))
> // then we consider the two are the same
> ---8<---
>
> The logic in kvm_deassign_ioeventfd_idx() is as follows:
> ---8<---
> if (p->bus_idx != bus_idx ||
> p->eventfd != eventfd ||
> p->addr != args->addr ||
> p->length != args->len ||
> p->wildcard != wildcard)
> continue;
>
> if (!p->wildcard && p->datamatch != args->datamatch)
> continue;
>
> // then we consider the two are the same
> ---8<---
>
> As we can see, there is extra check of p->eventfd in
>
> (). Why we don't check p->eventfd
> in kvm_assign_ioeventfd_idx()? Or should we delete this in
> kvm_deassign_ioeventfd_idx()?
>
>
> Thanks,
> Zhenyu
>
>
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next prev parent reply other threads:[~2020-07-30 18:03 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-30 14:19 [Question] the check of ioeventfd collision in kvm_*assign_ioeventfd_idx Zhenyu Ye
2020-07-30 18:03 ` Paolo Bonzini [this message]
2020-07-31 6:39 ` Zhenyu Ye
2020-07-31 6:44 ` Paolo Bonzini
2020-07-31 8:21 ` Zhenyu Ye
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