From: Zhenyu Ye <yezhenyu2@huawei.com>
To: <pbonzini@redhat.com>, <mst@redhat.com>, <gleb@redhat.com>,
<linux-kernel@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>, <kvm@vger.kernel.org>,
<kvmarm@lists.cs.columbia.edu>,
Xiexiangyou <xiexiangyou@huawei.com>, <ghaskins@novell.com>
Subject: [Question] the check of ioeventfd collision in kvm_*assign_ioeventfd_idx
Date: Thu, 30 Jul 2020 22:19:49 +0800 [thread overview]
Message-ID: <bbece68b-fb39-d599-9ba7-a8ee8be16525@huawei.com> (raw)
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
next reply other threads:[~2020-07-30 14:20 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-30 14:19 Zhenyu Ye [this message]
[not found] ` <CABgObfbFXYodCeGWSnKw0j_n2-QLxpnD_Uyc5r-_ApXv=x+qmw@mail.gmail.com>
2020-07-31 6:39 ` [Question] the check of ioeventfd collision in kvm_*assign_ioeventfd_idx Zhenyu Ye
2020-07-31 6:44 ` Paolo Bonzini
2020-07-31 8:21 ` Zhenyu Ye
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