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From: Frederic Weisbecker <frederic@kernel.org>
To: "Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	kvm@vger.kernel.org
Subject: Async page fault delivered while irq are disabled?
Date: Thu, 19 Dec 2019 16:28:15 +0100	[thread overview]
Message-ID: <20191219152814.GA24080@lenoir> (raw)

Hi,

While checking the x86 async page fault code, I can't
find anything that prevents KVM_PV_REASON_PAGE_READY to be injected
while the guest has interrupts disabled. If that page fault happens
to trap in an interrupt disabled section, there may be a deadlock due to the
call to wake_up_process() which locks the rq->lock (among others).

Given how long that code is there, I guess such an issue would
have been reported for a while already. But I just would like to
be sure we are checking that.

Can someone enlighten me?

Thanks.

             reply	other threads:[~2019-12-19 15:28 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-19 15:28 Frederic Weisbecker [this message]
2019-12-19 15:57 ` Async page fault delivered while irq are disabled? Sean Christopherson
2019-12-19 16:15   ` Frederic Weisbecker
2019-12-19 19:00     ` Sean Christopherson
2019-12-20  9:34       ` Paolo Bonzini
2019-12-23  2:17         ` Frederic Weisbecker
2019-12-23  8:38           ` Paolo Bonzini
2019-12-26 17:28             ` Frederic Weisbecker

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