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Date:   Thu, 19 Dec 2019 16:28:15 +0100
From:   Frederic Weisbecker <frederic@kernel.org>
To:     Paolo Bonzini <pbonzini@redhat.com>,
        Radim =?utf-8?B?S3LEjW3DocWZ?= <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?
Message-ID: <20191219152814.GA24080@lenoir>
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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.