From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Denis V. Lunev" <den-lists@parallels.com>
Subject: Re: [PATCH] kvm_irqchip_assign_irqfd: just set irqfd
 in case of kvm_irqfds_enabled()
Date: Fri, 26 Dec 2014 13:16:10 +0300
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	<CAFEAcA9yR2FPUF-T_ehMS4Yd0SL91mVADYwhDAuxCbkhQnNZiA@mail.gmail.com>
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Cc: QEMU Trivial <qemu-trivial@nongnu.org>, Paolo Bonzini <pbonzini@redhat.com>,
	QEMU Developers <qemu-devel@nongnu.org>, kvm-devel <kvm@vger.kernel.org>
To: Peter Maydell <peter.maydell@linaro.org>, Tiejun Chen
	<tiejun.chen@intel.com>
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On 26/12/14 13:00, Peter Maydell wrote:
> On 26 December 2014 at 08:05, Tiejun Chen <tiejun.chen@intel.com> wrote:
>> We should avoid to set irqfd{} unconditionally.
>>
>> Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
>
> Is there a hot path that we use this on such that the difference
> in code order matters at all?
>
> thanks
> -- PMM
>

IMHO the patch does not change anything even on hot-hot path.
the declaration 'struct kvm_irqfd irqfd = {};' will
result in memset inside.

Thus in order to achieve declared goal author should
declare
    struct kvm_irqfd irqfd;
and perform
    memset(&irqfd, 0, sizeof(irqfd));
later after the check.

Regards,
	Den