From: Christoffer Dall <christoffer.dall@linaro.org>
To: Pavel Fedin <p.fedin@samsung.com>
Cc: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org,
'Marc Zyngier' <marc.zyngier@arm.com>
Subject: Re: [PATCH 3/3] KVM: arm64: Implement accessors for vGIC CPU interface registers
Date: Tue, 1 Sep 2015 16:06:55 +0200 [thread overview]
Message-ID: <20150901140655.GF10991@cbox> (raw)
In-Reply-To: <010801d0e4b7$698757d0$3c960770$@samsung.com>
On Tue, Sep 01, 2015 at 04:09:18PM +0300, Pavel Fedin wrote:
> Hello!
>
> > Have you thought about proper locking/serializing of access to the GIC
> > state in these accessor functions?
>
> I am in the process of rewriting the whole thing, and i came to this point.
> What kind of locking would you expect ? It's a CPU interface, it does not affect state of any
> other vCPUs. And, since i am getting/setting its registers, i assume that the vCPU is not running.
> Well, i added the check. What next?
>
I think we make some assumptions throughout the vgic code that only the
vcpu itself touches the state of the registers. Maybe there is no need
for additional locking, but I'd sleep better at night if I knew that
whoever implemented save/restore logic had thought about concurrency.
-Christoffer
next prev parent reply other threads:[~2015-09-01 14:05 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-28 12:56 [PATCH 0/3] KVM: arm64: Implement API for vGICv3 live migration Pavel Fedin
2015-08-28 12:56 ` [PATCH 1/3] KVM: arm64: Implement vGICv3 distributor and redistributor access from userspace Pavel Fedin
2015-08-30 16:42 ` Christoffer Dall
2015-08-31 7:35 ` Pavel Fedin
2015-08-31 8:59 ` Christoffer Dall
2015-09-01 13:52 ` Andre Przywara
2015-09-01 14:27 ` Pavel Fedin
2015-09-01 14:46 ` Peter Maydell
2015-08-28 12:56 ` [PATCH 2/3] KVM: arm64: Allow to use accessors in KVM_SET_ONE_REG and KVM_GET_ONE_REG Pavel Fedin
2015-08-28 12:56 ` [PATCH 3/3] KVM: arm64: Implement accessors for vGIC CPU interface registers Pavel Fedin
2015-08-30 16:50 ` Christoffer Dall
2015-08-30 18:39 ` Peter Maydell
2015-08-31 7:43 ` Pavel Fedin
2015-08-31 9:03 ` Christoffer Dall
2015-08-31 11:49 ` Pavel Fedin
2015-08-31 9:01 ` Christoffer Dall
2015-09-01 13:09 ` Pavel Fedin
2015-09-01 14:06 ` Christoffer Dall [this message]
2015-08-30 16:29 ` [PATCH 0/3] KVM: arm64: Implement API for vGICv3 live migration Christoffer Dall
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