From: Oliver Upton <oliver.upton@linux.dev>
To: Marc Zyngier <maz@kernel.org>
Cc: kvm@vger.kernel.org, Catalin Marinas <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev,
Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org,
Marek Szyprowski <m.szyprowski@samsung.com>
Subject: Re: [PATCH v2] KVM: arm64: Don't acquire RCU read lock for exclusive table walks
Date: Wed, 16 Nov 2022 08:14:19 +0000 [thread overview]
Message-ID: <Y3Sb20U9rCIuOU3L@google.com> (raw)
In-Reply-To: <Y3SQ3wogsVUEu1Qe@google.com>
On Wed, Nov 16, 2022 at 07:27:27AM +0000, Oliver Upton wrote:
> On Wed, Nov 16, 2022 at 03:08:49AM +0000, Marc Zyngier wrote:
> > I'm not crazy about this sort of parameters. I think it would make a
> > lot more sense to pass a pointer to the walker structure and do the
> > flag check inside the helper.
> >
> > That way, we avoid extra churn if/when we need extra state or
> > bookkeeping around the walk.
>
> Sure, let's go that way instead. v3 on the way lol :)
Well, going this route is going to require hoisting around a few things.
I'd very much prefer to keep the RCU indirection ifdeffery all in one
place, but I'll need to haul it all after the definitions of kvm_pgtable_walker
and kvm_pgtable_walk_flags but before the definition of kvm_pgtable
(as it needs kvm_pteref_t).
I'm not too bothered by it, but not quite as small of a bandaid this
time around.
--
Thanks,
Oliver
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
WARNING: multiple messages have this Message-ID (diff)
From: Oliver Upton <oliver.upton@linux.dev>
To: Marc Zyngier <maz@kernel.org>
Cc: kvm@vger.kernel.org, Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org,
Marek Szyprowski <m.szyprowski@samsung.com>
Subject: Re: [PATCH v2] KVM: arm64: Don't acquire RCU read lock for exclusive table walks
Date: Wed, 16 Nov 2022 08:14:19 +0000 [thread overview]
Message-ID: <Y3Sb20U9rCIuOU3L@google.com> (raw)
Message-ID: <20221116081419.5_wOk5f4DF6xdklzPWtJH4c8Zh8dK0OMHGot6d-QDJk@z> (raw)
In-Reply-To: <Y3SQ3wogsVUEu1Qe@google.com>
On Wed, Nov 16, 2022 at 07:27:27AM +0000, Oliver Upton wrote:
> On Wed, Nov 16, 2022 at 03:08:49AM +0000, Marc Zyngier wrote:
> > I'm not crazy about this sort of parameters. I think it would make a
> > lot more sense to pass a pointer to the walker structure and do the
> > flag check inside the helper.
> >
> > That way, we avoid extra churn if/when we need extra state or
> > bookkeeping around the walk.
>
> Sure, let's go that way instead. v3 on the way lol :)
Well, going this route is going to require hoisting around a few things.
I'd very much prefer to keep the RCU indirection ifdeffery all in one
place, but I'll need to haul it all after the definitions of kvm_pgtable_walker
and kvm_pgtable_walk_flags but before the definition of kvm_pgtable
(as it needs kvm_pteref_t).
I'm not too bothered by it, but not quite as small of a bandaid this
time around.
--
Thanks,
Oliver
WARNING: multiple messages have this Message-ID (diff)
From: Oliver Upton <oliver.upton@linux.dev>
To: Marc Zyngier <maz@kernel.org>
Cc: kvm@vger.kernel.org, Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org,
Marek Szyprowski <m.szyprowski@samsung.com>
Subject: Re: [PATCH v2] KVM: arm64: Don't acquire RCU read lock for exclusive table walks
Date: Wed, 16 Nov 2022 08:14:19 +0000 [thread overview]
Message-ID: <Y3Sb20U9rCIuOU3L@google.com> (raw)
In-Reply-To: <Y3SQ3wogsVUEu1Qe@google.com>
On Wed, Nov 16, 2022 at 07:27:27AM +0000, Oliver Upton wrote:
> On Wed, Nov 16, 2022 at 03:08:49AM +0000, Marc Zyngier wrote:
> > I'm not crazy about this sort of parameters. I think it would make a
> > lot more sense to pass a pointer to the walker structure and do the
> > flag check inside the helper.
> >
> > That way, we avoid extra churn if/when we need extra state or
> > bookkeeping around the walk.
>
> Sure, let's go that way instead. v3 on the way lol :)
Well, going this route is going to require hoisting around a few things.
I'd very much prefer to keep the RCU indirection ifdeffery all in one
place, but I'll need to haul it all after the definitions of kvm_pgtable_walker
and kvm_pgtable_walk_flags but before the definition of kvm_pgtable
(as it needs kvm_pteref_t).
I'm not too bothered by it, but not quite as small of a bandaid this
time around.
--
Thanks,
Oliver
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2022-11-16 8:14 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-15 22:55 [PATCH v2] KVM: arm64: Don't acquire RCU read lock for exclusive table walks Oliver Upton
2022-11-15 22:55 ` Oliver Upton
2022-11-15 22:55 ` Oliver Upton
2022-11-16 3:08 ` Marc Zyngier
2022-11-16 3:08 ` Marc Zyngier
2022-11-16 3:08 ` Marc Zyngier
2022-11-16 7:27 ` Oliver Upton
2022-11-16 7:27 ` Oliver Upton
2022-11-16 7:27 ` Oliver Upton
2022-11-16 8:14 ` Oliver Upton [this message]
2022-11-16 8:14 ` Oliver Upton
2022-11-16 8:14 ` Oliver Upton
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