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Date:   Tue, 1 Feb 2022 16:51:51 +0000
From:   "Russell King (Oracle)" <linux@armlinux.org.uk>
To:     Marc Zyngier <maz@kernel.org>
Cc:     linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu,
        kvm@vger.kernel.org, Andre Przywara <andre.przywara@arm.com>,
        Christoffer Dall <christoffer.dall@arm.com>,
        Jintack Lim <jintack@cs.columbia.edu>,
        Haibo Xu <haibo.xu@linaro.org>,
        Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>,
        Chase Conklin <chase.conklin@arm.com>,
        James Morse <james.morse@arm.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>,
        Alexandru Elisei <alexandru.elisei@arm.com>,
        karl.heubaum@oracle.com, mihai.carabas@oracle.com,
        miguel.luis@oracle.com, kernel-team@android.com
Subject: Re: [PATCH v6 15/64] KVM: arm64: nv: Handle HCR_EL2.E2H specially
Message-ID: <YfllJ9WPx45nzeCZ@shell.armlinux.org.uk>
References: <20220128121912.509006-1-maz@kernel.org>
 <20220128121912.509006-16-maz@kernel.org>
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On Fri, Jan 28, 2022 at 12:18:23PM +0000, Marc Zyngier wrote:
> HCR_EL2.E2H is nasty, as a flip of this bit completely changes the way
> we deal with a lot of the state. So when the guest flips this bit
> (sysregs are live), do the put/load dance so that we have a consistent
> state.
> 
> Yes, this is slow. Don't do it.

I'd hope this is very unlikely!

> 
> Suggested-by: Alexandru Elisei <alexandru.elisei@arm.com>
> Signed-off-by: Marc Zyngier <maz@kernel.org>

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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