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From: Marc Zyngier <maz@kernel.org>
To: Chenxu Wang <irakatz51@gmail.com>
Cc: kvmarm@lists.cs.columbia.edu
Subject: Re: Problems about Stage-2 translation
Date: Mon, 18 Oct 2021 20:31:37 +0100	[thread overview]
Message-ID: <874k9euo2u.wl-maz@kernel.org> (raw)
In-Reply-To: <CAFLP=uDAvg_6m3NLgOXnAYLtZe74nqhv_bOJdTwX=iZCrwXs0A@mail.gmail.com>

Wang,

On Mon, 18 Oct 2021 20:01:23 +0100,
Chenxu Wang <irakatz51@gmail.com> wrote:
> 
> Hi Marc,
> 
> Sorry, but I could not find the bottom posting mode in Gmail.

Easy. You click on the '...' button at the bottom left of the reply
window, scroll down and place your cursor at the right location.

> Also, thanks for your reply, I continue to discover how the Stage-2
> translation works in KVM.
> But, when I read the HCR_EL2 register in Host  (it is v5.3.0) , its
> value is 0x4_8800_0000. So
> (1) I am in VHE mode.
> (2) The Stage-2 translation is disabled.
> 
> I am sure that I have run a Non-Secure VM with QEMU, so is it correct
> that the S-2 translation is disabled in VHE mode? If so, how it
> handles the memory management for Guest?

By switching stage-2 on when required. HCR_EL2 isn't a static setting,
and gets updated at run-time. Also, HCR_EL2.VM means exactly nothing
when HCR_EL2.{E2H,TGE}={1,1}.

	M.

-- 
Without deviation from the norm, progress is not possible.
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      reply	other threads:[~2021-10-18 19:31 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-16 12:21 Problems about Stage-2 translation Chenxu Wang
2021-10-16 21:19 ` Marc Zyngier
2021-10-18  8:36   ` Chenxu Wang
2021-10-18 10:06     ` Marc Zyngier
2021-10-18 19:01       ` Chenxu Wang
2021-10-18 19:31         ` Marc Zyngier [this message]

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