From: Andrew Jones <drjones@redhat.com>
To: Marc Zyngier <maz@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
kvm@vger.kernel.org, Suzuki K Poulose <suzuki.poulose@arm.com>,
James Morse <james.morse@arm.com>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu,
Julien Thierry <julien.thierry.kdev@gmail.com>
Subject: Re: [PATCH] KVM: arm64: Save/restore sp_el0 as part of __guest_enter
Date: Mon, 27 Apr 2020 09:28:25 +0200 [thread overview]
Message-ID: <20200427072825.ekcekll6f23bt2um@kamzik.brq.redhat.com> (raw)
In-Reply-To: <20200425094321.162752-1-maz@kernel.org>
On Sat, Apr 25, 2020 at 10:43:21AM +0100, Marc Zyngier wrote:
> We currently save/restore sp_el0 in C code. This is a bit unsafe,
> as a lot of the C code expects 'current' to be accessible from
> there (and the opportunity to run kernel code in HYP is specially
> great with VHE).
>
> Instead, let's move the save/restore of sp_el0 to the assembly
> code (in __guest_enter), making sure that sp_el0 is correct
> very early on when we exit the guest, and is preserved as long
> as possible to its host value when we enter the guest.
>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> arch/arm64/kvm/hyp/entry.S | 23 +++++++++++++++++++++++
> arch/arm64/kvm/hyp/sysreg-sr.c | 17 +++--------------
> 2 files changed, 26 insertions(+), 14 deletions(-)
>
Reviewed-by: Andrew Jones <drjones@redhat.com>
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next prev parent reply other threads:[~2020-04-27 7:31 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-25 9:43 [PATCH] KVM: arm64: Save/restore sp_el0 as part of __guest_enter Marc Zyngier
2020-04-27 7:28 ` Andrew Jones [this message]
2020-04-30 10:38 ` Mark Rutland
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