From mboxrd@z Thu Jan  1 00:00:00 1970
From: Marc Zyngier <marc.zyngier@arm.com>
Subject: Re: [PATCH] arm64: KVM: Guests can skip __install_bp_hardening_cb()s
 HYP work
Date: Fri, 19 Oct 2018 11:17:32 +0100
Message-ID: <de8be744-525a-2b75-ef77-e66d7fbabc40@arm.com>
References: <20180921204919.5790-1-james.morse@arm.com>
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To: James Morse <james.morse@arm.com>, linux-arm-kernel@lists.infradead.org
Cc: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will.deacon@arm.com>, kvmarm@lists.cs.columbia.edu
List-Id: kvmarm@lists.cs.columbia.edu

On 21/09/18 21:49, James Morse wrote:
> enable_smccc_arch_workaround_1() passes NULL as the hyp_vecs start and
> end if the HVC conduit is in use, and ARM_SMCCC_ARCH_WORKAROUND_1 is
> detected.
> 
> If the guest kernel happened to be built with KVM_INDIRECT_VECTORS,
> we go on to allocate a slot, memcpy() the empty workaround in and
> do the appropriate cache maintenance.
> 
> This works as we always tell memcpy() the range is 0, so it never
> accesses the NULL src pointer, but we still do the cache maintenance.
> 
> If hyp_vecs_start is NULL we know we're a guest, just update the fn
> like the !KVM_INDIRECT_VECTORS version.
> 
> Signed-off-by: James Morse <james.morse@arm.com>
> Reviewed-by: Julien Thierry <julien.thierry@arm.com>

Acked-by: Marc Zyngier <marc.zyngier@arm.com>

Catalin: could you sneak this one in for 4.20? It is strictly a KVM
patch, but its location makes it more suitable for the arm64 tree...

Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...