Re: [PATCH v8 01/26] arm64: Fix HCR.TGE status for NMI contexts

From: Marc Zyngier
Date: Mon Jan 28 2019 - 04:16:28 EST


On Tue, 08 Jan 2019 14:07:19 +0000,
Julien Thierry <julien.thierry@xxxxxxx> wrote:
>
> When using VHE, the host needs to clear HCR_EL2.TGE bit in order
> to interract with guest TLBs, switching from EL2&0 translation regime
> to EL1&0.
>
> However, some non-maskable asynchronous event could happen while TGE is
> cleared like SDEI. Because of this address translation operations
> relying on EL2&0 translation regime could fail (tlb invalidation,
> userspace access, ...).
>
> Fix this by properly setting HCR_EL2.TGE when entering NMI context and
> clear it if necessary when returning to the interrupted context.
>
> Signed-off-by: Julien Thierry <julien.thierry@xxxxxxx>
> Suggested-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Will Deacon <will.deacon@xxxxxxx>
> Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
> Cc: James Morse <james.morse@xxxxxxx>
> Cc: linux-arch@xxxxxxxxxxxxxxx
> Cc: stable@xxxxxxxxxxxxxxx

Reviewed-by: Marc Zyngier <marc.zyngier@xxxxxxx>

Thanks,

M.

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