From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: Jordan Niethe <jniethe5@gmail.com>,
linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org
Cc: Jordan Niethe <jniethe5@gmail.com>, oohall@gmail.com
Subject: Re: [PATCH v3] powerpc/mm: Remove kvm radix prefetch workaround for Power9 DD2.2
Date: Wed, 29 Jan 2020 16:17:26 +1100 (AEDT) [thread overview]
Message-ID: <486sDl09qNz9sRh@ozlabs.org> (raw)
In-Reply-To: <20191206031722.25781-1-jniethe5@gmail.com>
On Fri, 2019-12-06 at 03:17:22 UTC, Jordan Niethe wrote:
> Commit a25bd72badfa ("powerpc/mm/radix: Workaround prefetch issue with
> KVM") introduced a number of workarounds as coming out of a guest with
> the mmu enabled would make the cpu would start running in hypervisor
> state with the PID value from the guest. The cpu will then start
> prefetching for the hypervisor with that PID value.
>
> In Power9 DD2.2 the cpu behaviour was modified to fix this. When
> accessing Quadrant 0 in hypervisor mode with LPID != 0 prefetching will
> not be performed. This means that we can get rid of the workarounds for
> Power9 DD2.2 and later revisions. Add a new cpu feature
> CPU_FTR_P9_RADIX_PREFETCH_BUG to indicate if the workarounds are needed.
>
> Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/736bcdd3a9fc672af33fb83230ecd0570ec38ec6
cheers
prev parent reply other threads:[~2020-01-29 5:46 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-06 3:17 [PATCH v3] powerpc/mm: Remove kvm radix prefetch workaround for Power9 DD2.2 Jordan Niethe
2020-01-17 3:43 ` Paul Mackerras
2020-01-29 5:17 ` Michael Ellerman [this message]
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