From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: Michael Ellerman <mpe@ellerman.id.au>, linuxppc-dev@ozlabs.org
Cc: naveen.n.rao@linux.ibm.com, anton@samba.org, npiggin@gmail.com,
david@gibson.dropbear.id.au
Subject: Re: [PATCH] selftests/powerpc: Add a test of spectre_v2 mitigations
Date: Thu, 7 Nov 2019 14:45:33 +1100 (AEDT) [thread overview]
Message-ID: <477q7157kFz9sPk@ozlabs.org> (raw)
In-Reply-To: <20190520105520.22274-1-mpe@ellerman.id.au>
On Mon, 2019-05-20 at 10:55:20 UTC, Michael Ellerman wrote:
> This test uses the PMU to count branch prediction hits/misses for a
> known loop, and compare the result to the reported spectre v2
> mitigation.
>
> This gives us a way of sanity checking that the reported mitigation is
> actually in effect.
>
> Sample output for some cases, eg:
>
> Power9:
> sysfs reports: 'Vulnerable'
> PM_BR_PRED_CCACHE: result 368 running/enabled 5792777124
> PM_BR_MPRED_CCACHE: result 319 running/enabled 5792775546
> PM_BR_PRED_PCACHE: result 2147483281 running/enabled 5792773128
> PM_BR_MPRED_PCACHE: result 213604201 running/enabled 5792771640
> Miss percent 9 %
> OK - Measured branch prediction rates match reported spectre v2 mitigation.
...
>
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Applied to powerpc next.
https://git.kernel.org/powerpc/c/c790c3d2b0ec5979d83451d0688d1cd07e23d8ba
cheers
prev parent reply other threads:[~2019-11-07 3:47 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-20 10:55 [PATCH] selftests/powerpc: Add a test of spectre_v2 mitigations Michael Ellerman
2019-11-07 3:45 ` Michael Ellerman [this message]
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