This is a note to let you know that I've just added the patch titled powerpc/pseries: Use the security flags in pseries_setup_rfi_flush()
to the 4.16-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: powerpc-pseries-use-the-security-flags-in-pseries_setup_rfi_flush.patch and it can be found in the queue-4.16 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <sta...@vger.kernel.org> know about it. >From foo@baz Wed May 23 19:18:22 CEST 2018 From: Michael Ellerman <m...@ellerman.id.au> Date: Wed, 23 May 2018 00:41:20 +1000 Subject: powerpc/pseries: Use the security flags in pseries_setup_rfi_flush() To: g...@kroah.com Cc: sta...@vger.kernel.org, t...@linutronix.de, linuxppc-...@ozlabs.org Message-ID: <20180522144125.10345-10-...@ellerman.id.au> From: Michael Ellerman <m...@ellerman.id.au> commit 2e4a16161fcd324b1f9bf6cb6856529f7eaf0689 upstream. Now that we have the security flags we can simplify the code in pseries_setup_rfi_flush() because the security flags have pessimistic defaults. Signed-off-by: Michael Ellerman <m...@ellerman.id.au> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- arch/powerpc/platforms/pseries/setup.c | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-) --- a/arch/powerpc/platforms/pseries/setup.c +++ b/arch/powerpc/platforms/pseries/setup.c @@ -501,30 +501,27 @@ static void pseries_setup_rfi_flush(void bool enable; long rc; - /* Enable by default */ - enable = true; - types = L1D_FLUSH_FALLBACK; - rc = plpar_get_cpu_characteristics(&result); - if (rc == H_SUCCESS) { + if (rc == H_SUCCESS) init_cpu_char_feature_flags(&result); - if (result.character & H_CPU_CHAR_L1D_FLUSH_TRIG2) - types |= L1D_FLUSH_MTTRIG; - if (result.character & H_CPU_CHAR_L1D_FLUSH_ORI30) - types |= L1D_FLUSH_ORI; - - if ((!(result.behaviour & H_CPU_BEHAV_L1D_FLUSH_PR)) || - (!(result.behaviour & H_CPU_BEHAV_FAVOUR_SECURITY))) - enable = false; - } - /* * We're the guest so this doesn't apply to us, clear it to simplify * handling of it elsewhere. */ security_ftr_clear(SEC_FTR_L1D_FLUSH_HV); + types = L1D_FLUSH_FALLBACK; + + if (security_ftr_enabled(SEC_FTR_L1D_FLUSH_TRIG2)) + types |= L1D_FLUSH_MTTRIG; + + if (security_ftr_enabled(SEC_FTR_L1D_FLUSH_ORI30)) + types |= L1D_FLUSH_ORI; + + enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) && \ + security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR); + setup_rfi_flush(types, enable); } Patches currently in stable-queue which might be from m...@ellerman.id.au are queue-4.16/powerpc-pseries-fix-clearing-of-security-feature-flags.patch queue-4.16/powerpc-powernv-set-or-clear-security-feature-flags.patch queue-4.16/powerpc-64s-move-cpu_show_meltdown.patch queue-4.16/powerpc-pseries-set-or-clear-security-feature-flags.patch queue-4.16/powerpc-move-default-security-feature-flags.patch queue-4.16/powerpc-powernv-use-the-security-flags-in-pnv_setup_rfi_flush.patch queue-4.16/powerpc-add-security-feature-flags-for-spectre-meltdown.patch queue-4.16/powerpc-pseries-use-the-security-flags-in-pseries_setup_rfi_flush.patch queue-4.16/powerpc-64s-enhance-the-information-in-cpu_show_meltdown.patch queue-4.16/powerpc-rfi-flush-always-enable-fallback-flush-on-pseries.patch queue-4.16/powerpc-pseries-add-new-h_get_cpu_characteristics-flags.patch queue-4.16/powerpc-64s-add-support-for-a-store-forwarding-barrier-at-kernel-entry-exit.patch queue-4.16/powerpc-64s-wire-up-cpu_show_spectre_v1.patch queue-4.16/powerpc-64s-wire-up-cpu_show_spectre_v2.patch