Patch "powerpc/rfi-flush: Always enable fallback flush on pseries" has been added to the 4.16-stable tree

[gregkh at linuxfoundation.org]

This is a note to let you know that I've just added the patch titled

    powerpc/rfi-flush: Always enable fallback flush on pseries

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-rfi-flush-always-enable-fallback-flush-on-pseries.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 <stable at vger.kernel.org> know about it.


>From foo at baz Wed May 23 19:18:22 CEST 2018
From: Michael Ellerman <mpe at ellerman.id.au>
Date: Wed, 23 May 2018 00:41:12 +1000
Subject: powerpc/rfi-flush: Always enable fallback flush on pseries
To: greg at kroah.com
Cc: stable at vger.kernel.org, tglx at linutronix.de, linuxppc-dev at ozlabs.org
Message-ID: <20180522144125.10345-2-mpe at ellerman.id.au>

From: Michael Ellerman <mpe at ellerman.id.au>

commit 84749a58b6e382f109abf1e734bc4dd43c2c25bb upstream.

This ensures the fallback flush area is always allocated on pseries,
so in case a LPAR is migrated from a patched to an unpatched system,
it is possible to enable the fallback flush in the target system.

Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
Signed-off-by: Mauricio Faria de Oliveira <mauricfo at linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
 arch/powerpc/platforms/pseries/setup.c |   10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -468,26 +468,18 @@ static void pseries_setup_rfi_flush(void
 
 	/* Enable by default */
 	enable = true;
+	types = L1D_FLUSH_FALLBACK;
 
 	rc = plpar_get_cpu_characteristics(&result);
 	if (rc == H_SUCCESS) {
-		types = L1D_FLUSH_NONE;
-
 		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;
 
-		/* Use fallback if nothing set in hcall */
-		if (types == L1D_FLUSH_NONE)
-			types = L1D_FLUSH_FALLBACK;
-
 		if ((!(result.behaviour & H_CPU_BEHAV_L1D_FLUSH_PR)) ||
 		    (!(result.behaviour & H_CPU_BEHAV_FAVOUR_SECURITY)))
 			enable = false;
-	} else {
-		/* Default to fallback if case hcall is not available */
-		types = L1D_FLUSH_FALLBACK;
 	}
 
 	setup_rfi_flush(types, enable);


Patches currently in stable-queue which might be from mpe at 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