Patch "arm64: kvm: use inner-shareable barriers for inner-shareable maintenance" has been added to the 3.14-stable tree

Patch "arm64: kvm: use inner-shareable barriers for inner-shareable maintenance" has been added to the 3.14-stable tree

[gregkh]

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

    arm64: kvm: use inner-shareable barriers for inner-shareable maintenance

to the 3.14-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:
     arm64-kvm-use-inner-shareable-barriers-for-inner-shareable-maintenance.patch
and it can be found in the queue-3.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From ee9e101c11478680d579bd20bb38a4d3e2514fe3 Mon Sep 17 00:00:00 2001
From: Will Deacon <will.deacon@arm.com>
Date: Fri, 2 May 2014 16:24:14 +0100
Subject: arm64: kvm: use inner-shareable barriers for inner-shareable maintenance

From: Will Deacon <will.deacon@arm.com>

commit ee9e101c11478680d579bd20bb38a4d3e2514fe3 upstream.

In order to ensure completion of inner-shareable maintenance instructions
(cache and TLB) on AArch64, we can use the -ish suffix to the dsb
instruction.

This patch relaxes our dsb sy instructions to dsb ish where possible.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Shannon Zhao <shannon.zhao@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/arm64/kvm/hyp.S |   12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

--- a/arch/arm64/kvm/hyp.S
+++ b/arch/arm64/kvm/hyp.S
@@ -630,9 +630,15 @@ ENTRY(__kvm_tlb_flush_vmid_ipa)
 	 * whole of Stage-1. Weep...
 	 */
 	tlbi	ipas2e1is, x1
-	dsb	sy
+	/*
+	 * We have to ensure completion of the invalidation at Stage-2,
+	 * since a table walk on another CPU could refill a TLB with a
+	 * complete (S1 + S2) walk based on the old Stage-2 mapping if
+	 * the Stage-1 invalidation happened first.
+	 */
+	dsb	ish
 	tlbi	vmalle1is
-	dsb	sy
+	dsb	ish
 	isb
 
 	msr	vttbr_el2, xzr
@@ -643,7 +649,7 @@ ENTRY(__kvm_flush_vm_context)
 	dsb	ishst
 	tlbi	alle1is
 	ic	ialluis
-	dsb	sy
+	dsb	ish
 	ret
 ENDPROC(__kvm_flush_vm_context)
 


Patches currently in stable-queue which might be from will.deacon@arm.com are

queue-3.14/kvm-arm64-vgic-fix-hyp-panic-with-64k-pages-on-juno-platform.patch
queue-3.14/arm64-kvm-use-inner-shareable-barriers-for-inner-shareable-maintenance.patch