[PATCH 7/8] arm64: kvm: use inner-shareable barriers for inner-shareable maintenance
Will Deacon
will.deacon at arm.com
Fri May 2 08:24:14 PDT 2014
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 at arm.com>
Acked-by: Marc Zyngier <marc.zyngier at arm.com>
Signed-off-by: Will Deacon <will.deacon at arm.com>
---
arch/arm64/kvm/hyp.S | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
index 2c56012cb2d2..b0d1512acf08 100644
--- 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)
--
1.9.2
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