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Subject[PATCH 06/13] arm64: KVM: VHE: Patch out kern_hyp_va
Date
The kern_hyp_va macro is pretty meaninless with VHE, as there is
only one mapping - the kernel one.

In order to keep the code readable and efficient, use runtime
patching to replace the 'and' instruction used to compute the VA
with a 'nop'.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm64/include/asm/kvm_mmu.h | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index b525cd2..285642e 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -55,6 +55,8 @@

#ifdef __ASSEMBLY__

+#include <asm/alternative.h>
+#include <asm/cpufeature.h>
#include <asm/kvm_arm.h>

.macro setup_vtcr tmp1, tmp2
@@ -69,12 +71,18 @@
msr vtcr_el2, \tmp1
isb
.endm
+
+/* Stupid macro to deal with multiple level of macro expansion */
+.macro __vhe_nop inst val
+ alternative_insn "\inst\val", "nop", ARM64_HAS_VIRT_HOST_EXTN
+.endm
+
/*
* Convert a kernel VA into a HYP VA.
* reg: VA to be converted.
*/
.macro kern_hyp_va reg
- and \reg, \reg, #HYP_PAGE_OFFSET_MASK
+ __vhe_nop "and \reg, \reg, #", __stringify(HYP_PAGE_OFFSET_MASK)
.endm

#else
--
2.1.4


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