From: Vladimir Murzin <vladimir.murzin@xxxxxxx>
SCTLR_EL2.SPAN bit controls what happens with the PSTATE.PAN bit on an
exception. However, this bit has no effect on the PSTATE.PAN when
HCR_EL2.E2H or HCR_EL2.TGE is unset. Thus when VHE is used and
exception taken from a guest PSTATE.PAN bit left unchanged and we
continue with a value guest has set.
To address that always reset PSTATE.PAN on entry from EL1.
Fixes: 1f364c8c48a0 ("arm64: VHE: Add support for running Linux in EL2 mode")
Signed-off-by: Vladimir Murzin <vladimir.murzin@xxxxxxx>
Reviewed-by: James Morse <james.morse@xxxxxxx>
Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v4.6+
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
---
arch/arm64/kvm/hyp/entry.S | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S
index 3967c231..b5926ee 100644
--- a/arch/arm64/kvm/hyp/entry.S
+++ b/arch/arm64/kvm/hyp/entry.S
@@ -96,6 +96,8 @@ ENTRY(__guest_exit)
add x1, x1, #VCPU_CONTEXT
+ ALTERNATIVE(nop, SET_PSTATE_PAN(1), ARM64_HAS_PAN, CONFIG_ARM64_PAN)
+
// Store the guest regs x2 and x3
stp x2, x3, [x1, #CPU_XREG_OFFSET(2)]
--
2.9.0
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