arm64: KVM: VHE: reset PSTATE.PAN on entry to EL2

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: 1f364c8 ("arm64: VHE: Add support for running Linux in EL2 mode") Signed-off-by: Vladimir Murzin <[email protected]> Reviewed-by: James Morse <[email protected]> Acked-by: Marc Zyngier <[email protected]> Cc: <[email protected]> # v4.6+ Signed-off-by: Christoffer Dall <[email protected]>
ambv · Sep 8, 2016 · cb96408 · cb96408
1 parent cf0ba18
commit cb96408
Showing 1 changed file with 2 additions and 0 deletions.
diff --git 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)]