Commit 55f4b215 authored by Joey Gouly's avatar Joey Gouly Committed by Will Deacon
Browse files

KVM: arm64: use `at s1e1a` for POE 



FEAT_ATS1E1A introduces a new instruction: `at s1e1a`.
This is an address translation, without permission checks.

POE allows read permissions to be removed from S1 by the guest.  This means
that an `at` instruction could fail, and not get the IPA.

Switch to using `at s1e1a` so that KVM can get the IPA regardless of S1
permissions.

Signed-off-by: default avatarJoey Gouly <joey.gouly@arm.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240822151113.1479789-10-joey.gouly@arm.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent b86c9bea

arch/arm64/kvm/hyp/include/hyp/fault.h

+4 −1
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 


static inline bool __translate_far_to_hpfar(u64 far, u64 *hpfar)

{

	int ret;

	u64 par, tmp;



	/*
@@ -27,7 +28,9 @@ static inline bool __translate_far_to_hpfar(u64 far, u64 *hpfar) 
	 * saved the guest context yet, and we may return early...

	 */

	par = read_sysreg_par();

	if (!__kvm_at(OP_AT_S1E1R, far))

	ret = system_supports_poe() ? __kvm_at(OP_AT_S1E1A, far) :

	                              __kvm_at(OP_AT_S1E1R, far);

	if (!ret)

		tmp = read_sysreg_par();

	else

		tmp = SYS_PAR_EL1_F; /* back to the guest */