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KVM: arm64: use at s1e1a for POE

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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: Joey 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: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240822151113.1479789-10-joey.gouly@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
This commit is contained in:
Joey Gouly
2024-08-22 16:10:52 +01:00
committed by Will Deacon
parent b86c9bea63
commit 55f4b215fb
1 changed files with 4 additions and 1 deletions
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arch/arm64/kvm/hyp/include/hyp/fault.h
+4 -1
View File
@@ -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 */