[PATCH v2 4/5] KVM: arm64: Enable ST64BV0 for guests with FEAT_LS64_ACCDATA

[Fuad Tabba]

Since commit 58ce78667a641 ("arm64: Add support for FEAT_{LS64,
LS64_V}"), a guest sees the host's ID_AA64ISAR1_EL1.LS64, but KVM only
enables the FEAT_LS64 and FEAT_LS64_V instructions in HCRX_EL2. On a
host with FEAT_LS64_ACCDATA, a guest's ST64BV0 therefore traps and hits
the WARN_ON_ONCE() in handle_other().

Set HCRX_EL2.EnAS0 when the guest has FEAT_LS64_ACCDATA, now that
ACCDATA_EL1 is context-switched.

Fixes: 58ce78667a641 ("arm64: Add support for FEAT_{LS64, LS64_V}")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Fuad Tabba <fuad.tabba@xxxxxxxxx>
---
 arch/arm64/include/asm/kvm_emulate.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index a3c1928bdf743..d07f72082531c 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -712,6 +712,9 @@ static inline void vcpu_set_hcrx(struct kvm_vcpu *vcpu)
 		if (kvm_has_feat(kvm, ID_AA64ISAR1_EL1, LS64, LS64_V))
 			vcpu->arch.hcrx_el2 |= HCRX_EL2_EnASR;
 
+		if (kvm_has_feat(kvm, ID_AA64ISAR1_EL1, LS64, LS64_ACCDATA))
+			vcpu->arch.hcrx_el2 |= HCRX_EL2_EnAS0;
+
 		/*
 		 * NV3 is a host-specific extension, and we always use
 		 * it when present and that the guest uses NV. It may
-- 
2.47.3