KVM: arm64: Correctly honor the presence of FEAT_TCRX

We currently blindly enable TCR2_EL1 use in a guest, irrespective
of the feature set. This is obviously wrong, and we should actually
honor the guest configuration and handle the possible trap resulting
from the guest being buggy.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20240625130042.259175-2-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
This commit is contained in:
Marc Zyngier 2024-06-25 14:00:37 +01:00 committed by Oliver Upton
parent 83a7eefedc
commit 9b58e665d6
2 changed files with 10 additions and 1 deletions

View File

@ -102,7 +102,7 @@
#define HCR_HOST_NVHE_PROTECTED_FLAGS (HCR_HOST_NVHE_FLAGS | HCR_TSC)
#define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H)
#define HCRX_GUEST_FLAGS (HCRX_EL2_SMPME | HCRX_EL2_TCR2En)
#define HCRX_GUEST_FLAGS (HCRX_EL2_SMPME)
#define HCRX_HOST_FLAGS (HCRX_EL2_MSCEn | HCRX_EL2_TCR2En | HCRX_EL2_EnFPM)
/* TCR_EL2 Registers bits */

View File

@ -383,6 +383,12 @@ static bool access_vm_reg(struct kvm_vcpu *vcpu,
bool was_enabled = vcpu_has_cache_enabled(vcpu);
u64 val, mask, shift;
if (reg_to_encoding(r) == SYS_TCR2_EL1 &&
!kvm_has_feat(vcpu->kvm, ID_AA64MMFR3_EL1, TCRX, IMP)) {
kvm_inject_undefined(vcpu);
return false;
}
BUG_ON(!p->is_write);
get_access_mask(r, &mask, &shift);
@ -4060,6 +4066,9 @@ void kvm_init_sysreg(struct kvm_vcpu *vcpu)
if (kvm_has_feat(kvm, ID_AA64ISAR2_EL1, MOPS, IMP))
vcpu->arch.hcrx_el2 |= (HCRX_EL2_MSCEn | HCRX_EL2_MCE2);
if (kvm_has_feat(kvm, ID_AA64MMFR3_EL1, TCRX, IMP))
vcpu->arch.hcrx_el2 |= HCRX_EL2_TCR2En;
}
if (test_bit(KVM_ARCH_FLAG_FGU_INITIALIZED, &kvm->arch.flags))