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| author |   Oliver Upton <oliver.upton@linux.dev> | 2025-03-05 15:08:23 -0800 |
|---|---|---|
| committer | Oliver Upton <oliver.upton@linux.dev> | 2025-03-05 16:55:41 -0800 |
| commit | 9d91227364330fd1735d6fc3f7226f854f9f7b8c (patch) | |
| tree | 660e490e1cadab9a88e736111ac54feea2f6ebeb | |
| parent | KVM: selftests: arm64: Test writes to MIDR,REVIDR,AIDR (diff) | |
| download | linux-rng-9d91227364330fd1735d6fc3f7226f854f9f7b8c.tar.xz linux-rng-9d91227364330fd1735d6fc3f7226f854f9f7b8c.zip | |
KVM: arm64: Copy guest CTR_EL0 into hyp VM
Since commit 2843cae26644 ("KVM: arm64: Treat CTR_EL0 as a VM feature
ID register") KVM has allowed userspace to configure the VM-wide view of
CTR_EL0, falling back to trap-n-emulate if the value doesn't match
hardware. It appears that this has worked by chance in protected-mode
for some time, and on systems with FEAT_EVT protected-mode
unconditionally sets TID4 (i.e. TID2 traps sans CTR_EL0).
Forward the guest CTR_EL0 value through to the hyp VM and align the
TID2/TID4 configuration with the non-protected setup.
Fixes: 2843cae26644 ("KVM: arm64: Treat CTR_EL0 as a VM feature ID register")
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250305230825.484091-2-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/pkvm.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c index 3927fe52a3dd..96348abeb5c2 100644 --- a/arch/arm64/kvm/hyp/nvhe/pkvm.c +++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c @@ -46,7 +46,8 @@ static void pkvm_vcpu_reset_hcr(struct kvm_vcpu *vcpu) vcpu->arch.hcr_el2 |= HCR_FWB; if (cpus_have_final_cap(ARM64_HAS_EVT) && - !cpus_have_final_cap(ARM64_MISMATCHED_CACHE_TYPE)) + !cpus_have_final_cap(ARM64_MISMATCHED_CACHE_TYPE) && + kvm_read_vm_id_reg(vcpu->kvm, SYS_CTR_EL0) == read_cpuid(CTR_EL0)) vcpu->arch.hcr_el2 |= HCR_TID4; else vcpu->arch.hcr_el2 |= HCR_TID2; @@ -315,6 +316,9 @@ static void pkvm_init_features_from_host(struct pkvm_hyp_vm *hyp_vm, const struc unsigned long host_arch_flags = READ_ONCE(host_kvm->arch.flags); DECLARE_BITMAP(allowed_features, KVM_VCPU_MAX_FEATURES); + /* CTR_EL0 is always under host control, even for protected VMs. */ + hyp_vm->kvm.arch.ctr_el0 = host_kvm->arch.ctr_el0; + if (test_bit(KVM_ARCH_FLAG_MTE_ENABLED, &host_kvm->arch.flags)) set_bit(KVM_ARCH_FLAG_MTE_ENABLED, &kvm->arch.flags); |