diff options
| author | Oliver Upton <oliver.upton@linux.dev> | 2025-09-17 13:31:25 -0700 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2025-09-18 16:46:20 +0100 |
| commit | 3af1105c4fa362d17d577b55d2b8a7c4609f16fc (patch) | |
| tree | ce8e9148d1e9fa0e7a342d422f41c6b7164877f8 | |
| parent | 4a684088421d5a1ffb3b13243c58a9078c99e4b9 (diff) | |
KVM: arm64: nv: Apply guest's MDCR traps in nested context
KVM needs to ensure the guest hypervisor's traps take effect when the
vCPU is in a nested context. While supporting infrastructure is in place
for most of the EL2 trap registers, MDCR_EL2 is not.
Fold the guest's trap configuration into the effective MDCR_EL2. Apply
it directly to the in-memory representation as it gets recomputed on
every vcpu_load() anyway.
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
| -rw-r--r-- | arch/arm64/kvm/nested.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index 9559c64e7e0c..61542d6fd8f5 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -1797,8 +1797,25 @@ void kvm_nested_sync_hwstate(struct kvm_vcpu *vcpu) kvm_inject_serror_esr(vcpu, vcpu_get_vsesr(vcpu)); } +/* + * KVM unconditionally sets most of these traps anyway but use an allowlist + * to document the guest hypervisor traps that may take precedence and guard + * against future changes to the non-nested trap configuration. + */ +#define NV_MDCR_GUEST_INCLUDE (MDCR_EL2_TDE | \ + MDCR_EL2_TDA | \ + MDCR_EL2_TDRA | \ + MDCR_EL2_TTRF | \ + MDCR_EL2_TPMS | \ + MDCR_EL2_TPM | \ + MDCR_EL2_TPMCR | \ + MDCR_EL2_TDCC | \ + MDCR_EL2_TDOSA) + void kvm_nested_setup_mdcr_el2(struct kvm_vcpu *vcpu) { + u64 guest_mdcr = __vcpu_sys_reg(vcpu, MDCR_EL2); + /* * In yet another example where FEAT_NV2 is fscking broken, accesses * to MDSCR_EL1 are redirected to the VNCR despite having an effect @@ -1806,4 +1823,6 @@ void kvm_nested_setup_mdcr_el2(struct kvm_vcpu *vcpu) */ if (is_hyp_ctxt(vcpu)) vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA; + else + vcpu->arch.mdcr_el2 |= (guest_mdcr & NV_MDCR_GUEST_INCLUDE); } |