diff options
| -rw-r--r-- | arch/arm64/include/asm/kvm_nested.h | 2 | ||||
| -rw-r--r-- | arch/arm64/kvm/debug.c | 3 | ||||
| -rw-r--r-- | arch/arm64/kvm/nested.c | 30 |
3 files changed, 35 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h index 2be6c3de74e3..f7c06a840963 100644 --- a/arch/arm64/include/asm/kvm_nested.h +++ b/arch/arm64/include/asm/kvm_nested.h @@ -83,6 +83,8 @@ extern void check_nested_vcpu_requests(struct kvm_vcpu *vcpu); extern void kvm_nested_flush_hwstate(struct kvm_vcpu *vcpu); extern void kvm_nested_sync_hwstate(struct kvm_vcpu *vcpu); +extern void kvm_nested_setup_mdcr_el2(struct kvm_vcpu *vcpu); + struct kvm_s2_trans { phys_addr_t output; unsigned long block_size; diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c index 381382c19fe4..fc275335c0ee 100644 --- a/arch/arm64/kvm/debug.c +++ b/arch/arm64/kvm/debug.c @@ -56,6 +56,9 @@ static void kvm_arm_setup_mdcr_el2(struct kvm_vcpu *vcpu) if (!kvm_guest_owns_debug_regs(vcpu)) vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA; + if (vcpu_has_nv(vcpu)) + kvm_nested_setup_mdcr_el2(vcpu); + /* Write MDCR_EL2 directly if we're already at EL2 */ if (has_vhe()) write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c index cb36974e010a..fae1c6d975e3 100644 --- a/arch/arm64/kvm/nested.c +++ b/arch/arm64/kvm/nested.c @@ -1796,3 +1796,33 @@ void kvm_nested_sync_hwstate(struct kvm_vcpu *vcpu) if (unlikely(vcpu_test_and_clear_flag(vcpu, NESTED_SERROR_PENDING))) 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 + * at EL2. Use a big hammer to apply sanity. + */ + if (is_hyp_ctxt(vcpu)) + vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA; + else + vcpu->arch.mdcr_el2 |= (guest_mdcr & NV_MDCR_GUEST_INCLUDE); +} |