Add the HCR_EL2 configuration for FEAT_NV2, adding the required bits for running a guest hypervisor, and overall merging the allowed bits provided by the guest. This heavily replies on unavaliable features being sanitised when the HCR_EL2 shadow register is accessed, and only a couple of bits must be explicitly disabled. Non-NV guests are completely unaffected by any of this. Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx> --- arch/arm64/include/asm/sysreg.h | 1 + arch/arm64/kvm/hyp/include/hyp/switch.h | 4 +-- arch/arm64/kvm/hyp/nvhe/switch.c | 2 +- arch/arm64/kvm/hyp/vhe/switch.c | 34 ++++++++++++++++++++++++- 4 files changed, 36 insertions(+), 5 deletions(-) diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 9e8999592f3a..a5361d9032a4 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -498,6 +498,7 @@ #define SYS_TCR_EL2 sys_reg(3, 4, 2, 0, 2) #define SYS_VTTBR_EL2 sys_reg(3, 4, 2, 1, 0) #define SYS_VTCR_EL2 sys_reg(3, 4, 2, 1, 2) +#define SYS_VNCR_EL2 sys_reg(3, 4, 2, 2, 0) #define SYS_TRFCR_EL2 sys_reg(3, 4, 1, 2, 1) #define SYS_VNCR_EL2 sys_reg(3, 4, 2, 2, 0) diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index e3fcf8c4d5b4..f5f701f309a9 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -271,10 +271,8 @@ static inline void __deactivate_traps_common(struct kvm_vcpu *vcpu) __deactivate_traps_hfgxtr(vcpu); } -static inline void ___activate_traps(struct kvm_vcpu *vcpu) +static inline void ___activate_traps(struct kvm_vcpu *vcpu, u64 hcr) { - u64 hcr = vcpu->arch.hcr_el2; - if (cpus_have_final_cap(ARM64_WORKAROUND_CAVIUM_TX2_219_TVM)) hcr |= HCR_TVM; diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c index c50f8459e4fc..4103625e46c5 100644 --- a/arch/arm64/kvm/hyp/nvhe/switch.c +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -40,7 +40,7 @@ static void __activate_traps(struct kvm_vcpu *vcpu) { u64 val; - ___activate_traps(vcpu); + ___activate_traps(vcpu, vcpu->arch.hcr_el2); __activate_traps_common(vcpu); val = vcpu->arch.cptr_el2; diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c index 58415783fd53..29f59c374f7a 100644 --- a/arch/arm64/kvm/hyp/vhe/switch.c +++ b/arch/arm64/kvm/hyp/vhe/switch.c @@ -33,11 +33,43 @@ DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data); DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt); DEFINE_PER_CPU(unsigned long, kvm_hyp_vector); +/* + * HCR_EL2 bits that the NV guest can freely change (no RES0/RES1 + * semantics, irrespective of the configuration), but that cannot be + * applied to the actual HW as things would otherwise break badly. + * + * - TGE: we want to use EL1, which is incompatible with it being set + * + * - API/APK: for hysterical raisins, we enable PAuth lazily, which + * means that the guest's bits cannot be directly applied (we really + * want to see the traps). Revisit this at some point. + */ +#define NV_HCR_GUEST_EXCLUDE (HCR_TGE | HCR_API | HCR_APK) + +static u64 __compute_hcr(struct kvm_vcpu *vcpu) +{ + u64 hcr = vcpu->arch.hcr_el2; + + if (!vcpu_has_nv(vcpu)) + return hcr; + + if (is_hyp_ctxt(vcpu)) { + hcr |= HCR_NV | HCR_NV2 | HCR_AT | HCR_TTLB; + + if (!vcpu_el2_e2h_is_set(vcpu)) + hcr |= HCR_NV1; + + write_sysreg_s(vcpu->arch.ctxt.vncr_array, SYS_VNCR_EL2); + } + + return hcr | (__vcpu_sys_reg(vcpu, HCR_EL2) & ~NV_HCR_GUEST_EXCLUDE); +} + static void __activate_traps(struct kvm_vcpu *vcpu) { u64 val; - ___activate_traps(vcpu); + ___activate_traps(vcpu, __compute_hcr(vcpu)); if (has_cntpoff()) { struct timer_map map; -- 2.39.2