On Wed, Sep 22, 2021 at 01:46:55PM +0100, Fuad Tabba wrote:
> From: Marc Zyngier <maz@xxxxxxxxxx>
>
> Simplify the early exception handling by slicing the gigantic decoding
> tree into a more manageable set of functions, similar to what we have
> in handle_exit.c.
>
> This will also make the structure reusable for pKVM's own early exit
> handling.
>
> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
> Signed-off-by: Fuad Tabba <tabba@xxxxxxxxxx>
> ---
> arch/arm64/kvm/hyp/include/hyp/switch.h | 160 ++++++++++++++----------
> arch/arm64/kvm/hyp/nvhe/switch.c | 17 +++
> arch/arm64/kvm/hyp/vhe/switch.c | 17 +++
> 3 files changed, 126 insertions(+), 68 deletions(-)
>
> diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
> index 54abc8298ec3..0397606c0951 100644
> --- a/arch/arm64/kvm/hyp/include/hyp/switch.h
> +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
> @@ -136,16 +136,7 @@ static inline void ___deactivate_traps(struct kvm_vcpu *vcpu)
>
> static inline bool __populate_fault_info(struct kvm_vcpu *vcpu)
> {
> - u8 ec;
> - u64 esr;
> -
> - esr = vcpu->arch.fault.esr_el2;
> - ec = ESR_ELx_EC(esr);
> -
> - if (ec != ESR_ELx_EC_DABT_LOW && ec != ESR_ELx_EC_IABT_LOW)
> - return true;
> -
> - return __get_fault_info(esr, &vcpu->arch.fault);
> + return __get_fault_info(vcpu->arch.fault.esr_el2, &vcpu->arch.fault);
> }
>
> static inline void __hyp_sve_save_host(struct kvm_vcpu *vcpu)
> @@ -166,8 +157,13 @@ static inline void __hyp_sve_restore_guest(struct kvm_vcpu *vcpu)
> write_sysreg_el1(__vcpu_sys_reg(vcpu, ZCR_EL1), SYS_ZCR);
> }
>
> -/* Check for an FPSIMD/SVE trap and handle as appropriate */
> -static inline bool __hyp_handle_fpsimd(struct kvm_vcpu *vcpu)
> +/*
> + * We trap the first access to the FP/SIMD to save the host context and
> + * restore the guest context lazily.
> + * If FP/SIMD is not implemented, handle the trap and inject an undefined
> + * instruction exception to the guest. Similarly for trapped SVE accesses.
> + */
> +static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
> {
> bool sve_guest, sve_host;
> u8 esr_ec;
> @@ -185,9 +181,6 @@ static inline bool __hyp_handle_fpsimd(struct kvm_vcpu *vcpu)
> }
>
> esr_ec = kvm_vcpu_trap_get_class(vcpu);
> - if (esr_ec != ESR_ELx_EC_FP_ASIMD &&
> - esr_ec != ESR_ELx_EC_SVE)
> - return false;
>
> /* Don't handle SVE traps for non-SVE vcpus here: */
> if (!sve_guest && esr_ec != ESR_ELx_EC_FP_ASIMD)
> @@ -325,7 +318,7 @@ static inline bool esr_is_ptrauth_trap(u32 esr)
>
> DECLARE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt);
>
> -static inline bool __hyp_handle_ptrauth(struct kvm_vcpu *vcpu)
> +static bool kvm_hyp_handle_ptrauth(struct kvm_vcpu *vcpu, u64 *exit_code)
> {
> struct kvm_cpu_context *ctxt;
> u64 val;
> @@ -350,6 +343,87 @@ static inline bool __hyp_handle_ptrauth(struct kvm_vcpu *vcpu)
> return true;
> }
>
> +static bool kvm_hyp_handle_sysreg(struct kvm_vcpu *vcpu, u64 *exit_code)
> +{
> + if (cpus_have_final_cap(ARM64_WORKAROUND_CAVIUM_TX2_219_TVM) &&
> + handle_tx2_tvm(vcpu))
> + return true;
> +
> + if (static_branch_unlikely(&vgic_v3_cpuif_trap) &&
> + __vgic_v3_perform_cpuif_access(vcpu) == 1)
> + return true;
> +
> + return false;
> +}
> +
> +static bool kvm_hyp_handle_cp15(struct kvm_vcpu *vcpu, u64 *exit_code)
> +{
> + if (static_branch_unlikely(&vgic_v3_cpuif_trap) &&
> + __vgic_v3_perform_cpuif_access(vcpu) == 1)
> + return true;
I think you're now calling this for the 64-bit CP15 access path, which I
don't think is correct. Maybe have separate handlers for 32-bit v4 64-bit
accesses?
Will
