[PATCH v4 25/28] KVM: arm64: nv: Add switching support for HFGxTR/HDFGxTR

[Jing Zhang]

Hi Marc,

On Tue, Aug 15, 2023 at 11:47 AM Marc Zyngier <maz at kernel.org> wrote:
>
> Now that we can evaluate the FGT registers, allow them to be merged
> with the hypervisor's own configuration (in the case of HFG{RW}TR_EL2)
> or simply set for HFGITR_EL2, HDGFRTR_EL2 and HDFGWTR_EL2.
>
> Reviewed-by: Eric Auger <eric.auger at redhat.com>
> Signed-off-by: Marc Zyngier <maz at kernel.org>
> ---
>  arch/arm64/kvm/hyp/include/hyp/switch.h | 48 +++++++++++++++++++++++++
>  1 file changed, 48 insertions(+)
>
> diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
> index e096b16e85fd..a4750070563f 100644
> --- a/arch/arm64/kvm/hyp/include/hyp/switch.h
> +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
> @@ -70,6 +70,13 @@ static inline void __activate_traps_fpsimd32(struct kvm_vcpu *vcpu)
>         }
>  }
>
> +#define compute_clr_set(vcpu, reg, clr, set)                           \
> +       do {                                                            \
> +               u64 hfg;                                                \
> +               hfg = __vcpu_sys_reg(vcpu, reg) & ~__ ## reg ## _RES0;  \
> +               set |= hfg & __ ## reg ## _MASK;                        \
> +               clr |= ~hfg & __ ## reg ## _nMASK;                      \
> +       } while(0)
>
>
>  static inline void __activate_traps_hfgxtr(struct kvm_vcpu *vcpu)
> @@ -97,6 +104,10 @@ static inline void __activate_traps_hfgxtr(struct kvm_vcpu *vcpu)
>         if (cpus_have_final_cap(ARM64_WORKAROUND_AMPERE_AC03_CPU_38))
>                 w_set |= HFGxTR_EL2_TCR_EL1_MASK;
>
> +       if (vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu)) {
> +               compute_clr_set(vcpu, HFGRTR_EL2, r_clr, r_set);
> +               compute_clr_set(vcpu, HFGWTR_EL2, w_clr, w_set);
> +       }
>
>         /* The default is not to trap anything but ACCDATA_EL1 */
>         r_val = __HFGRTR_EL2_nMASK & ~HFGxTR_EL2_nACCDATA_EL1;
> @@ -109,6 +120,38 @@ static inline void __activate_traps_hfgxtr(struct kvm_vcpu *vcpu)
>
>         write_sysreg_s(r_val, SYS_HFGRTR_EL2);
>         write_sysreg_s(w_val, SYS_HFGWTR_EL2);
> +
> +       if (!vcpu_has_nv(vcpu) || is_hyp_ctxt(vcpu))
> +               return;
> +
> +       ctxt_sys_reg(hctxt, HFGITR_EL2) = read_sysreg_s(SYS_HFGITR_EL2);
> +
> +       r_set = r_clr = 0;
> +       compute_clr_set(vcpu, HFGITR_EL2, r_clr, r_set);
> +       r_val = __HFGITR_EL2_nMASK;
> +       r_val |= r_set;
> +       r_val &= ~r_clr;
> +
> +       write_sysreg_s(r_val, SYS_HFGITR_EL2);
> +
> +       ctxt_sys_reg(hctxt, HDFGRTR_EL2) = read_sysreg_s(SYS_HDFGRTR_EL2);
> +       ctxt_sys_reg(hctxt, HDFGWTR_EL2) = read_sysreg_s(SYS_HDFGWTR_EL2);
> +
> +       r_clr = r_set = w_clr = w_set = 0;
> +
> +       compute_clr_set(vcpu, HDFGRTR_EL2, r_clr, r_set);
> +       compute_clr_set(vcpu, HDFGWTR_EL2, w_clr, w_set);
> +
> +       r_val = __HDFGRTR_EL2_nMASK;
> +       r_val |= r_set;
> +       r_val &= ~r_clr;
> +
> +       w_val = __HDFGWTR_EL2_nMASK;
> +       w_val |= w_set;
> +       w_val &= ~w_clr;
> +
> +       write_sysreg_s(r_val, SYS_HDFGRTR_EL2);
> +       write_sysreg_s(w_val, SYS_HDFGWTR_EL2);
>  }
>
>  static inline void __deactivate_traps_hfgxtr(struct kvm_vcpu *vcpu)
> @@ -121,7 +164,12 @@ static inline void __deactivate_traps_hfgxtr(struct kvm_vcpu *vcpu)
>         write_sysreg_s(ctxt_sys_reg(hctxt, HFGRTR_EL2), SYS_HFGRTR_EL2);
>         write_sysreg_s(ctxt_sys_reg(hctxt, HFGWTR_EL2), SYS_HFGWTR_EL2);
>
> +       if (!vcpu_has_nv(vcpu) || is_hyp_ctxt(vcpu))
> +               return;
>
> +       write_sysreg_s(ctxt_sys_reg(hctxt, HFGITR_EL2), SYS_HFGITR_EL2);
> +       write_sysreg_s(ctxt_sys_reg(hctxt, HDFGRTR_EL2), SYS_HDFGRTR_EL2);
> +       write_sysreg_s(ctxt_sys_reg(hctxt, HDFGWTR_EL2), SYS_HDFGWTR_EL2);
>  }
>
>  static inline void __activate_traps_common(struct kvm_vcpu *vcpu)
> --
> 2.34.1
>

Reviewed-by: Jing Zhang <jingzhangos at google.com>

Jing