On Fri, 03 May 2024 14:01:25 +0100,
Joey Gouly <joey.gouly@xxxxxxx> wrote:
>
> Define the new system registers that POE introduces and context switch them.
>
> Signed-off-by: Joey Gouly <joey.gouly@xxxxxxx>
> Cc: Marc Zyngier <maz@xxxxxxxxxx>
> Cc: Oliver Upton <oliver.upton@xxxxxxxxx>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>
> ---
> arch/arm64/include/asm/kvm_host.h | 4 +++
> arch/arm64/include/asm/vncr_mapping.h | 1 +
> arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 29 ++++++++++++++++++++++
> arch/arm64/kvm/sys_regs.c | 8 ++++--
> 4 files changed, 40 insertions(+), 2 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 9e8a496fb284..28042da0befd 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -419,6 +419,8 @@ enum vcpu_sysreg {
> GCR_EL1, /* Tag Control Register */
> TFSRE0_EL1, /* Tag Fault Status Register (EL0) */
>
> + POR_EL0, /* Permission Overlay Register 0 (EL0) */
> +
> /* 32bit specific registers. */
> DACR32_EL2, /* Domain Access Control Register */
> IFSR32_EL2, /* Instruction Fault Status Register */
> @@ -489,6 +491,8 @@ enum vcpu_sysreg {
> VNCR(PIR_EL1), /* Permission Indirection Register 1 (EL1) */
> VNCR(PIRE0_EL1), /* Permission Indirection Register 0 (EL1) */
>
> + VNCR(POR_EL1), /* Permission Overlay Register 1 (EL1) */
> +
> VNCR(HFGRTR_EL2),
> VNCR(HFGWTR_EL2),
> VNCR(HFGITR_EL2),
> diff --git a/arch/arm64/include/asm/vncr_mapping.h b/arch/arm64/include/asm/vncr_mapping.h
> index df2c47c55972..06f8ec0906a6 100644
> --- a/arch/arm64/include/asm/vncr_mapping.h
> +++ b/arch/arm64/include/asm/vncr_mapping.h
> @@ -52,6 +52,7 @@
> #define VNCR_PIRE0_EL1 0x290
> #define VNCR_PIRE0_EL2 0x298
> #define VNCR_PIR_EL1 0x2A0
> +#define VNCR_POR_EL1 0x2A8
> #define VNCR_ICH_LR0_EL2 0x400
> #define VNCR_ICH_LR1_EL2 0x408
> #define VNCR_ICH_LR2_EL2 0x410
> diff --git a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
> index 4be6a7fa0070..1c9536557bae 100644
> --- a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
> +++ b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
> @@ -16,9 +16,15 @@
> #include <asm/kvm_hyp.h>
> #include <asm/kvm_mmu.h>
>
> +static inline bool ctxt_has_s1poe(struct kvm_cpu_context *ctxt);
> +
> static inline void __sysreg_save_common_state(struct kvm_cpu_context *ctxt)
> {
> ctxt_sys_reg(ctxt, MDSCR_EL1) = read_sysreg(mdscr_el1);
> +
> + // POR_EL0 can affect uaccess, so must be saved/restored early.
> + if (ctxt_has_s1poe(ctxt))
> + ctxt_sys_reg(ctxt, POR_EL0) = read_sysreg_s(SYS_POR_EL0);
> }
>
> static inline void __sysreg_save_user_state(struct kvm_cpu_context *ctxt)
> @@ -55,6 +61,17 @@ static inline bool ctxt_has_s1pie(struct kvm_cpu_context *ctxt)
> return kvm_has_feat(kern_hyp_va(vcpu->kvm), ID_AA64MMFR3_EL1, S1PIE, IMP);
> }
>
> +static inline bool ctxt_has_s1poe(struct kvm_cpu_context *ctxt)
> +{
> + struct kvm_vcpu *vcpu;
> +
> + if (!system_supports_poe())
> + return false;
> +
> + vcpu = ctxt_to_vcpu(ctxt);
> + return kvm_has_feat(kern_hyp_va(vcpu->kvm), ID_AA64MMFR3_EL1, S1POE, IMP);
> +}
> +
> static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
> {
> ctxt_sys_reg(ctxt, SCTLR_EL1) = read_sysreg_el1(SYS_SCTLR);
> @@ -77,6 +94,10 @@ static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
> ctxt_sys_reg(ctxt, PIR_EL1) = read_sysreg_el1(SYS_PIR);
> ctxt_sys_reg(ctxt, PIRE0_EL1) = read_sysreg_el1(SYS_PIRE0);
> }
> +
> + if (ctxt_has_s1poe(ctxt))
> + ctxt_sys_reg(ctxt, POR_EL1) = read_sysreg_el1(SYS_POR);
> +
> ctxt_sys_reg(ctxt, PAR_EL1) = read_sysreg_par();
> ctxt_sys_reg(ctxt, TPIDR_EL1) = read_sysreg(tpidr_el1);
>
> @@ -107,6 +128,10 @@ static inline void __sysreg_save_el2_return_state(struct kvm_cpu_context *ctxt)
> static inline void __sysreg_restore_common_state(struct kvm_cpu_context *ctxt)
> {
> write_sysreg(ctxt_sys_reg(ctxt, MDSCR_EL1), mdscr_el1);
> +
> + // POR_EL0 can affect uaccess, so must be saved/restored early.
> + if (ctxt_has_s1poe(ctxt))
> + write_sysreg_s(ctxt_sys_reg(ctxt, POR_EL0), SYS_POR_EL0);
> }
>
> static inline void __sysreg_restore_user_state(struct kvm_cpu_context *ctxt)
> @@ -153,6 +178,10 @@ static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
> write_sysreg_el1(ctxt_sys_reg(ctxt, PIR_EL1), SYS_PIR);
> write_sysreg_el1(ctxt_sys_reg(ctxt, PIRE0_EL1), SYS_PIRE0);
> }
> +
> + if (ctxt_has_s1poe(ctxt))
> + write_sysreg_el1(ctxt_sys_reg(ctxt, POR_EL1), SYS_POR);
> +
> write_sysreg(ctxt_sys_reg(ctxt, PAR_EL1), par_el1);
> write_sysreg(ctxt_sys_reg(ctxt, TPIDR_EL1), tpidr_el1);
>
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index c9f4f387155f..be04fae35afb 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -2423,6 +2423,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
> { SYS_DESC(SYS_MAIR_EL1), access_vm_reg, reset_unknown, MAIR_EL1 },
> { SYS_DESC(SYS_PIRE0_EL1), NULL, reset_unknown, PIRE0_EL1 },
> { SYS_DESC(SYS_PIR_EL1), NULL, reset_unknown, PIR_EL1 },
> + { SYS_DESC(SYS_POR_EL1), NULL, reset_unknown, POR_EL1 },
> { SYS_DESC(SYS_AMAIR_EL1), access_vm_reg, reset_amair_el1, AMAIR_EL1 },
>
> { SYS_DESC(SYS_LORSA_EL1), trap_loregion },
> @@ -2506,6 +2507,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
> .access = access_pmovs, .reg = PMOVSSET_EL0,
> .get_user = get_pmreg, .set_user = set_pmreg },
>
> + { SYS_DESC(SYS_POR_EL0), NULL, reset_unknown, POR_EL0 },
> { SYS_DESC(SYS_TPIDR_EL0), NULL, reset_unknown, TPIDR_EL0 },
> { SYS_DESC(SYS_TPIDRRO_EL0), NULL, reset_unknown, TPIDRRO_EL0 },
> { SYS_DESC(SYS_TPIDR2_EL0), undef_access },
> @@ -4057,8 +4059,6 @@ void kvm_init_sysreg(struct kvm_vcpu *vcpu)
> kvm->arch.fgu[HFGxTR_GROUP] = (HFGxTR_EL2_nAMAIR2_EL1 |
> HFGxTR_EL2_nMAIR2_EL1 |
> HFGxTR_EL2_nS2POR_EL1 |
> - HFGxTR_EL2_nPOR_EL1 |
> - HFGxTR_EL2_nPOR_EL0 |
> HFGxTR_EL2_nACCDATA_EL1 |
> HFGxTR_EL2_nSMPRI_EL1_MASK |
> HFGxTR_EL2_nTPIDR2_EL0_MASK);
> @@ -4093,6 +4093,10 @@ void kvm_init_sysreg(struct kvm_vcpu *vcpu)
> kvm->arch.fgu[HFGxTR_GROUP] |= (HFGxTR_EL2_nPIRE0_EL1 |
> HFGxTR_EL2_nPIR_EL1);
>
> + if (!kvm_has_feat(kvm, ID_AA64MMFR3_EL1, S1POE, IMP))
> + kvm->arch.fgu[HFGxTR_GROUP] |= (HFGxTR_EL2_nPOR_EL1 |
> + HFGxTR_EL2_nPOR_EL0);
> +
As Broonie pointed out in a separate thread, this cannot work, short
of making ID_AA64MMFR3_EL1 writable.
This can be done in a separate patch, but it needs doing as it
otherwise breaks migration.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
