Re: [PATCH V3 06/14] KVM: MIPS: Introduce and use cpu_guest_has_ldpte

Aleksandar Markovic
2020-05-08T10:50:33Z

нед, 3. мај 2020. у 12:11 Huacai Chen <chenhc@lemote.com> је написао/ла:
>
> Loongson-3 has lddir/ldpte instructions and their related CP0 registers
> are the same as HTW. So we introduce a cpu_guest_has_ldpte flag and use
> it to indicate whether we need to save/restore HTW related CP0 registers
> (PWBase, PWSize, PWField and PWCtl).
>
> Signed-off-by: Huacai Chen <chenhc@lemote.com>
> Co-developed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
> arch/mips/include/asm/cpu-features.h | 3 +++
> arch/mips/kernel/cpu-probe.c | 1 +
> arch/mips/kvm/vz.c | 26 +++++++++++++-------------
> 3 files changed, 17 insertions(+), 13 deletions(-)
>
> diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
> index 400b123..e127495 100644
> --- a/arch/mips/include/asm/cpu-features.h
> +++ b/arch/mips/include/asm/cpu-features.h
> @@ -659,6 +659,9 @@
> #ifndef cpu_guest_has_htw
> #define cpu_guest_has_htw (cpu_data[0].guest.options & MIPS_CPU_HTW)
> #endif
> +#ifndef cpu_guest_has_ldpte
> +#define cpu_guest_has_ldpte (cpu_data[0].guest.options & MIPS_CPU_LDPTE)
> +#endif
> #ifndef cpu_guest_has_mvh
> #define cpu_guest_has_mvh (cpu_data[0].guest.options & MIPS_CPU_MVH)
> #endif
> diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
> index ca2e6f1..be1b556 100644
> --- a/arch/mips/kernel/cpu-probe.c
> +++ b/arch/mips/kernel/cpu-probe.c
> @@ -2004,6 +2004,7 @@ static inline void cpu_probe_loongson(struct cpuinfo_mips *c, unsigned int cpu)
> * register, we correct it here.
> */
> c->options |= MIPS_CPU_FTLB | MIPS_CPU_TLBINV | MIPS_CPU_LDPTE;
> + c->guest.options |= MIPS_CPU_LDPTE;
> c->writecombine = _CACHE_UNCACHED_ACCELERATED;
> c->ases |= (MIPS_ASE_LOONGSON_MMI | MIPS_ASE_LOONGSON_CAM |
> MIPS_ASE_LOONGSON_EXT | MIPS_ASE_LOONGSON_EXT2);
> diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c
> index 17932ab..422cd06 100644
> --- a/arch/mips/kvm/vz.c
> +++ b/arch/mips/kvm/vz.c
> @@ -1706,7 +1706,7 @@ static unsigned long kvm_vz_num_regs(struct kvm_vcpu *vcpu)
> ret += ARRAY_SIZE(kvm_vz_get_one_regs_contextconfig);
> if (cpu_guest_has_segments)
> ret += ARRAY_SIZE(kvm_vz_get_one_regs_segments);
> - if (cpu_guest_has_htw)
> + if (cpu_guest_has_htw || cpu_guest_has_ldpte)
> ret += ARRAY_SIZE(kvm_vz_get_one_regs_htw);
> if (cpu_guest_has_maar && !cpu_guest_has_dyn_maar)
> ret += 1 + ARRAY_SIZE(vcpu->arch.maar);
> @@ -1755,7 +1755,7 @@ static int kvm_vz_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices)
> return -EFAULT;
> indices += ARRAY_SIZE(kvm_vz_get_one_regs_segments);
> }
> - if (cpu_guest_has_htw) {
> + if (cpu_guest_has_htw || cpu_guest_has_ldpte) {
> if (copy_to_user(indices, kvm_vz_get_one_regs_htw,
> sizeof(kvm_vz_get_one_regs_htw)))
> return -EFAULT;
> @@ -1878,17 +1878,17 @@ static int kvm_vz_get_one_reg(struct kvm_vcpu *vcpu,
> *v = read_gc0_segctl2();
> break;
> case KVM_REG_MIPS_CP0_PWBASE:
> - if (!cpu_guest_has_htw)
> + if (!cpu_guest_has_htw && !cpu_guest_has_ldpte)
> return -EINVAL;
> *v = read_gc0_pwbase();
> break;
> case KVM_REG_MIPS_CP0_PWFIELD:
> - if (!cpu_guest_has_htw)
> + if (!cpu_guest_has_htw && !cpu_guest_has_ldpte)
> return -EINVAL;
> *v = read_gc0_pwfield();
> break;
> case KVM_REG_MIPS_CP0_PWSIZE:
> - if (!cpu_guest_has_htw)
> + if (!cpu_guest_has_htw && !cpu_guest_has_ldpte)
> return -EINVAL;
> *v = read_gc0_pwsize();
> break;
> @@ -1896,7 +1896,7 @@ static int kvm_vz_get_one_reg(struct kvm_vcpu *vcpu,
> *v = (long)read_gc0_wired();
> break;
> case KVM_REG_MIPS_CP0_PWCTL:
> - if (!cpu_guest_has_htw)
> + if (!cpu_guest_has_htw && !cpu_guest_has_ldpte)
> return -EINVAL;
> *v = read_gc0_pwctl();
> break;
> @@ -2101,17 +2101,17 @@ static int kvm_vz_set_one_reg(struct kvm_vcpu *vcpu,
> write_gc0_segctl2(v);
> break;
> case KVM_REG_MIPS_CP0_PWBASE:
> - if (!cpu_guest_has_htw)
> + if (!cpu_guest_has_htw && !cpu_guest_has_ldpte)
> return -EINVAL;
> write_gc0_pwbase(v);
> break;
> case KVM_REG_MIPS_CP0_PWFIELD:
> - if (!cpu_guest_has_htw)
> + if (!cpu_guest_has_htw && !cpu_guest_has_ldpte)
> return -EINVAL;
> write_gc0_pwfield(v);
> break;
> case KVM_REG_MIPS_CP0_PWSIZE:
> - if (!cpu_guest_has_htw)
> + if (!cpu_guest_has_htw && !cpu_guest_has_ldpte)
> return -EINVAL;
> write_gc0_pwsize(v);
> break;
> @@ -2119,7 +2119,7 @@ static int kvm_vz_set_one_reg(struct kvm_vcpu *vcpu,
> change_gc0_wired(MIPSR6_WIRED_WIRED, v);
> break;
> case KVM_REG_MIPS_CP0_PWCTL:
> - if (!cpu_guest_has_htw)
> + if (!cpu_guest_has_htw && !cpu_guest_has_ldpte)
> return -EINVAL;
> write_gc0_pwctl(v);
> break;
> @@ -2580,7 +2580,7 @@ static int kvm_vz_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
> }
>
> /* restore HTW registers */
> - if (cpu_guest_has_htw) {
> + if (cpu_guest_has_htw || cpu_guest_has_ldpte) {
> kvm_restore_gc0_pwbase(cop0);
> kvm_restore_gc0_pwfield(cop0);
> kvm_restore_gc0_pwsize(cop0);
> @@ -2685,8 +2685,8 @@ static int kvm_vz_vcpu_put(struct kvm_vcpu *vcpu, int cpu)
> }
>
> /* save HTW registers if enabled in guest */
> - if (cpu_guest_has_htw &&
> - kvm_read_sw_gc0_config3(cop0) & MIPS_CONF3_PW) {
> + if (cpu_guest_has_ldpte || (cpu_guest_has_htw &&
> + kvm_read_sw_gc0_config3(cop0) & MIPS_CONF3_PW)) {
> kvm_save_gc0_pwbase(cop0);
> kvm_save_gc0_pwfield(cop0);
> kvm_save_gc0_pwsize(cop0);
> --
> 2.7.0
>

Reviewed-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>