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| author | Tianrui Zhao <zhaotianrui@loongson.cn> | 2023-12-19 05:48:28 +0300 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2023-12-19 05:48:28 +0300 |
| commit | 118e10cd893d57df55b3302dfd188a981b6e6d1c (patch) | |
| tree | 43f25b27af229cc68bdc42dc3d874a0b8e4e510f /arch/loongarch/kvm/vcpu.c | |
| parent | db1ecca22edf27c5a3dd66af406c88b5b5ac7cc1 (diff) | |
| download | linux-118e10cd893d57df55b3302dfd188a981b6e6d1c.tar.xz | |
LoongArch: KVM: Add LASX (256bit SIMD) support
This patch adds LASX (256bit SIMD) support for LoongArch KVM.
There will be LASX exception in KVM when guest use the LASX instructions.
KVM will enable LASX and restore the vector registers for guest and then
return to guest to continue running.
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch/kvm/vcpu.c')
| -rw-r--r-- | arch/loongarch/kvm/vcpu.c | 51 |
1 files changed, 50 insertions, 1 deletions
diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c index 80487d177ca4..27701991886d 100644 --- a/arch/loongarch/kvm/vcpu.c +++ b/arch/loongarch/kvm/vcpu.c @@ -317,6 +317,13 @@ static int _kvm_get_cpucfg(int id, u64 *v) */ if (cpu_has_lsx) *v |= CPUCFG2_LSX; + /* + * if LASX is supported by CPU, it is also supported by KVM, + * as we implement it. + */ + if (cpu_has_lasx) + *v |= CPUCFG2_LASX; + break; default: ret = -EINVAL; @@ -753,12 +760,54 @@ int kvm_own_lsx(struct kvm_vcpu *vcpu) } #endif +#ifdef CONFIG_CPU_HAS_LASX +/* Enable LASX and restore context */ +int kvm_own_lasx(struct kvm_vcpu *vcpu) +{ + if (!kvm_guest_has_fpu(&vcpu->arch) || !kvm_guest_has_lsx(&vcpu->arch) || !kvm_guest_has_lasx(&vcpu->arch)) + return -EINVAL; + + preempt_disable(); + + set_csr_euen(CSR_EUEN_FPEN | CSR_EUEN_LSXEN | CSR_EUEN_LASXEN); + switch (vcpu->arch.aux_inuse & (KVM_LARCH_FPU | KVM_LARCH_LSX)) { + case KVM_LARCH_LSX: + case KVM_LARCH_LSX | KVM_LARCH_FPU: + /* Guest LSX state already loaded, only restore upper LASX state */ + _restore_lasx_upper(&vcpu->arch.fpu); + break; + case KVM_LARCH_FPU: + /* Guest FP state already loaded, only restore upper LSX & LASX state */ + _restore_lsx_upper(&vcpu->arch.fpu); + _restore_lasx_upper(&vcpu->arch.fpu); + break; + default: + /* Neither FP or LSX already active, restore full LASX state */ + kvm_restore_lasx(&vcpu->arch.fpu); + break; + } + + trace_kvm_aux(vcpu, KVM_TRACE_AUX_RESTORE, KVM_TRACE_AUX_LASX); + vcpu->arch.aux_inuse |= KVM_LARCH_LASX | KVM_LARCH_LSX | KVM_LARCH_FPU; + preempt_enable(); + + return 0; +} +#endif + /* Save context and disable FPU */ void kvm_lose_fpu(struct kvm_vcpu *vcpu) { preempt_disable(); - if (vcpu->arch.aux_inuse & KVM_LARCH_LSX) { + if (vcpu->arch.aux_inuse & KVM_LARCH_LASX) { + kvm_save_lasx(&vcpu->arch.fpu); + vcpu->arch.aux_inuse &= ~(KVM_LARCH_LSX | KVM_LARCH_FPU | KVM_LARCH_LASX); + trace_kvm_aux(vcpu, KVM_TRACE_AUX_SAVE, KVM_TRACE_AUX_LASX); + + /* Disable LASX & LSX & FPU */ + clear_csr_euen(CSR_EUEN_FPEN | CSR_EUEN_LSXEN | CSR_EUEN_LASXEN); + } else if (vcpu->arch.aux_inuse & KVM_LARCH_LSX) { kvm_save_lsx(&vcpu->arch.fpu); vcpu->arch.aux_inuse &= ~(KVM_LARCH_LSX | KVM_LARCH_FPU); trace_kvm_aux(vcpu, KVM_TRACE_AUX_SAVE, KVM_TRACE_AUX_LSX); |