From: Jintack Lim <jintack....@linaro.org> Forward exceptions due to WFI or WFE instructions to the virtual EL2 if they are not coming from the virtual EL2 and virtual HCR_EL2.TWX is set.
Signed-off-by: Jintack Lim <jintack....@linaro.org> Signed-off-by: Marc Zyngier <marc.zyng...@arm.com> --- arch/arm64/include/asm/kvm_nested.h | 2 ++ arch/arm64/kvm/Makefile | 1 + arch/arm64/kvm/handle_exit.c | 13 +++++++++- arch/arm64/kvm/nested.c | 39 +++++++++++++++++++++++++++++ 4 files changed, 54 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/kvm/nested.c diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h index 8a3d121a0b42..645e5e11b749 100644 --- a/arch/arm64/include/asm/kvm_nested.h +++ b/arch/arm64/include/asm/kvm_nested.h @@ -10,4 +10,6 @@ static inline bool nested_virt_in_use(const struct kvm_vcpu *vcpu) test_bit(KVM_ARM_VCPU_NESTED_VIRT, vcpu->arch.features); } +int handle_wfx_nested(struct kvm_vcpu *vcpu, bool is_wfe); + #endif /* __ARM64_KVM_NESTED_H */ diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 9e450aea7db6..f11bd8b0d837 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -36,4 +36,5 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/irqchip.o kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/arch_timer.o kvm-$(CONFIG_KVM_ARM_PMU) += $(KVM)/arm/pmu.o +kvm-$(CONFIG_KVM_ARM_HOST) += nested.o kvm-$(CONFIG_KVM_ARM_HOST) += emulate-nested.o diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index e348c15c81bc..ddba212fd6ec 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -127,7 +127,18 @@ static int handle_no_fpsimd(struct kvm_vcpu *vcpu, struct kvm_run *run) */ static int kvm_handle_wfx(struct kvm_vcpu *vcpu, struct kvm_run *run) { - if (kvm_vcpu_get_hsr(vcpu) & ESR_ELx_WFx_ISS_WFE) { + bool is_wfe = !!(kvm_vcpu_get_hsr(vcpu) & ESR_ELx_WFx_ISS_WFE); + + if (nested_virt_in_use(vcpu)) { + int ret = handle_wfx_nested(vcpu, is_wfe); + + if (ret < 0 && ret != -EINVAL) + return ret; + else if (ret >= 0) + return ret; + } + + if (is_wfe) { trace_kvm_wfx_arm64(*vcpu_pc(vcpu), true); vcpu->stat.wfe_exit_stat++; kvm_vcpu_on_spin(vcpu, vcpu_mode_priv(vcpu)); diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c new file mode 100644 index 000000000000..3872e3cf1691 --- /dev/null +++ b/arch/arm64/kvm/nested.c @@ -0,0 +1,39 @@ +/* + * Copyright (C) 2017 - Columbia University and Linaro Ltd. + * Author: Jintack Lim <jintack....@linaro.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/kvm.h> +#include <linux/kvm_host.h> + +#include <asm/kvm_emulate.h> + +/* + * Inject wfx to the virtual EL2 if this is not from the virtual EL2 and + * the virtual HCR_EL2.TWX is set. Otherwise, let the host hypervisor + * handle this. + */ +int handle_wfx_nested(struct kvm_vcpu *vcpu, bool is_wfe) +{ + u64 hcr_el2 = __vcpu_sys_reg(vcpu, HCR_EL2); + + if (vcpu_mode_el2(vcpu)) + return -EINVAL; + + if ((is_wfe && (hcr_el2 & HCR_TWE)) || (!is_wfe && (hcr_el2 & HCR_TWI))) + return kvm_inject_nested_sync(vcpu, kvm_vcpu_get_hsr(vcpu)); + + return -EINVAL; +} -- 2.20.1 _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm