Marc Zyngier <marc.zyngier@xxxxxxx> writes: > Implement the core of the world switch in C. Not everything is there > yet, and there is nothing to re-enter the world switch either. > > But this already outlines the code structure well enough. > > Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> > --- > arch/arm64/kvm/hyp/Makefile | 1 + > arch/arm64/kvm/hyp/switch.c | 134 ++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 135 insertions(+) > create mode 100644 arch/arm64/kvm/hyp/switch.c > > diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile > index 1e1ff06..9c11b0f 100644 > --- a/arch/arm64/kvm/hyp/Makefile > +++ b/arch/arm64/kvm/hyp/Makefile > @@ -8,3 +8,4 @@ obj-$(CONFIG_KVM_ARM_HOST) += timer-sr.o > obj-$(CONFIG_KVM_ARM_HOST) += sysreg-sr.o > obj-$(CONFIG_KVM_ARM_HOST) += debug-sr.o > obj-$(CONFIG_KVM_ARM_HOST) += entry.o > +obj-$(CONFIG_KVM_ARM_HOST) += switch.o > diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c > new file mode 100644 > index 0000000..a3af81a > --- /dev/null > +++ b/arch/arm64/kvm/hyp/switch.c > @@ -0,0 +1,134 @@ > +/* > + * Copyright (C) 2015 - ARM Ltd > + * Author: Marc Zyngier <marc.zyngier@xxxxxxx> > + * > + * 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 "hyp.h" > + > +static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu) > +{ > + u64 val; > + > + /* > + * We are about to set CPTR_EL2.TFP to trap all floating point > + * register accesses to EL2, however, the ARM ARM clearly states that > + * traps are only taken to EL2 if the operation would not otherwise > + * trap to EL1. Therefore, always make sure that for 32-bit guests, > + * we set FPEXC.EN to prevent traps to EL1, when setting the TFP bit. > + */ > + val = vcpu->arch.hcr_el2; > + if (val & HCR_RW) { > + write_sysreg(1 << 30, fpexc32_el2); > + isb(); > + } > + write_sysreg(val, hcr_el2); > + write_sysreg(1 << 15, hstr_el2); > + write_sysreg(CPTR_EL2_TTA | CPTR_EL2_TFP, cptr_el2); > + write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2); > +} > + > +static void __hyp_text __deactivate_traps(struct kvm_vcpu *vcpu) > +{ > + write_sysreg(HCR_RW, hcr_el2); > + write_sysreg(0, hstr_el2); > + write_sysreg(read_sysreg(mdcr_el2) & MDCR_EL2_HPMN_MASK, mdcr_el2); > + write_sysreg(0, cptr_el2); > +} > + > +static void __hyp_text __activate_vm(struct kvm_vcpu *vcpu) > +{ > + struct kvm *kvm = kern_hyp_va(vcpu->kvm); > + write_sysreg(kvm->arch.vttbr, vttbr_el2); > +} > + > +static void __hyp_text __deactivate_vm(struct kvm_vcpu *vcpu) > +{ > + write_sysreg(0, vttbr_el2); > +} > + > +static hyp_alternate_select(__vgic_call_save_state, > + __vgic_v2_save_state, __vgic_v3_save_state, > + ARM64_HAS_SYSREG_GIC_CPUIF); > + > +static hyp_alternate_select(__vgic_call_restore_state, > + __vgic_v2_restore_state, __vgic_v3_restore_state, > + ARM64_HAS_SYSREG_GIC_CPUIF); > + > +static void __hyp_text __vgic_save_state(struct kvm_vcpu *vcpu) > +{ > + __vgic_call_save_state()(vcpu); > + write_sysreg(read_sysreg(hcr_el2) & ~HCR_INT_OVERRIDE, hcr_el2); > +} > + > +static void __hyp_text __vgic_restore_state(struct kvm_vcpu *vcpu) > +{ > + u64 val; > + > + val = read_sysreg(hcr_el2); > + val |= HCR_INT_OVERRIDE; > + val |= vcpu->arch.irq_lines; > + write_sysreg(val, hcr_el2); > + > + __vgic_call_restore_state()(vcpu); > +} > + > +int __hyp_text __guest_run(struct kvm_vcpu *vcpu) > +{ > + struct kvm_cpu_context *host_ctxt; > + struct kvm_cpu_context *guest_ctxt; > + u64 exit_code; > + > + vcpu = kern_hyp_va(vcpu); > + write_sysreg(vcpu, tpidr_el2); > + > + host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); > + guest_ctxt = &vcpu->arch.ctxt; > + > + __sysreg_save_state(host_ctxt); > + __debug_cond_save_state(vcpu, &vcpu->arch.host_debug_state, host_ctxt); > + > + __activate_traps(vcpu); > + __activate_vm(vcpu); > + > + __vgic_restore_state(vcpu); > + __timer_restore_state(vcpu); > + > + /* > + * We must restore the 32-bit state before the sysregs, thanks > + * to Cortex-A57 erratum #852523. > + */ > + __sysreg32_restore_state(vcpu); > + __sysreg_restore_state(guest_ctxt); > + __debug_restore_state(vcpu, &vcpu->arch.vcpu_debug_state, > guest_ctxt); Did you right this before guest debug was merged? Now vcpu.debug_ptr/VCPU_DEBUG_PTR selects which set of debug registers we are going to use before entering the guest. > + > + /* Jump in the fire! */ > + exit_code = __guest_enter(vcpu, host_ctxt); > + /* And we're baaack! */ > + > + __sysreg_save_state(guest_ctxt); > + __sysreg32_save_state(vcpu); > + __timer_save_state(vcpu); > + __vgic_save_state(vcpu); > + > + __deactivate_traps(vcpu); > + __deactivate_vm(vcpu); > + > + __sysreg_restore_state(host_ctxt); > + > + __debug_save_state(vcpu, &vcpu->arch.vcpu_debug_state, guest_ctxt); > + __debug_clear_restore_state(vcpu, &vcpu->arch.host_debug_state, host_ctxt); > + > + return exit_code; > +} -- Alex Bennée -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
