On Tue, 24 Nov 2015 17:29:14 +0000 Alex Bennée <alex.bennee@xxxxxxxxxx> wrote: > > 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. I probably just overlooked that bit. Thanks for noticing it! M. -- Jazz is not dead. It just smells funny. -- 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
