On Thu, Feb 04, 2016 at 11:00:33AM +0000, Marc Zyngier wrote: > The new world switch implementation is modeled after the arm64 one, > calling the various save/restore functions in turn, and having as > little state as possible. > > Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> > --- > arch/arm/kvm/hyp/Makefile | 1 + > arch/arm/kvm/hyp/hyp.h | 7 +++ > arch/arm/kvm/hyp/switch.c | 136 ++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 144 insertions(+) > create mode 100644 arch/arm/kvm/hyp/switch.c > > diff --git a/arch/arm/kvm/hyp/Makefile b/arch/arm/kvm/hyp/Makefile > index c779690..cfab402 100644 > --- a/arch/arm/kvm/hyp/Makefile > +++ b/arch/arm/kvm/hyp/Makefile > @@ -9,3 +9,4 @@ obj-$(CONFIG_KVM_ARM_HOST) += vgic-v2-sr.o > obj-$(CONFIG_KVM_ARM_HOST) += vfp.o > obj-$(CONFIG_KVM_ARM_HOST) += banked-sr.o > obj-$(CONFIG_KVM_ARM_HOST) += entry.o > +obj-$(CONFIG_KVM_ARM_HOST) += switch.o > diff --git a/arch/arm/kvm/hyp/hyp.h b/arch/arm/kvm/hyp/hyp.h > index b3f6ed2..2ca651f 100644 > --- a/arch/arm/kvm/hyp/hyp.h > +++ b/arch/arm/kvm/hyp/hyp.h > @@ -60,11 +60,16 @@ > #define CNTV_CVAL __ACCESS_CP15_64(3, c14) > #define CNTVOFF __ACCESS_CP15_64(4, c14) > > +#define MIDR __ACCESS_CP15(c0, 0, c0, 0) > #define CSSELR __ACCESS_CP15(c0, 2, c0, 0) > +#define VMIDR __ACCESS_CP15(c0, 4, c0, 0) Nit: This is called VPIDR in v7 and VMPIDR_EL2 in v8 IIUC. Should we refer to it by one of those names instead? > #define VMPIDR __ACCESS_CP15(c0, 4, c0, 5) > #define SCTLR __ACCESS_CP15(c1, 0, c0, 0) > #define CPACR __ACCESS_CP15(c1, 0, c0, 2) > +#define HCR __ACCESS_CP15(c1, 4, c1, 0) > +#define HDCR __ACCESS_CP15(c1, 4, c1, 1) > #define HCPTR __ACCESS_CP15(c1, 4, c1, 2) > +#define HSTR __ACCESS_CP15(c1, 4, c1, 3) > #define TTBCR __ACCESS_CP15(c2, 0, c0, 2) > #define DACR __ACCESS_CP15(c3, 0, c0, 0) > #define DFSR __ACCESS_CP15(c5, 0, c0, 0) > @@ -73,6 +78,7 @@ > #define AIFSR __ACCESS_CP15(c5, 0, c1, 1) > #define DFAR __ACCESS_CP15(c6, 0, c0, 0) > #define IFAR __ACCESS_CP15(c6, 0, c0, 2) > +#define HDFAR __ACCESS_CP15(c6, 4, c0, 0) > #define ICIALLUIS __ACCESS_CP15(c7, 0, c1, 0) > #define TLBIALLIS __ACCESS_CP15(c8, 0, c3, 0) > #define TLBIALLNSNHIS __ACCESS_CP15(c8, 4, c3, 4) > @@ -85,6 +91,7 @@ > #define TID_URW __ACCESS_CP15(c13, 0, c0, 2) > #define TID_URO __ACCESS_CP15(c13, 0, c0, 3) > #define TID_PRIV __ACCESS_CP15(c13, 0, c0, 4) > +#define HTPIDR __ACCESS_CP15(c13, 4, c0, 2) > #define CNTKCTL __ACCESS_CP15(c14, 0, c1, 0) > #define CNTV_CTL __ACCESS_CP15(c14, 0, c3, 1) > #define CNTHCTL __ACCESS_CP15(c14, 4, c1, 0) > diff --git a/arch/arm/kvm/hyp/switch.c b/arch/arm/kvm/hyp/switch.c > new file mode 100644 > index 0000000..f715b0d > --- /dev/null > +++ b/arch/arm/kvm/hyp/switch.c > @@ -0,0 +1,136 @@ > +/* > + * 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 <asm/kvm_asm.h> > +#include "hyp.h" > + > +__asm__(".arch_extension virt"); > + > +static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu, u32 *fpexc) Nit: can you document the fpexc or name it host_fpexc_preserve or something? > +{ > + u32 val; > + > + /* > + * We are about to set HCPTR.TCP10/11 to trap all floating point > + * register accesses to HYP, however, the ARM ARM clearly states that > + * traps are only taken to HYP if the operation would not otherwise > + * trap to SVC. Therefore, always make sure that for 32-bit guests, > + * we set FPEXC.EN to prevent traps to SVC, when setting the TCP bits. > + */ > + val = read_sysreg(VFP_FPEXC); > + *fpexc = val; > + if (!(val & FPEXC_EN)) { > + write_sysreg(val | FPEXC_EN, VFP_FPEXC); > + isb(); > + } > + > + write_sysreg(vcpu->arch.hcr | vcpu->arch.irq_lines, HCR); > + /* Trap on AArch32 cp15 c15 accesses (EL1 or EL0) */ > + write_sysreg(HSTR_T(15), HSTR); > + write_sysreg(HCPTR_TTA | HCPTR_TCP(10) | HCPTR_TCP(11), HCPTR); > + val = read_sysreg(HDCR); > + write_sysreg(val | HDCR_TPM | HDCR_TPMCR, HDCR); > +} > + > +static void __hyp_text __deactivate_traps(struct kvm_vcpu *vcpu) > +{ > + u32 val; > + > + write_sysreg(0, HCR); > + write_sysreg(0, HSTR); > + val = read_sysreg(HDCR); > + write_sysreg(val & ~(HDCR_TPM | HDCR_TPMCR), HDCR); > + write_sysreg(0, HCPTR); > +} > + > +static void __hyp_text __activate_vm(struct kvm_vcpu *vcpu) > +{ > + struct kvm *kvm = kern_hyp_va(vcpu->kvm); > + write_sysreg(kvm->arch.vttbr, VTTBR); > + write_sysreg(vcpu->arch.midr, VMIDR); > +} > + > +static void __hyp_text __deactivate_vm(struct kvm_vcpu *vcpu) > +{ > + write_sysreg(0, VTTBR); > + write_sysreg(read_sysreg(MIDR), VMIDR); > +} > + > +static void __hyp_text __vgic_save_state(struct kvm_vcpu *vcpu) > +{ > + __vgic_v2_save_state(vcpu); > +} > + > +static void __hyp_text __vgic_restore_state(struct kvm_vcpu *vcpu) > +{ > + __vgic_v2_restore_state(vcpu); > +} > + > +static int __hyp_text __guest_run(struct kvm_vcpu *vcpu) > +{ > + struct kvm_cpu_context *host_ctxt; > + struct kvm_cpu_context *guest_ctxt; > + bool fp_enabled; > + u64 exit_code; > + u32 fpexc; > + > + vcpu = kern_hyp_va(vcpu); > + write_sysreg(vcpu, HTPIDR); > + > + host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); > + guest_ctxt = &vcpu->arch.ctxt; > + > + __sysreg_save_state(host_ctxt); > + __banked_save_state(host_ctxt); > + > + __activate_traps(vcpu, &fpexc); > + __activate_vm(vcpu); > + > + __vgic_restore_state(vcpu); > + __timer_restore_state(vcpu); > + > + __sysreg_restore_state(guest_ctxt); > + __banked_restore_state(guest_ctxt); > + > + /* Jump in the fire! */ > + exit_code = __guest_enter(vcpu, host_ctxt); > + /* And we're baaack! */ > + > + fp_enabled = __vfp_enabled(); > + > + __banked_save_state(guest_ctxt); > + __sysreg_save_state(guest_ctxt); > + __timer_save_state(vcpu); > + __vgic_save_state(vcpu); > + > + __deactivate_traps(vcpu); > + __deactivate_vm(vcpu); > + > + __banked_restore_state(host_ctxt); > + __sysreg_restore_state(host_ctxt); > + > + if (fp_enabled) { > + __vfp_save_state(&guest_ctxt->vfp); > + __vfp_restore_state(&host_ctxt->vfp); > + } > + > + write_sysreg(fpexc, VFP_FPEXC); > + > + return exit_code; > +} > + > +__alias(__guest_run) int __weak __kvm_vcpu_run(struct kvm_vcpu *vcpu); > -- > 2.1.4 > Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> -- 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
