From c13d1683df16db16c91372177ca10c31677b5ed5 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Mon, 26 Oct 2015 08:34:09 +0000 Subject: [PATCH] arm64: KVM: Implement fpsimd save/restore Implement the fpsimd save restore, keeping the lazy part in assembler (as returning to C would be overkill). Signed-off-by: Marc Zyngier Reviewed-by: Christoffer Dall --- arch/arm64/kvm/hyp/Makefile | 1 + arch/arm64/kvm/hyp/entry.S | 32 +++++++++++++++++++++++++++++++- arch/arm64/kvm/hyp/fpsimd.S | 33 +++++++++++++++++++++++++++++++++ arch/arm64/kvm/hyp/hyp.h | 7 +++++++ arch/arm64/kvm/hyp/switch.c | 8 ++++++++ arch/arm64/kvm/hyp/sysreg-sr.c | 2 +- 6 files changed, 81 insertions(+), 2 deletions(-) create mode 100644 arch/arm64/kvm/hyp/fpsimd.S diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile index 9c11b0fe1646..56238d08d36f 100644 --- a/arch/arm64/kvm/hyp/Makefile +++ b/arch/arm64/kvm/hyp/Makefile @@ -9,3 +9,4 @@ 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 +obj-$(CONFIG_KVM_ARM_HOST) += fpsimd.o diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S index ff196951e63b..90cbf0fee88a 100644 --- a/arch/arm64/kvm/hyp/entry.S +++ b/arch/arm64/kvm/hyp/entry.S @@ -27,6 +27,7 @@ #define CPU_GP_REG_OFFSET(x) (CPU_GP_REGS + x) #define CPU_XREG_OFFSET(x) CPU_GP_REG_OFFSET(CPU_USER_PT_REGS + 8*x) +#define CPU_SYSREG_OFFSET(x) (CPU_SYSREGS + 8*x) .text .pushsection .hyp.text, "ax" @@ -127,4 +128,33 @@ ENTRY(__guest_exit) ret ENDPROC(__guest_exit) - /* Insert fault handling here */ +ENTRY(__fpsimd_guest_restore) + stp x4, lr, [sp, #-16]! + + mrs x2, cptr_el2 + bic x2, x2, #CPTR_EL2_TFP + msr cptr_el2, x2 + isb + + mrs x3, tpidr_el2 + + ldr x0, [x3, #VCPU_HOST_CONTEXT] + kern_hyp_va x0 + add x0, x0, #CPU_GP_REG_OFFSET(CPU_FP_REGS) + bl __fpsimd_save_state + + add x2, x3, #VCPU_CONTEXT + add x0, x2, #CPU_GP_REG_OFFSET(CPU_FP_REGS) + bl __fpsimd_restore_state + + mrs x1, hcr_el2 + tbnz x1, #HCR_RW_SHIFT, 1f + ldr x4, [x2, #CPU_SYSREG_OFFSET(FPEXC32_EL2)] + msr fpexc32_el2, x4 +1: + ldp x4, lr, [sp], #16 + ldp x2, x3, [sp], #16 + ldp x0, x1, [sp], #16 + + eret +ENDPROC(__fpsimd_guest_restore) diff --git a/arch/arm64/kvm/hyp/fpsimd.S b/arch/arm64/kvm/hyp/fpsimd.S new file mode 100644 index 000000000000..da3f22c7f14a --- /dev/null +++ b/arch/arm64/kvm/hyp/fpsimd.S @@ -0,0 +1,33 @@ +/* + * Copyright (C) 2015 - ARM Ltd + * Author: Marc Zyngier + * + * 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 . + */ + +#include + +#include + + .text + .pushsection .hyp.text, "ax" + +ENTRY(__fpsimd_save_state) + fpsimd_save x0, 1 + ret +ENDPROC(__fpsimd_save_state) + +ENTRY(__fpsimd_restore_state) + fpsimd_restore x0, 1 + ret +ENDPROC(__fpsimd_restore_state) diff --git a/arch/arm64/kvm/hyp/hyp.h b/arch/arm64/kvm/hyp/hyp.h index 73419a769112..70d4f696c862 100644 --- a/arch/arm64/kvm/hyp/hyp.h +++ b/arch/arm64/kvm/hyp/hyp.h @@ -76,6 +76,13 @@ void __debug_restore_state(struct kvm_vcpu *vcpu, void __debug_cond_save_host_state(struct kvm_vcpu *vcpu); void __debug_cond_restore_host_state(struct kvm_vcpu *vcpu); +void __fpsimd_save_state(struct user_fpsimd_state *fp_regs); +void __fpsimd_restore_state(struct user_fpsimd_state *fp_regs); +static inline bool __fpsimd_enabled(void) +{ + return !(read_sysreg(cptr_el2) & CPTR_EL2_TFP); +} + u64 __guest_enter(struct kvm_vcpu *vcpu, struct kvm_cpu_context *host_ctxt); #endif /* __ARM64_KVM_HYP_H__ */ diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 79f59c98b148..608155f5b856 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -89,6 +89,7 @@ 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; vcpu = kern_hyp_va(vcpu); @@ -118,6 +119,8 @@ int __hyp_text __guest_run(struct kvm_vcpu *vcpu) exit_code = __guest_enter(vcpu, host_ctxt); /* And we're baaack! */ + fp_enabled = __fpsimd_enabled(); + __sysreg_save_state(guest_ctxt); __sysreg32_save_state(vcpu); __timer_save_state(vcpu); @@ -128,6 +131,11 @@ int __hyp_text __guest_run(struct kvm_vcpu *vcpu) __sysreg_restore_state(host_ctxt); + if (fp_enabled) { + __fpsimd_save_state(&guest_ctxt->gp_regs.fp_regs); + __fpsimd_restore_state(&host_ctxt->gp_regs.fp_regs); + } + __debug_save_state(vcpu, kern_hyp_va(vcpu->arch.debug_ptr), guest_ctxt); __debug_cond_restore_host_state(vcpu); diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c index eb05afb77ee8..36035417ec52 100644 --- a/arch/arm64/kvm/hyp/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/sysreg-sr.c @@ -107,7 +107,7 @@ void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu) sysreg[DACR32_EL2] = read_sysreg(dacr32_el2); sysreg[IFSR32_EL2] = read_sysreg(ifsr32_el2); - if (!(read_sysreg(cptr_el2) & CPTR_EL2_TFP)) + if (__fpsimd_enabled()) sysreg[FPEXC32_EL2] = read_sysreg(fpexc32_el2); if (vcpu->arch.debug_flags & KVM_ARM64_DEBUG_DIRTY) -- 2.30.2