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| author | Marc Zyngier <marc.zyngier@arm.com> | 2016-01-05 21:40:51 +0300 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2016-02-29 21:34:13 +0300 |
| commit | 89ef2b21ed2173e01995371261a9f9789bc1e47a (patch) | |
| tree | a082baca9cc3ae93a67e840178757b16b49f1fc7 /arch/arm/kvm/hyp | |
| parent | 33280b4cd1dc0bc7df8d6d3bd1b64c377c9e44d9 (diff) | |
| download | linux-89ef2b21ed2173e01995371261a9f9789bc1e47a.tar.xz | |
ARM: KVM: Add guest entry code
Add the very minimal piece of code that is now required to jump
into the guest (and return from it). This code is only concerned
with save/restoring the USR registers (r0-r12+lr for the guest,
r4-r12+lr for the host), as everything else is dealt with in C
(VFP is another matter though).
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm/kvm/hyp')
| -rw-r--r-- | arch/arm/kvm/hyp/Makefile | 1 | ||||
| -rw-r--r-- | arch/arm/kvm/hyp/entry.S | 70 | ||||
| -rw-r--r-- | arch/arm/kvm/hyp/hyp.h | 2 |
3 files changed, 73 insertions, 0 deletions
diff --git a/arch/arm/kvm/hyp/Makefile b/arch/arm/kvm/hyp/Makefile index 173bd1dd77e7..c77969008665 100644 --- a/arch/arm/kvm/hyp/Makefile +++ b/arch/arm/kvm/hyp/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_KVM_ARM_HOST) += timer-sr.o obj-$(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 diff --git a/arch/arm/kvm/hyp/entry.S b/arch/arm/kvm/hyp/entry.S new file mode 100644 index 000000000000..32f79b090040 --- /dev/null +++ b/arch/arm/kvm/hyp/entry.S @@ -0,0 +1,70 @@ +/* + * Copyright (C) 2016 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + * + * 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/linkage.h> +#include <asm/asm-offsets.h> +#include <asm/kvm_arm.h> + + .arch_extension virt + + .text + .pushsection .hyp.text, "ax" + +#define USR_REGS_OFFSET (CPU_CTXT_GP_REGS + GP_REGS_USR) + +/* int __guest_enter(struct kvm_vcpu *vcpu, struct kvm_cpu_context *host) */ +ENTRY(__guest_enter) + @ Save host registers + add r1, r1, #(USR_REGS_OFFSET + S_R4) + stm r1!, {r4-r12} + str lr, [r1, #4] @ Skip SP_usr (already saved) + + @ Restore guest registers + add r0, r0, #(VCPU_GUEST_CTXT + USR_REGS_OFFSET + S_R0) + ldr lr, [r0, #S_LR] + ldm r0, {r0-r12} + + clrex + eret +ENDPROC(__guest_enter) + +ENTRY(__guest_exit) + /* + * return convention: + * guest r0, r1, r2 saved on the stack + * r0: vcpu pointer + * r1: exception code + */ + + add r2, r0, #(VCPU_GUEST_CTXT + USR_REGS_OFFSET + S_R3) + stm r2!, {r3-r12} + str lr, [r2, #4] + add r2, r0, #(VCPU_GUEST_CTXT + USR_REGS_OFFSET + S_R0) + pop {r3, r4, r5} @ r0, r1, r2 + stm r2, {r3-r5} + + ldr r0, [r0, #VCPU_HOST_CTXT] + add r0, r0, #(USR_REGS_OFFSET + S_R4) + ldm r0!, {r4-r12} + ldr lr, [r0, #4] + + mov r0, r1 + bx lr +ENDPROC(__guest_exit) + + .popsection + diff --git a/arch/arm/kvm/hyp/hyp.h b/arch/arm/kvm/hyp/hyp.h index 278eb1fa5231..b3f6ed233564 100644 --- a/arch/arm/kvm/hyp/hyp.h +++ b/arch/arm/kvm/hyp/hyp.h @@ -110,4 +110,6 @@ static inline bool __vfp_enabled(void) void __hyp_text __banked_save_state(struct kvm_cpu_context *ctxt); void __hyp_text __banked_restore_state(struct kvm_cpu_context *ctxt); +int asmlinkage __guest_enter(struct kvm_vcpu *vcpu, + struct kvm_cpu_context *host); #endif /* __ARM_KVM_HYP_H__ */ |