ARM: KVM: Add banked registers save/restore

Banked registers are one of the many perks of the 32bit architecture,
and the world switch needs to cope with it.

This requires some "special" accessors, as these are not accessed
using a standard coprocessor instruction.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

1 files changed, 77 insertions, 0 deletions

diff --git a/arch/arm/kvm/hyp/banked-sr.c b/arch/arm/kvm/hyp/banked-sr.c
new file mode 100644
index 000000000000..d02dc804f611
--- /dev/null
+++ b/arch/arm/kvm/hyp/banked-sr.c
@@ -0,0 +1,77 @@
+/*
+ * Original code:
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Author: Christoffer Dall <c.dall@virtualopensystems.com>
+ *
+ * Mostly rewritten in C by 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 "hyp.h"
+
+__asm__(".arch_extension     virt");
+
+void __hyp_text __banked_save_state(struct kvm_cpu_context *ctxt)
+{
+	ctxt->gp_regs.usr_regs.ARM_sp	= read_special(SP_usr);
+	ctxt->gp_regs.usr_regs.ARM_pc	= read_special(ELR_hyp);
+	ctxt->gp_regs.usr_regs.ARM_cpsr	= read_special(SPSR);
+	ctxt->gp_regs.KVM_ARM_SVC_sp	= read_special(SP_svc);
+	ctxt->gp_regs.KVM_ARM_SVC_lr	= read_special(LR_svc);
+	ctxt->gp_regs.KVM_ARM_SVC_spsr	= read_special(SPSR_svc);
+	ctxt->gp_regs.KVM_ARM_ABT_sp	= read_special(SP_abt);
+	ctxt->gp_regs.KVM_ARM_ABT_lr	= read_special(LR_abt);
+	ctxt->gp_regs.KVM_ARM_ABT_spsr	= read_special(SPSR_abt);
+	ctxt->gp_regs.KVM_ARM_UND_sp	= read_special(SP_und);
+	ctxt->gp_regs.KVM_ARM_UND_lr	= read_special(LR_und);
+	ctxt->gp_regs.KVM_ARM_UND_spsr	= read_special(SPSR_und);
+	ctxt->gp_regs.KVM_ARM_IRQ_sp	= read_special(SP_irq);
+	ctxt->gp_regs.KVM_ARM_IRQ_lr	= read_special(LR_irq);
+	ctxt->gp_regs.KVM_ARM_IRQ_spsr	= read_special(SPSR_irq);
+	ctxt->gp_regs.KVM_ARM_FIQ_r8	= read_special(R8_fiq);
+	ctxt->gp_regs.KVM_ARM_FIQ_r9	= read_special(R9_fiq);
+	ctxt->gp_regs.KVM_ARM_FIQ_r10	= read_special(R10_fiq);
+	ctxt->gp_regs.KVM_ARM_FIQ_fp	= read_special(R11_fiq);
+	ctxt->gp_regs.KVM_ARM_FIQ_ip	= read_special(R12_fiq);
+	ctxt->gp_regs.KVM_ARM_FIQ_sp	= read_special(SP_fiq);
+	ctxt->gp_regs.KVM_ARM_FIQ_lr	= read_special(LR_fiq);
+	ctxt->gp_regs.KVM_ARM_FIQ_spsr	= read_special(SPSR_fiq);
+}
+
+void __hyp_text __banked_restore_state(struct kvm_cpu_context *ctxt)
+{
+	write_special(ctxt->gp_regs.usr_regs.ARM_sp,	SP_usr);
+	write_special(ctxt->gp_regs.usr_regs.ARM_pc,	ELR_hyp);
+	write_special(ctxt->gp_regs.usr_regs.ARM_cpsr,	SPSR_cxsf);
+	write_special(ctxt->gp_regs.KVM_ARM_SVC_sp,	SP_svc);
+	write_special(ctxt->gp_regs.KVM_ARM_SVC_lr,	LR_svc);
+	write_special(ctxt->gp_regs.KVM_ARM_SVC_spsr,	SPSR_svc);
+	write_special(ctxt->gp_regs.KVM_ARM_ABT_sp,	SP_abt);
+	write_special(ctxt->gp_regs.KVM_ARM_ABT_lr,	LR_abt);
+	write_special(ctxt->gp_regs.KVM_ARM_ABT_spsr,	SPSR_abt);
+	write_special(ctxt->gp_regs.KVM_ARM_UND_sp,	SP_und);
+	write_special(ctxt->gp_regs.KVM_ARM_UND_lr,	LR_und);
+	write_special(ctxt->gp_regs.KVM_ARM_UND_spsr,	SPSR_und);
+	write_special(ctxt->gp_regs.KVM_ARM_IRQ_sp,	SP_irq);
+	write_special(ctxt->gp_regs.KVM_ARM_IRQ_lr,	LR_irq);
+	write_special(ctxt->gp_regs.KVM_ARM_IRQ_spsr,	SPSR_irq);
+	write_special(ctxt->gp_regs.KVM_ARM_FIQ_r8,	R8_fiq);
+	write_special(ctxt->gp_regs.KVM_ARM_FIQ_r9,	R9_fiq);
+	write_special(ctxt->gp_regs.KVM_ARM_FIQ_r10,	R10_fiq);
+	write_special(ctxt->gp_regs.KVM_ARM_FIQ_fp,	R11_fiq);
+	write_special(ctxt->gp_regs.KVM_ARM_FIQ_ip,	R12_fiq);
+	write_special(ctxt->gp_regs.KVM_ARM_FIQ_sp,	SP_fiq);
+	write_special(ctxt->gp_regs.KVM_ARM_FIQ_lr,	LR_fiq);
+	write_special(ctxt->gp_regs.KVM_ARM_FIQ_spsr,	SPSR_fiq);
+}