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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /arch/arm/kvm/hyp
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/arm/kvm/hyp')
-rw-r--r--arch/arm/kvm/hyp/Makefile34
-rw-r--r--arch/arm/kvm/hyp/banked-sr.c81
-rw-r--r--arch/arm/kvm/hyp/cp15-sr.c84
-rw-r--r--arch/arm/kvm/hyp/entry.S132
-rw-r--r--arch/arm/kvm/hyp/hyp-entry.S307
-rw-r--r--arch/arm/kvm/hyp/s2-setup.c33
-rw-r--r--arch/arm/kvm/hyp/switch.c253
-rw-r--r--arch/arm/kvm/hyp/tlb.c79
-rw-r--r--arch/arm/kvm/hyp/vfp.S68
9 files changed, 1071 insertions, 0 deletions
diff --git a/arch/arm/kvm/hyp/Makefile b/arch/arm/kvm/hyp/Makefile
new file mode 100644
index 000000000..ba88b1eca
--- /dev/null
+++ b/arch/arm/kvm/hyp/Makefile
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for Kernel-based Virtual Machine module, HYP part
+#
+
+ccflags-y += -fno-stack-protector -DDISABLE_BRANCH_PROFILING
+
+KVM=../../../../virt/kvm
+
+CFLAGS_ARMV7VE :=$(call cc-option, -march=armv7ve)
+
+obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/vgic-v3-sr.o
+obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/timer-sr.o
+obj-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/hyp/aarch32.o
+
+obj-$(CONFIG_KVM_ARM_HOST) += tlb.o
+obj-$(CONFIG_KVM_ARM_HOST) += cp15-sr.o
+obj-$(CONFIG_KVM_ARM_HOST) += vfp.o
+obj-$(CONFIG_KVM_ARM_HOST) += banked-sr.o
+CFLAGS_banked-sr.o += $(CFLAGS_ARMV7VE)
+
+obj-$(CONFIG_KVM_ARM_HOST) += entry.o
+obj-$(CONFIG_KVM_ARM_HOST) += hyp-entry.o
+obj-$(CONFIG_KVM_ARM_HOST) += switch.o
+CFLAGS_switch.o += $(CFLAGS_ARMV7VE)
+obj-$(CONFIG_KVM_ARM_HOST) += s2-setup.o
+
+# KVM code is run at a different exception code with a different map, so
+# compiler instrumentation that inserts callbacks or checks into the code may
+# cause crashes. Just disable it.
+GCOV_PROFILE := n
+KASAN_SANITIZE := n
+UBSAN_SANITIZE := n
+KCOV_INSTRUMENT := n
diff --git a/arch/arm/kvm/hyp/banked-sr.c b/arch/arm/kvm/hyp/banked-sr.c
new file mode 100644
index 000000000..be4b8b0a4
--- /dev/null
+++ b/arch/arm/kvm/hyp/banked-sr.c
@@ -0,0 +1,81 @@
+/*
+ * 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 <asm/kvm_hyp.h>
+
+/*
+ * gcc before 4.9 doesn't understand -march=armv7ve, so we have to
+ * trick the assembler.
+ */
+__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);
+}
diff --git a/arch/arm/kvm/hyp/cp15-sr.c b/arch/arm/kvm/hyp/cp15-sr.c
new file mode 100644
index 000000000..c47828127
--- /dev/null
+++ b/arch/arm/kvm/hyp/cp15-sr.c
@@ -0,0 +1,84 @@
+/*
+ * 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 <asm/kvm_hyp.h>
+
+static u64 *cp15_64(struct kvm_cpu_context *ctxt, int idx)
+{
+ return (u64 *)(ctxt->cp15 + idx);
+}
+
+void __hyp_text __sysreg_save_state(struct kvm_cpu_context *ctxt)
+{
+ ctxt->cp15[c0_MPIDR] = read_sysreg(VMPIDR);
+ ctxt->cp15[c0_CSSELR] = read_sysreg(CSSELR);
+ ctxt->cp15[c1_SCTLR] = read_sysreg(SCTLR);
+ ctxt->cp15[c1_CPACR] = read_sysreg(CPACR);
+ *cp15_64(ctxt, c2_TTBR0) = read_sysreg(TTBR0);
+ *cp15_64(ctxt, c2_TTBR1) = read_sysreg(TTBR1);
+ ctxt->cp15[c2_TTBCR] = read_sysreg(TTBCR);
+ ctxt->cp15[c3_DACR] = read_sysreg(DACR);
+ ctxt->cp15[c5_DFSR] = read_sysreg(DFSR);
+ ctxt->cp15[c5_IFSR] = read_sysreg(IFSR);
+ ctxt->cp15[c5_ADFSR] = read_sysreg(ADFSR);
+ ctxt->cp15[c5_AIFSR] = read_sysreg(AIFSR);
+ ctxt->cp15[c6_DFAR] = read_sysreg(DFAR);
+ ctxt->cp15[c6_IFAR] = read_sysreg(IFAR);
+ *cp15_64(ctxt, c7_PAR) = read_sysreg(PAR);
+ ctxt->cp15[c10_PRRR] = read_sysreg(PRRR);
+ ctxt->cp15[c10_NMRR] = read_sysreg(NMRR);
+ ctxt->cp15[c10_AMAIR0] = read_sysreg(AMAIR0);
+ ctxt->cp15[c10_AMAIR1] = read_sysreg(AMAIR1);
+ ctxt->cp15[c12_VBAR] = read_sysreg(VBAR);
+ ctxt->cp15[c13_CID] = read_sysreg(CID);
+ ctxt->cp15[c13_TID_URW] = read_sysreg(TID_URW);
+ ctxt->cp15[c13_TID_URO] = read_sysreg(TID_URO);
+ ctxt->cp15[c13_TID_PRIV] = read_sysreg(TID_PRIV);
+ ctxt->cp15[c14_CNTKCTL] = read_sysreg(CNTKCTL);
+}
+
+void __hyp_text __sysreg_restore_state(struct kvm_cpu_context *ctxt)
+{
+ write_sysreg(ctxt->cp15[c0_MPIDR], VMPIDR);
+ write_sysreg(ctxt->cp15[c0_CSSELR], CSSELR);
+ write_sysreg(ctxt->cp15[c1_SCTLR], SCTLR);
+ write_sysreg(ctxt->cp15[c1_CPACR], CPACR);
+ write_sysreg(*cp15_64(ctxt, c2_TTBR0), TTBR0);
+ write_sysreg(*cp15_64(ctxt, c2_TTBR1), TTBR1);
+ write_sysreg(ctxt->cp15[c2_TTBCR], TTBCR);
+ write_sysreg(ctxt->cp15[c3_DACR], DACR);
+ write_sysreg(ctxt->cp15[c5_DFSR], DFSR);
+ write_sysreg(ctxt->cp15[c5_IFSR], IFSR);
+ write_sysreg(ctxt->cp15[c5_ADFSR], ADFSR);
+ write_sysreg(ctxt->cp15[c5_AIFSR], AIFSR);
+ write_sysreg(ctxt->cp15[c6_DFAR], DFAR);
+ write_sysreg(ctxt->cp15[c6_IFAR], IFAR);
+ write_sysreg(*cp15_64(ctxt, c7_PAR), PAR);
+ write_sysreg(ctxt->cp15[c10_PRRR], PRRR);
+ write_sysreg(ctxt->cp15[c10_NMRR], NMRR);
+ write_sysreg(ctxt->cp15[c10_AMAIR0], AMAIR0);
+ write_sysreg(ctxt->cp15[c10_AMAIR1], AMAIR1);
+ write_sysreg(ctxt->cp15[c12_VBAR], VBAR);
+ write_sysreg(ctxt->cp15[c13_CID], CID);
+ write_sysreg(ctxt->cp15[c13_TID_URW], TID_URW);
+ write_sysreg(ctxt->cp15[c13_TID_URO], TID_URO);
+ write_sysreg(ctxt->cp15[c13_TID_PRIV], TID_PRIV);
+ write_sysreg(ctxt->cp15[c14_CNTKCTL], CNTKCTL);
+}
diff --git a/arch/arm/kvm/hyp/entry.S b/arch/arm/kvm/hyp/entry.S
new file mode 100644
index 000000000..60783f3b5
--- /dev/null
+++ b/arch/arm/kvm/hyp/entry.S
@@ -0,0 +1,132 @@
+/*
+ * 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>
+#include <asm/kvm_asm.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
+ mrs r1, SPSR
+ mrs r2, ELR_hyp
+ mrc p15, 4, r3, c5, c2, 0 @ HSR
+
+ /*
+ * Force loads and stores to complete before unmasking aborts
+ * and forcing the delivery of the exception. This gives us a
+ * single instruction window, which the handler will try to
+ * match.
+ */
+ dsb sy
+ cpsie a
+
+ .global abort_guest_exit_start
+abort_guest_exit_start:
+
+ isb
+
+ .global abort_guest_exit_end
+abort_guest_exit_end:
+
+ /*
+ * If we took an abort, r0[31] will be set, and cmp will set
+ * the N bit in PSTATE.
+ */
+ cmp r0, #0
+ msrmi SPSR_cxsf, r1
+ msrmi ELR_hyp, r2
+ mcrmi p15, 4, r3, c5, c2, 0 @ HSR
+
+ bx lr
+ENDPROC(__guest_exit)
+
+/*
+ * If VFPv3 support is not available, then we will not switch the VFP
+ * registers; however cp10 and cp11 accesses will still trap and fallback
+ * to the regular coprocessor emulation code, which currently will
+ * inject an undefined exception to the guest.
+ */
+#ifdef CONFIG_VFPv3
+ENTRY(__vfp_guest_restore)
+ push {r3, r4, lr}
+
+ @ NEON/VFP used. Turn on VFP access.
+ mrc p15, 4, r1, c1, c1, 2 @ HCPTR
+ bic r1, r1, #(HCPTR_TCP(10) | HCPTR_TCP(11))
+ mcr p15, 4, r1, c1, c1, 2 @ HCPTR
+ isb
+
+ @ Switch VFP/NEON hardware state to the guest's
+ mov r4, r0
+ ldr r0, [r0, #VCPU_HOST_CTXT]
+ add r0, r0, #CPU_CTXT_VFP
+ bl __vfp_save_state
+ add r0, r4, #(VCPU_GUEST_CTXT + CPU_CTXT_VFP)
+ bl __vfp_restore_state
+
+ pop {r3, r4, lr}
+ pop {r0, r1, r2}
+ clrex
+ eret
+ENDPROC(__vfp_guest_restore)
+#endif
+
+ .popsection
+
diff --git a/arch/arm/kvm/hyp/hyp-entry.S b/arch/arm/kvm/hyp/hyp-entry.S
new file mode 100644
index 000000000..aa3f9a983
--- /dev/null
+++ b/arch/arm/kvm/hyp/hyp-entry.S
@@ -0,0 +1,307 @@
+/*
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Author: Christoffer Dall <c.dall@virtualopensystems.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, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#include <linux/arm-smccc.h>
+#include <linux/linkage.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_asm.h>
+
+ .arch_extension virt
+
+ .text
+ .pushsection .hyp.text, "ax"
+
+.macro load_vcpu reg
+ mrc p15, 4, \reg, c13, c0, 2 @ HTPIDR
+.endm
+
+/********************************************************************
+ * Hypervisor exception vector and handlers
+ *
+ *
+ * The KVM/ARM Hypervisor ABI is defined as follows:
+ *
+ * Entry to Hyp mode from the host kernel will happen _only_ when an HVC
+ * instruction is issued since all traps are disabled when running the host
+ * kernel as per the Hyp-mode initialization at boot time.
+ *
+ * HVC instructions cause a trap to the vector page + offset 0x14 (see hyp_hvc
+ * below) when the HVC instruction is called from SVC mode (i.e. a guest or the
+ * host kernel) and they cause a trap to the vector page + offset 0x8 when HVC
+ * instructions are called from within Hyp-mode.
+ *
+ * Hyp-ABI: Calling HYP-mode functions from host (in SVC mode):
+ * Switching to Hyp mode is done through a simple HVC #0 instruction. The
+ * exception vector code will check that the HVC comes from VMID==0.
+ * - r0 contains a pointer to a HYP function
+ * - r1, r2, and r3 contain arguments to the above function.
+ * - The HYP function will be called with its arguments in r0, r1 and r2.
+ * On HYP function return, we return directly to SVC.
+ *
+ * Note that the above is used to execute code in Hyp-mode from a host-kernel
+ * point of view, and is a different concept from performing a world-switch and
+ * executing guest code SVC mode (with a VMID != 0).
+ */
+
+ .align 5
+__kvm_hyp_vector:
+ .global __kvm_hyp_vector
+
+ @ Hyp-mode exception vector
+ W(b) hyp_reset
+ W(b) hyp_undef
+ W(b) hyp_svc
+ W(b) hyp_pabt
+ W(b) hyp_dabt
+ W(b) hyp_hvc
+ W(b) hyp_irq
+ W(b) hyp_fiq
+
+#ifdef CONFIG_HARDEN_BRANCH_PREDICTOR
+ .align 5
+__kvm_hyp_vector_ic_inv:
+ .global __kvm_hyp_vector_ic_inv
+
+ /*
+ * We encode the exception entry in the bottom 3 bits of
+ * SP, and we have to guarantee to be 8 bytes aligned.
+ */
+ W(add) sp, sp, #1 /* Reset 7 */
+ W(add) sp, sp, #1 /* Undef 6 */
+ W(add) sp, sp, #1 /* Syscall 5 */
+ W(add) sp, sp, #1 /* Prefetch abort 4 */
+ W(add) sp, sp, #1 /* Data abort 3 */
+ W(add) sp, sp, #1 /* HVC 2 */
+ W(add) sp, sp, #1 /* IRQ 1 */
+ W(nop) /* FIQ 0 */
+
+ mcr p15, 0, r0, c7, c5, 0 /* ICIALLU */
+ isb
+
+ b decode_vectors
+
+ .align 5
+__kvm_hyp_vector_bp_inv:
+ .global __kvm_hyp_vector_bp_inv
+
+ /*
+ * We encode the exception entry in the bottom 3 bits of
+ * SP, and we have to guarantee to be 8 bytes aligned.
+ */
+ W(add) sp, sp, #1 /* Reset 7 */
+ W(add) sp, sp, #1 /* Undef 6 */
+ W(add) sp, sp, #1 /* Syscall 5 */
+ W(add) sp, sp, #1 /* Prefetch abort 4 */
+ W(add) sp, sp, #1 /* Data abort 3 */
+ W(add) sp, sp, #1 /* HVC 2 */
+ W(add) sp, sp, #1 /* IRQ 1 */
+ W(nop) /* FIQ 0 */
+
+ mcr p15, 0, r0, c7, c5, 6 /* BPIALL */
+ isb
+
+decode_vectors:
+
+#ifdef CONFIG_THUMB2_KERNEL
+ /*
+ * Yet another silly hack: Use VPIDR as a temp register.
+ * Thumb2 is really a pain, as SP cannot be used with most
+ * of the bitwise instructions. The vect_br macro ensures
+ * things gets cleaned-up.
+ */
+ mcr p15, 4, r0, c0, c0, 0 /* VPIDR */
+ mov r0, sp
+ and r0, r0, #7
+ sub sp, sp, r0
+ push {r1, r2}
+ mov r1, r0
+ mrc p15, 4, r0, c0, c0, 0 /* VPIDR */
+ mrc p15, 0, r2, c0, c0, 0 /* MIDR */
+ mcr p15, 4, r2, c0, c0, 0 /* VPIDR */
+#endif
+
+.macro vect_br val, targ
+ARM( eor sp, sp, #\val )
+ARM( tst sp, #7 )
+ARM( eorne sp, sp, #\val )
+
+THUMB( cmp r1, #\val )
+THUMB( popeq {r1, r2} )
+
+ beq \targ
+.endm
+
+ vect_br 0, hyp_fiq
+ vect_br 1, hyp_irq
+ vect_br 2, hyp_hvc
+ vect_br 3, hyp_dabt
+ vect_br 4, hyp_pabt
+ vect_br 5, hyp_svc
+ vect_br 6, hyp_undef
+ vect_br 7, hyp_reset
+#endif
+
+.macro invalid_vector label, cause
+ .align
+\label: mov r0, #\cause
+ b __hyp_panic
+.endm
+
+ invalid_vector hyp_reset ARM_EXCEPTION_RESET
+ invalid_vector hyp_undef ARM_EXCEPTION_UNDEFINED
+ invalid_vector hyp_svc ARM_EXCEPTION_SOFTWARE
+ invalid_vector hyp_pabt ARM_EXCEPTION_PREF_ABORT
+ invalid_vector hyp_fiq ARM_EXCEPTION_FIQ
+
+ENTRY(__hyp_do_panic)
+ mrs lr, cpsr
+ bic lr, lr, #MODE_MASK
+ orr lr, lr, #SVC_MODE
+THUMB( orr lr, lr, #PSR_T_BIT )
+ msr spsr_cxsf, lr
+ ldr lr, =panic
+ msr ELR_hyp, lr
+ ldr lr, =kvm_call_hyp
+ clrex
+ eret
+ENDPROC(__hyp_do_panic)
+
+hyp_hvc:
+ /*
+ * Getting here is either because of a trap from a guest,
+ * or from executing HVC from the host kernel, which means
+ * "do something in Hyp mode".
+ */
+ push {r0, r1, r2}
+
+ @ Check syndrome register
+ mrc p15, 4, r1, c5, c2, 0 @ HSR
+ lsr r0, r1, #HSR_EC_SHIFT
+ cmp r0, #HSR_EC_HVC
+ bne guest_trap @ Not HVC instr.
+
+ /*
+ * Let's check if the HVC came from VMID 0 and allow simple
+ * switch to Hyp mode
+ */
+ mrrc p15, 6, r0, r2, c2
+ lsr r2, r2, #16
+ and r2, r2, #0xff
+ cmp r2, #0
+ bne guest_hvc_trap @ Guest called HVC
+
+ /*
+ * Getting here means host called HVC, we shift parameters and branch
+ * to Hyp function.
+ */
+ pop {r0, r1, r2}
+
+ /*
+ * Check if we have a kernel function, which is guaranteed to be
+ * bigger than the maximum hyp stub hypercall
+ */
+ cmp r0, #HVC_STUB_HCALL_NR
+ bhs 1f
+
+ /*
+ * Not a kernel function, treat it as a stub hypercall.
+ * Compute the physical address for __kvm_handle_stub_hvc
+ * (as the code lives in the idmaped page) and branch there.
+ * We hijack ip (r12) as a tmp register.
+ */
+ push {r1}
+ ldr r1, =kimage_voffset
+ ldr r1, [r1]
+ ldr ip, =__kvm_handle_stub_hvc
+ sub ip, ip, r1
+ pop {r1}
+
+ bx ip
+
+1:
+ /*
+ * Pushing r2 here is just a way of keeping the stack aligned to
+ * 8 bytes on any path that can trigger a HYP exception. Here,
+ * we may well be about to jump into the guest, and the guest
+ * exit would otherwise be badly decoded by our fancy
+ * "decode-exception-without-a-branch" code...
+ */
+ push {r2, lr}
+
+ mov lr, r0
+ mov r0, r1
+ mov r1, r2
+ mov r2, r3
+
+THUMB( orr lr, #1)
+ blx lr @ Call the HYP function
+
+ pop {r2, lr}
+ eret
+
+guest_hvc_trap:
+ movw r2, #:lower16:ARM_SMCCC_ARCH_WORKAROUND_1
+ movt r2, #:upper16:ARM_SMCCC_ARCH_WORKAROUND_1
+ ldr r0, [sp] @ Guest's r0
+ teq r0, r2
+ bne guest_trap
+ add sp, sp, #12
+ @ Returns:
+ @ r0 = 0
+ @ r1 = HSR value (perfectly predictable)
+ @ r2 = ARM_SMCCC_ARCH_WORKAROUND_1
+ mov r0, #0
+ eret
+
+guest_trap:
+ load_vcpu r0 @ Load VCPU pointer to r0
+
+#ifdef CONFIG_VFPv3
+ @ Check for a VFP access
+ lsr r1, r1, #HSR_EC_SHIFT
+ cmp r1, #HSR_EC_CP_0_13
+ beq __vfp_guest_restore
+#endif
+
+ mov r1, #ARM_EXCEPTION_HVC
+ b __guest_exit
+
+hyp_irq:
+ push {r0, r1, r2}
+ mov r1, #ARM_EXCEPTION_IRQ
+ load_vcpu r0 @ Load VCPU pointer to r0
+ b __guest_exit
+
+hyp_dabt:
+ push {r0, r1}
+ mrs r0, ELR_hyp
+ ldr r1, =abort_guest_exit_start
+THUMB( add r1, r1, #1)
+ cmp r0, r1
+ ldrne r1, =abort_guest_exit_end
+THUMB( addne r1, r1, #1)
+ cmpne r0, r1
+ pop {r0, r1}
+ bne __hyp_panic
+
+ orr r0, r0, #(1 << ARM_EXIT_WITH_ABORT_BIT)
+ eret
+
+ .ltorg
+
+ .popsection
diff --git a/arch/arm/kvm/hyp/s2-setup.c b/arch/arm/kvm/hyp/s2-setup.c
new file mode 100644
index 000000000..7be39af2e
--- /dev/null
+++ b/arch/arm/kvm/hyp/s2-setup.c
@@ -0,0 +1,33 @@
+/*
+ * 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/types.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_hyp.h>
+
+void __hyp_text __init_stage2_translation(void)
+{
+ u64 val;
+
+ val = read_sysreg(VTCR) & ~VTCR_MASK;
+
+ val |= read_sysreg(HTCR) & VTCR_HTCR_SH;
+ val |= KVM_VTCR_SL0 | KVM_VTCR_T0SZ | KVM_VTCR_S;
+
+ write_sysreg(val, VTCR);
+}
diff --git a/arch/arm/kvm/hyp/switch.c b/arch/arm/kvm/hyp/switch.c
new file mode 100644
index 000000000..acf1c37fa
--- /dev/null
+++ b/arch/arm/kvm/hyp/switch.c
@@ -0,0 +1,253 @@
+/*
+ * Copyright (C) 2015 - 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/jump_label.h>
+
+#include <asm/kvm_asm.h>
+#include <asm/kvm_hyp.h>
+#include <asm/kvm_mmu.h>
+
+__asm__(".arch_extension virt");
+
+/*
+ * Activate the traps, saving the host's fpexc register before
+ * overwriting it. We'll restore it on VM exit.
+ */
+static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu, u32 *fpexc_host)
+{
+ 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_host = val;
+ if (!(val & FPEXC_EN)) {
+ write_sysreg(val | FPEXC_EN, VFP_FPEXC);
+ isb();
+ }
+
+ write_sysreg(vcpu->arch.hcr, 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);
+ val |= HDCR_TPM | HDCR_TPMCR; /* trap performance monitors */
+ val |= HDCR_TDRA | HDCR_TDOSA | HDCR_TDA; /* trap debug regs */
+ write_sysreg(val, HDCR);
+}
+
+static void __hyp_text __deactivate_traps(struct kvm_vcpu *vcpu)
+{
+ u32 val;
+
+ /*
+ * If we pended a virtual abort, preserve it until it gets
+ * cleared. See B1.9.9 (Virtual Abort exception) for details,
+ * but the crucial bit is the zeroing of HCR.VA in the
+ * pseudocode.
+ */
+ if (vcpu->arch.hcr & HCR_VA)
+ vcpu->arch.hcr = read_sysreg(HCR);
+
+ 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, VPIDR);
+}
+
+static void __hyp_text __deactivate_vm(struct kvm_vcpu *vcpu)
+{
+ write_sysreg(0, VTTBR);
+ write_sysreg(read_sysreg(MIDR), VPIDR);
+}
+
+
+static void __hyp_text __vgic_save_state(struct kvm_vcpu *vcpu)
+{
+ if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
+ __vgic_v3_save_state(vcpu);
+ __vgic_v3_deactivate_traps(vcpu);
+ }
+}
+
+static void __hyp_text __vgic_restore_state(struct kvm_vcpu *vcpu)
+{
+ if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
+ __vgic_v3_activate_traps(vcpu);
+ __vgic_v3_restore_state(vcpu);
+ }
+}
+
+static bool __hyp_text __populate_fault_info(struct kvm_vcpu *vcpu)
+{
+ u32 hsr = read_sysreg(HSR);
+ u8 ec = hsr >> HSR_EC_SHIFT;
+ u32 hpfar, far;
+
+ vcpu->arch.fault.hsr = hsr;
+
+ if (ec == HSR_EC_IABT)
+ far = read_sysreg(HIFAR);
+ else if (ec == HSR_EC_DABT)
+ far = read_sysreg(HDFAR);
+ else
+ return true;
+
+ /*
+ * B3.13.5 Reporting exceptions taken to the Non-secure PL2 mode:
+ *
+ * Abort on the stage 2 translation for a memory access from a
+ * Non-secure PL1 or PL0 mode:
+ *
+ * For any Access flag fault or Translation fault, and also for any
+ * Permission fault on the stage 2 translation of a memory access
+ * made as part of a translation table walk for a stage 1 translation,
+ * the HPFAR holds the IPA that caused the fault. Otherwise, the HPFAR
+ * is UNKNOWN.
+ */
+ if (!(hsr & HSR_DABT_S1PTW) && (hsr & HSR_FSC_TYPE) == FSC_PERM) {
+ u64 par, tmp;
+
+ par = read_sysreg(PAR);
+ write_sysreg(far, ATS1CPR);
+ isb();
+
+ tmp = read_sysreg(PAR);
+ write_sysreg(par, PAR);
+
+ if (unlikely(tmp & 1))
+ return false; /* Translation failed, back to guest */
+
+ hpfar = ((tmp >> 12) & ((1UL << 28) - 1)) << 4;
+ } else {
+ hpfar = read_sysreg(HPFAR);
+ }
+
+ vcpu->arch.fault.hxfar = far;
+ vcpu->arch.fault.hpfar = hpfar;
+ return true;
+}
+
+int __hyp_text __kvm_vcpu_run_nvhe(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_enable_traps(vcpu);
+
+ __sysreg_restore_state(guest_ctxt);
+ __banked_restore_state(guest_ctxt);
+
+ /* Jump in the fire! */
+again:
+ exit_code = __guest_enter(vcpu, host_ctxt);
+ /* And we're baaack! */
+
+ if (exit_code == ARM_EXCEPTION_HVC && !__populate_fault_info(vcpu))
+ goto again;
+
+ fp_enabled = __vfp_enabled();
+
+ __banked_save_state(guest_ctxt);
+ __sysreg_save_state(guest_ctxt);
+ __timer_disable_traps(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;
+}
+
+static const char * const __hyp_panic_string[] = {
+ [ARM_EXCEPTION_RESET] = "\nHYP panic: RST PC:%08x CPSR:%08x",
+ [ARM_EXCEPTION_UNDEFINED] = "\nHYP panic: UNDEF PC:%08x CPSR:%08x",
+ [ARM_EXCEPTION_SOFTWARE] = "\nHYP panic: SVC PC:%08x CPSR:%08x",
+ [ARM_EXCEPTION_PREF_ABORT] = "\nHYP panic: PABRT PC:%08x CPSR:%08x",
+ [ARM_EXCEPTION_DATA_ABORT] = "\nHYP panic: DABRT PC:%08x ADDR:%08x",
+ [ARM_EXCEPTION_IRQ] = "\nHYP panic: IRQ PC:%08x CPSR:%08x",
+ [ARM_EXCEPTION_FIQ] = "\nHYP panic: FIQ PC:%08x CPSR:%08x",
+ [ARM_EXCEPTION_HVC] = "\nHYP panic: HVC PC:%08x CPSR:%08x",
+};
+
+void __hyp_text __noreturn __hyp_panic(int cause)
+{
+ u32 elr = read_special(ELR_hyp);
+ u32 val;
+
+ if (cause == ARM_EXCEPTION_DATA_ABORT)
+ val = read_sysreg(HDFAR);
+ else
+ val = read_special(SPSR);
+
+ if (read_sysreg(VTTBR)) {
+ struct kvm_vcpu *vcpu;
+ struct kvm_cpu_context *host_ctxt;
+
+ vcpu = (struct kvm_vcpu *)read_sysreg(HTPIDR);
+ host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
+ __timer_disable_traps(vcpu);
+ __deactivate_traps(vcpu);
+ __deactivate_vm(vcpu);
+ __banked_restore_state(host_ctxt);
+ __sysreg_restore_state(host_ctxt);
+ }
+
+ /* Call panic for real */
+ __hyp_do_panic(__hyp_panic_string[cause], elr, val);
+
+ unreachable();
+}
diff --git a/arch/arm/kvm/hyp/tlb.c b/arch/arm/kvm/hyp/tlb.c
new file mode 100644
index 000000000..c0edd450e
--- /dev/null
+++ b/arch/arm/kvm/hyp/tlb.c
@@ -0,0 +1,79 @@
+/*
+ * 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 <asm/kvm_hyp.h>
+#include <asm/kvm_mmu.h>
+
+/**
+ * Flush per-VMID TLBs
+ *
+ * __kvm_tlb_flush_vmid(struct kvm *kvm);
+ *
+ * We rely on the hardware to broadcast the TLB invalidation to all CPUs
+ * inside the inner-shareable domain (which is the case for all v7
+ * implementations). If we come across a non-IS SMP implementation, we'll
+ * have to use an IPI based mechanism. Until then, we stick to the simple
+ * hardware assisted version.
+ *
+ * As v7 does not support flushing per IPA, just nuke the whole TLB
+ * instead, ignoring the ipa value.
+ */
+void __hyp_text __kvm_tlb_flush_vmid(struct kvm *kvm)
+{
+ dsb(ishst);
+
+ /* Switch to requested VMID */
+ kvm = kern_hyp_va(kvm);
+ write_sysreg(kvm->arch.vttbr, VTTBR);
+ isb();
+
+ write_sysreg(0, TLBIALLIS);
+ dsb(ish);
+ isb();
+
+ write_sysreg(0, VTTBR);
+}
+
+void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
+{
+ __kvm_tlb_flush_vmid(kvm);
+}
+
+void __hyp_text __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu)
+{
+ struct kvm *kvm = kern_hyp_va(kern_hyp_va(vcpu)->kvm);
+
+ /* Switch to requested VMID */
+ write_sysreg(kvm->arch.vttbr, VTTBR);
+ isb();
+
+ write_sysreg(0, TLBIALL);
+ dsb(nsh);
+ isb();
+
+ write_sysreg(0, VTTBR);
+}
+
+void __hyp_text __kvm_flush_vm_context(void)
+{
+ write_sysreg(0, TLBIALLNSNHIS);
+ write_sysreg(0, ICIALLUIS);
+ dsb(ish);
+}
diff --git a/arch/arm/kvm/hyp/vfp.S b/arch/arm/kvm/hyp/vfp.S
new file mode 100644
index 000000000..7c297e87e
--- /dev/null
+++ b/arch/arm/kvm/hyp/vfp.S
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Author: Christoffer Dall <c.dall@virtualopensystems.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/vfpmacros.h>
+
+ .text
+ .pushsection .hyp.text, "ax"
+
+/* void __vfp_save_state(struct vfp_hard_struct *vfp); */
+ENTRY(__vfp_save_state)
+ push {r4, r5}
+ VFPFMRX r1, FPEXC
+
+ @ Make sure *really* VFP is enabled so we can touch the registers.
+ orr r5, r1, #FPEXC_EN
+ tst r5, #FPEXC_EX @ Check for VFP Subarchitecture
+ bic r5, r5, #FPEXC_EX @ FPEXC_EX disable
+ VFPFMXR FPEXC, r5
+ isb
+
+ VFPFMRX r2, FPSCR
+ beq 1f
+
+ @ If FPEXC_EX is 0, then FPINST/FPINST2 reads are upredictable, so
+ @ we only need to save them if FPEXC_EX is set.
+ VFPFMRX r3, FPINST
+ tst r5, #FPEXC_FP2V
+ VFPFMRX r4, FPINST2, ne @ vmrsne
+1:
+ VFPFSTMIA r0, r5 @ Save VFP registers
+ stm r0, {r1-r4} @ Save FPEXC, FPSCR, FPINST, FPINST2
+ pop {r4, r5}
+ bx lr
+ENDPROC(__vfp_save_state)
+
+/* void __vfp_restore_state(struct vfp_hard_struct *vfp);
+ * Assume FPEXC_EN is on and FPEXC_EX is off */
+ENTRY(__vfp_restore_state)
+ VFPFLDMIA r0, r1 @ Load VFP registers
+ ldm r0, {r0-r3} @ Load FPEXC, FPSCR, FPINST, FPINST2
+
+ VFPFMXR FPSCR, r1
+ tst r0, #FPEXC_EX @ Check for VFP Subarchitecture
+ beq 1f
+ VFPFMXR FPINST, r2
+ tst r0, #FPEXC_FP2V
+ VFPFMXR FPINST2, r3, ne
+1:
+ VFPFMXR FPEXC, r0 @ FPEXC (last, in case !EN)
+ bx lr
+ENDPROC(__vfp_restore_state)
+
+ .popsection