1 files changed, 109 insertions, 0 deletions

diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S
new file mode 100644
index 000000000000..0959611d9ff1
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+++ b/arch/arm64/kernel/hyp-stub.S
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+/*
+ * Hypervisor stub
+ *
+ * Copyright (C) 2012 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/init.h>
+#include <linux/linkage.h>
+
+#include <asm/assembler.h>
+#include <asm/ptrace.h>
+#include <asm/virt.h>
+
+        .text
+        .align 11
+
+ENTRY(__hyp_stub_vectors)
+        ventry  el2_sync_invalid                // Synchronous EL2t
+        ventry  el2_irq_invalid                 // IRQ EL2t
+        ventry  el2_fiq_invalid                 // FIQ EL2t
+        ventry  el2_error_invalid               // Error EL2t
+
+        ventry  el2_sync_invalid                // Synchronous EL2h
+        ventry  el2_irq_invalid                 // IRQ EL2h
+        ventry  el2_fiq_invalid                 // FIQ EL2h
+        ventry  el2_error_invalid               // Error EL2h
+
+        ventry  el1_sync                        // Synchronous 64-bit EL1
+        ventry  el1_irq_invalid                 // IRQ 64-bit EL1
+        ventry  el1_fiq_invalid                 // FIQ 64-bit EL1
+        ventry  el1_error_invalid               // Error 64-bit EL1
+
+        ventry  el1_sync_invalid                // Synchronous 32-bit EL1
+        ventry  el1_irq_invalid                 // IRQ 32-bit EL1
+        ventry  el1_fiq_invalid                 // FIQ 32-bit EL1
+        ventry  el1_error_invalid               // Error 32-bit EL1
+ENDPROC(__hyp_stub_vectors)
+
+        .align 11
+
+el1_sync:
+        mrs     x1, esr_el2
+        lsr     x1, x1, #26
+        cmp     x1, #0x16
+        b.ne    2f                              // Not an HVC trap
+        cbz     x0, 1f
+        msr     vbar_el2, x0                    // Set vbar_el2
+        b       2f
+1:      mrs     x0, vbar_el2                    // Return vbar_el2
+2:      eret
+ENDPROC(el1_sync)
+
+.macro invalid_vector   label
+\label:
+        b \label
+ENDPROC(\label)
+.endm
+
+        invalid_vector  el2_sync_invalid
+        invalid_vector  el2_irq_invalid
+        invalid_vector  el2_fiq_invalid
+        invalid_vector  el2_error_invalid
+        invalid_vector  el1_sync_invalid
+        invalid_vector  el1_irq_invalid
+        invalid_vector  el1_fiq_invalid
+        invalid_vector  el1_error_invalid
+
+/*
+ * __hyp_set_vectors: Call this after boot to set the initial hypervisor
+ * vectors as part of hypervisor installation.  On an SMP system, this should
+ * be called on each CPU.
+ *
+ * x0 must be the physical address of the new vector table, and must be
+ * 2KB aligned.
+ *
+ * Before calling this, you must check that the stub hypervisor is installed
+ * everywhere, by waiting for any secondary CPUs to be brought up and then
+ * checking that is_hyp_mode_available() is true.
+ *
+ * If not, there is a pre-existing hypervisor, some CPUs failed to boot, or
+ * something else went wrong... in such cases, trying to install a new
+ * hypervisor is unlikely to work as desired.
+ *
+ * When you call into your shiny new hypervisor, sp_el2 will contain junk,
+ * so you will need to set that to something sensible at the new hypervisor's
+ * initialisation entry point.
+ */
+
+ENTRY(__hyp_get_vectors)
+        mov     x0, xzr
+        // fall through
+ENTRY(__hyp_set_vectors)
+        hvc     #0
+        ret
+ENDPROC(__hyp_get_vectors)
+ENDPROC(__hyp_set_vectors)