diff options
author | Marc Zyngier <marc.zyngier@arm.com> | 2012-10-19 18:46:27 +0200 |
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committer | Catalin Marinas <catalin.marinas@arm.com> | 2012-12-05 12:26:49 +0100 |
commit | 712c6ff4dba4917a440be601dc312506322bffe8 (patch) | |
tree | 70890fcc3d289c04126fea2474f8a31fd79e3fcc /arch/arm64/kernel/hyp-stub.S | |
parent | arm64: record boot mode when entering the kernel (diff) | |
download | linux-712c6ff4dba4917a440be601dc312506322bffe8.tar.xz linux-712c6ff4dba4917a440be601dc312506322bffe8.zip |
arm64: add hypervisor stub
If booted in EL2, install an dummy hypervisor whose only purpose
is to be replaced by a full fledged one.
A minimal API allows to:
- obtain the current HYP vectors (__hyp_get_vectors)
- set new HYP vectors (__hyp_set_vectors)
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/hyp-stub.S')
-rw-r--r-- | arch/arm64/kernel/hyp-stub.S | 109 |
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 --- /dev/null +++ b/arch/arm64/kernel/hyp-stub.S @@ -0,0 +1,109 @@ +/* + * 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) |