Commit 712c6ff4 authored by Marc Zyngier's avatar Marc Zyngier Committed by Catalin Marinas

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: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent f35a9205
...@@ -33,6 +33,9 @@ ...@@ -33,6 +33,9 @@
*/ */
extern u32 __boot_cpu_mode[2]; extern u32 __boot_cpu_mode[2];
void __hyp_set_vectors(phys_addr_t phys_vector_base);
phys_addr_t __hyp_get_vectors(void);
/* Reports the availability of HYP mode */ /* Reports the availability of HYP mode */
static inline bool is_hyp_mode_available(void) static inline bool is_hyp_mode_available(void)
{ {
......
...@@ -8,7 +8,8 @@ AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET) ...@@ -8,7 +8,8 @@ AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET)
# Object file lists. # Object file lists.
arm64-obj-y := cputable.o debug-monitors.o entry.o irq.o fpsimd.o \ arm64-obj-y := cputable.o debug-monitors.o entry.o irq.o fpsimd.o \
entry-fpsimd.o process.o ptrace.o setup.o signal.o \ entry-fpsimd.o process.o ptrace.o setup.o signal.o \
sys.o stacktrace.o time.o traps.o io.o vdso.o sys.o stacktrace.o time.o traps.o io.o vdso.o \
hyp-stub.o
arm64-obj-$(CONFIG_COMPAT) += sys32.o kuser32.o signal32.o \ arm64-obj-$(CONFIG_COMPAT) += sys32.o kuser32.o signal32.o \
sys_compat.o sys_compat.o
......
...@@ -185,6 +185,10 @@ ENTRY(el2_setup) ...@@ -185,6 +185,10 @@ ENTRY(el2_setup)
msr hstr_el2, xzr // Disable CP15 traps to EL2 msr hstr_el2, xzr // Disable CP15 traps to EL2
#endif #endif
/* Hypervisor stub */
adr x0, __hyp_stub_vectors
msr vbar_el2, x0
/* spsr */ /* spsr */
mov x0, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\ mov x0, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\
PSR_MODE_EL1h) PSR_MODE_EL1h)
......
/*
* 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)
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment