From: Marc Zyngier Date: Fri, 19 Oct 2012 16:46:27 +0000 (+0100) Subject: arm64: add hypervisor stub X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=712c6ff4dba4917a440be601dc312506322bffe8;p=deliverable%2Flinux.git 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 Signed-off-by: Catalin Marinas --- diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index f28547d9edfa..439827271e3d 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -33,6 +33,9 @@ */ 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 */ static inline bool is_hyp_mode_available(void) { diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index e2caff1b812a..74239c31e25a 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -8,7 +8,8 @@ AFLAGS_head.o := -DTEXT_OFFSET=$(TEXT_OFFSET) # Object file lists. arm64-obj-y := cputable.o debug-monitors.o entry.o irq.o fpsimd.o \ entry-fpsimd.o process.o ptrace.o setup.o signal.o \ - sys.o stacktrace.o time.o traps.o io.o vdso.o + sys.o stacktrace.o time.o traps.o io.o vdso.o \ + hyp-stub.o arm64-obj-$(CONFIG_COMPAT) += sys32.o kuser32.o signal32.o \ sys_compat.o diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index bc6d991f8c59..5792749e34c4 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -185,6 +185,10 @@ ENTRY(el2_setup) msr hstr_el2, xzr // Disable CP15 traps to EL2 #endif + /* Hypervisor stub */ + adr x0, __hyp_stub_vectors + msr vbar_el2, x0 + /* spsr */ mov x0, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\ PSR_MODE_EL1h) 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 + * + * 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 . + */ + +#include +#include + +#include +#include +#include + + .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)