Commit 687413d3 authored by David Brazdil's avatar David Brazdil Committed by Marc Zyngier
Browse files

KVM: arm64: Support per_cpu_ptr in nVHE hyp code 



When compiling with __KVM_NVHE_HYPERVISOR__, redefine per_cpu_offset()
to __hyp_per_cpu_offset() which looks up the base of the nVHE per-CPU
region of the given cpu and computes its offset from the
.hyp.data..percpu section.

This enables use of per_cpu_ptr() helpers in nVHE hyp code. Until now
only this_cpu_ptr() was supported by setting TPIDR_EL2.

Signed-off-by: default avatarDavid Brazdil <dbrazdil@google.com>
Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201202184122.26046-14-dbrazdil@google.com
parent 2d7bf218

arch/arm64/include/asm/percpu.h

+6 −0
Original line number Diff line number Diff line
@@ -239,6 +239,12 @@ PERCPU_RET_OP(add, add, ldadd) 
#define this_cpu_cmpxchg_8(pcp, o, n)	\

	_pcp_protect_return(cmpxchg_relaxed, pcp, o, n)



#ifdef __KVM_NVHE_HYPERVISOR__

extern unsigned long __hyp_per_cpu_offset(unsigned int cpu);

#define __per_cpu_offset

#define per_cpu_offset(cpu)	__hyp_per_cpu_offset((cpu))

#endif



#include <asm-generic/percpu.h>



/* Redefine macros for nVHE hyp under DEBUG_PREEMPT to avoid its dependencies. */

arch/arm64/kernel/image-vars.h

+3 −0
Original line number Diff line number Diff line
@@ -99,6 +99,9 @@ KVM_NVHE_ALIAS(gic_nonsecure_priorities); 
KVM_NVHE_ALIAS(__start___kvm_ex_table);

KVM_NVHE_ALIAS(__stop___kvm_ex_table);



/* Array containing bases of nVHE per-CPU memory regions. */

KVM_NVHE_ALIAS(kvm_arm_hyp_percpu_base);



#endif /* CONFIG_KVM */



#endif /* __ARM64_KERNEL_IMAGE_VARS_H */

arch/arm64/kvm/hyp/nvhe/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -6,7 +6,8 @@ 
asflags-y := -D__KVM_NVHE_HYPERVISOR__

ccflags-y := -D__KVM_NVHE_HYPERVISOR__



obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o hyp-main.o

obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o \

	 hyp-main.o hyp-smp.o

obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \

	 ../fpsimd.o ../hyp-entry.o

arch/arm64/kvm/hyp/nvhe/hyp-smp.c

0 → 100644
+24 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/*

 * Copyright (C) 2020 - Google LLC

 * Author: David Brazdil <dbrazdil@google.com>

 */



#include <asm/kvm_asm.h>

#include <asm/kvm_hyp.h>

#include <asm/kvm_mmu.h>



unsigned long __hyp_per_cpu_offset(unsigned int cpu)

{

	unsigned long *cpu_base_array;

	unsigned long this_cpu_base;

	unsigned long elf_base;



	if (cpu >= ARRAY_SIZE(kvm_arm_hyp_percpu_base))

		hyp_panic();



	cpu_base_array = (unsigned long *)hyp_symbol_addr(kvm_arm_hyp_percpu_base);

	this_cpu_base = kern_hyp_va(cpu_base_array[cpu]);

	elf_base = (unsigned long)hyp_symbol_addr(__per_cpu_start);

	return this_cpu_base - elf_base;

}

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