Commit 8a14849b authored by Marc Zyngier's avatar Marc Zyngier Committed by Catalin Marinas
Browse files

arm64: KVM: Switch vgic save/restore to alternative_insn 



So far, we configured the world-switch by having a small array
of pointers to the save and restore functions, depending on the
GIC used on the platform.

Loading these values each time is a bit silly (they never change),
and it makes sense to rely on the instruction patching instead.

This leads to a nice cleanup of the code.

Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 94a9e04a

arch/arm/include/asm/kvm_host.h

+0 −5
Original line number Diff line number Diff line
@@ -218,11 +218,6 @@ static inline int kvm_arch_dev_ioctl_check_extension(long ext) 
	return 0;

}



static inline void vgic_arch_setup(const struct vgic_params *vgic)

{

	BUG_ON(vgic->type != VGIC_V2);

}



int kvm_perf_init(void);

int kvm_perf_teardown(void);

arch/arm64/include/asm/kvm_asm.h

+0 −5
Original line number Diff line number Diff line
@@ -132,11 +132,6 @@ extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu); 


extern u64 __vgic_v3_get_ich_vtr_el2(void);



extern char __save_vgic_v2_state[];

extern char __restore_vgic_v2_state[];

extern char __save_vgic_v3_state[];

extern char __restore_vgic_v3_state[];



#endif



#endif /* __ARM_KVM_ASM_H__ */

arch/arm64/include/asm/kvm_host.h

+0 −23
Original line number Diff line number Diff line
@@ -221,29 +221,6 @@ struct vgic_sr_vectors { 
	void	*restore_vgic;

};



static inline void vgic_arch_setup(const struct vgic_params *vgic)

{

	extern struct vgic_sr_vectors __vgic_sr_vectors;



	switch(vgic->type)

	{

	case VGIC_V2:

		__vgic_sr_vectors.save_vgic	= __save_vgic_v2_state;

		__vgic_sr_vectors.restore_vgic	= __restore_vgic_v2_state;

		break;



#ifdef CONFIG_ARM_GIC_V3

	case VGIC_V3:

		__vgic_sr_vectors.save_vgic	= __save_vgic_v3_state;

		__vgic_sr_vectors.restore_vgic	= __restore_vgic_v3_state;

		break;

#endif



	default:

		BUG();

	}

}



static inline void kvm_arch_hardware_disable(void) {}

static inline void kvm_arch_hardware_unsetup(void) {}

static inline void kvm_arch_sync_events(struct kvm *kvm) {}

arch/arm64/kernel/asm-offsets.c

+0 −1
Original line number Diff line number Diff line
@@ -127,7 +127,6 @@ int main(void) 
  DEFINE(VCPU_VGIC_CPU,		offsetof(struct kvm_vcpu, arch.vgic_cpu));

  DEFINE(VGIC_SAVE_FN,		offsetof(struct vgic_sr_vectors, save_vgic));

  DEFINE(VGIC_RESTORE_FN,	offsetof(struct vgic_sr_vectors, restore_vgic));

  DEFINE(VGIC_SR_VECTOR_SZ,	sizeof(struct vgic_sr_vectors));

  DEFINE(VGIC_V2_CPU_HCR,	offsetof(struct vgic_cpu, vgic_v2.vgic_hcr));

  DEFINE(VGIC_V2_CPU_VMCR,	offsetof(struct vgic_cpu, vgic_v2.vgic_vmcr));

  DEFINE(VGIC_V2_CPU_MISR,	offsetof(struct vgic_cpu, vgic_v2.vgic_misr));

arch/arm64/kvm/hyp.S

+4 −14
Original line number Diff line number Diff line
@@ -17,8 +17,10 @@ 


#include <linux/linkage.h>



#include <asm/alternative.h>

#include <asm/asm-offsets.h>

#include <asm/assembler.h>

#include <asm/cpufeature.h>

#include <asm/debug-monitors.h>

#include <asm/esr.h>

#include <asm/fpsimdmacros.h>
@@ -808,10 +810,7 @@ 
 * Call into the vgic backend for state saving

 */

.macro save_vgic_state

	adr	x24, __vgic_sr_vectors

	ldr	x24, [x24, VGIC_SAVE_FN]

	kern_hyp_va	x24

	blr	x24

	alternative_insn "bl __save_vgic_v2_state", "bl __save_vgic_v3_state", ARM64_HAS_SYSREG_GIC_CPUIF

	mrs	x24, hcr_el2

	mov	x25, #HCR_INT_OVERRIDE

	neg	x25, x25
@@ -828,10 +827,7 @@ 
	orr	x24, x24, #HCR_INT_OVERRIDE

	orr	x24, x24, x25

	msr	hcr_el2, x24

	adr	x24, __vgic_sr_vectors

	ldr	x24, [x24, #VGIC_RESTORE_FN]

	kern_hyp_va	x24

	blr	x24

	alternative_insn "bl __restore_vgic_v2_state", "bl __restore_vgic_v3_state", ARM64_HAS_SYSREG_GIC_CPUIF

.endm



.macro save_timer_state
@@ -1062,12 +1058,6 @@ ENTRY(__kvm_flush_vm_context) 
	ret

ENDPROC(__kvm_flush_vm_context)



	// struct vgic_sr_vectors __vgi_sr_vectors;

	.align 3

ENTRY(__vgic_sr_vectors)

	.skip	VGIC_SR_VECTOR_SZ

ENDPROC(__vgic_sr_vectors)



__kvm_hyp_panic:

	// Guess the context by looking at VTTBR:

	// If zero, then we're already a host.

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