Commit cdb5e02e authored by Marc Zyngier's avatar Marc Zyngier
Browse files

KVM: arm64: Make kvm_skip_instr() and co private to HYP 



In an effort to remove the vcpu PC manipulations from EL1 on nVHE
systems, move kvm_skip_instr() to be HYP-specific. EL1's intent
to increment PC post emulation is now signalled via a flag in the
vcpu structure.

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent 6ddbc281

arch/arm64/include/asm/kvm_emulate.h

+2 −25
Original line number Diff line number Diff line
@@ -472,32 +472,9 @@ static inline unsigned long vcpu_data_host_to_guest(struct kvm_vcpu *vcpu, 
	return data;		/* Leave LE untouched */

}



static __always_inline void kvm_skip_instr(struct kvm_vcpu *vcpu)

static __always_inline void kvm_incr_pc(struct kvm_vcpu *vcpu)

{

	if (vcpu_mode_is_32bit(vcpu)) {

		kvm_skip_instr32(vcpu);

	} else {

		*vcpu_pc(vcpu) += 4;

		*vcpu_cpsr(vcpu) &= ~PSR_BTYPE_MASK;

	}



	/* advance the singlestep state machine */

	*vcpu_cpsr(vcpu) &= ~DBG_SPSR_SS;

}



/*

 * Skip an instruction which has been emulated at hyp while most guest sysregs

 * are live.

 */

static __always_inline void __kvm_skip_instr(struct kvm_vcpu *vcpu)

{

	*vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR);

	vcpu_gp_regs(vcpu)->pstate = read_sysreg_el2(SYS_SPSR);



	kvm_skip_instr(vcpu);



	write_sysreg_el2(vcpu_gp_regs(vcpu)->pstate, SYS_SPSR);

	write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR);

	vcpu->arch.flags |= KVM_ARM64_INCREMENT_PC;

}



#endif /* __ARM64_KVM_EMULATE_H__ */

arch/arm64/include/asm/kvm_host.h

+1 −0
Original line number Diff line number Diff line
@@ -407,6 +407,7 @@ struct kvm_vcpu_arch { 
#define KVM_ARM64_GUEST_HAS_SVE		(1 << 5) /* SVE exposed to guest */

#define KVM_ARM64_VCPU_SVE_FINALIZED	(1 << 6) /* SVE config completed */

#define KVM_ARM64_GUEST_HAS_PTRAUTH	(1 << 7) /* PTRAUTH exposed to guest */

#define KVM_ARM64_INCREMENT_PC		(1 << 8) /* Increment PC */



#define vcpu_has_sve(vcpu) (system_supports_sve() && \

			    ((vcpu)->arch.flags & KVM_ARM64_GUEST_HAS_SVE))

arch/arm64/kvm/handle_exit.c

+3 −3
Original line number Diff line number Diff line
@@ -61,7 +61,7 @@ static int handle_smc(struct kvm_vcpu *vcpu) 
	 * otherwise return to the same address...

	 */

	vcpu_set_reg(vcpu, 0, ~0UL);

	kvm_skip_instr(vcpu);

	kvm_incr_pc(vcpu);

	return 1;

}
@@ -100,7 +100,7 @@ static int kvm_handle_wfx(struct kvm_vcpu *vcpu) 
		kvm_clear_request(KVM_REQ_UNHALT, vcpu);

	}



	kvm_skip_instr(vcpu);

	kvm_incr_pc(vcpu);



	return 1;

}
@@ -221,7 +221,7 @@ static int handle_trap_exceptions(struct kvm_vcpu *vcpu) 
	 * that fail their condition code check"

	 */

	if (!kvm_condition_valid(vcpu)) {

		kvm_skip_instr(vcpu);

		kvm_incr_pc(vcpu);

		handled = 1;

	} else {

		exit_handle_fn exit_handler;

arch/arm64/kvm/hyp/include/hyp/adjust_pc.h

0 → 100644
+56 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/*

 * Guest PC manipulation helpers

 *

 * Copyright (C) 2012,2013 - ARM Ltd

 * Copyright (C) 2020 - Google LLC

 * Author: Marc Zyngier <maz@kernel.org>

 */



#ifndef __ARM64_KVM_HYP_ADJUST_PC_H__

#define __ARM64_KVM_HYP_ADJUST_PC_H__



#include <asm/kvm_emulate.h>

#include <asm/kvm_host.h>



static inline void kvm_skip_instr(struct kvm_vcpu *vcpu)

{

	if (vcpu_mode_is_32bit(vcpu)) {

		kvm_skip_instr32(vcpu);

	} else {

		*vcpu_pc(vcpu) += 4;

		*vcpu_cpsr(vcpu) &= ~PSR_BTYPE_MASK;

	}



	/* advance the singlestep state machine */

	*vcpu_cpsr(vcpu) &= ~DBG_SPSR_SS;

}



/*

 * Skip an instruction which has been emulated at hyp while most guest sysregs

 * are live.

 */

static inline void __kvm_skip_instr(struct kvm_vcpu *vcpu)

{

	*vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR);

	vcpu_gp_regs(vcpu)->pstate = read_sysreg_el2(SYS_SPSR);



	kvm_skip_instr(vcpu);



	write_sysreg_el2(vcpu_gp_regs(vcpu)->pstate, SYS_SPSR);

	write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR);

}



/*

 * Adjust the guest PC on entry, depending on flags provided by EL1

 * for the purpose of emulation (MMIO, sysreg).

 */

static inline void __adjust_pc(struct kvm_vcpu *vcpu)

{

	if (vcpu->arch.flags & KVM_ARM64_INCREMENT_PC) {

		kvm_skip_instr(vcpu);

		vcpu->arch.flags &= ~KVM_ARM64_INCREMENT_PC;

	}

}



#endif

arch/arm64/kvm/hyp/include/hyp/switch.h

+2 −0
Original line number Diff line number Diff line
@@ -7,6 +7,8 @@ 
#ifndef __ARM64_KVM_HYP_SWITCH_H__

#define __ARM64_KVM_HYP_SWITCH_H__



#include <hyp/adjust_pc.h>



#include <linux/arm-smccc.h>

#include <linux/kvm_host.h>

#include <linux/types.h>