Commit 72564016 authored by Marc Zyngier's avatar Marc Zyngier Committed by Christoffer Dall
Browse files

arm64: KVM: common infrastructure for handling AArch32 CP14/CP15 



As we're about to trap a bunch of CP14 registers, let's rework
the CP15 handling so it can be generalized and work with multiple
tables.

Reviewed-by: default avatarAnup Patel <anup.patel@linaro.org>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 0c557ed4

arch/arm64/include/asm/kvm_asm.h

+1 −1
Original line number Diff line number Diff line
@@ -95,7 +95,7 @@ 
#define c10_AMAIR0	(AMAIR_EL1 * 2)	/* Aux Memory Attr Indirection Reg */

#define c10_AMAIR1	(c10_AMAIR0 + 1)/* Aux Memory Attr Indirection Reg */

#define c14_CNTKCTL	(CNTKCTL_EL1 * 2) /* Timer Control Register (PL1) */

#define NR_CP15_REGS	(NR_SYS_REGS * 2)

#define NR_COPRO_REGS	(NR_SYS_REGS * 2)



#define ARM_EXCEPTION_IRQ	  0

#define ARM_EXCEPTION_TRAP	  1

arch/arm64/include/asm/kvm_coproc.h

+2 −1
Original line number Diff line number Diff line
@@ -39,7 +39,8 @@ void kvm_register_target_sys_reg_table(unsigned int target, 
				       struct kvm_sys_reg_target_table *table);



int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu, struct kvm_run *run);

int kvm_handle_cp14_access(struct kvm_vcpu *vcpu, struct kvm_run *run);

int kvm_handle_cp14_32(struct kvm_vcpu *vcpu, struct kvm_run *run);

int kvm_handle_cp14_64(struct kvm_vcpu *vcpu, struct kvm_run *run);

int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run);

int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run);

int kvm_handle_sys_reg(struct kvm_vcpu *vcpu, struct kvm_run *run);

arch/arm64/include/asm/kvm_host.h

+9 −4
Original line number Diff line number Diff line
@@ -86,7 +86,7 @@ struct kvm_cpu_context { 
	struct kvm_regs	gp_regs;

	union {

		u64 sys_regs[NR_SYS_REGS];

		u32 cp15[NR_CP15_REGS];

		u32 copro[NR_COPRO_REGS];

	};

};
@@ -141,12 +141,17 @@ struct kvm_vcpu_arch { 


#define vcpu_gp_regs(v)		(&(v)->arch.ctxt.gp_regs)

#define vcpu_sys_reg(v,r)	((v)->arch.ctxt.sys_regs[(r)])

#define vcpu_cp15(v,r)		((v)->arch.ctxt.cp15[(r)])

/*

 * CP14 and CP15 live in the same array, as they are backed by the

 * same system registers.

 */

#define vcpu_cp14(v,r)		((v)->arch.ctxt.copro[(r)])

#define vcpu_cp15(v,r)		((v)->arch.ctxt.copro[(r)])



#ifdef CONFIG_CPU_BIG_ENDIAN

#define vcpu_cp15_64_low(v,r) ((v)->arch.ctxt.cp15[((r) + 1)])

#define vcpu_cp15_64_low(v,r) ((v)->arch.ctxt.copro[((r) + 1)])

#else

#define vcpu_cp15_64_low(v,r) ((v)->arch.ctxt.cp15[((r) + 0)])

#define vcpu_cp15_64_low(v,r) ((v)->arch.ctxt.copro[((r) + 0)])

#endif



struct kvm_vm_stat {

arch/arm64/kvm/handle_exit.c

+2 −2
Original line number Diff line number Diff line
@@ -73,9 +73,9 @@ static exit_handle_fn arm_exit_handlers[] = { 
	[ESR_EL2_EC_WFI]	= kvm_handle_wfx,

	[ESR_EL2_EC_CP15_32]	= kvm_handle_cp15_32,

	[ESR_EL2_EC_CP15_64]	= kvm_handle_cp15_64,

	[ESR_EL2_EC_CP14_MR]	= kvm_handle_cp14_access,

	[ESR_EL2_EC_CP14_MR]	= kvm_handle_cp14_32,

	[ESR_EL2_EC_CP14_LS]	= kvm_handle_cp14_load_store,

	[ESR_EL2_EC_CP14_64]	= kvm_handle_cp14_access,

	[ESR_EL2_EC_CP14_64]	= kvm_handle_cp14_64,

	[ESR_EL2_EC_HVC32]	= handle_hvc,

	[ESR_EL2_EC_SMC32]	= handle_smc,

	[ESR_EL2_EC_HVC64]	= handle_hvc,

arch/arm64/kvm/sys_regs.c

+110 −23
Original line number Diff line number Diff line
@@ -494,6 +494,10 @@ static const struct sys_reg_desc sys_reg_descs[] = { 
	  NULL, reset_val, FPEXC32_EL2, 0x70 },

};



/* Trapped cp14 registers */

static const struct sys_reg_desc cp14_regs[] = {

};



/*

 * Trapped cp15 registers. TTBR0/TTBR1 get a double encoding,

 * depending on the way they are accessed (as a 32bit or a 64bit
@@ -601,26 +605,29 @@ int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu, struct kvm_run *run) 
	return 1;

}



int kvm_handle_cp14_access(struct kvm_vcpu *vcpu, struct kvm_run *run)

{

	kvm_inject_undefined(vcpu);

	return 1;

}



static void emulate_cp15(struct kvm_vcpu *vcpu,

			 const struct sys_reg_params *params)

/*

 * emulate_cp --  tries to match a sys_reg access in a handling table, and

 *                call the corresponding trap handler.

 *

 * @params: pointer to the descriptor of the access

 * @table: array of trap descriptors

 * @num: size of the trap descriptor array

 *

 * Return 0 if the access has been handled, and -1 if not.

 */

static int emulate_cp(struct kvm_vcpu *vcpu,

		      const struct sys_reg_params *params,

		      const struct sys_reg_desc *table,

		      size_t num)

{

	size_t num;

	const struct sys_reg_desc *table, *r;

	const struct sys_reg_desc *r;



	table = get_target_table(vcpu->arch.target, false, &num);

	if (!table)

		return -1;	/* Not handled */



	/* Search target-specific then generic table. */

	r = find_reg(params, table, num);

	if (!r)

		r = find_reg(params, cp15_regs, ARRAY_SIZE(cp15_regs));



	if (likely(r)) {

	if (r) {

		/*

		 * Not having an accessor means that we have

		 * configured a trap that we don't know how to
@@ -632,22 +639,51 @@ static void emulate_cp15(struct kvm_vcpu *vcpu, 
		if (likely(r->access(vcpu, params, r))) {

			/* Skip instruction, since it was emulated */

			kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));

			return;

		}

		/* If access function fails, it should complain. */



		/* Handled */

		return 0;

	}



	/* Not handled */

	return -1;

}



static void unhandled_cp_access(struct kvm_vcpu *vcpu,

				struct sys_reg_params *params)

{

	u8 hsr_ec = kvm_vcpu_trap_get_class(vcpu);

	int cp;



	switch(hsr_ec) {

	case ESR_EL2_EC_CP15_32:

	case ESR_EL2_EC_CP15_64:

		cp = 15;

		break;

	case ESR_EL2_EC_CP14_MR:

	case ESR_EL2_EC_CP14_64:

		cp = 14;

		break;

	default:

		WARN_ON((cp = -1));

	}



	kvm_err("Unsupported guest CP15 access at: %08lx\n", *vcpu_pc(vcpu));

	kvm_err("Unsupported guest CP%d access at: %08lx\n",

		cp, *vcpu_pc(vcpu));

	print_sys_reg_instr(params);

	kvm_inject_undefined(vcpu);

}



/**

 * kvm_handle_cp15_64 -- handles a mrrc/mcrr trap on a guest CP15 access

 * kvm_handle_cp_64 -- handles a mrrc/mcrr trap on a guest CP15 access

 * @vcpu: The VCPU pointer

 * @run:  The kvm_run struct

 */

int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)

static int kvm_handle_cp_64(struct kvm_vcpu *vcpu,

			    const struct sys_reg_desc *global,

			    size_t nr_global,

			    const struct sys_reg_desc *target_specific,

			    size_t nr_specific)

{

	struct sys_reg_params params;

	u32 hsr = kvm_vcpu_get_hsr(vcpu);
@@ -676,8 +712,14 @@ int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run) 
		*vcpu_reg(vcpu, params.Rt) = val;

	}



	emulate_cp15(vcpu, &params);

	if (!emulate_cp(vcpu, &params, target_specific, nr_specific))

		goto out;

	if (!emulate_cp(vcpu, &params, global, nr_global))

		goto out;



	unhandled_cp_access(vcpu, &params);



out:

	/* Do the opposite hack for the read side */

	if (!params.is_write) {

		u64 val = *vcpu_reg(vcpu, params.Rt);
@@ -693,7 +735,11 @@ int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run) 
 * @vcpu: The VCPU pointer

 * @run:  The kvm_run struct

 */

int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run)

static int kvm_handle_cp_32(struct kvm_vcpu *vcpu,

			    const struct sys_reg_desc *global,

			    size_t nr_global,

			    const struct sys_reg_desc *target_specific,

			    size_t nr_specific)

{

	struct sys_reg_params params;

	u32 hsr = kvm_vcpu_get_hsr(vcpu);
@@ -708,10 +754,51 @@ int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run) 
	params.Op1 = (hsr >> 14) & 0x7;

	params.Op2 = (hsr >> 17) & 0x7;



	emulate_cp15(vcpu, &params);

	if (!emulate_cp(vcpu, &params, target_specific, nr_specific))

		return 1;

	if (!emulate_cp(vcpu, &params, global, nr_global))

		return 1;



	unhandled_cp_access(vcpu, &params);

	return 1;

}



int kvm_handle_cp15_64(struct kvm_vcpu *vcpu, struct kvm_run *run)

{

	const struct sys_reg_desc *target_specific;

	size_t num;



	target_specific = get_target_table(vcpu->arch.target, false, &num);

	return kvm_handle_cp_64(vcpu,

				cp15_regs, ARRAY_SIZE(cp15_regs),

				target_specific, num);

}



int kvm_handle_cp15_32(struct kvm_vcpu *vcpu, struct kvm_run *run)

{

	const struct sys_reg_desc *target_specific;

	size_t num;



	target_specific = get_target_table(vcpu->arch.target, false, &num);

	return kvm_handle_cp_32(vcpu,

				cp15_regs, ARRAY_SIZE(cp15_regs),

				target_specific, num);

}



int kvm_handle_cp14_64(struct kvm_vcpu *vcpu, struct kvm_run *run)

{

	return kvm_handle_cp_64(vcpu,

				cp14_regs, ARRAY_SIZE(cp14_regs),

				NULL, 0);

}



int kvm_handle_cp14_32(struct kvm_vcpu *vcpu, struct kvm_run *run)

{

	return kvm_handle_cp_32(vcpu,

				cp14_regs, ARRAY_SIZE(cp14_regs),

				NULL, 0);

}



static int emulate_sys_reg(struct kvm_vcpu *vcpu,

			   const struct sys_reg_params *params)

{

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