Commit 8b48d5b7 authored by James Hogan's avatar James Hogan
Browse files

KVM: MIPS/Emulate: De-duplicate MMIO emulation 



Refactor MIPS KVM MMIO load/store emulation to reduce code duplication.
Each duplicate differed slightly anyway, and it will simplify adding
64-bit MMIO support for VZ.

kvm_mips_emulate_store() and kvm_mips_emulate_load() can now return
EMULATE_DO_MMIO (as possibly originally intended). We therefore stop
calling either of these from kvm_mips_emulate_inst(), which is now only
used by kvm_trap_emul_handle_cop_unusable() which is picky about return
values.

Signed-off-by: default avatarJames Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
parent 955d8dc3

arch/mips/kvm/emulate.c

+50 −156
Original line number Diff line number Diff line
@@ -1477,9 +1477,8 @@ enum emulation_result kvm_mips_emulate_store(union mips_instruction inst, 
					     struct kvm_run *run,

					     struct kvm_vcpu *vcpu)

{

	enum emulation_result er = EMULATE_DO_MMIO;

	enum emulation_result er;

	u32 rt;

	u32 bytes;

	void *data = run->mmio.data;

	unsigned long curr_pc;
@@ -1494,49 +1493,14 @@ enum emulation_result kvm_mips_emulate_store(union mips_instruction inst, 


	rt = inst.i_format.rt;



	switch (inst.i_format.opcode) {

	case sb_op:

		bytes = 1;

		if (bytes > sizeof(run->mmio.data)) {

			kvm_err("%s: bad MMIO length: %d\n", __func__,

			       run->mmio.len);

		}

		run->mmio.phys_addr =

		    kvm_mips_callbacks->gva_to_gpa(vcpu->arch.

						   host_cp0_badvaddr);

		if (run->mmio.phys_addr == KVM_INVALID_ADDR) {

			er = EMULATE_FAIL;

			break;

		}

		run->mmio.len = bytes;

		run->mmio.is_write = 1;

		vcpu->mmio_needed = 1;

		vcpu->mmio_is_write = 1;

		*(u8 *) data = vcpu->arch.gprs[rt];

		kvm_debug("OP_SB: eaddr: %#lx, gpr: %#lx, data: %#x\n",

			  vcpu->arch.host_cp0_badvaddr, vcpu->arch.gprs[rt],

			  *(u8 *) data);



		break;

	run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(

						vcpu->arch.host_cp0_badvaddr);

	if (run->mmio.phys_addr == KVM_INVALID_ADDR)

		goto out_fail;



	switch (inst.i_format.opcode) {

	case sw_op:

		bytes = 4;

		if (bytes > sizeof(run->mmio.data)) {

			kvm_err("%s: bad MMIO length: %d\n", __func__,

			       run->mmio.len);

		}

		run->mmio.phys_addr =

		    kvm_mips_callbacks->gva_to_gpa(vcpu->arch.

						   host_cp0_badvaddr);

		if (run->mmio.phys_addr == KVM_INVALID_ADDR) {

			er = EMULATE_FAIL;

			break;

		}



		run->mmio.len = bytes;

		run->mmio.is_write = 1;

		vcpu->mmio_needed = 1;

		vcpu->mmio_is_write = 1;

		run->mmio.len = 4;

		*(u32 *)data = vcpu->arch.gprs[rt];



		kvm_debug("[%#lx] OP_SW: eaddr: %#lx, gpr: %#lx, data: %#x\n",
@@ -1545,52 +1509,47 @@ enum emulation_result kvm_mips_emulate_store(union mips_instruction inst, 
		break;



	case sh_op:

		bytes = 2;

		if (bytes > sizeof(run->mmio.data)) {

			kvm_err("%s: bad MMIO length: %d\n", __func__,

			       run->mmio.len);

		}

		run->mmio.phys_addr =

		    kvm_mips_callbacks->gva_to_gpa(vcpu->arch.

						   host_cp0_badvaddr);

		if (run->mmio.phys_addr == KVM_INVALID_ADDR) {

			er = EMULATE_FAIL;

			break;

		}



		run->mmio.len = bytes;

		run->mmio.is_write = 1;

		vcpu->mmio_needed = 1;

		vcpu->mmio_is_write = 1;

		run->mmio.len = 2;

		*(u16 *)data = vcpu->arch.gprs[rt];



		kvm_debug("[%#lx] OP_SH: eaddr: %#lx, gpr: %#lx, data: %#x\n",

			  vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,

			  vcpu->arch.gprs[rt], *(u32 *) data);

			  vcpu->arch.gprs[rt], *(u16 *)data);

		break;



	case sb_op:

		run->mmio.len = 1;

		*(u8 *)data = vcpu->arch.gprs[rt];



		kvm_debug("[%#lx] OP_SB: eaddr: %#lx, gpr: %#lx, data: %#x\n",

			  vcpu->arch.pc, vcpu->arch.host_cp0_badvaddr,

			  vcpu->arch.gprs[rt], *(u8 *)data);

		break;



	default:

		kvm_err("Store not yet supported (inst=0x%08x)\n",

			inst.word);

		er = EMULATE_FAIL;

		break;

		goto out_fail;

	}



	run->mmio.is_write = 1;

	vcpu->mmio_needed = 1;

	vcpu->mmio_is_write = 1;

	return EMULATE_DO_MMIO;



out_fail:

	/* Rollback PC if emulation was unsuccessful */

	if (er == EMULATE_FAIL)

	vcpu->arch.pc = curr_pc;



	return er;

	return EMULATE_FAIL;

}



enum emulation_result kvm_mips_emulate_load(union mips_instruction inst,

					    u32 cause, struct kvm_run *run,

					    struct kvm_vcpu *vcpu)

{

	enum emulation_result er = EMULATE_DO_MMIO;

	enum emulation_result er;

	unsigned long curr_pc;

	u32 op, rt;

	u32 bytes;



	rt = inst.i_format.rt;

	op = inst.i_format.opcode;
@@ -1609,94 +1568,41 @@ enum emulation_result kvm_mips_emulate_load(union mips_instruction inst, 


	vcpu->arch.io_gpr = rt;



	run->mmio.phys_addr = kvm_mips_callbacks->gva_to_gpa(

						vcpu->arch.host_cp0_badvaddr);

	if (run->mmio.phys_addr == KVM_INVALID_ADDR)

		return EMULATE_FAIL;



	vcpu->mmio_needed = 2;	/* signed */

	switch (op) {

	case lw_op:

		bytes = 4;

		if (bytes > sizeof(run->mmio.data)) {

			kvm_err("%s: bad MMIO length: %d\n", __func__,

			       run->mmio.len);

			er = EMULATE_FAIL;

			break;

		}

		run->mmio.phys_addr =

		    kvm_mips_callbacks->gva_to_gpa(vcpu->arch.

						   host_cp0_badvaddr);

		if (run->mmio.phys_addr == KVM_INVALID_ADDR) {

			er = EMULATE_FAIL;

		run->mmio.len = 4;

		break;

		}



		run->mmio.len = bytes;

		run->mmio.is_write = 0;

		vcpu->mmio_needed = 1;

		vcpu->mmio_is_write = 0;

		break;



	case lh_op:

	case lhu_op:

		bytes = 2;

		if (bytes > sizeof(run->mmio.data)) {

			kvm_err("%s: bad MMIO length: %d\n", __func__,

			       run->mmio.len);

			er = EMULATE_FAIL;

			break;

		}

		run->mmio.phys_addr =

		    kvm_mips_callbacks->gva_to_gpa(vcpu->arch.

						   host_cp0_badvaddr);

		if (run->mmio.phys_addr == KVM_INVALID_ADDR) {

			er = EMULATE_FAIL;

			break;

		}



		run->mmio.len = bytes;

		run->mmio.is_write = 0;

		vcpu->mmio_needed = 1;

		vcpu->mmio_is_write = 0;



		if (op == lh_op)

			vcpu->mmio_needed = 2;

		else

			vcpu->mmio_needed = 1;



		vcpu->mmio_needed = 1;	/* unsigned */

		/* fall through */

	case lh_op:

		run->mmio.len = 2;

		break;



	case lbu_op:

		vcpu->mmio_needed = 1;	/* unsigned */

		/* fall through */

	case lb_op:

		bytes = 1;

		if (bytes > sizeof(run->mmio.data)) {

			kvm_err("%s: bad MMIO length: %d\n", __func__,

			       run->mmio.len);

			er = EMULATE_FAIL;

			break;

		}

		run->mmio.phys_addr =

		    kvm_mips_callbacks->gva_to_gpa(vcpu->arch.

						   host_cp0_badvaddr);

		if (run->mmio.phys_addr == KVM_INVALID_ADDR) {

			er = EMULATE_FAIL;

			break;

		}



		run->mmio.len = bytes;

		run->mmio.is_write = 0;

		vcpu->mmio_is_write = 0;



		if (op == lb_op)

			vcpu->mmio_needed = 2;

		else

			vcpu->mmio_needed = 1;



		run->mmio.len = 1;

		break;



	default:

		kvm_err("Load not yet supported (inst=0x%08x)\n",

			inst.word);

		er = EMULATE_FAIL;

		break;

		vcpu->mmio_needed = 0;

		return EMULATE_FAIL;

	}



	return er;

	run->mmio.is_write = 0;

	vcpu->mmio_is_write = 0;

	return EMULATE_DO_MMIO;

}



static enum emulation_result kvm_mips_guest_cache_op(int (*fn)(unsigned long),
@@ -1873,18 +1779,6 @@ enum emulation_result kvm_mips_emulate_inst(u32 cause, u32 *opc, 
	case cop0_op:

		er = kvm_mips_emulate_CP0(inst, opc, cause, run, vcpu);

		break;

	case sb_op:

	case sh_op:

	case sw_op:

		er = kvm_mips_emulate_store(inst, cause, run, vcpu);

		break;

	case lb_op:

	case lbu_op:

	case lhu_op:

	case lh_op:

	case lw_op:

		er = kvm_mips_emulate_load(inst, cause, run, vcpu);

		break;



#ifndef CONFIG_CPU_MIPSR6

	case cache_op: