Commit cb7485da authored by Christian Borntraeger's avatar Christian Borntraeger
Browse files

KVM: s390: use switch vs jump table in intercept.c 



Instead of having huge jump tables for function selection,
let's use normal switch/case statements for the instruction
handlers in intercept.c We can now also get rid of
intercept_handler_t.

This allows the compiler to make the right decision depending
on the situation (e.g. avoid jump-tables for thunks).

Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: default avatarJanosch Frank <frankja@linux.vnet.ibm.com>
Reviewed-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarCornelia Huck <cohuck@redhat.com>
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 6db4263f

arch/s390/kvm/intercept.c

+29 −22
Original line number Diff line number Diff line
@@ -22,22 +22,6 @@ 
#include "trace.h"

#include "trace-s390.h"





static const intercept_handler_t instruction_handlers[256] = {

	[0x01] = kvm_s390_handle_01,

	[0x82] = kvm_s390_handle_lpsw,

	[0x83] = kvm_s390_handle_diag,

	[0xaa] = kvm_s390_handle_aa,

	[0xae] = kvm_s390_handle_sigp,

	[0xb2] = kvm_s390_handle_b2,

	[0xb6] = kvm_s390_handle_stctl,

	[0xb7] = kvm_s390_handle_lctl,

	[0xb9] = kvm_s390_handle_b9,

	[0xe3] = kvm_s390_handle_e3,

	[0xe5] = kvm_s390_handle_e5,

	[0xeb] = kvm_s390_handle_eb,

};



u8 kvm_s390_get_ilen(struct kvm_vcpu *vcpu)

{

	struct kvm_s390_sie_block *sie_block = vcpu->arch.sie_block;
@@ -129,17 +113,40 @@ static int handle_validity(struct kvm_vcpu *vcpu) 


static int handle_instruction(struct kvm_vcpu *vcpu)

{

	intercept_handler_t handler;



	vcpu->stat.exit_instruction++;

	trace_kvm_s390_intercept_instruction(vcpu,

					     vcpu->arch.sie_block->ipa,

					     vcpu->arch.sie_block->ipb);

	handler = instruction_handlers[vcpu->arch.sie_block->ipa >> 8];

	if (handler)

		return handler(vcpu);



	switch (vcpu->arch.sie_block->ipa >> 8) {

	case 0x01:

		return kvm_s390_handle_01(vcpu);

	case 0x82:

		return kvm_s390_handle_lpsw(vcpu);

	case 0x83:

		return kvm_s390_handle_diag(vcpu);

	case 0xaa:

		return kvm_s390_handle_aa(vcpu);

	case 0xae:

		return kvm_s390_handle_sigp(vcpu);

	case 0xb2:

		return kvm_s390_handle_b2(vcpu);

	case 0xb6:

		return kvm_s390_handle_stctl(vcpu);

	case 0xb7:

		return kvm_s390_handle_lctl(vcpu);

	case 0xb9:

		return kvm_s390_handle_b9(vcpu);

	case 0xe3:

		return kvm_s390_handle_e3(vcpu);

	case 0xe5:

		return kvm_s390_handle_e5(vcpu);

	case 0xeb:

		return kvm_s390_handle_eb(vcpu);

	default:

		return -EOPNOTSUPP;

	}

}



static int inject_prog_on_prog_intercept(struct kvm_vcpu *vcpu)

{

arch/s390/kvm/kvm-s390.h

+0 −2
Original line number Diff line number Diff line
@@ -19,8 +19,6 @@ 
#include <asm/processor.h>

#include <asm/sclp.h>



typedef int (*intercept_handler_t)(struct kvm_vcpu *vcpu);



/* Transactional Memory Execution related macros */

#define IS_TE_ENABLED(vcpu)	((vcpu->arch.sie_block->ecb & ECB_TE))

#define TDB_FORMAT1		1

CRA Git | Maintained and supported by SUSTech CRA and CCSE