arch/s390/kvm/diag.c

Source file repositories/reference/linux-study-clean/arch/s390/kvm/diag.c

File Facts

System
Linux kernel
Corpus path
arch/s390/kvm/diag.c
Extension
.c
Size
9521 bytes
Lines
328
Domain
Architecture Layer
Bucket
arch/s390
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

struct prs_parm {
		u16 code;
		u16 subcode;
		u16 parm_len;
		u16 parm_version;
		u64 token_addr;
		u64 select_mask;
		u64 compare_mask;
		u64 zarch;
	};
	struct prs_parm parm;
	int rc;
	u16 rx = (vcpu->arch.sie_block->ipa & 0xf0) >> 4;
	u16 ry = (vcpu->arch.sie_block->ipa & 0x0f);

	VCPU_EVENT(vcpu, 3, "diag page reference parameter block at 0x%llx",
		   vcpu->run->s.regs.gprs[rx]);
	vcpu->stat.instruction_diagnose_258++;
	if (vcpu->run->s.regs.gprs[rx] & 7)
		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
	rc = read_guest_real(vcpu, vcpu->run->s.regs.gprs[rx], &parm, sizeof(parm));
	if (rc)
		return kvm_s390_inject_prog_cond(vcpu, rc);
	if (parm.parm_version != 2 || parm.parm_len < 5 || parm.code != 0x258)
		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

	switch (parm.subcode) {
	case 0: /* TOKEN */
		VCPU_EVENT(vcpu, 3, "pageref token addr 0x%llx "
			   "select mask 0x%llx compare mask 0x%llx",
			   parm.token_addr, parm.select_mask, parm.compare_mask);
		if (vcpu->arch.pfault_token != KVM_S390_PFAULT_TOKEN_INVALID) {
			/*
			 * If the pagefault handshake is already activated,
			 * the token must not be changed.  We have to return
			 * decimal 8 instead, as mandated in SC24-6084.
			 */
			vcpu->run->s.regs.gprs[ry] = 8;
			return 0;
		}

		if ((parm.compare_mask & parm.select_mask) != parm.compare_mask ||
		    parm.token_addr & 7 || parm.zarch != 0x8000000000000000ULL)
			return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

		if (!kvm_is_gpa_in_memslot(vcpu->kvm, parm.token_addr))
			return kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);

		vcpu->arch.pfault_token = parm.token_addr;
		vcpu->arch.pfault_select = parm.select_mask;
		vcpu->arch.pfault_compare = parm.compare_mask;
		vcpu->run->s.regs.gprs[ry] = 0;
		rc = 0;
		break;
	case 1: /*
		 * CANCEL
		 * Specification allows to let already pending tokens survive
		 * the cancel, therefore to reduce code complexity, we assume
		 * all outstanding tokens are already pending.
		 */
		VCPU_EVENT(vcpu, 3, "pageref cancel addr 0x%llx", parm.token_addr);
		if (parm.token_addr || parm.select_mask ||
		    parm.compare_mask || parm.zarch)
			return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

		vcpu->run->s.regs.gprs[ry] = 0;
		/*
		 * If the pfault handling was not established or is already
		 * canceled SC24-6084 requests to return decimal 4.
		 */
		if (vcpu->arch.pfault_token == KVM_S390_PFAULT_TOKEN_INVALID)
			vcpu->run->s.regs.gprs[ry] = 4;
		else
			vcpu->arch.pfault_token = KVM_S390_PFAULT_TOKEN_INVALID;

		rc = 0;
		break;
	default:
		rc = -EOPNOTSUPP;
		break;
	}

	return rc;
}

static int __diag_time_slice_end(struct kvm_vcpu *vcpu)
{
	VCPU_EVENT(vcpu, 5, "%s", "diag time slice end");
	vcpu->stat.instruction_diagnose_44++;
	kvm_vcpu_on_spin(vcpu, true);

Annotation

Implementation Notes