KVM: PPC: Convert DAR to shared page.

The DAR register contains the address a data page fault occured at. This
register behaves pretty much like a simple data storage register that gets
written to on data faults. There is no hypervisor interaction required on
read or write.

This patch converts all users of the current field to the shared page.

Signed-off-by: Alexander Graf <[e-mail]>
Signed-off-by: Avi Kivity <[e-mail]>

arch/powerpc/include/asm/kvm_host.h

···
 	ulong csrr1;
 	ulong dsrr0;
 	ulong dsrr1;
-	ulong dear;
 	ulong esr;
 	u32 dec;
 	u32 decar;

arch/powerpc/include/asm/kvm_para.h

···
 #include <linux/types.h>
 
 struct kvm_vcpu_arch_shared {
+	__u64 dar;
 	__u64 msr;
 	__u32 dsisr;
 };

arch/powerpc/kvm/book3s.c

···
 
 	if (page_found == -ENOENT) {
 		/* Page not found in guest PTE entries */
-		vcpu->arch.dear = kvmppc_get_fault_dar(vcpu);
+		vcpu->arch.shared->dar = kvmppc_get_fault_dar(vcpu);
 		vcpu->arch.shared->dsisr = to_svcpu(vcpu)->fault_dsisr;
 		vcpu->arch.shared->msr |=
 			(to_svcpu(vcpu)->shadow_srr1 & 0x00000000f8000000ULL);
 		kvmppc_book3s_queue_irqprio(vcpu, vec);
 	} else if (page_found == -EPERM) {
 		/* Storage protection */
-		vcpu->arch.dear = kvmppc_get_fault_dar(vcpu);
+		vcpu->arch.shared->dar = kvmppc_get_fault_dar(vcpu);
 		vcpu->arch.shared->dsisr =
 			to_svcpu(vcpu)->fault_dsisr & ~DSISR_NOHPTE;
 		vcpu->arch.shared->dsisr |= DSISR_PROTFAULT;
···
 		kvmppc_book3s_queue_irqprio(vcpu, vec);
 	} else if (page_found == -EINVAL) {
 		/* Page not found in guest SLB */
-		vcpu->arch.dear = kvmppc_get_fault_dar(vcpu);
+		vcpu->arch.shared->dar = kvmppc_get_fault_dar(vcpu);
 		kvmppc_book3s_queue_irqprio(vcpu, vec + 0x80);
 	} else if (!is_mmio &&
 		   kvmppc_visible_gfn(vcpu, pte.raddr >> PAGE_SHIFT)) {
···
 		if (to_svcpu(vcpu)->fault_dsisr & DSISR_NOHPTE) {
 			r = kvmppc_handle_pagefault(run, vcpu, dar, exit_nr);
 		} else {
-			vcpu->arch.dear = dar;
+			vcpu->arch.shared->dar = dar;
 			vcpu->arch.shared->dsisr = to_svcpu(vcpu)->fault_dsisr;
 			kvmppc_book3s_queue_irqprio(vcpu, exit_nr);
-			kvmppc_mmu_pte_flush(vcpu, vcpu->arch.dear, ~0xFFFUL);
+			kvmppc_mmu_pte_flush(vcpu, dar, ~0xFFFUL);
 			r = RESUME_GUEST;
 		}
 		break;
 	}
 	case BOOK3S_INTERRUPT_DATA_SEGMENT:
 		if (kvmppc_mmu_map_segment(vcpu, kvmppc_get_fault_dar(vcpu)) < 0) {
-			vcpu->arch.dear = kvmppc_get_fault_dar(vcpu);
+			vcpu->arch.shared->dar = kvmppc_get_fault_dar(vcpu);
 			kvmppc_book3s_queue_irqprio(vcpu,
 				BOOK3S_INTERRUPT_DATA_SEGMENT);
 		}
···
 		if (kvmppc_read_inst(vcpu) == EMULATE_DONE) {
 			vcpu->arch.shared->dsisr = kvmppc_alignment_dsisr(vcpu,
 				kvmppc_get_last_inst(vcpu));
-			vcpu->arch.dear = kvmppc_alignment_dar(vcpu,
+			vcpu->arch.shared->dar = kvmppc_alignment_dar(vcpu,
 				kvmppc_get_last_inst(vcpu));
 			kvmppc_book3s_queue_irqprio(vcpu, exit_nr);
 		}

arch/powerpc/kvm/book3s_emulate.c

···
 			r = kvmppc_st(vcpu, &addr, 32, zeros, true);
 			if ((r == -ENOENT) || (r == -EPERM)) {
 				*advance = 0;
-				vcpu->arch.dear = vaddr;
+				vcpu->arch.shared->dar = vaddr;
 				to_svcpu(vcpu)->fault_dar = vaddr;
 
 				dsisr = DSISR_ISSTORE;
···
 		vcpu->arch.shared->dsisr = spr_val;
 		break;
 	case SPRN_DAR:
-		vcpu->arch.dear = spr_val;
+		vcpu->arch.shared->dar = spr_val;
 		break;
 	case SPRN_HIOR:
 		to_book3s(vcpu)->hior = spr_val;
···
 		kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->dsisr);
 		break;
 	case SPRN_DAR:
-		kvmppc_set_gpr(vcpu, rt, vcpu->arch.dear);
+		kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->dar);
 		break;
 	case SPRN_HIOR:
 		kvmppc_set_gpr(vcpu, rt, to_book3s(vcpu)->hior);

arch/powerpc/kvm/book3s_paired_singles.c

···
 
 	shared->msr = kvmppc_set_field(shared->msr, 33, 36, 0);
 	shared->msr = kvmppc_set_field(shared->msr, 42, 47, 0);
-	vcpu->arch.dear = eaddr;
+	shared->dar = eaddr;
 	/* Page Fault */
 	dsisr = kvmppc_set_field(0, 33, 33, 1);
 	if (is_store)

arch/powerpc/kvm/booke.c

···
 		if (update_esr == true)
 			vcpu->arch.esr = vcpu->arch.queued_esr;
 		if (update_dear == true)
-			vcpu->arch.dear = vcpu->arch.queued_dear;
+			vcpu->arch.shared->dar = vcpu->arch.queued_dear;
 		kvmppc_set_msr(vcpu, vcpu->arch.shared->msr & msr_mask);
 
 		clear_bit(priority, &vcpu->arch.pending_exceptions);

arch/powerpc/kvm/booke_emulate.c

···
 
 	switch (sprn) {
 	case SPRN_DEAR:
-		vcpu->arch.dear = spr_val; break;
+		vcpu->arch.shared->dar = spr_val; break;
 	case SPRN_ESR:
 		vcpu->arch.esr = spr_val; break;
 	case SPRN_DBCR0:
···
 	case SPRN_IVPR:
 		kvmppc_set_gpr(vcpu, rt, vcpu->arch.ivpr); break;
 	case SPRN_DEAR:
-		kvmppc_set_gpr(vcpu, rt, vcpu->arch.dear); break;
+		kvmppc_set_gpr(vcpu, rt, vcpu->arch.shared->dar); break;
 	case SPRN_ESR:
 		kvmppc_set_gpr(vcpu, rt, vcpu->arch.esr); break;
 	case SPRN_DBCR0: