KVM: MIPS: Abstract guest CP0 register access for VZ

Abstract the MIPS KVM guest CP0 register access macros into inline
functions which are generated by macros. This allows them to be
generated differently for VZ, where they will usually need to access the
hardware guest CP0 context rather than the saved values in RAM.

Accessors for each individual register are generated using these macros:

 - __BUILD_KVM_*_SW() for registers which are not present in the VZ
   hardware guest context, so kvm_{read,write}_c0_guest_##name() will
   access the saved value in RAM regardless of whether VZ is enabled.

 - __BUILD_KVM_*_HW() for registers which are present in the VZ hardware
   guest context, so kvm_{read,write}_c0_guest_##name() will access the
   hardware register when VZ is enabled.

These build the underlying accessors using further macros:

 - __BUILD_KVM_*_SAVED() builds e.g. kvm_{read,write}_sw_gc0_##name()
   functions for accessing the saved versions of the registers in RAM.
   This is used for implementing the common
   kvm_{read,write}_c0_guest_##name() accessors with T&E where registers
   are always stored in RAM, but are also available with VZ HW registers
   to allow them to be accessed while saved.

 - __BUILD_KVM_*_VZ() builds e.g. kvm_{read,write}_vz_gc0_##name()
   functions for accessing the VZ hardware guest context registers
   directly. This is used for implementing the common
   kvm_{read,write}_c0_guest_##name() accessors with VZ.

 - __BUILD_KVM_*_WRAP() builds wrappers with different names, which
   allows the common kvm_{read,write}_c0_guest_##name() functions to be
   implemented using the VZ accessors while still having the SAVED
   accessors available too.

 - __BUILD_KVM_SAVE_VZ() builds functions for saving and restoring VZ
   hardware guest context register state to RAM, improving conciseness
   of VZ context saving and restoring.

Similar macros exist for generating modifiers (set, clear, change),
either with a normal unlocked read/modify/write, or using atomic LL/SC
sequences.

These changes change the types of 32-bit registers to u32 instead of
unsigned long, which requires some changes to printk() functions in MIPS
KVM.
Signed-off-by: James 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

arch/mips/kvm/emulate.c

@@ -881,7 +881,7 @@ enum emulation_result kvm_mips_emul_tlbr(struct kvm_vcpu *vcpu)
 	struct mips_coproc *cop0 = vcpu->arch.cop0;
 	unsigned long pc = vcpu->arch.pc;
 
-	kvm_err("[%#lx] COP0_TLBR [%ld]\n", pc, kvm_read_c0_guest_index(cop0));
+	kvm_err("[%#lx] COP0_TLBR [%d]\n", pc, kvm_read_c0_guest_index(cop0));
 	return EMULATE_FAIL;
 }
 

arch/mips/kvm/mips.c

@@ -1112,7 +1112,7 @@ int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu)
 	kvm_debug("\tlo: 0x%08lx\n", vcpu->arch.lo);
 
 	cop0 = vcpu->arch.cop0;
-	kvm_debug("\tStatus: 0x%08lx, Cause: 0x%08lx\n",
+	kvm_debug("\tStatus: 0x%08x, Cause: 0x%08x\n",
 		  kvm_read_c0_guest_status(cop0),
 		  kvm_read_c0_guest_cause(cop0));
 
@@ -1287,7 +1287,7 @@ int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
 		break;
 
 	case EXCCODE_TLBS:
-		kvm_debug("TLB ST fault:  cause %#x, status %#lx, PC: %p, BadVaddr: %#lx\n",
+		kvm_debug("TLB ST fault:  cause %#x, status %#x, PC: %p, BadVaddr: %#lx\n",
 			  cause, kvm_read_c0_guest_status(vcpu->arch.cop0), opc,
 			  badvaddr);
 
@@ -1358,7 +1358,7 @@ int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
 			opc += 1;
 		inst = 0;
 		kvm_get_badinstr(opc, vcpu, &inst);
-		kvm_err("Exception Code: %d, not yet handled, @ PC: %p, inst: 0x%08x  BadVaddr: %#lx Status: %#lx\n",
+		kvm_err("Exception Code: %d, not yet handled, @ PC: %p, inst: 0x%08x  BadVaddr: %#lx Status: %#x\n",
 			exccode, opc, inst, badvaddr,
 			kvm_read_c0_guest_status(vcpu->arch.cop0));
 		kvm_arch_vcpu_dump_regs(vcpu);

arch/mips/kvm/trap_emul.c

@@ -55,7 +55,7 @@ static int kvm_trap_emul_no_handler(struct kvm_vcpu *vcpu)
 		opc += 1;
 	kvm_get_badinstr(opc, vcpu, &inst);
 
-	kvm_err("Exception Code: %d not handled @ PC: %p, inst: 0x%08x BadVaddr: %#lx Status: %#lx\n",
+	kvm_err("Exception Code: %d not handled @ PC: %p, inst: 0x%08x BadVaddr: %#lx Status: %#x\n",
 		exccode, opc, inst, badvaddr,
 		kvm_read_c0_guest_status(vcpu->arch.cop0));
 	kvm_arch_vcpu_dump_regs(vcpu);
@@ -947,10 +947,12 @@ static int kvm_trap_emul_set_one_reg(struct kvm_vcpu *vcpu,
 			if (v & CAUSEF_DC) {
 				/* disable timer first */
 				kvm_mips_count_disable_cause(vcpu);
-				kvm_change_c0_guest_cause(cop0, ~CAUSEF_DC, v);
+				kvm_change_c0_guest_cause(cop0, (u32)~CAUSEF_DC,
+							  v);
 			} else {
 				/* enable timer last */
-				kvm_change_c0_guest_cause(cop0, ~CAUSEF_DC, v);
+				kvm_change_c0_guest_cause(cop0, (u32)~CAUSEF_DC,
+							  v);
 				kvm_mips_count_enable_cause(vcpu);
 			}
 		} else {