[v22,19/25] LoongArch: KVM: Implement handle mmio exception
Commit Message
Implement handle mmio exception, setting the mmio info into vcpu_run and
return to user space to handle it.
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Tested-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Tianrui Zhao <zhaotianrui@loongson.cn>
---
arch/loongarch/kvm/exit.c | 310 ++++++++++++++++++++++++++++++++++++++
1 file changed, 310 insertions(+)
@@ -321,3 +321,313 @@ static int kvm_handle_gspr(struct kvm_vcpu *vcpu)
return ret;
}
+
+int kvm_emu_mmio_read(struct kvm_vcpu *vcpu, larch_inst inst)
+{
+ int ret;
+ unsigned int op8, opcode, rd;
+ struct kvm_run *run = vcpu->run;
+
+ run->mmio.phys_addr = vcpu->arch.badv;
+ vcpu->mmio_needed = 2; /* signed */
+ op8 = (inst.word >> 24) & 0xff;
+ ret = EMULATE_DO_MMIO;
+
+ switch (op8) {
+ case 0x24 ... 0x27: /* ldptr.w/d process */
+ rd = inst.reg2i14_format.rd;
+ opcode = inst.reg2i14_format.opcode;
+
+ switch (opcode) {
+ case ldptrw_op:
+ run->mmio.len = 4;
+ break;
+ case ldptrd_op:
+ run->mmio.len = 8;
+ break;
+ default:
+ break;
+ }
+ break;
+ case 0x28 ... 0x2e: /* ld.b/h/w/d, ld.bu/hu/wu process */
+ rd = inst.reg2i12_format.rd;
+ opcode = inst.reg2i12_format.opcode;
+
+ switch (opcode) {
+ case ldb_op:
+ run->mmio.len = 1;
+ break;
+ case ldbu_op:
+ vcpu->mmio_needed = 1; /* unsigned */
+ run->mmio.len = 1;
+ break;
+ case ldh_op:
+ run->mmio.len = 2;
+ break;
+ case ldhu_op:
+ vcpu->mmio_needed = 1; /* unsigned */
+ run->mmio.len = 2;
+ break;
+ case ldw_op:
+ run->mmio.len = 4;
+ break;
+ case ldwu_op:
+ vcpu->mmio_needed = 1; /* unsigned */
+ run->mmio.len = 4;
+ break;
+ case ldd_op:
+ run->mmio.len = 8;
+ break;
+ default:
+ ret = EMULATE_FAIL;
+ break;
+ }
+ break;
+ case 0x38: /* ldx.b/h/w/d, ldx.bu/hu/wu process */
+ rd = inst.reg3_format.rd;
+ opcode = inst.reg3_format.opcode;
+
+ switch (opcode) {
+ case ldxb_op:
+ run->mmio.len = 1;
+ break;
+ case ldxbu_op:
+ run->mmio.len = 1;
+ vcpu->mmio_needed = 1; /* unsigned */
+ break;
+ case ldxh_op:
+ run->mmio.len = 2;
+ break;
+ case ldxhu_op:
+ run->mmio.len = 2;
+ vcpu->mmio_needed = 1; /* unsigned */
+ break;
+ case ldxw_op:
+ run->mmio.len = 4;
+ break;
+ case ldxwu_op:
+ run->mmio.len = 4;
+ vcpu->mmio_needed = 1; /* unsigned */
+ break;
+ case ldxd_op:
+ run->mmio.len = 8;
+ break;
+ default:
+ ret = EMULATE_FAIL;
+ break;
+ }
+ break;
+ default:
+ ret = EMULATE_FAIL;
+ }
+
+ if (ret == EMULATE_DO_MMIO) {
+ /* Set for kvm_complete_mmio_read() use */
+ vcpu->arch.io_gpr = rd;
+ run->mmio.is_write = 0;
+ vcpu->mmio_is_write = 0;
+ } else {
+ kvm_err("Read not supported Inst=0x%08x @%lx BadVaddr:%#lx\n",
+ inst.word, vcpu->arch.pc, vcpu->arch.badv);
+ kvm_arch_vcpu_dump_regs(vcpu);
+ vcpu->mmio_needed = 0;
+ }
+
+ return ret;
+}
+
+int kvm_complete_mmio_read(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+ enum emulation_result er = EMULATE_DONE;
+ unsigned long *gpr = &vcpu->arch.gprs[vcpu->arch.io_gpr];
+
+ /* Update with new PC */
+ update_pc(&vcpu->arch);
+ switch (run->mmio.len) {
+ case 1:
+ if (vcpu->mmio_needed == 2)
+ *gpr = *(s8 *)run->mmio.data;
+ else
+ *gpr = *(u8 *)run->mmio.data;
+ break;
+ case 2:
+ if (vcpu->mmio_needed == 2)
+ *gpr = *(s16 *)run->mmio.data;
+ else
+ *gpr = *(u16 *)run->mmio.data;
+ break;
+ case 4:
+ if (vcpu->mmio_needed == 2)
+ *gpr = *(s32 *)run->mmio.data;
+ else
+ *gpr = *(u32 *)run->mmio.data;
+ break;
+ case 8:
+ *gpr = *(s64 *)run->mmio.data;
+ break;
+ default:
+ kvm_err("Bad MMIO length: %d, addr is 0x%lx\n",
+ run->mmio.len, vcpu->arch.badv);
+ er = EMULATE_FAIL;
+ break;
+ }
+
+ return er;
+}
+
+int kvm_emu_mmio_write(struct kvm_vcpu *vcpu, larch_inst inst)
+{
+ int ret;
+ unsigned int rd, op8, opcode;
+ unsigned long curr_pc, rd_val = 0;
+ struct kvm_run *run = vcpu->run;
+ void *data = run->mmio.data;
+
+ /*
+ * Update PC and hold onto current PC in case there is
+ * an error and we want to rollback the PC
+ */
+ curr_pc = vcpu->arch.pc;
+ update_pc(&vcpu->arch);
+
+ op8 = (inst.word >> 24) & 0xff;
+ run->mmio.phys_addr = vcpu->arch.badv;
+ ret = EMULATE_DO_MMIO;
+ switch (op8) {
+ case 0x24 ... 0x27: /* stptr.w/d process */
+ rd = inst.reg2i14_format.rd;
+ opcode = inst.reg2i14_format.opcode;
+
+ switch (opcode) {
+ case stptrw_op:
+ run->mmio.len = 4;
+ *(unsigned int *)data = vcpu->arch.gprs[rd];
+ break;
+ case stptrd_op:
+ run->mmio.len = 8;
+ *(unsigned long *)data = vcpu->arch.gprs[rd];
+ break;
+ default:
+ ret = EMULATE_FAIL;
+ break;
+ }
+ break;
+ case 0x28 ... 0x2e: /* st.b/h/w/d process */
+ rd = inst.reg2i12_format.rd;
+ opcode = inst.reg2i12_format.opcode;
+ rd_val = vcpu->arch.gprs[rd];
+
+ switch (opcode) {
+ case stb_op:
+ run->mmio.len = 1;
+ *(unsigned char *)data = rd_val;
+ break;
+ case sth_op:
+ run->mmio.len = 2;
+ *(unsigned short *)data = rd_val;
+ break;
+ case stw_op:
+ run->mmio.len = 4;
+ *(unsigned int *)data = rd_val;
+ break;
+ case std_op:
+ run->mmio.len = 8;
+ *(unsigned long *)data = rd_val;
+ break;
+ default:
+ ret = EMULATE_FAIL;
+ break;
+ }
+ break;
+ case 0x38: /* stx.b/h/w/d process */
+ rd = inst.reg3_format.rd;
+ opcode = inst.reg3_format.opcode;
+
+ switch (opcode) {
+ case stxb_op:
+ run->mmio.len = 1;
+ *(unsigned char *)data = vcpu->arch.gprs[rd];
+ break;
+ case stxh_op:
+ run->mmio.len = 2;
+ *(unsigned short *)data = vcpu->arch.gprs[rd];
+ break;
+ case stxw_op:
+ run->mmio.len = 4;
+ *(unsigned int *)data = vcpu->arch.gprs[rd];
+ break;
+ case stxd_op:
+ run->mmio.len = 8;
+ *(unsigned long *)data = vcpu->arch.gprs[rd];
+ break;
+ default:
+ ret = EMULATE_FAIL;
+ break;
+ }
+ break;
+ default:
+ ret = EMULATE_FAIL;
+ }
+
+ if (ret == EMULATE_DO_MMIO) {
+ run->mmio.is_write = 1;
+ vcpu->mmio_needed = 1;
+ vcpu->mmio_is_write = 1;
+ } else {
+ vcpu->arch.pc = curr_pc;
+ kvm_err("Write not supported Inst=0x%08x @%lx BadVaddr:%#lx\n",
+ inst.word, vcpu->arch.pc, vcpu->arch.badv);
+ kvm_arch_vcpu_dump_regs(vcpu);
+ /* Rollback PC if emulation was unsuccessful */
+ }
+
+ return ret;
+}
+
+static int kvm_handle_rdwr_fault(struct kvm_vcpu *vcpu, bool write)
+{
+ int ret;
+ larch_inst inst;
+ enum emulation_result er = EMULATE_DONE;
+ struct kvm_run *run = vcpu->run;
+ unsigned long badv = vcpu->arch.badv;
+
+ ret = kvm_handle_mm_fault(vcpu, badv, write);
+ if (ret) {
+ /* Treat as MMIO */
+ inst.word = vcpu->arch.badi;
+ if (write) {
+ er = kvm_emu_mmio_write(vcpu, inst);
+ } else {
+ /* A code fetch fault doesn't count as an MMIO */
+ if (kvm_is_ifetch_fault(&vcpu->arch)) {
+ kvm_queue_exception(vcpu, EXCCODE_ADE, EXSUBCODE_ADEF);
+ return RESUME_GUEST;
+ }
+
+ er = kvm_emu_mmio_read(vcpu, inst);
+ }
+ }
+
+ if (er == EMULATE_DONE) {
+ ret = RESUME_GUEST;
+ } else if (er == EMULATE_DO_MMIO) {
+ run->exit_reason = KVM_EXIT_MMIO;
+ ret = RESUME_HOST;
+ } else {
+ kvm_queue_exception(vcpu, EXCCODE_ADE, EXSUBCODE_ADEM);
+ ret = RESUME_GUEST;
+ }
+
+ return ret;
+}
+
+static int kvm_handle_read_fault(struct kvm_vcpu *vcpu)
+{
+ return kvm_handle_rdwr_fault(vcpu, false);
+}
+
+static int kvm_handle_write_fault(struct kvm_vcpu *vcpu)
+{
+ return kvm_handle_rdwr_fault(vcpu, true);
+}