From nobody Wed Feb 11 04:20:16 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DAE06CE7A8B for ; Wed, 27 Sep 2023 04:13:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229608AbjI0ENm (ORCPT ); Wed, 27 Sep 2023 00:13:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41582 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229764AbjI0EM3 (ORCPT ); Wed, 27 Sep 2023 00:12:29 -0400 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 58768CEA; Tue, 26 Sep 2023 20:10:18 -0700 (PDT) Received: from loongson.cn (unknown [10.2.5.185]) by gateway (Coremail) with SMTP id _____8AxDOsRnRNlnxctAA--.15597S3; Wed, 27 Sep 2023 11:10:09 +0800 (CST) Received: from localhost.localdomain (unknown [10.2.5.185]) by localhost.localdomain (Coremail) with SMTP id AQAAf8Cxjd4InRNlhZETAA--.42466S21; Wed, 27 Sep 2023 11:10:07 +0800 (CST) From: Tianrui Zhao To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: Paolo Bonzini , Huacai Chen , WANG Xuerui , Greg Kroah-Hartman , loongarch@lists.linux.dev, Jens Axboe , Mark Brown , Alex Deucher , Oliver Upton , maobibo@loongson.cn, Xi Ruoyao , zhaotianrui@loongson.cn, Huacai Chen Subject: [PATCH v22 19/25] LoongArch: KVM: Implement handle mmio exception Date: Wed, 27 Sep 2023 11:09:53 +0800 Message-Id: <20230927030959.3629941-20-zhaotianrui@loongson.cn> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230927030959.3629941-1-zhaotianrui@loongson.cn> References: <20230927030959.3629941-1-zhaotianrui@loongson.cn> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: AQAAf8Cxjd4InRNlhZETAA--.42466S21 X-CM-SenderInfo: p2kd03xldq233l6o00pqjv00gofq/ X-Coremail-Antispam: 1Uk129KBjDUn29KB7ZKAUJUUUUU529EdanIXcx71UUUUU7KY7 ZEXasCq-sGcSsGvfJ3UbIjqfuFe4nvWSU5nxnvy29KBjDU0xBIdaVrnUUvcSsGvfC2Kfnx nUUI43ZEXa7xR_UUUUUUUUU== Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Implement handle mmio exception, setting the mmio info into vcpu_run and return to user space to handle it. Reviewed-by: Bibo Mao Tested-by: Huacai Chen Signed-off-by: Tianrui Zhao --- arch/loongarch/kvm/exit.c | 310 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 310 insertions(+) diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c index 33d1b4190a..c31894b75b 100644 --- a/arch/loongarch/kvm/exit.c +++ b/arch/loongarch/kvm/exit.c @@ -321,3 +321,313 @@ static int kvm_handle_gspr(struct kvm_vcpu *vcpu) =20 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 =3D vcpu->run; + + run->mmio.phys_addr =3D vcpu->arch.badv; + vcpu->mmio_needed =3D 2; /* signed */ + op8 =3D (inst.word >> 24) & 0xff; + ret =3D EMULATE_DO_MMIO; + + switch (op8) { + case 0x24 ... 0x27: /* ldptr.w/d process */ + rd =3D inst.reg2i14_format.rd; + opcode =3D inst.reg2i14_format.opcode; + + switch (opcode) { + case ldptrw_op: + run->mmio.len =3D 4; + break; + case ldptrd_op: + run->mmio.len =3D 8; + break; + default: + break; + } + break; + case 0x28 ... 0x2e: /* ld.b/h/w/d, ld.bu/hu/wu process */ + rd =3D inst.reg2i12_format.rd; + opcode =3D inst.reg2i12_format.opcode; + + switch (opcode) { + case ldb_op: + run->mmio.len =3D 1; + break; + case ldbu_op: + vcpu->mmio_needed =3D 1; /* unsigned */ + run->mmio.len =3D 1; + break; + case ldh_op: + run->mmio.len =3D 2; + break; + case ldhu_op: + vcpu->mmio_needed =3D 1; /* unsigned */ + run->mmio.len =3D 2; + break; + case ldw_op: + run->mmio.len =3D 4; + break; + case ldwu_op: + vcpu->mmio_needed =3D 1; /* unsigned */ + run->mmio.len =3D 4; + break; + case ldd_op: + run->mmio.len =3D 8; + break; + default: + ret =3D EMULATE_FAIL; + break; + } + break; + case 0x38: /* ldx.b/h/w/d, ldx.bu/hu/wu process */ + rd =3D inst.reg3_format.rd; + opcode =3D inst.reg3_format.opcode; + + switch (opcode) { + case ldxb_op: + run->mmio.len =3D 1; + break; + case ldxbu_op: + run->mmio.len =3D 1; + vcpu->mmio_needed =3D 1; /* unsigned */ + break; + case ldxh_op: + run->mmio.len =3D 2; + break; + case ldxhu_op: + run->mmio.len =3D 2; + vcpu->mmio_needed =3D 1; /* unsigned */ + break; + case ldxw_op: + run->mmio.len =3D 4; + break; + case ldxwu_op: + run->mmio.len =3D 4; + vcpu->mmio_needed =3D 1; /* unsigned */ + break; + case ldxd_op: + run->mmio.len =3D 8; + break; + default: + ret =3D EMULATE_FAIL; + break; + } + break; + default: + ret =3D EMULATE_FAIL; + } + + if (ret =3D=3D EMULATE_DO_MMIO) { + /* Set for kvm_complete_mmio_read() use */ + vcpu->arch.io_gpr =3D rd; + run->mmio.is_write =3D 0; + vcpu->mmio_is_write =3D 0; + } else { + kvm_err("Read not supported Inst=3D0x%08x @%lx BadVaddr:%#lx\n", + inst.word, vcpu->arch.pc, vcpu->arch.badv); + kvm_arch_vcpu_dump_regs(vcpu); + vcpu->mmio_needed =3D 0; + } + + return ret; +} + +int kvm_complete_mmio_read(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + enum emulation_result er =3D EMULATE_DONE; + unsigned long *gpr =3D &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 =3D=3D 2) + *gpr =3D *(s8 *)run->mmio.data; + else + *gpr =3D *(u8 *)run->mmio.data; + break; + case 2: + if (vcpu->mmio_needed =3D=3D 2) + *gpr =3D *(s16 *)run->mmio.data; + else + *gpr =3D *(u16 *)run->mmio.data; + break; + case 4: + if (vcpu->mmio_needed =3D=3D 2) + *gpr =3D *(s32 *)run->mmio.data; + else + *gpr =3D *(u32 *)run->mmio.data; + break; + case 8: + *gpr =3D *(s64 *)run->mmio.data; + break; + default: + kvm_err("Bad MMIO length: %d, addr is 0x%lx\n", + run->mmio.len, vcpu->arch.badv); + er =3D 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 =3D 0; + struct kvm_run *run =3D vcpu->run; + void *data =3D 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 =3D vcpu->arch.pc; + update_pc(&vcpu->arch); + + op8 =3D (inst.word >> 24) & 0xff; + run->mmio.phys_addr =3D vcpu->arch.badv; + ret =3D EMULATE_DO_MMIO; + switch (op8) { + case 0x24 ... 0x27: /* stptr.w/d process */ + rd =3D inst.reg2i14_format.rd; + opcode =3D inst.reg2i14_format.opcode; + + switch (opcode) { + case stptrw_op: + run->mmio.len =3D 4; + *(unsigned int *)data =3D vcpu->arch.gprs[rd]; + break; + case stptrd_op: + run->mmio.len =3D 8; + *(unsigned long *)data =3D vcpu->arch.gprs[rd]; + break; + default: + ret =3D EMULATE_FAIL; + break; + } + break; + case 0x28 ... 0x2e: /* st.b/h/w/d process */ + rd =3D inst.reg2i12_format.rd; + opcode =3D inst.reg2i12_format.opcode; + rd_val =3D vcpu->arch.gprs[rd]; + + switch (opcode) { + case stb_op: + run->mmio.len =3D 1; + *(unsigned char *)data =3D rd_val; + break; + case sth_op: + run->mmio.len =3D 2; + *(unsigned short *)data =3D rd_val; + break; + case stw_op: + run->mmio.len =3D 4; + *(unsigned int *)data =3D rd_val; + break; + case std_op: + run->mmio.len =3D 8; + *(unsigned long *)data =3D rd_val; + break; + default: + ret =3D EMULATE_FAIL; + break; + } + break; + case 0x38: /* stx.b/h/w/d process */ + rd =3D inst.reg3_format.rd; + opcode =3D inst.reg3_format.opcode; + + switch (opcode) { + case stxb_op: + run->mmio.len =3D 1; + *(unsigned char *)data =3D vcpu->arch.gprs[rd]; + break; + case stxh_op: + run->mmio.len =3D 2; + *(unsigned short *)data =3D vcpu->arch.gprs[rd]; + break; + case stxw_op: + run->mmio.len =3D 4; + *(unsigned int *)data =3D vcpu->arch.gprs[rd]; + break; + case stxd_op: + run->mmio.len =3D 8; + *(unsigned long *)data =3D vcpu->arch.gprs[rd]; + break; + default: + ret =3D EMULATE_FAIL; + break; + } + break; + default: + ret =3D EMULATE_FAIL; + } + + if (ret =3D=3D EMULATE_DO_MMIO) { + run->mmio.is_write =3D 1; + vcpu->mmio_needed =3D 1; + vcpu->mmio_is_write =3D 1; + } else { + vcpu->arch.pc =3D curr_pc; + kvm_err("Write not supported Inst=3D0x%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 =3D EMULATE_DONE; + struct kvm_run *run =3D vcpu->run; + unsigned long badv =3D vcpu->arch.badv; + + ret =3D kvm_handle_mm_fault(vcpu, badv, write); + if (ret) { + /* Treat as MMIO */ + inst.word =3D vcpu->arch.badi; + if (write) { + er =3D 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 =3D kvm_emu_mmio_read(vcpu, inst); + } + } + + if (er =3D=3D EMULATE_DONE) { + ret =3D RESUME_GUEST; + } else if (er =3D=3D EMULATE_DO_MMIO) { + run->exit_reason =3D KVM_EXIT_MMIO; + ret =3D RESUME_HOST; + } else { + kvm_queue_exception(vcpu, EXCCODE_ADE, EXSUBCODE_ADEM); + ret =3D 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); +} --=20 2.39.3