From nobody Fri Dec 19 14:10:11 2025 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 4B126C83F2F for ; Thu, 31 Aug 2023 08:32:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345976AbjHaIcp (ORCPT ); Thu, 31 Aug 2023 04:32:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32872 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242877AbjHaIbx (ORCPT ); Thu, 31 Aug 2023 04:31:53 -0400 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 007A310FD; Thu, 31 Aug 2023 01:30:47 -0700 (PDT) Received: from loongson.cn (unknown [10.2.5.185]) by gateway (Coremail) with SMTP id _____8DxRvGuT_Bk4F4dAA--.60072S3; Thu, 31 Aug 2023 16:30:38 +0800 (CST) Received: from localhost.localdomain (unknown [10.2.5.185]) by localhost.localdomain (Coremail) with SMTP id AQAAf8Ax3c6gT_BkOPVnAA--.55892S26; Thu, 31 Aug 2023 16:30:37 +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 Subject: [PATCH v20 24/30] LoongArch: KVM: Implement handle mmio exception Date: Thu, 31 Aug 2023 16:30:14 +0800 Message-Id: <20230831083020.2187109-25-zhaotianrui@loongson.cn> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230831083020.2187109-1-zhaotianrui@loongson.cn> References: <20230831083020.2187109-1-zhaotianrui@loongson.cn> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: AQAAf8Ax3c6gT_BkOPVnAA--.55892S26 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 Signed-off-by: Tianrui Zhao --- arch/loongarch/kvm/exit.c | 308 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 308 insertions(+) diff --git a/arch/loongarch/kvm/exit.c b/arch/loongarch/kvm/exit.c index b0781ea100..491d1c39a9 100644 --- a/arch/loongarch/kvm/exit.c +++ b/arch/loongarch/kvm/exit.c @@ -209,6 +209,265 @@ int _kvm_emu_idle(struct kvm_vcpu *vcpu) return EMULATE_DONE; } =20 +int _kvm_emu_mmio_write(struct kvm_vcpu *vcpu, larch_inst inst) +{ + struct kvm_run *run =3D vcpu->run; + unsigned int rd, op8, opcode; + unsigned long rd_val =3D 0; + void *data =3D run->mmio.data; + unsigned long curr_pc; + int ret; + + /* + * 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; + if (op8 < 0x28) { + /* stptrw/d process */ + rd =3D inst.reg2i14_format.rd; + opcode =3D inst.reg2i14_format.opcode; + + switch (opcode) { + case stptrd_op: + run->mmio.len =3D 8; + *(unsigned long *)data =3D vcpu->arch.gprs[rd]; + break; + case stptrw_op: + run->mmio.len =3D 4; + *(unsigned int *)data =3D vcpu->arch.gprs[rd]; + break; + default: + ret =3D EMULATE_FAIL; + break; + } + } else if (op8 < 0x30) { + /* 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 std_op: + run->mmio.len =3D 8; + *(unsigned long *)data =3D rd_val; + break; + case stw_op: + run->mmio.len =3D 4; + *(unsigned int *)data =3D rd_val; + break; + case sth_op: + run->mmio.len =3D 2; + *(unsigned short *)data =3D rd_val; + break; + case stb_op: + run->mmio.len =3D 1; + *(unsigned char *)data =3D rd_val; + break; + default: + ret =3D EMULATE_FAIL; + break; + } + } else if (op8 =3D=3D 0x38) { + /* stxb/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; + } + } else + 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 supporded 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; +} + +int _kvm_emu_mmio_read(struct kvm_vcpu *vcpu, larch_inst inst) +{ + unsigned int op8, opcode, rd; + struct kvm_run *run =3D vcpu->run; + int ret; + + 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; + + if (op8 < 0x28) { + /* ldptr.w/d process */ + rd =3D inst.reg2i14_format.rd; + opcode =3D inst.reg2i14_format.opcode; + + switch (opcode) { + case ldptrd_op: + run->mmio.len =3D 8; + break; + case ldptrw_op: + run->mmio.len =3D 4; + break; + default: + break; + } + } else if (op8 < 0x2f) { + /* 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 ldd_op: + run->mmio.len =3D 8; + break; + case ldwu_op: + vcpu->mmio_needed =3D 1; /* unsigned */ + run->mmio.len =3D 4; + break; + case ldw_op: + run->mmio.len =3D 4; + break; + case ldhu_op: + vcpu->mmio_needed =3D 1; /* unsigned */ + run->mmio.len =3D 2; + break; + case ldh_op: + run->mmio.len =3D 2; + break; + case ldbu_op: + vcpu->mmio_needed =3D 1; /* unsigned */ + run->mmio.len =3D 1; + break; + case ldb_op: + run->mmio.len =3D 1; + break; + default: + ret =3D EMULATE_FAIL; + break; + } + } else if (op8 =3D=3D 0x38) { + /* ldxb/h/w/d, ldxb/h/wu, ldgtb/h/w/d, ldleb/h/w/d 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; + } + } else + 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("Load not supporded 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) +{ + unsigned long *gpr =3D &vcpu->arch.gprs[vcpu->arch.io_gpr]; + enum emulation_result er =3D EMULATE_DONE; + + /* update with new PC */ + update_pc(&vcpu->arch); + switch (run->mmio.len) { + case 8: + *gpr =3D *(s64 *)run->mmio.data; + break; + case 4: + if (vcpu->mmio_needed =3D=3D 2) + *gpr =3D *(int *)run->mmio.data; + else + *gpr =3D *(unsigned int *)run->mmio.data; + break; + case 2: + if (vcpu->mmio_needed =3D=3D 2) + *gpr =3D *(short *) run->mmio.data; + else + *gpr =3D *(unsigned short *)run->mmio.data; + + break; + case 1: + if (vcpu->mmio_needed =3D=3D 2) + *gpr =3D *(char *) run->mmio.data; + else + *gpr =3D *(unsigned char *) run->mmio.data; + break; + default: + kvm_err("Bad MMIO length: %d,addr is 0x%lx", + run->mmio.len, vcpu->arch.badv); + er =3D EMULATE_FAIL; + break; + } + + return er; +} + static int _kvm_trap_handle_gspr(struct kvm_vcpu *vcpu) { enum emulation_result er =3D EMULATE_DONE; @@ -320,3 +579,52 @@ static int _kvm_handle_gspr(struct kvm_vcpu *vcpu) } return ret; } + +static int _kvm_handle_mmu_fault(struct kvm_vcpu *vcpu, bool write) +{ + struct kvm_run *run =3D vcpu->run; + unsigned long badv =3D vcpu->arch.badv; + larch_inst inst; + enum emulation_result er =3D EMULATE_DONE; + int ret; + + 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_err("%s ifetch error addr:%lx\n", __func__, badv); + run->exit_reason =3D KVM_EXIT_INTERNAL_ERROR; + return RESUME_HOST; + } + + 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 { + run->exit_reason =3D KVM_EXIT_INTERNAL_ERROR; + ret =3D RESUME_HOST; + } + + return ret; +} + +static int _kvm_handle_write_fault(struct kvm_vcpu *vcpu) +{ + return _kvm_handle_mmu_fault(vcpu, true); +} + +static int _kvm_handle_read_fault(struct kvm_vcpu *vcpu) +{ + return _kvm_handle_mmu_fault(vcpu, false); +} --=20 2.27.0