From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8AB0C432C1 for ; Tue, 24 Sep 2019 15:22:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ADD9F21655 for ; Tue, 24 Sep 2019 15:22:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732590AbfIXPWb (ORCPT ); Tue, 24 Sep 2019 11:22:31 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:46846 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727382AbfIXPWa (ORCPT ); Tue, 24 Sep 2019 11:22:30 -0400 Received: from DGGEMS401-HUB.china.huawei.com (unknown [172.30.72.59]) by Forcepoint Email with ESMTP id 3D655AAB33C626A11C05; Tue, 24 Sep 2019 23:22:29 +0800 (CST) Received: from linux-Bxxcye.huawei.com (10.175.104.222) by DGGEMS401-HUB.china.huawei.com (10.3.19.201) with Microsoft SMTP Server id 14.3.439.0; Tue, 24 Sep 2019 23:22:20 +0800 From: Heyi Guo To: , , , , CC: , Heyi Guo , Peter Maydell , Dave Martin , Marc Zyngier , Mark Rutland , James Morse , Julien Thierry , "Suzuki K Poulose" , Russell King , Catalin Marinas , Will Deacon Subject: [RFC PATCH 1/2] kvm/arm: add capability to forward hypercall to user space Date: Tue, 24 Sep 2019 23:20:53 +0800 Message-ID: <1569338454-26202-2-git-send-email-guoheyi@huawei.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1569338454-26202-1-git-send-email-guoheyi@huawei.com> References: <1569338454-26202-1-git-send-email-guoheyi@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.104.222] X-CFilter-Loop: Reflected Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org As more SMC/HVC usages emerge on arm64 platforms, like SDEI, it makes sense for kvm to have the capability of forwarding such calls to user space for further emulation. We reuse the existing term "hypercall" for SMC/HVC, as well as the hypercall structure in kvm_run to exchange arguments and return values. The definition on arm64 is as below: exit_reason: KVM_EXIT_HYPERCALL Input: nr: the immediate value of SMC/HVC calls; not really used today. args[6]: x0..x5 (This is not fully conform with SMCCC which requires x6 as argument as well, but use space can use GET_ONE_REG ioctl for such rare case). Return: args[0..3]: x0..x3 as defined in SMCCC. We need to extract args[0..3] and write them to x0..x3 when hypercall exit returns. Flag hypercall_forward is added to turn on/off hypercall forwarding and the default is false. Another flag hypercall_excl_psci is to exclude PSCI from forwarding for backward compatible, and it only makes sense to check its value when hypercall_forward is enabled. Signed-off-by: Heyi Guo Cc: Peter Maydell Cc: Dave Martin Cc: Marc Zyngier Cc: Mark Rutland Cc: James Morse Cc: Julien Thierry Cc: Suzuki K Poulose CC: Russell King Cc: Catalin Marinas Cc: Will Deacon --- arch/arm/include/asm/kvm_host.h | 5 +++++ arch/arm64/include/asm/kvm_host.h | 5 +++++ include/kvm/arm_psci.h | 1 + virt/kvm/arm/arm.c | 2 ++ virt/kvm/arm/psci.c | 30 ++++++++++++++++++++++++++++-- 5 files changed, 41 insertions(+), 2 deletions(-) diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h index 8a37c8e..68ccaf0 100644 --- a/arch/arm/include/asm/kvm_host.h +++ b/arch/arm/include/asm/kvm_host.h @@ -76,6 +76,11 @@ struct kvm_arch { /* Mandated version of PSCI */ u32 psci_version; + + /* Flags to control hypercall forwarding to userspace */ + bool hypercall_forward; + /* Exclude PSCI from hypercall forwarding and let kvm to handle it */ + bool hypercall_excl_psci; }; #define KVM_NR_MEM_OBJS 40 diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index f656169..e47ac25 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -83,6 +83,11 @@ struct kvm_arch { /* Mandated version of PSCI */ u32 psci_version; + + /* Flags to control hypercall forwarding to userspace */ + bool hypercall_forward; + /* Exclude PSCI from hypercall forwarding and let kvm to handle it */ + bool hypercall_excl_psci; }; #define KVM_NR_MEM_OBJS 40 diff --git a/include/kvm/arm_psci.h b/include/kvm/arm_psci.h index 632e78b..9c9a2dc 100644 --- a/include/kvm/arm_psci.h +++ b/include/kvm/arm_psci.h @@ -48,5 +48,6 @@ static inline int kvm_psci_version(struct kvm_vcpu *vcpu, struct kvm *kvm) int kvm_arm_copy_fw_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices); int kvm_arm_get_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg); int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg); +void kvm_handle_hypercall_return(struct kvm_vcpu *vcpu, struct kvm_run *run); #endif /* __KVM_ARM_PSCI_H__ */ diff --git a/virt/kvm/arm/arm.c b/virt/kvm/arm/arm.c index 35a0698..2f4ca21 100644 --- a/virt/kvm/arm/arm.c +++ b/virt/kvm/arm/arm.c @@ -673,6 +673,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) ret = kvm_handle_mmio_return(vcpu, vcpu->run); if (ret) return ret; + } else if (run->exit_reason == KVM_EXIT_HYPERCALL) { + kvm_handle_hypercall_return(vcpu, vcpu->run); } if (run->immediate_exit) diff --git a/virt/kvm/arm/psci.c b/virt/kvm/arm/psci.c index 87927f7..7e1f735 100644 --- a/virt/kvm/arm/psci.c +++ b/virt/kvm/arm/psci.c @@ -389,6 +389,7 @@ static int kvm_psci_call(struct kvm_vcpu *vcpu) int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) { + struct kvm *kvm = vcpu->kvm; u32 func_id = smccc_get_function(vcpu); u32 val = SMCCC_RET_NOT_SUPPORTED; u32 feature; @@ -428,8 +429,27 @@ int kvm_hvc_call_handler(struct kvm_vcpu *vcpu) break; } break; - default: - return kvm_psci_call(vcpu); + default: { + if (!kvm->arch.hypercall_forward || + kvm->arch.hypercall_excl_psci) { + u32 id = func_id & ~PSCI_0_2_64BIT; + + if (id >= PSCI_0_2_FN_BASE && id <= PSCI_0_2_FN(0x1f)) + return kvm_psci_call(vcpu); + } + + if (kvm->arch.hypercall_forward) { + /* Exit to user space to process */ + vcpu->run->exit_reason = KVM_EXIT_HYPERCALL; + vcpu->run->hypercall.nr = kvm_vcpu_get_hsr(vcpu) & + ESR_ELx_ISS_MASK; + vcpu->run->hypercall.args[0] = func_id; + vcpu->run->hypercall.args[1] = smccc_get_arg1(vcpu); + vcpu->run->hypercall.args[2] = smccc_get_arg2(vcpu); + vcpu->run->hypercall.args[3] = smccc_get_arg3(vcpu); + return 0; + } + } } smccc_set_retval(vcpu, val, 0, 0, 0); @@ -603,3 +623,9 @@ int kvm_arm_set_fw_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) return -EINVAL; } + +void kvm_handle_hypercall_return(struct kvm_vcpu *vcpu, struct kvm_run *run) +{ + smccc_set_retval(vcpu, run->hypercall.args[0], run->hypercall.args[1], + run->hypercall.args[2], run->hypercall.args[3]); +} -- 1.8.3.1