From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7EE7E3101AD; Thu, 12 Mar 2026 08:08:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773302921; cv=none; b=cMDrtRhvSca2+EgXbQ0pEnRxBbcNKA+MH8Q/iazAG2g2wkPOPLgrFC9Yj8xPaDO8TQEzfbe3sIuyl9UurHukqxM8NdAd1cCCUXGYX2RW+2dRcUP+Nl2soIrzBtahZ7Ec8Jp11wsar0Yp/mnMb5snT/xmYkHokpqTQVd8hGY33JA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773302921; c=relaxed/simple; bh=AIcxrskhjV16J/y4kRg5qatXDqQyVjJGwRlt50pWiKo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Ba9AYgHIOMHYEHB9bnlT0YH07jYFuSR+yvGqHWD60jkSCXwbGIcYeU49edVWfav+MNYFimxNM4Gf+CWW8yjaJfT/9lv/i9FHAac0q2pfiXUswUZySPb73fiig7Pa1lutaY+k30jDKLP0AdggqaCJJWcTjfSfeQj31gJZ7TWXiy8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ayvQ7Uvv; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ayvQ7Uvv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9F7DEC4CEF7; Thu, 12 Mar 2026 08:08:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773302921; bh=AIcxrskhjV16J/y4kRg5qatXDqQyVjJGwRlt50pWiKo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ayvQ7UvvPq4elBLij/SRIpZIdDFu7ZLLrsbHYazSTYTqPacXPZfPG04hNmFUP0I/s GbjosUxybE01/WKg7EjbnWOPCT6YFO1vVCNmRMl9QVdirOcfELBjN3IS9KmB99GxQW iG7aqivKPXsBKDGIvPtkzLFxKJsnWr9Fzrgdu1WANvfyB+12Kqf9Nwesi4dZBaWmN4 uqZMCTG85cgf9LhVCNI0vSd3gkRCFe62Ec4zDSw0Ow7xBJZ+2qDsEFS67kkPjUmTJ0 uBXe/6AKTIikizP527IvPoXbT7PZ9NsERXusIXHVLYKTo38TQWhozfhJy7vWv/wcCd zwPLmz1V0+6PQ== From: "Aneesh Kumar K.V (Arm)" To: linux-coco@lists.linux.dev, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org, "Aneesh Kumar K.V (Arm)" , Marc Zyngier , Catalin Marinas , Will Deacon , Jonathan Cameron , Jason Gunthorpe , Dan Williams , Alexey Kardashevskiy , Samuel Ortiz , Xu Yilun , Suzuki K Poulose , Steven Price Subject: [RFC PATCH v3 08/12] coco: host: KVM: arm64: Handle vdev request exits and completion Date: Thu, 12 Mar 2026 13:37:39 +0530 Message-ID: <20260312080743.3487326-9-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260312080743.3487326-1-aneesh.kumar@kernel.org> References: <20260312080743.3487326-1-aneesh.kumar@kernel.org> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit - add the RMI/RHI definitions for RMI_VDEV_COMPLETE, the new exit reason, and the extended REC exit payload - update KVM to recognize RMI_EXIT_VDEV_REQUEST and surface it to userspace via KVM_EXIT_ARM64_TIO - Add CCA TSM guest request handler for __REC_EXIT_DA_VDEV_REQUEST which takes a vCPU fd and verify it belongs to the same VM before calling rmi_vdev_complete() This lets Realm firmware hand control back to the VMM when it needs host assistance for vdev operations, and gives userspace a way to finish the request. Cc: Marc Zyngier Cc: Catalin Marinas Cc: Will Deacon Cc: Jonathan Cameron Cc: Jason Gunthorpe Cc: Dan Williams Cc: Alexey Kardashevskiy Cc: Samuel Ortiz Cc: Xu Yilun Cc: Suzuki K Poulose Cc: Steven Price Signed-off-by: Aneesh Kumar K.V (Arm) --- Documentation/virt/kvm/api.rst | 22 +++++++++++++++++ arch/arm64/include/asm/rhi.h | 1 + arch/arm64/include/asm/rmi_cmds.h | 10 ++++++++ arch/arm64/include/asm/rmi_smc.h | 17 ++++++++++++-- arch/arm64/include/uapi/asm/rmi-da.h | 5 ++++ arch/arm64/kvm/rmi-exit.c | 17 ++++++++++++++ drivers/virt/coco/arm-cca-host/arm-cca.c | 12 ++++++++++ drivers/virt/coco/arm-cca-host/rmi-da.c | 30 ++++++++++++++++++++++++ drivers/virt/coco/arm-cca-host/rmi-da.h | 2 ++ include/linux/kvm_host.h | 1 + include/uapi/linux/kvm.h | 10 ++++++++ virt/kvm/kvm_main.c | 6 +++++ 12 files changed, 131 insertions(+), 2 deletions(-) diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst index bd2f0dd0aeda..041009307ee8 100644 --- a/Documentation/virt/kvm/api.rst +++ b/Documentation/virt/kvm/api.rst @@ -7429,6 +7429,28 @@ the ``KVM_EXIT_ARM_SEA_FLAG_GPA_VALID`` flag is set. Otherwise, the value of ``gpa`` is unknown. :: + /* KVM_EXIT_ARM64_TIO*/ + struct { + __u64 flags; + __u64 nr; + __u64 vdev_id; + __u64 gpa_base; + __u64 gpa_top; + __u64 pa_base; + } cca_exit; + +Used on arm64 systems. When the VM capability ``KVM_CAP_ARM_RMI`` is enabled, +KVM generates a VM exit whenever the guest needs host assistance to map a vdev +ID to a vdev object, or to validate a device-memory GPA-to-PA mapping. The +``nr`` field records the exit reason; currently the following values are +defined: + +* ``RMI_EXIT_VDEV_REQUEST``: the RMM is requiring host to provide the vdev + object details matching a specific virtual device id. +* ``RMI_EXIT_VDEV_MAP``: the guest wants the host to validate or install a + device-memory mapping. + +The ``flags`` field must be zero. /* Fix the size of the union. */ char padding[256]; diff --git a/arch/arm64/include/asm/rhi.h b/arch/arm64/include/asm/rhi.h index a18ad7bbc028..888b3a1c3953 100644 --- a/arch/arm64/include/asm/rhi.h +++ b/arch/arm64/include/asm/rhi.h @@ -84,5 +84,6 @@ enum rhi_tdi_state { #define __RHI_DA_OBJECT_READ 0x2 #define __RHI_DA_VDEV_GET_INTERFACE_REPORT 0x3 #define __RHI_DA_VDEV_GET_MEASUREMENTS 0x4 +#define __REC_EXIT_DA_VDEV_REQUEST 0x5 #endif diff --git a/arch/arm64/include/asm/rmi_cmds.h b/arch/arm64/include/asm/rmi_cmds.h index aad245675c7d..f29c2de5d3b9 100644 --- a/arch/arm64/include/asm/rmi_cmds.h +++ b/arch/arm64/include/asm/rmi_cmds.h @@ -685,4 +685,14 @@ rmi_vdev_get_device_measurements(unsigned long rd, unsigned long pdev_phys, return res.a0; } + +static inline unsigned long rmi_vdev_complete(unsigned long rec_phys, unsigned long vdev_phys) +{ + struct arm_smccc_res res; + + arm_smccc_1_1_invoke(SMC_RMI_VDEV_COMPLETE, rec_phys, vdev_phys, &res); + + return res.a0; +} + #endif /* __ASM_RMI_CMDS_H */ diff --git a/arch/arm64/include/asm/rmi_smc.h b/arch/arm64/include/asm/rmi_smc.h index 36c3db8b821d..6b685585e750 100644 --- a/arch/arm64/include/asm/rmi_smc.h +++ b/arch/arm64/include/asm/rmi_smc.h @@ -60,6 +60,7 @@ #define SMC_RMI_VDEV_DESTROY SMC_RMI_CALL(0x0188) #define SMC_RMI_VDEV_GET_STATE SMC_RMI_CALL(0x0189) #define SMC_RMI_VDEV_UNLOCK SMC_RMI_CALL(0x018A) +#define SMC_RMI_VDEV_COMPLETE SMC_RMI_CALL(0x018e) #define SMC_RMI_VDEV_GET_INTERFACE_REPORT SMC_RMI_CALL(0x01D0) #define SMC_RMI_VDEV_GET_DEV_MEASUREMENTS SMC_RMI_CALL(0x01D1) #define SMC_RMI_VDEV_LOCK SMC_RMI_CALL(0x01D2) @@ -225,6 +226,7 @@ struct rec_enter { #define RMI_EXIT_RIPAS_CHANGE 0x04 #define RMI_EXIT_HOST_CALL 0x05 #define RMI_EXIT_SERROR 0x06 +#define RMI_EXIT_VDEV_REQUEST 0x08 struct rec_exit { union { /* 0x000 */ @@ -266,12 +268,23 @@ struct rec_exit { u64 ripas_base; u64 ripas_top; u8 ripas_value; - u8 padding8[7]; + u8 padding8[15]; + u64 s2ap_base; + u64 s2ap_top; + u64 vdev_id_1; + u64 vdev_id_2; + u64 dev_mem_base; + u64 dev_mem_top; + u64 dev_mem_pa; }; u8 padding5[0x100]; }; union { /* 0x600 */ - u16 imm; + struct { + u16 imm; + u8 padding[6]; + u64 plane; + }; u8 padding6[0x100]; }; union { /* 0x700 */ diff --git a/arch/arm64/include/uapi/asm/rmi-da.h b/arch/arm64/include/uapi/asm/rmi-da.h index 1c21a5e78eb5..ac6e2fd2807d 100644 --- a/arch/arm64/include/uapi/asm/rmi-da.h +++ b/arch/arm64/include/uapi/asm/rmi-da.h @@ -22,4 +22,9 @@ struct arm64_vdev_device_measurement_guest_req { __aligned_u64 nonce; }; +struct arm64_vdev_device_idmap_guest_req { + __u32 req_type; + __s32 vcpu_fd; +}; + #endif diff --git a/arch/arm64/kvm/rmi-exit.c b/arch/arm64/kvm/rmi-exit.c index 7eff6967530c..3bba5e6afe88 100644 --- a/arch/arm64/kvm/rmi-exit.c +++ b/arch/arm64/kvm/rmi-exit.c @@ -129,6 +129,21 @@ static int rec_exit_host_call(struct kvm_vcpu *vcpu) return kvm_smccc_call_handler(vcpu); } +static inline void kvm_prepare_vdev_request_exit(struct kvm_vcpu *vcpu, unsigned long vdev_id) +{ + vcpu->run->exit_reason = KVM_EXIT_ARM64_TIO; + vcpu->run->cca_exit.nr = RMI_EXIT_VDEV_REQUEST; + vcpu->run->cca_exit.vdev_id = vdev_id; + vcpu->run->cca_exit.flags = 0; +} + +static int rec_exit_vdev_request(struct kvm_vcpu *vcpu) +{ + struct realm_rec *rec = &vcpu->arch.rec; + + kvm_prepare_vdev_request_exit(vcpu, rec->run->exit.vdev_id_1); + return 0; +} static void update_arch_timer_irq_lines(struct kvm_vcpu *vcpu) { struct realm_rec *rec = &vcpu->arch.rec; @@ -198,6 +213,8 @@ int handle_rec_exit(struct kvm_vcpu *vcpu, int rec_run_ret) return rec_exit_ripas_change(vcpu); case RMI_EXIT_HOST_CALL: return rec_exit_host_call(vcpu); + case RMI_EXIT_VDEV_REQUEST: + return rec_exit_vdev_request(vcpu); } kvm_pr_unimpl("Unsupported exit reason: %u\n", diff --git a/drivers/virt/coco/arm-cca-host/arm-cca.c b/drivers/virt/coco/arm-cca-host/arm-cca.c index ba2751eb06f7..8aa362f44090 100644 --- a/drivers/virt/coco/arm-cca-host/arm-cca.c +++ b/drivers/virt/coco/arm-cca-host/arm-cca.c @@ -362,6 +362,18 @@ static ssize_t cca_tsm_guest_req(struct pci_tdi *tdi, enum pci_tsm_req_scope sco (u8 *)req_obj.nonce); return ret; } + case __REC_EXIT_DA_VDEV_REQUEST: + { + struct arm64_vdev_device_idmap_guest_req req_obj; + + if (req_len != sizeof(req_obj)) + return -EINVAL; + + if (copy_from_user((void *)&req_obj, req.user, req_len)) + return -EFAULT; + + return cca_vdev_device_request(pdev, req_obj.vcpu_fd); + } default: return -EINVAL; } diff --git a/drivers/virt/coco/arm-cca-host/rmi-da.c b/drivers/virt/coco/arm-cca-host/rmi-da.c index 58a20877c6b6..3c19dfe89c0a 100644 --- a/drivers/virt/coco/arm-cca-host/rmi-da.c +++ b/drivers/virt/coco/arm-cca-host/rmi-da.c @@ -1078,3 +1078,33 @@ int cca_vdev_get_device_measurements(struct pci_dev *pdev, unsigned long flags, /* get and update the interface report cache. */ return vdev_update_device_measurements_cache(pdev); } + +int cca_vdev_device_request(struct pci_dev *pdev, unsigned long vcpu_fd) +{ + struct kvm *kvm; + struct kvm_vcpu *vcpu; + unsigned long rec_phys; + struct cca_host_tdi *host_tdi = NULL; + struct file *vcpu_filp __free(fput) = fget(vcpu_fd); + + if (!file_is_vcpu(vcpu_filp)) + return -EINVAL; + + vcpu = vcpu_filp->private_data; + if (!vcpu) + return -EINVAL; + + rec_phys = virt_to_phys(vcpu->arch.rec.rec_page); + host_tdi = to_cca_host_tdi(pdev); + if (!host_tdi) + return -EINVAL; + + kvm = host_tdi->tdi.kvm; + /* make sure this is the same vm */ + if (vcpu->kvm != kvm) + return -EINVAL; + + if (rmi_vdev_complete(rec_phys, virt_to_phys(host_tdi->rmm_vdev))) + return -ENXIO; + return 0; +} diff --git a/drivers/virt/coco/arm-cca-host/rmi-da.h b/drivers/virt/coco/arm-cca-host/rmi-da.h index 6304cee85874..2547afa1256f 100644 --- a/drivers/virt/coco/arm-cca-host/rmi-da.h +++ b/drivers/virt/coco/arm-cca-host/rmi-da.h @@ -93,6 +93,7 @@ struct cca_host_tdi { struct pci_tdi tdi; struct realm *realm; void *rmm_vdev; + unsigned long vdev_id; /* protected by cca_host_pf0_dsc.object_lock */ struct cache_object *interface_report; struct cache_object *measurements; @@ -152,4 +153,5 @@ int cca_vdev_read_cached_object(struct pci_dev *pdev, int type, unsigned long of unsigned long max_len, void __user *user_buf); int cca_vdev_get_interface_report(struct pci_dev *pdev); int cca_vdev_get_device_measurements(struct pci_dev *pdev, unsigned long flags, u8 *nonce); +int cca_vdev_device_request(struct pci_dev *pdev, unsigned long rec_id); #endif diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 34759a262b28..26a9619c364c 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1066,6 +1066,7 @@ void kvm_get_kvm(struct kvm *kvm); bool kvm_get_kvm_safe(struct kvm *kvm); void kvm_put_kvm(struct kvm *kvm); bool file_is_kvm(struct file *file); +bool file_is_vcpu(struct file *file); void kvm_put_kvm_no_destroy(struct kvm *kvm); static inline struct kvm_memslots *__kvm_memslots(struct kvm *kvm, int as_id) diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 49d5ce0b7a26..c2e12a1bb23b 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -188,6 +188,7 @@ struct kvm_exit_snp_req_certs { #define KVM_EXIT_ARM_SEA 41 #define KVM_EXIT_ARM_LDST64B 42 #define KVM_EXIT_SNP_REQ_CERTS 43 +#define KVM_EXIT_ARM64_TIO 44 /* For KVM_EXIT_INTERNAL_ERROR */ /* Emulate instruction failed. */ @@ -492,6 +493,15 @@ struct kvm_run { } arm_sea; /* KVM_EXIT_SNP_REQ_CERTS */ struct kvm_exit_snp_req_certs snp_req_certs; + /* KVM_EXIT_ARM64_TIO*/ + struct { + __u64 flags; + __u64 nr; + __u64 vdev_id; + __u64 gpa_base; + __u64 gpa_top; + __u64 pa_base; + } cca_exit; /* Fix the size of the union. */ char padding[256]; }; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index f076c5a7a290..229c2b14bc83 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4110,6 +4110,12 @@ static struct file_operations kvm_vcpu_fops = { KVM_COMPAT(kvm_vcpu_compat_ioctl), }; +bool file_is_vcpu(struct file *file) +{ + return file && file->f_op == &kvm_vcpu_fops; +} +EXPORT_SYMBOL_GPL(file_is_vcpu); + /* * Allocates an inode for the vcpu. */ -- 2.43.0