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Date:   Mon, 9 Jan 2023 12:43:09 +0530
From:   Srivatsa Vaddagiri <quic_svaddagi@quicinc.com>
To:     Elliot Berman <quic_eberman@quicinc.com>
CC:     Bjorn Andersson <quic_bjorande@quicinc.com>,
        Murali Nalajala <quic_mnalajal@quicinc.com>,
        Trilok Soni <quic_tsoni@quicinc.com>,
        "Carl van Schaik" <quic_cvanscha@quicinc.com>,
        Prakruthi Deepak Heragu <quic_pheragu@quicinc.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Rob Herring <robh+dt@kernel.org>,
        "Krzysztof Kozlowski" <krzysztof.kozlowski+dt@linaro.org>,
        Jonathan Corbet <corbet@lwn.net>,
        Bagas Sanjaya <bagasdotme@gmail.com>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Will Deacon <will@kernel.org>,
        Jassi Brar <jassisinghbrar@gmail.com>,
        Sudeep Holla <sudeep.holla@arm.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Lorenzo Pieralisi <lpieralisi@kernel.org>,
        "Dmitry Baryshkov" <dmitry.baryshkov@linaro.org>,
        <linux-arm-msm@vger.kernel.org>, <devicetree@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <linux-doc@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        <linux-acpi@vger.kernel.org>
Subject: Re: [PATCH v8 11/28] gunyah: rsc_mgr: Add VM lifecycle RPC
Message-ID: <20230109071309.GA3480070@quicinc.com>
Reply-To: Srivatsa Vaddagiri <quic_svaddagi@quicinc.com>
References: <20221219225850.2397345-1-quic_eberman@quicinc.com>
 <20221219225850.2397345-12-quic_eberman@quicinc.com>
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* Elliot Berman <quic_eberman@quicinc.com> [2022-12-19 14:58:32]:

> +/* Call: CONSOLE_OPEN, CONSOLE_CLOSE, CONSOLE_FLUSH */

I think this struct is used by other calls as well?
Also CONSOLE_** functions are not yet introduced in this patch

> +struct gh_vm_common_vmid_req {
> +	__le16 vmid;
> +	__le16 reserved0;
> +} __packed;

[snip]

> +int gh_rm_alloc_vmid(struct gh_rm_rpc *rm, u16 vmid)
> +{
> +	void *resp;
> +	struct gh_vm_common_vmid_req req_payload = {
> +		.vmid = cpu_to_le16(vmid),
> +	};
> +	struct gh_vm_common_vmid_req *resp_payload;
> +	size_t resp_size;
> +	int ret;
> +
> +	if (vmid == GH_VMID_INVAL)
> +		vmid = 0;
> +
> +	ret = gh_rm_call(rm, GH_RM_RPC_VM_ALLOC_VMID, &req_payload, sizeof(req_payload), &resp,
> +			&resp_size);
> +	if (ret)
> +		return ret;
> +
> +	if (!vmid) {
> +		if (resp_size != sizeof(*resp_payload)) {
> +			ret = -EINVAL;
> +		} else {
> +			resp_payload = resp;
> +			ret = resp_payload->vmid;

Do we need a le_to_cpu() wrapper on the response here?

> +int gh_rm_vm_stop(struct gh_rm_rpc *rm, u16 vmid)
> +{
> +	struct gh_vm_stop_req req_payload = {
> +		.vmid = cpu_to_le16(vmid),
> +	};
> +	void *resp;
> +	size_t resp_size;
> +	int ret;
> +
> +	ret = gh_rm_call(rm, GH_RM_RPC_VM_STOP, &req_payload, sizeof(req_payload),
> +			&resp, &resp_size);
> +	if (ret)
> +		return ret;
> +	kfree(resp);

Why not use gh_rm_common_vmid_call() here as well?

	return gh_rm_common_vmid_call(rm, GH_RM_RPC_VM_STOP, vmid);

> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(gh_rm_vm_stop);
> +

[snip]

> +ssize_t gh_rm_get_hyp_resources(struct gh_rm_rpc *rm, u16 vmid,
> +				struct gh_rm_hyp_resource **resources)
> +{
> +	struct gh_vm_get_hyp_resources_resp *resp;
> +	size_t resp_size;
> +	int ret;
> +	struct gh_vm_common_vmid_req req_payload = {
> +		.vmid = cpu_to_le16(vmid),
> +	};
> +
> +	ret = gh_rm_call(rm, GH_RM_RPC_VM_GET_HYP_RESOURCES,
> +			 &req_payload, sizeof(req_payload),
> +			 (void **)&resp, &resp_size);
> +	if (ret)
> +		return ret;
> +
> +	if (resp_size < sizeof(*resp) ||
> +		(sizeof(*resp->entries) && (resp->n_entries > U32_MAX / sizeof(*resp->entries))) ||
> +		(resp_size != sizeof(*resp) + (resp->n_entries * sizeof(*resp->entries)))) {
> +		ret = -EIO;
> +		goto out;
> +	}
> +
> +	*resources = kmemdup(resp->entries, (resp->n_entries * sizeof(*resp->entries)), GFP_KERNEL);

Consider NULL return value from kmemdup

> +	ret = resp->n_entries;
> +
> +out:
> +	kfree(resp);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(gh_rm_get_hyp_resources);
> +
> +/**
> + * gh_rm_get_vmid() - Retrieve VMID of this virtual machine
> + * @vmid: Filled with the VMID of this VM
> + */
> +int gh_rm_get_vmid(struct gh_rm_rpc *rm, u16 *vmid)
> +{
> +	static u16 cached_vmid = GH_VMID_INVAL;
> +	void *resp;
> +	size_t resp_size;
> +	int ret;
> +	int payload = 0;
> +
> +	if (cached_vmid != GH_VMID_INVAL) {
> +		*vmid = cached_vmid;
> +		return 0;
> +	}
> +
> +	ret = gh_rm_call(rm, GH_RM_RPC_VM_GET_VMID, &payload, sizeof(payload), &resp, &resp_size);
> +	if (ret)
> +		return ret;
> +
> +	if (resp_size != sizeof(*vmid))

kfree(resp) in this case?

> +		return -EIO;
> +	*vmid = *(u16 *)resp;

Do we need a le_to_cpu() wrapper on the response?
Also update cached_vmid in success case.

> +	kfree(resp);
> +
> +	return ret;
> +}