Re: [PATCH v8 11/28] gunyah: rsc_mgr: Add VM lifecycle RPC

From: Elliot Berman <quic_eberman@quicinc.com>
To: Srivatsa Vaddagiri <quic_svaddagi@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
Date: Mon, 9 Jan 2023 10:51:19 -0800	[thread overview]
Message-ID: <f30261bc-7d4c-b074-4531-2b244afe0e59@quicinc.com> (raw)
In-Reply-To: <20230109071309.GA3480070@quicinc.com>

On 1/8/2023 11:13 PM, Srivatsa Vaddagiri wrote:
> * 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;
>> +}

Applied all these.

Thanks,
Elliot