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Message-ID: <028b5a7f-7d7d-178d-be74-6c93368e06f5@linaro.org>
Date:   Mon, 5 Jun 2023 14:48:23 -0500
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From:   Alex Elder <elder@linaro.org>
Subject: Re: [PATCH v13 11/24] gunyah: vm_mgr: Add ioctls to support basic
 non-proxy VM boot
To:     Elliot Berman <quic_eberman@quicinc.com>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        Prakruthi Deepak Heragu <quic_pheragu@quicinc.com>
Cc:     Murali Nalajala <quic_mnalajal@quicinc.com>,
        Trilok Soni <quic_tsoni@quicinc.com>,
        Srivatsa Vaddagiri <quic_svaddagi@quicinc.com>,
        Carl van Schaik <quic_cvanscha@quicinc.com>,
        Dmitry Baryshkov <dmitry.baryshkov@linaro.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        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>,
        Will Deacon <will@kernel.org>, Andy Gross <agross@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        Jassi Brar <jassisinghbrar@gmail.com>,
        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
References: <20230509204801.2824351-1-quic_eberman@quicinc.com>
 <20230509204801.2824351-12-quic_eberman@quicinc.com>
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On 5/9/23 3:47 PM, Elliot Berman wrote:
> Add remaining ioctls to support non-proxy VM boot:
> 
>   - Gunyah Resource Manager uses the VM's devicetree to configure the
>     virtual machine. The location of the devicetree in the guest's
>     virtual memory can be declared via the SET_DTB_CONFIG ioctl.
>   - Trigger start of the virtual machine with VM_START ioctl.
> 
> Co-developed-by: Prakruthi Deepak Heragu <quic_pheragu@quicinc.com>
> Signed-off-by: Prakruthi Deepak Heragu <quic_pheragu@quicinc.com>
> Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>

I point out a spelling error, but otherwise this looks OK to me.

Reviewed-by: Alex Elder <elder@linaro.org>

> ---
>   drivers/virt/gunyah/vm_mgr.c    | 215 ++++++++++++++++++++++++++++++++
>   drivers/virt/gunyah/vm_mgr.h    |  11 ++
>   drivers/virt/gunyah/vm_mgr_mm.c |  20 +++
>   include/uapi/linux/gunyah.h     |  15 +++
>   4 files changed, 261 insertions(+)
> 


. . .

> +static int gh_vm_ensure_started(struct gh_vm *ghvm)
> +{
> +	int ret;
> +
> +	ret = down_read_interruptible(&ghvm->status_lock);
> +	if (ret)
> +		return ret;
> +
> +	/* Unlikely because VM is typically started */
> +	if (unlikely(ghvm->vm_status == GH_RM_VM_STATUS_NO_STATE)) {
> +		up_read(&ghvm->status_lock);
> +		ret = gh_vm_start(ghvm);
> +		if (ret)
> +			return ret;
> +		/** gh_vm_start() is guaranteed to bring status out of
> +		 * GH_RM_VM_STATUS_LOAD, thus inifitely recursive call is not

s/inifitely/infinitely/

> +		 * possible
> +		 */
> +		return gh_vm_ensure_started(ghvm);
> +	}
> +
> +	/* Unlikely because VM is typically running */
> +	if (unlikely(ghvm->vm_status != GH_RM_VM_STATUS_RUNNING))
> +		ret = -ENODEV;
> +
> +	up_read(&ghvm->status_lock);
> +	return ret;
> +}
> +
>   static long gh_vm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>   {
>   	struct gh_vm *ghvm = filp->private_data;
. . .