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Date: Tue, 22 Oct 2024 07:18:44 +0200
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Yuanchu Xie <yuanchu@google.com>
Cc: Wei Liu <liuwe@microsoft.com>, Rob Bradford <rbradford@rivosinc.com>,
	Theodore Ts'o <tytso@mit.edu>,
	Pasha Tatashin <pasha.tatashin@soleen.com>,
	linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	virtualization@lists.linux.dev, dev@lists.cloudhypervisor.org
Subject: Re: [PATCH v4 1/2] virt: pvmemcontrol: control guest physical memory
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Message-ID: <2024102220-creed-darkening-aac0@gregkh>
References: <20241021204849.1580384-1-yuanchu@google.com>
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In-Reply-To: <20241021204849.1580384-1-yuanchu@google.com>

On Mon, Oct 21, 2024 at 01:48:48PM -0700, Yuanchu Xie wrote:
> +static DEFINE_RWLOCK(pvmemcontrol_lock);

What does this lock control?

> +static struct pvmemcontrol *pvmemcontrol __read_mostly;

Having a single static device should not be needed, please tie this
properly to the pci device that the driver core gives you.  With this
design, you have limited yourself to a fixed number of devices in the
system at once (i.e. 1).  This isn't the 1990's anymore, drivers should
be able to handle any number of devices at once.

thanks,

greg k-h