From: Eugeniu Rosca <erosca@de.adit-jv.com>
To: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Linus Walleij <linus.walleij@linaro.org>,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Jonathan Corbet <corbet@lwn.net>,
Harish Jenny K N <harish_kandiga@mentor.com>,
Eugeniu Rosca <erosca@de.adit-jv.com>,
Alexander Graf <graf@amazon.com>,
Peter Maydell <peter.maydell@linaro.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Phil Reid <preid@electromag.com.au>,
Marc Zyngier <marc.zyngier@arm.com>,
Christoffer Dall <christoffer.dall@arm.com>,
Magnus Damm <magnus.damm@gmail.com>,
Rob Herring <robh+dt@kernel.org>,
Mark Rutland <mark.rutland@arm.com>, <linux-gpio@vger.kernel.org>,
<linux-doc@vger.kernel.org>, <linux-renesas-soc@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, <qemu-devel@nongnu.org>,
Eugeniu Rosca <roscaeugeniu@gmail.com>
Subject: Re: [PATCH v4 0/5] gpio: Add GPIO Aggregator
Date: Mon, 20 Jan 2020 14:26:07 +0100 [thread overview]
Message-ID: <20200120132607.GB24951@lxhi-065.adit-jv.com> (raw)
In-Reply-To: <20200115181523.23556-1-geert+renesas@glider.be>
Hi Geert,
On Wed, Jan 15, 2020 at 07:15:18PM +0100, Geert Uytterhoeven wrote:
> Hi all,
>
> GPIO controllers are exported to userspace using /dev/gpiochip*
> character devices. Access control to these devices is provided by
> standard UNIX file system permissions, on an all-or-nothing basis:
> either a GPIO controller is accessible for a user, or it is not.
> Currently no mechanism exists to control access to individual GPIOs.
>
> Hence this adds a GPIO driver to aggregate existing GPIOs, and expose
> them as a new gpiochip. This is useful for implementing access control,
> and assigning a set of GPIOs to a specific user. Furthermore, this
> simplifies and hardens exporting GPIOs to a virtual machine, as the VM
> can just grab the full GPIO controller, and no longer needs to care
> about which GPIOs to grab and which not, reducing the attack surface.
>
> Recently, other use cases have been discovered[1]:
> - Describing simple GPIO-operated devices in DT, and using the GPIO
> Aggregator as a generic GPIO driver for userspace, which is useful
> for industrial control.
As per comments and test results in [*] (accidentally attached to v3):
Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com>
[*] https://lore.kernel.org/linux-renesas-soc/20200120121439.GA24951@lxhi-065.adit-jv.com/
("Re: [PATCH v3 0/7] gpio: Add GPIO Aggregator/Repeater")
--
Best Regards,
Eugeniu Rosca
WARNING: multiple messages have this Message-ID (diff)
From: Eugeniu Rosca <erosca@de.adit-jv.com>
To: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Mark Rutland <mark.rutland@arm.com>,
Peter Maydell <peter.maydell@linaro.org>,
qemu-devel@nongnu.org, Phil Reid <preid@electromag.com.au>,
Eugeniu Rosca <roscaeugeniu@gmail.com>,
Jonathan Corbet <corbet@lwn.net>,
Marc Zyngier <marc.zyngier@arm.com>,
Linus Walleij <linus.walleij@linaro.org>,
linux-doc@vger.kernel.org, Magnus Damm <magnus.damm@gmail.com>,
Christoffer Dall <christoffer.dall@arm.com>,
linux-kernel@vger.kernel.org, linux-renesas-soc@vger.kernel.org,
Bartosz Golaszewski <bgolaszewski@baylibre.com>,
Rob Herring <robh+dt@kernel.org>,
Harish Jenny K N <harish_kandiga@mentor.com>,
linux-gpio@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>,
Alexander Graf <graf@amazon.com>,
Eugeniu Rosca <erosca@de.adit-jv.com>
Subject: Re: [PATCH v4 0/5] gpio: Add GPIO Aggregator
Date: Mon, 20 Jan 2020 14:26:07 +0100 [thread overview]
Message-ID: <20200120132607.GB24951@lxhi-065.adit-jv.com> (raw)
In-Reply-To: <20200115181523.23556-1-geert+renesas@glider.be>
Hi Geert,
On Wed, Jan 15, 2020 at 07:15:18PM +0100, Geert Uytterhoeven wrote:
> Hi all,
>
> GPIO controllers are exported to userspace using /dev/gpiochip*
> character devices. Access control to these devices is provided by
> standard UNIX file system permissions, on an all-or-nothing basis:
> either a GPIO controller is accessible for a user, or it is not.
> Currently no mechanism exists to control access to individual GPIOs.
>
> Hence this adds a GPIO driver to aggregate existing GPIOs, and expose
> them as a new gpiochip. This is useful for implementing access control,
> and assigning a set of GPIOs to a specific user. Furthermore, this
> simplifies and hardens exporting GPIOs to a virtual machine, as the VM
> can just grab the full GPIO controller, and no longer needs to care
> about which GPIOs to grab and which not, reducing the attack surface.
>
> Recently, other use cases have been discovered[1]:
> - Describing simple GPIO-operated devices in DT, and using the GPIO
> Aggregator as a generic GPIO driver for userspace, which is useful
> for industrial control.
As per comments and test results in [*] (accidentally attached to v3):
Reviewed-by: Eugeniu Rosca <erosca@de.adit-jv.com>
Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com>
[*] https://lore.kernel.org/linux-renesas-soc/20200120121439.GA24951@lxhi-065.adit-jv.com/
("Re: [PATCH v3 0/7] gpio: Add GPIO Aggregator/Repeater")
--
Best Regards,
Eugeniu Rosca
next prev parent reply other threads:[~2020-01-20 13:26 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-15 18:15 [PATCH v4 0/5] gpio: Add GPIO Aggregator Geert Uytterhoeven
2020-01-15 18:15 ` Geert Uytterhoeven
2020-01-15 18:15 ` [PATCH v4 1/5] gpiolib: Add support for gpiochipN-based table lookup Geert Uytterhoeven
2020-01-15 18:15 ` Geert Uytterhoeven
2020-01-15 18:15 ` [PATCH v4 2/5] gpiolib: Add support for GPIO line " Geert Uytterhoeven
2020-01-15 18:15 ` Geert Uytterhoeven
2020-01-15 18:15 ` [PATCH v4 3/5] gpio: Add GPIO Aggregator Geert Uytterhoeven
2020-01-15 18:15 ` Geert Uytterhoeven
2020-01-15 18:15 ` [PATCH v4 4/5] docs: gpio: Add GPIO Aggregator documentation Geert Uytterhoeven
2020-01-15 18:15 ` Geert Uytterhoeven
2020-01-15 18:15 ` [PATCH v4 5/5] MAINTAINERS: Add GPIO Aggregator section Geert Uytterhoeven
2020-01-15 18:15 ` Geert Uytterhoeven
2020-01-20 13:26 ` Eugeniu Rosca [this message]
2020-01-20 13:26 ` [PATCH v4 0/5] gpio: Add GPIO Aggregator Eugeniu Rosca
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