From: Rob Herring <robh@kernel.org>
To: Sebastian Ene <sebastianene@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Arnd Bergmann <arnd@arndb.de>,
Dragan Cvetic <dragan.cvetic@xilinx.com>,
linux-kernel@vger.kernel.org, devicetree@vger.kernel.org,
maz@kernel.org, will@kernel.org, qperret@google.com,
Guenter Roeck <linux@roeck-us.net>
Subject: Re: [PATCH v4 0/2] Detect stalls on guest vCPUS
Date: Fri, 29 Apr 2022 15:25:45 -0500 [thread overview]
Message-ID: <YmxJyUqdsZmm8yE2@robh.at.kernel.org> (raw)
In-Reply-To: <20220429083030.3241640-1-sebastianene@google.com>
On Fri, Apr 29, 2022 at 08:30:29AM +0000, Sebastian Ene wrote:
> This adds a mechanism to detect stalls on the guest vCPUS by creating a
> per CPU hrtimer which periodically 'pets' the host backend driver.
> On a conventional watchdog-core driver, the userspace is responsible for
> delivering the 'pet' events by writing to the particular /dev/watchdogN node.
> In this case we require a strong thread affinity to be able to
> account for lost time on a per vCPU basis.
>
> This device driver acts as a soft lockup detector by relying on the host
> backend driver to measure the elapesed time between subsequent 'pet' events.
> If the elapsed time doesn't match an expected value, the backend driver
> decides that the guest vCPU is locked and resets the guest. The host
> backend driver takes into account the time that the guest is not
> running. The communication with the backend driver is done through MMIO
> and the register layout of the virtual watchdog is described as part of
> the backend driver changes.
>
> The host backend driver is implemented as part of:
> https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3548817
>
> Changelog v4:
> - rename the source from vm-wdt.c -> vm-watchdog.c
> - convert all the error logging calls from pr_* to dev_* calls
> - rename the DTS node "clock" to "clock-frequency"
Why do I have a v4 now when the discussion on v3 is not concluded. Give
folks some time to respond. We're busy drinking from the firehose.
Rob
next prev parent reply other threads:[~2022-04-29 20:25 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-29 8:30 [PATCH v4 0/2] Detect stalls on guest vCPUS Sebastian Ene
2022-04-29 8:30 ` [PATCH v4 1/2] dt-bindings: vm-wdt: Add qemu,vm-watchdog compatible Sebastian Ene
2022-04-29 15:53 ` Rob Herring
2022-05-07 8:16 ` Sebastian Ene
2022-04-29 8:30 ` [PATCH v4 2/2] misc: Add a mechanism to detect stalls on guest vCPUs Sebastian Ene
2022-04-29 8:48 ` Greg Kroah-Hartman
2022-04-29 16:51 ` Guenter Roeck
2022-04-30 6:18 ` Greg Kroah-Hartman
2022-04-30 12:36 ` Guenter Roeck
2022-05-02 5:58 ` Sebastian Ene
2022-04-29 8:51 ` Greg Kroah-Hartman
2022-04-29 9:26 ` Sebastian Ene
2022-04-29 9:38 ` Greg Kroah-Hartman
2022-04-29 21:03 ` Rob Herring
2022-05-04 7:29 ` Sebastian Ene
2022-04-29 17:02 ` Guenter Roeck
2022-04-29 20:25 ` Rob Herring [this message]
2022-05-02 6:03 ` [PATCH v4 0/2] Detect stalls on guest vCPUS Sebastian Ene
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