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authorSebastian Ene <sebastianene@google.com>2022-07-11 10:17:20 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-07-14 16:54:17 +0200
commit6c93c6f3bad468ce4b8c843227d60fbeb02fd741 (patch)
treeeecf58af1a6c98b6fba0aaa679df66399f787830 /drivers/misc/Kconfig
parentdt-bindings: vcpu_stall_detector: Add qemu,vcpu-stall-detector compatible (diff)
downloadlinux-6c93c6f3bad468ce4b8c843227d60fbeb02fd741.tar.xz
linux-6c93c6f3bad468ce4b8c843227d60fbeb02fd741.zip
misc: Add a mechanism to detect stalls on guest vCPUs
This driver creates per-cpu hrtimers which are required to do the periodic 'pet' operation. 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. This part of the driver is the 'frontend' which is reponsible for delivering the periodic 'pet' events, configuring the virtual peripheral and listening for cpu hotplug events. The other part of the driver is an emulated MMIO device which is part of the KVM virtual machine monitor and this part accounts for lost time by looking at the /proc/{}/task/{}/stat entries. Reviewed-by: Guenter Roeck <linux@roeck-us.net> Reviewed-by: Will Deacon <will@kernel.org> Signed-off-by: Sebastian Ene <sebastianene@google.com> Link: https://lore.kernel.org/r/20220711081720.2870509-3-sebastianene@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/Kconfig')
-rw-r--r--drivers/misc/Kconfig13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 41d2bb0ae23a..94e9fb4cdd76 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -483,6 +483,19 @@ config OPEN_DICE
If unsure, say N.
+config VCPU_STALL_DETECTOR
+ tristate "Guest vCPU stall detector"
+ depends on OF && HAS_IOMEM
+ help
+ When this driver is bound inside a KVM guest, it will
+ periodically "pet" an MMIO stall detector device from each vCPU
+ and allow the host to detect vCPU stalls.
+
+ To compile this driver as a module, choose M here: the module
+ will be called vcpu_stall_detector.
+
+ If you do not intend to run this kernel as a guest, say N.
+
source "drivers/misc/c2port/Kconfig"
source "drivers/misc/eeprom/Kconfig"
source "drivers/misc/cb710/Kconfig"