From 93de2a6a4b91b72607136dd656edf03fb399d27f Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 23 Sep 2026 09:37:21 -0700 Subject: KVM: SEV: Do cache maintenance on the source VM during intra-host migration Manually perform cache maintenance on the source VM during intra-host migration to ensure no stale data is left in CPU caches after the VM is destroyed. Because the source VM is "converted" to a non-SEV VM, KVM's memory reclaim flows won't trigger cache maintenance, e.g. when all guest memory is reclaimed in response to detaching from the mmu_notifier. Note, relying on the destination VM to do cache maintenance isn't an option as KVM doesn't require identical guest memory configurations, i.e. the source VM may have access to memory that the destination VM does not. Enforcing equivalent memory configurations is infeasible, as it would require a *deep* comparison of memslots, e.g. to verify that not only are the memslot identical, but what the memslots point at is also identical. Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration") Cc: stable@vger.kernel.org Reported-by: Stefan Teodorescu Signed-off-by: Sean Christopherson Message-ID: <20260923163721.1584779-3-seanjc@google.com> Signed-off-by: Paolo Bonzini --- Documentation/ABI/testing/sysfs-class-led-flash | 89 +++++++++++++++++++++++++ 1 file changed, 89 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-led-flash (limited to 'Documentation/ABI/testing/sysfs-class-led-flash') diff --git a/Documentation/ABI/testing/sysfs-class-led-flash b/Documentation/ABI/testing/sysfs-class-led-flash new file mode 100644 index 000000000..11e5677c3 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-led-flash @@ -0,0 +1,89 @@ +What: /sys/class/leds//flash_brightness +Date: March 2015 +KernelVersion: 4.0 +Contact: Jacek Anaszewski +Description: read/write + Set the brightness of this LED in the flash strobe mode, in + microamperes. The file is created only for the flash LED devices + that support setting flash brightness. + + The value is between 0 and + /sys/class/leds//max_flash_brightness. + +What: /sys/class/leds//max_flash_brightness +Date: March 2015 +KernelVersion: 4.0 +Contact: Jacek Anaszewski +Description: read only + Maximum brightness level for this LED in the flash strobe mode, + in microamperes. + +What: /sys/class/leds//flash_timeout +Date: March 2015 +KernelVersion: 4.0 +Contact: Jacek Anaszewski +Description: read/write + Hardware timeout for flash, in microseconds. The flash strobe + is stopped after this period of time has passed from the start + of the strobe. The file is created only for the flash LED + devices that support setting flash timeout. + +What: /sys/class/leds//max_flash_timeout +Date: March 2015 +KernelVersion: 4.0 +Contact: Jacek Anaszewski +Description: read only + Maximum flash timeout for this LED, in microseconds. + +What: /sys/class/leds//flash_strobe +Date: March 2015 +KernelVersion: 4.0 +Contact: Jacek Anaszewski +Description: read/write + Flash strobe state. When written with 1 it triggers flash strobe + and when written with 0 it turns the flash off. + + On read 1 means that flash is currently strobing and 0 means + that flash is off. + +What: /sys/class/leds//flash_fault +Date: March 2015 +KernelVersion: 4.0 +Contact: Jacek Anaszewski +Description: read only + Space separated list of flash faults that may have occurred. + Flash faults are re-read after strobing the flash. Possible + flash faults: + + * led-over-voltage + flash controller voltage to the flash LED + has exceeded the limit specific to the flash controller + * flash-timeout-exceeded + the flash strobe was still on when + the timeout set by the user has expired; not all flash + controllers may set this in all such conditions + * controller-over-temperature + the flash controller has + overheated + * controller-short-circuit + the short circuit protection + of the flash controller has been triggered + * led-power-supply-over-current + current in the LED power + supply has exceeded the limit specific to the flash + controller + * indicator-led-fault + the flash controller has detected + a short or open circuit condition on the indicator LED + * led-under-voltage + flash controller voltage to the flash + LED has been below the minimum limit specific to + the flash + * controller-under-voltage + the input voltage of the flash + controller is below the limit under which strobing the + flash at full current will not be possible; + the condition persists until this flag is no longer set + * led-over-temperature + the temperature of the LED has exceeded + its allowed upper limit -- cgit v1.3.1