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-devices-sun | 14 ++++++++++++++ 1 file changed, 14 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-devices-sun (limited to 'Documentation/ABI/testing/sysfs-devices-sun') diff --git a/Documentation/ABI/testing/sysfs-devices-sun b/Documentation/ABI/testing/sysfs-devices-sun new file mode 100644 index 000000000..625ce4b63 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-sun @@ -0,0 +1,14 @@ +What: /sys/devices/.../sun +Date: October 2012 +Contact: Yasuaki Ishimatsu +Description: + The file contains a Slot-unique ID which provided by the _SUN + method in the ACPI namespace. The value is written in Advanced + Configuration and Power Interface Specification as follows: + + "The _SUN value is required to be unique among the slots of + the same type. It is also recommended that this number match + the slot number printed on the physical slot whenever possible." + + So reading the sysfs file, we can identify a physical position + of the slot in the system. -- cgit v1.3.1