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/removed/sysfs-kernel-uids | 14 ++++++++++++++ 1 file changed, 14 insertions(+) create mode 100644 Documentation/ABI/removed/sysfs-kernel-uids (limited to 'Documentation/ABI/removed/sysfs-kernel-uids') diff --git a/Documentation/ABI/removed/sysfs-kernel-uids b/Documentation/ABI/removed/sysfs-kernel-uids new file mode 100644 index 000000000..85a90b86c --- /dev/null +++ b/Documentation/ABI/removed/sysfs-kernel-uids @@ -0,0 +1,14 @@ +What: /sys/kernel/uids//cpu_shares +Date: December 2007, finally removed in kernel v2.6.34-rc1 +Contact: Dhaval Giani + Srivatsa Vaddagiri +Description: + The /sys/kernel/uids//cpu_shares tunable is used + to set the cpu bandwidth a user is allowed. This is a + proportional value. What that means is that if there + are two users logged in, each with an equal number of + shares, then they will get equal CPU bandwidth. Another + example would be, if User A has shares = 1024 and user + B has shares = 2048, User B will get twice the CPU + bandwidth user A will. For more details refer + Documentation/scheduler/sched-design-CFS.rst -- cgit v1.3.1