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-module | 84 ++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-module (limited to 'Documentation/ABI/testing/sysfs-module') diff --git a/Documentation/ABI/testing/sysfs-module b/Documentation/ABI/testing/sysfs-module new file mode 100644 index 000000000..d5b7d19bd --- /dev/null +++ b/Documentation/ABI/testing/sysfs-module @@ -0,0 +1,84 @@ +What: /sys/module/pch_phub/drivers/.../pch_mac +Date: August 2010 +KernelVersion: 2.6.35 +Contact: masa-korg@dsn.okisemi.com +Description: Write/read GbE MAC address. + +What: /sys/module/pch_phub/drivers/.../pch_firmware +Date: August 2010 +KernelVersion: 2.6.35 +Contact: masa-korg@dsn.okisemi.com +Description: Write/read Option ROM data. + + +What: /sys/module/ehci_hcd/drivers/.../uframe_periodic_max +Date: July 2011 +KernelVersion: 3.1 +Contact: Kirill Smelkov +Description: Maximum time allowed for periodic transfers per microframe (μs) + + Note: + USB 2.0 sets maximum allowed time for periodic transfers per + microframe to be 80%, that is 100 microseconds out of 125 + microseconds (full microframe). + + However there are cases, when 80% max isochronous bandwidth is + too limiting. For example two video streams could require 110 + microseconds of isochronous bandwidth per microframe to work + together. + + Through this setting it is possible to raise the limit so that + the host controller would allow allocating more than 100 + microseconds of periodic bandwidth per microframe. + + Beware, non-standard modes are usually not thoroughly tested by + hardware designers, and the hardware can malfunction when this + setting differ from default 100. + +What: /sys/module/*/{coresize,initsize} +Date: Jan 2012 +KernelVersion: 3.3 +Contact: Kay Sievers +Description: Module size in bytes. + +What: /sys/module/*/initstate +Date: Nov 2006 +KernelVersion: 2.6.19 +Contact: Kay Sievers +Description: Show the initialization state(live, coming, going) of + the module. + +What: /sys/module/*/import_ns +Date: January 2026 +KernelVersion: 7.1 +Contact: linux-modules@vger.kernel.org +Description: List of symbol namespaces imported by this module via + MODULE_IMPORT_NS(). Each namespace appears on a separate line. + This file only exists for modules that import at least one + namespace. + +What: /sys/module/*/taint +Date: Jan 2012 +KernelVersion: 3.3 +Contact: Kay Sievers +Description: Module taint flags: + == ===================== + P proprietary module + O out-of-tree module + F force-loaded module + C staging driver module + E unsigned module + K livepatch module + N in-kernel test module + == ===================== + +What: /sys/module/grant_table/parameters/free_per_iteration +Date: July 2023 +KernelVersion: 6.5 but backported to all supported stable branches +Contact: Xen developer discussion +Description: Read and write number of grant entries to attempt to free per iteration. + + Note: Future versions of Xen and Linux may provide a better + interface for controlling the rate of deferred grant reclaim + or may not need it at all. +Users: Qubes OS (https://www.qubes-os.org) -- cgit v1.3.1