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/gpu/panfrost.rst | 49 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 49 insertions(+) create mode 100644 Documentation/gpu/panfrost.rst (limited to 'Documentation/gpu/panfrost.rst') diff --git a/Documentation/gpu/panfrost.rst b/Documentation/gpu/panfrost.rst new file mode 100644 index 000000000..51ba375fd --- /dev/null +++ b/Documentation/gpu/panfrost.rst @@ -0,0 +1,49 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +========================= + drm/Panfrost Mali Driver +========================= + +.. _panfrost-usage-stats: + +Panfrost DRM client usage stats implementation +============================================== + +The drm/Panfrost driver implements the DRM client usage stats specification as +documented in :ref:`drm-client-usage-stats`. + +Example of the output showing the implemented key value pairs and entirety of +the currently possible format options: + +:: + pos: 0 + flags: 02400002 + mnt_id: 27 + ino: 531 + drm-driver: panfrost + drm-client-id: 14 + drm-engine-fragment: 1846584880 ns + drm-cycles-fragment: 1424359409 + drm-maxfreq-fragment: 799999987 Hz + drm-curfreq-fragment: 799999987 Hz + drm-engine-vertex-tiler: 71932239 ns + drm-cycles-vertex-tiler: 52617357 + drm-maxfreq-vertex-tiler: 799999987 Hz + drm-curfreq-vertex-tiler: 799999987 Hz + drm-total-memory: 290 MiB + drm-shared-memory: 0 MiB + drm-active-memory: 226 MiB + drm-resident-memory: 36496 KiB + drm-purgeable-memory: 128 KiB + +Possible `drm-engine-` key names are: `fragment`, and `vertex-tiler`. +`drm-curfreq-` values convey the current operating frequency for that engine. + +Users must bear in mind that engine and cycle sampling are disabled by default, +because of power saving concerns. `fdinfo` users and benchmark applications which +query the fdinfo file must make sure to toggle the job profiling status of the +driver by writing into the appropriate sysfs node:: + + echo > /sys/bus/platform/drivers/panfrost/[a-f0-9]*.gpu/profiling + +Where `N` is either `0` or `1`, depending on the desired enablement status. -- cgit v1.3.1