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 --- drivers/md/raid0.h | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 drivers/md/raid0.h (limited to 'drivers/md/raid0.h') diff --git a/drivers/md/raid0.h b/drivers/md/raid0.h new file mode 100644 index 000000000..8cc761ca7 --- /dev/null +++ b/drivers/md/raid0.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _RAID0_H +#define _RAID0_H + +struct strip_zone { + sector_t zone_end; /* Start of the next zone (in sectors) */ + sector_t dev_start; /* Zone offset in real dev (in sectors) */ + int nb_dev; /* # of devices attached to the zone */ + int disk_shift; /* start disk for the original layout */ +}; + +/* Linux 3.14 (20d0189b101) made an unintended change to + * the RAID0 layout for multi-zone arrays (where devices aren't all + * the same size. + * RAID0_ORIG_LAYOUT restores the original layout + * RAID0_ALT_MULTIZONE_LAYOUT uses the altered layout + * The layouts are identical when there is only one zone (all + * devices the same size). + */ + +enum r0layout { + RAID0_ORIG_LAYOUT = 1, + RAID0_ALT_MULTIZONE_LAYOUT = 2, +}; +struct r0conf { + struct strip_zone *strip_zone; + struct md_rdev **devlist; /* lists of rdevs, pointed to + * by strip_zone->dev */ + int nr_strip_zones; + enum r0layout layout; +}; + +#endif -- cgit v1.3.1