KVM: SEV: Do cache maintenance on the source VM during intra-host migrationgrafted

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 <fane@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260923163721.1584779-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 77 insertions, 0 deletions

diff --git a/drivers/net/team/Kconfig b/drivers/net/team/Kconfig
new file mode 100644
index 000000000..4d449845d
--- /dev/null
+++ b/drivers/net/team/Kconfig
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menuconfig NET_TEAM
+	tristate "Ethernet team driver support"
+	help
+	  This allows one to create virtual interfaces that teams together
+	  multiple ethernet devices.
+
+	  Team devices can be added using the "ip" command from the
+	  iproute2 package:
+
+	  "ip link add link [ address MAC ] [ NAME ] type team"
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called team.
+
+if NET_TEAM
+
+config NET_TEAM_MODE_BROADCAST
+	tristate "Broadcast mode support"
+	depends on NET_TEAM
+	help
+	  Basic mode where packets are transmitted always by all suitable ports.
+
+	  All added ports are setup to have team's device address.
+
+	  To compile this team mode as a module, choose M here: the module
+	  will be called team_mode_broadcast.
+
+config NET_TEAM_MODE_ROUNDROBIN
+	tristate "Round-robin mode support"
+	depends on NET_TEAM
+	help
+	  Basic mode where port used for transmitting packets is selected in
+	  round-robin fashion using packet counter.
+
+	  All added ports are setup to have team's device address.
+
+	  To compile this team mode as a module, choose M here: the module
+	  will be called team_mode_roundrobin.
+
+config NET_TEAM_MODE_RANDOM
+	tristate "Random mode support"
+	depends on NET_TEAM
+	help
+	  Basic mode where port used for transmitting packets is selected
+	  randomly.
+
+	  All added ports are setup to have team's device address.
+
+	  To compile this team mode as a module, choose M here: the module
+	  will be called team_mode_random.
+
+config NET_TEAM_MODE_ACTIVEBACKUP
+	tristate "Active-backup mode support"
+	depends on NET_TEAM
+	help
+	  Only one port is active at a time and the rest of ports are used
+	  for backup.
+
+	  Mac addresses of ports are not modified. Userspace is responsible
+	  to do so.
+
+	  To compile this team mode as a module, choose M here: the module
+	  will be called team_mode_activebackup.
+
+config NET_TEAM_MODE_LOADBALANCE
+	tristate "Load-balance mode support"
+	depends on NET_TEAM
+	help
+	  This mode provides load balancing functionality. Tx port selection
+	  is done using BPF function set up from userspace (bpf_hash_func
+	  option)
+
+	  To compile this team mode as a module, choose M here: the module
+	  will be called team_mode_loadbalance.
+
+endif # NET_TEAM