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>

2 files changed, 64 insertions, 0 deletions

diff --git a/Documentation/PCI/endpoint/function/binding/pci-ntb.rst b/Documentation/PCI/endpoint/function/binding/pci-ntb.rst
new file mode 100644
index 000000000..40253d3d5
--- /dev/null
+++ b/Documentation/PCI/endpoint/function/binding/pci-ntb.rst
@@ -0,0 +1,38 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==========================
+PCI NTB Endpoint Function
+==========================
+
+1) Create a subdirectory to pci_epf_ntb directory in configfs.
+
+Standard EPF Configurable Fields:
+
+================   ===========================================================
+vendorid	   should be 0x104c
+deviceid	   should be 0xb00d for TI's J721E SoC
+revid		   don't care
+progif_code	   don't care
+subclass_code	   should be 0x00
+baseclass_code	   should be 0x5
+cache_line_size	   don't care
+subsys_vendor_id   don't care
+subsys_id	   don't care
+interrupt_pin	   don't care
+msi_interrupts	   don't care
+msix_interrupts	   don't care
+================   ===========================================================
+
+2) Create a subdirectory to directory created in 1
+
+NTB EPF specific configurable fields:
+
+================   ===========================================================
+db_count	   Number of doorbells; default = 4
+mw1     	   size of memory window1
+mw2     	   size of memory window2
+mw3     	   size of memory window3
+mw4     	   size of memory window4
+num_mws     	   Number of memory windows; max = 4
+spad_count     	   Number of scratchpad registers; default = 64
+================   ===========================================================
diff --git a/Documentation/PCI/endpoint/function/binding/pci-test.rst b/Documentation/PCI/endpoint/function/binding/pci-test.rst
new file mode 100644
index 000000000..57ee866fb
--- /dev/null
+++ b/Documentation/PCI/endpoint/function/binding/pci-test.rst
@@ -0,0 +1,26 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==========================
+PCI Test Endpoint Function
+==========================
+
+name: Should be "pci_epf_test" to bind to the pci_epf_test driver.
+
+Configurable Fields:
+
+================   ===========================================================
+vendorid	   should be 0x104c
+deviceid	   should be 0xb500 for DRA74x and 0xb501 for DRA72x
+revid		   don't care
+progif_code	   don't care
+subclass_code	   don't care
+baseclass_code	   should be 0xff
+cache_line_size	   don't care
+subsys_vendor_id   don't care
+subsys_id	   don't care
+interrupt_pin	   Should be 1 - INTA, 2 - INTB, 3 - INTC, 4 -INTD
+msi_interrupts	   Should be 1 to 32 depending on the number of MSI interrupts
+		   to test
+msix_interrupts	   Should be 1 to 2048 depending on the number of MSI-X
+		   interrupts to test
+================   ===========================================================