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-driver-pciback | 28 ++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-driver-pciback (limited to 'Documentation/ABI/testing/sysfs-driver-pciback') diff --git a/Documentation/ABI/testing/sysfs-driver-pciback b/Documentation/ABI/testing/sysfs-driver-pciback new file mode 100644 index 000000000..49f5fd0c8 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-driver-pciback @@ -0,0 +1,28 @@ +What: /sys/bus/pci/drivers/pciback/quirks +Date: Oct 2011 +KernelVersion: 3.1 +Contact: xen-devel@lists.xenproject.org +Description: + If the permissive attribute is set, then writing a string in + the format of DDDD:BB:DD.F-REG:SIZE:MASK will allow the guest + to write and read from the PCI device. That is Domain:Bus: + Device.Function-Register:Size:Mask (Domain is optional). + For example:: + + #echo 00:19.0-E0:2:FF > /sys/bus/pci/drivers/pciback/quirks + + will allow the guest to read and write to the configuration + register 0x0E. + +What: /sys/bus/pci/drivers/pciback/allow_interrupt_control +Date: Jan 2020 +KernelVersion: 5.6 +Contact: xen-devel@lists.xenproject.org +Description: + List of devices which can have interrupt control flag (INTx, + MSI, MSI-X) set by a connected guest. It is meant to be set + only when the guest is a stubdomain hosting device model (qemu) + and the actual device is assigned to a HVM. It is not safe + (similar to permissive attribute) to set for a devices assigned + to a PV guest. The device is automatically removed from this + list when the connected pcifront terminates. -- cgit v1.3.1