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-uacce | 57 ++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-driver-uacce (limited to 'Documentation/ABI/testing/sysfs-driver-uacce') diff --git a/Documentation/ABI/testing/sysfs-driver-uacce b/Documentation/ABI/testing/sysfs-driver-uacce new file mode 100644 index 000000000..d3f0b8f3c --- /dev/null +++ b/Documentation/ABI/testing/sysfs-driver-uacce @@ -0,0 +1,57 @@ +What: /sys/class/uacce//api +Date: Feb 2020 +KernelVersion: 5.7 +Contact: linux-accelerators@lists.ozlabs.org +Description: Api of the device + Can be any string and up to userspace to parse. + Application use the api to match the correct driver + +What: /sys/class/uacce//flags +Date: Feb 2020 +KernelVersion: 5.7 +Contact: linux-accelerators@lists.ozlabs.org +Description: Attributes of the device, see UACCE_DEV_xxx flag defined in uacce.h + +What: /sys/class/uacce//available_instances +Date: Feb 2020 +KernelVersion: 5.7 +Contact: linux-accelerators@lists.ozlabs.org +Description: Available instances left of the device + Return -ENODEV if uacce_ops get_available_instances is not provided + +What: /sys/class/uacce//isolate_strategy +Date: Nov 2022 +KernelVersion: 6.1 +Contact: linux-accelerators@lists.ozlabs.org +Description: (RW) A sysfs node that configure the error threshold for the hardware + isolation strategy. This size is a configured integer value, which is the + number of threshold for hardware errors occurred in one hour. The default is 0. + 0 means never isolate the device. The maximum value is 65535. You can write + a number of threshold based on your hardware. + +What: /sys/class/uacce//isolate +Date: Nov 2022 +KernelVersion: 6.1 +Contact: linux-accelerators@lists.ozlabs.org +Description: (R) A sysfs node that read the device isolated state. The value 1 + means the device is unavailable. The 0 means the device is + available. + +What: /sys/class/uacce//algorithms +Date: Feb 2020 +KernelVersion: 5.7 +Contact: linux-accelerators@lists.ozlabs.org +Description: Algorithms supported by this accelerator, separated by new line. + Can be any string and up to userspace to parse. + +What: /sys/class/uacce//region_mmio_size +Date: Feb 2020 +KernelVersion: 5.7 +Contact: linux-accelerators@lists.ozlabs.org +Description: Size (bytes) of mmio region queue file + +What: /sys/class/uacce//region_dus_size +Date: Feb 2020 +KernelVersion: 5.7 +Contact: linux-accelerators@lists.ozlabs.org +Description: Size (bytes) of dus region queue file -- cgit v1.3.1