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/gpu/amdgpu/flashing.rst | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) create mode 100644 Documentation/gpu/amdgpu/flashing.rst (limited to 'Documentation/gpu/amdgpu/flashing.rst') diff --git a/Documentation/gpu/amdgpu/flashing.rst b/Documentation/gpu/amdgpu/flashing.rst new file mode 100644 index 000000000..bd745c42a --- /dev/null +++ b/Documentation/gpu/amdgpu/flashing.rst @@ -0,0 +1,33 @@ +======================= + dGPU firmware flashing +======================= + +IFWI +---- +Flashing the dGPU integrated firmware image (IFWI) is supported by GPUs that +use the PSP to orchestrate the update (Navi3x or newer GPUs). +For supported GPUs, `amdgpu` will export a series of sysfs files that can be +used for the flash process. + +The IFWI flash process is: + +1. Ensure the IFWI image is intended for the dGPU on the system. +2. "Write" the IFWI image to the sysfs file `psp_vbflash`. This will stage the IFWI in memory. +3. "Read" from the `psp_vbflash` sysfs file to initiate the flash process. +4. Poll the `psp_vbflash_status` sysfs file to determine when the flash process completes. + +USB-C PD F/W +------------ +On GPUs that support flashing an updated USB-C PD firmware image, the process +is done using the `usbc_pd_fw` sysfs file. + +* Reading the file will provide the current firmware version. +* Writing the name of a firmware payload stored in `/lib/firmware/amdgpu` to the sysfs file will initiate the flash process. + +The firmware payload stored in `/lib/firmware/amdgpu` can be named any name +as long as it doesn't conflict with other existing binaries that are used by +`amdgpu`. + +sysfs files +----------- +.. kernel-doc:: drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c -- cgit v1.3.1