When doing memory hotplug on a secure VM, the secure pages are not well
cleaned from the secure device when dropping the memslot. This silent
error, is then preventing the SVM to reboot properly after the following
sequence of commands are run in the Qemu monitor:
device_add pc-dimm,id=dimm1,memdev=mem1
device_del dimm1
device_add pc-dimm,id=dimm1,memdev=mem1
At reboot time, when the kernel is booting again and switching to the
secure mode, the page_in is failing for the pages in the memslot because
the cleanup was not done properly, because the memslot is flagged as
invalid during the hot unplug and thus the page fault mechanism is not
triggered.
To prevent that during the memslot dropping, instead of belonging on the
page fault mechanism to trigger the page out of the secured pages, it seems
simpler to directly call the function doing the page out. This way the
state of the memslot is not interfering on the page out process.
This series applies on top of the Ram's one titled:
"PATCH v3 0/4] Migrate non-migrated pages of a SVM."
https://lore.kernel.org/linuxppc-dev/[email protected]/#r
Laurent Dufour (2):
KVM: PPC: Book3S HV: move kvmppc_svm_page_out up
KVM: PPC: Book3S HV: rework secure mem slot dropping
arch/powerpc/kvm/book3s_hv_uvmem.c | 220 +++++++++++++++++------------
1 file changed, 127 insertions(+), 93 deletions(-)
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2.27.0