On Tue 2017-03-14 10:05:08, Thomas Garnier wrote:
This patch makes the GDT remapped pages read-only to prevent corruption.
This change is done only on 64-bit.
The native_load_tr_desc function was adapted to correctly handle a
read-only GDT. The LTR instruction always writes to the GDT TSS entry.
This generates a page fault if the GDT is read-only. This change checks
if the current GDT is a remap and swap GDTs as needed. This function was
tested by booting multiple machines and checking hibernation works
properly.
KVM SVM and VMX were adapted to use the writeable GDT. On VMX, the
per-cpu variable was removed for functions to fetch the original GDT.
Instead of reloading the previous GDT, VMX will reload the fixmap GDT as
expected. For testing, VMs were started and restored on multiple
configurations.
Signed-off-by: Thomas Garnier <redacted>
Can we get the same change for 32-bit, too? Growing differences
between 32 and 64 bit are a bit of a problem...
Pavel
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