Gleb, so I just did a trace of KVM MMU to try to understand why L2 is
stuck with shadow on EPT
Ensure, EPT is enabled on L0 & disabled on L1
On L0:
---------
$ cat /sys/module/kvm_intel/parameters/ept
Y
On L1
---------
$ cat /sys/module/kvm_intel/parameters/ept
N
Build and install trace-cmd on L1:
$ git clone
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/trace-cmd.git
trace-cmd
$ make && sudo make-install
Run trace command (on L1) to capture kvmmmu event:
$ trace-cmd record -b 2000 -e kvmmmu
/sys/kernel/debug/tracing/events/kvmmmu/filter
/sys/kernel/debug/tracing/events/*/kvmmmu/filter
Hit Ctrl^C to stop recording
Boot L2 guest:
$ virsh start nguest-01 --console
After a minute or two, ctl-C the trace-cmd, generate the report:
$ trace-cmd report
version = 6
trace-cmd: No such file or directory
function is_writable_pte not defined
CPU 1 is empty
CPU 2 is empty
CPU 3 is empty
cpus=4
qemu-system-x86-2554 [000] 90667.995345:
kvm_mmu_invalidate_zap_all_pages: kvm-mmu-valid-gen 0 used_pages 0
qemu-system-x86-2557 [000] 90668.078978: kvm_mmu_get_page: new
sp gfn 0 0/2 q0 direct --- !pge !nxe root 0 sync
qemu-system-x86-2557 [000] 90668.078980: kvm_mmu_get_page: new
sp gfn 40000 0/2 q0 direct --- !pge !nxe root 0 sync
qemu-system-x86-2557 [000] 90668.078980: kvm_mmu_get_page: new
sp gfn 80000 0/2 q0 direct --- !pge !nxe root 0 sync
qemu-system-x86-2557 [000] 90668.078981: kvm_mmu_get_page: new
sp gfn c0000 0/2 q0 direct --- !pge !nxe root 0 sync
qemu-system-x86-2557 [000] 90668.079025: kvm_mmu_get_page: new
sp gfn 0 0/1 q0 direct --- !pge !nxe root 0 sync
Side question: I wonder why would trace-cmd say "trace-cmd: No such
file or directory"?
/kashyap
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