On Mon, Oct 07, 2013 at 06:29:30PM +0530, Kashyap Chamarthy wrote: > 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 You need to trace kvm events too and make buffer bigger trace-cmd record -b 100000 -e kvmmmu -e kvm. > /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 Is this all? > > Side question: I wonder why would trace-cmd say "trace-cmd: No such > file or directory"? > Ignore it. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
