Hi! This patch series implements caching of the whole nested guest vmcb as opposed to current code that only caches its control area. This allows us to avoid race in which guest changes the data area while we are verifying it. In adddition to that I also implemented on demand nested state area to compensate a bit for memory usage increase from this caching. This way at least guests that don't use nesting won't waste memory on nested state. Patches 1,2,3 are just refactoring, Patches 4,5 are for ondemand nested state, while patches 6,7,8 are for caching of the nested state. Patch 8 is more of an optimization and can be dropped if you like to. The series was tested with various nested guests, in one case even with L3 running, but note that due to unrelated issue, migration with nested guest running didn't work for me with or without this series. I am investigating this currently. Best regards, Maxim Levitsky Maxim Levitsky (8): KVM: SVM: rename a variable in the svm_create_vcpu KVM: nSVM: rename nested 'vmcb' to vmcb_gpa in few places KVM: SVM: refactor msr permission bitmap allocation KVM: x86: allow kvm_x86_ops.set_efer to return a value KVM: nSVM: implement ondemand allocation of the nested state SVM: nSVM: cache whole nested vmcb instead of only its control area KVM: nSVM: implement caching of nested vmcb save area KVM: nSVM: read only changed fields of the nested guest data area arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/svm/nested.c | 296 +++++++++++++++++++++++--------- arch/x86/kvm/svm/svm.c | 129 +++++++------- arch/x86/kvm/svm/svm.h | 32 ++-- arch/x86/kvm/vmx/vmx.c | 5 +- arch/x86/kvm/x86.c | 3 +- 6 files changed, 312 insertions(+), 155 deletions(-) -- 2.26.2
