KVM: nVMX: Add nested msr load/restore algorithm

Several hypervisors need MSR auto load/restore feature.
We read MSRs from VM-entry MSR load area which specified by L1,
and load them via kvm_set_msr in the nested entry.
When nested exit occurs, we get MSRs via kvm_get_msr, writing
them to L1`s MSR store area. After this, we read MSRs from VM-exit
MSR load area, and load them via kvm_set_msr.

Signed-off-by: Wincy Van <fanwenyi0529@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 1cc6e2e19982..167e8c14b143 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1593,6 +1593,7 @@ int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data,
         }
         return 0;
 }
+EXPORT_SYMBOL_GPL(kvm_write_guest);
 
 int kvm_gfn_to_hva_cache_init(struct kvm *kvm, struct gfn_to_hva_cache *ghc,
                               gpa_t gpa, unsigned long len)