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Liran Alon authored
When guest transitions from/to long-mode by modifying MSR_EFER.LMA, the list of shared MSRs to be saved/restored on guest<->host transitions is updated (See vmx_set_efer() call to setup_msrs()). On every entry to guest, vcpu_enter_guest() calls vmx_prepare_switch_to_guest(). This function should also take care of setting the shared MSRs to be saved/restored. However, the function does nothing in case we are already running with loaded guest state (vmx->loaded_cpu_state != NULL). This means that even when guest modifies MSR_EFER.LMA which results in updating the list of shared MSRs, it isn't being taken into account by vmx_prepare_switch_to_guest() because it happens while we are running with loaded guest state. To fix above mentioned issue, add a flag to mark that the list of shared MSRs has been updated and modify vmx_prepare_switch_to_guest() to set shared MSRs when running with host state *OR* list of shared MSRs has been updated. Note that this issue was mistakenly introduced by commit 678e315e ("KVM: vmx: add dedicated utility to access guest's kernel_gs_base") because previously vmx_set_efer() always called vmx_load_host_state() which resulted in vmx_prepare_switch_to_guest() to set shared MSRs. Fixes: 678e315e ("KVM: vmx: add dedicated utility to access guest's kernel_gs_base") Reported-by:
Eyal Moscovici <eyal.moscovici@oracle.com> Reviewed-by:
Mihai Carabas <mihai.carabas@oracle.com> Reviewed-by:
Liam Merwick <liam.merwick@oracle.com> Reviewed-by:
Jim Mattson <jmattson@google.com> Signed-off-by:
Liran Alon <liran.alon@oracle.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
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