On Fri, Nov 14, 2025, Yosry Ahmed wrote:
On Fri, Nov 14, 2025 at 08:34:54AM -0800, Sean Christopherson wrote:
On Wed, Nov 12, 2025, Yosry Ahmed wrote:
svm_update_lbrv() always updates LBR MSRs intercepts, even when they are already set correctly. This results in force_msr_bitmap_recalc always being set to true on every nested transition,
Nit, it's only on VMRUN, not on every transition (i.e. not on nested #VMEXIT).
How so? svm_update_lbrv() will also be called in nested_svm_vmexit(), and it will eventually lead to force_msr_bitmap_recalc being set to true.
I guess what you meant is the "undoing the Hyper-V optimization" part. That is indeed only affected by the svm_update_lbrv() call in the nested VMRUN path.
Ooh, yeah, my mind was fully on when the intercepts would be recomputed, not on when the flag could be set.