KVM: nVMX: Reset register cache (available and dirty masks) on VMCS switch
Reset the per-vCPU available and dirty register masks when switching between vmcs01 and vmcs02, as the masks track state relative to the current VMCS. The stale masks don't cause problems in the current code base because the registers are either unconditionally written on nested transitions or, in the case of segment registers, have an additional tracker that is manually reset. Note, by dropping (previously implicitly, now explicitly) the dirty mask when switching the active VMCS, KVM is technically losing writes to the associated fields. But, the only regs that can be dirtied (RIP, RSP and PDPTRs) are unconditionally written on nested transitions, e.g. explicit writeback is a waste of cycles, and a WARN_ON would be rather pointless. Signed-off-by:Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200415203454.8296-3-sean.j.christopherson@intel.com> Signed-off-by:
Paolo Bonzini <pbonzini@redhat.com>
parent
9932b49e
Please register or sign in to comment