KVM: nVMX: Do a bitwise-AND of regs_avail when switching active VMCS

When switching between vmcs01 and vmcs02, do a bitwise-AND of regs_avail
to effectively reset the mask for the new VMCS, purely to be consistent
with all other "full" writes of regs_avail.  In practice, a straight write
versus a bitwise-AND will yield the same result, as kvm_arch_vcpu_create()
marks *all* registers available (and dirty), and KVM never marks registers
unavailable unless they're lazily loaded.

This will allow adding wrapper APIs to set regs_{avail,dirty} without
having to add special handling for a nVMX use case that doesn't exist in
practice.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Message-ID: <20260409224236.2021562-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Sean Christopherson 2026-04-09 15:42:32 -07:00 committed by Paolo Bonzini
parent e31de57910
commit 3b628ef168

View File

@ -310,7 +310,7 @@ static void vmx_switch_vmcs(struct kvm_vcpu *vcpu, struct loaded_vmcs *vmcs)
vmx_sync_vmcs_host_state(vmx, prev);
put_cpu();
vcpu->arch.regs_avail = ~VMX_REGS_LAZY_LOAD_SET;
vcpu->arch.regs_avail &= ~VMX_REGS_LAZY_LOAD_SET;
/*
* All lazily updated registers will be reloaded from VMCS12 on both