Sean Christopherson d2060bd42e KVM: nVMX: Open a window for pending nested VMX preemption timer ... Add a kvm_x86_ops hook to detect a nested pending "hypervisor timer" and use it to effectively open a window for servicing the expired timer. Like pending SMIs on VMX, opening a window simply means requesting an immediate exit. This fixes a bug where an expired VMX preemption timer (for L2) will be delayed and/or lost if a pending exception is injected into L2. The pending exception is rightly prioritized by vmx_check_nested_events() and injected into L2, with the preemption timer left pending. Because no window opened, L2 is free to run uninterrupted. Fixes: f4124500c2 ("KVM: nVMX: Fully emulate preemption timer") Reported-by: Jim Mattson <jmattson@google.com> Cc: Oliver Upton <oupton@google.com> Cc: Peter Shier <pshier@google.com> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200423022550.15113-3-sean.j.christopherson@intel.com> [Check it in kvm_vcpu_has_events too, to ensure that the preemption timer is serviced promptly even if the vCPU is halted and L1 is not intercepting HLT. - Paolo] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>		2020-05-13 12:14:27 -04:00
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asm	KVM: nVMX: Open a window for pending nested VMX preemption timer	2020-05-13 12:14:27 -04:00
uapi/asm	KVM: nVMX: Emulate MTF when performing instruction emulation	2020-02-23 09:36:23 +01:00