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author | Sean Christopherson <sean.j.christopherson@intel.com> | 2020-04-22 19:25:39 -0700 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-05-13 12:14:27 -0400 |
commit | d2060bd42e4482b15c35f961a294ee57f369027d (patch) | |
tree | 860fb89ee17052748e003aa336eab08b74826c57 /arch/x86/include/asm/kvm_host.h | |
parent | 6ce347af1499deff5890a52aedacd451330af706 (diff) | |
download | linux-stable-d2060bd42e4482b15c35f961a294ee57f369027d.tar.gz linux-stable-d2060bd42e4482b15c35f961a294ee57f369027d.tar.bz2 linux-stable-d2060bd42e4482b15c35f961a294ee57f369027d.zip |
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: f4124500c2c13 ("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>
Diffstat (limited to 'arch/x86/include/asm/kvm_host.h')
-rw-r--r-- | arch/x86/include/asm/kvm_host.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index b3a5da27c2a5..e6671c61fd65 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1256,6 +1256,7 @@ struct kvm_x86_ops { struct kvm_x86_nested_ops { int (*check_events)(struct kvm_vcpu *vcpu); + bool (*hv_timer_pending)(struct kvm_vcpu *vcpu); int (*get_state)(struct kvm_vcpu *vcpu, struct kvm_nested_state __user *user_kvm_nested_state, unsigned user_data_size); |