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| author |   Sean Christopherson <sean.j.christopherson@intel.com> | 2019-12-18 13:55:06 -0800 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2020-01-24 09:19:05 +0100 |
| commit | 208050dac5ef4de5cb83ffcafa78499c94d0b5ad (patch) | |
| tree | f4bd295aa3a13360c1a20dd9eb9797402042e9f6 /arch | |
| parent | KVM: x86: Remove spurious kvm_mmu_unload() from vcpu destruction path (diff) | |
| download | linux-dev-208050dac5ef4de5cb83ffcafa78499c94d0b5ad.tar.xz linux-dev-208050dac5ef4de5cb83ffcafa78499c94d0b5ad.zip | |
KVM: x86: Remove spurious clearing of async #PF MSR
Remove a bogus clearing of apf.msr_val from kvm_arch_vcpu_destroy().
apf.msr_val is only set to a non-zero value by kvm_pv_enable_async_pf(),
which is only reachable by kvm_set_msr_common(), i.e. by writing
MSR_KVM_ASYNC_PF_EN. KVM does not autonomously write said MSR, i.e.
can only be written via KVM_SET_MSRS or KVM_RUN. Since KVM_SET_MSRS and
KVM_RUN are vcpu ioctls, they require a valid vcpu file descriptor.
kvm_arch_vcpu_destroy() is only called if KVM_CREATE_VCPU fails, and KVM
declares KVM_CREATE_VCPU successful once the vcpu fd is installed and
thus visible to userspace. Ergo, apf.msr_val cannot be non-zero when
kvm_arch_vcpu_destroy() is called.
Fixes: 344d9588a9df0 ("KVM: Add PV MSR to enable asynchronous page faults delivery.")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/x86.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index b731fc7d0306..0c3633f9559d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -9257,8 +9257,6 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) { - vcpu->arch.apf.msr_val = 0; - kvm_arch_vcpu_free(vcpu); } |