Messages in this thread | | | Subject | Re: [PATCH] kvm: Fixes lack of KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 enabled check | From | Paolo Bonzini <> | Date | Tue, 12 Jan 2021 11:20:56 +0100 |
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On 12/01/21 10:29, Kunkun Jiang wrote: > The KVM_CLEAR_DIRTY_LOG ioctl lacks the check whether the capability > KVM_CAP_MANUAL_DIRTY_LOG_PROTECT is enabled or not. This may cause > some problems if userspace calls the KVM_CLEAR_DIRTY_LOG ioctl, but > dose't enable this capability. So we'd better to add it. > > Fixes: 2a31b9db15353 ("kvm: introduce manual dirty log reprotect") > Signed-off-by: Kunkun Jiang <jiangkunkun@huawei.com> > --- > virt/kvm/kvm_main.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index fa9e3614d30e..8f5633d8a0e8 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -1602,6 +1602,9 @@ static int kvm_clear_dirty_log_protect(struct kvm *kvm, > unsigned long *dirty_bitmap_buffer; > bool flush; > > + if (!kvm->manual_dirty_log_protect) > + return -EPERM; > + > /* Dirty ring tracking is exclusive to dirty log tracking */ > if (kvm->dirty_ring_size) > return -ENXIO;
This is not a problem, KVM_CLEAR_DIRTY_LOG can always be used even if KVM_CAP_MANUAL_DIRTY_LOG_PROTECT was not enabled. The meaning is the same: clear the bits without returning them.
Paolo
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