| Message ID | 20221031003621.164306-4-gshan@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM: arm64: Enable ring-based dirty memory tracking | expand |
On Mon, Oct 31, 2022 at 08:36:15AM +0800, Gavin Shan wrote: > There are two capabilities related to ring-based dirty page tracking: > KVM_CAP_DIRTY_LOG_RING and KVM_CAP_DIRTY_LOG_RING_ACQ_REL. Both are > supported by x86. However, arm64 supports KVM_CAP_DIRTY_LOG_RING_ACQ_REL > only when the feature is supported on arm64. The userspace doesn't have > to enable the advertised capability, meaning KVM_CAP_DIRTY_LOG_RING can > be enabled on arm64 by userspace and it's wrong. > > Fix it by double checking if the capability has been advertised prior to > enabling it. It's rejected to enable the capability if it hasn't been > advertised. > > Fixes: 17601bfed909 ("KVM: Add KVM_CAP_DIRTY_LOG_RING_ACQ_REL capability and config option") > Reported-by: Sean Christopherson <seanjc@google.com> > Suggested-by: Sean Christopherson <seanjc@google.com> > Signed-off-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Oliver Upton <oliver.upton@linux.dev> This patch should be picked up separate from this series for 6.1. The original patch went through kvmarm and I think there are a few other arm64 fixes to be sent out anyway. Marc, can you grab this? :) -- Thanks, Oliver
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 30ff73931e1c..91cf51a25394 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4584,6 +4584,9 @@ static int kvm_vm_ioctl_enable_cap_generic(struct kvm *kvm, } case KVM_CAP_DIRTY_LOG_RING: case KVM_CAP_DIRTY_LOG_RING_ACQ_REL: + if (!kvm_vm_ioctl_check_extension_generic(kvm, cap->cap)) + return -EINVAL; + return kvm_vm_ioctl_enable_dirty_log_ring(kvm, cap->args[0]); default: return kvm_vm_ioctl_enable_cap(kvm, cap);
There are two capabilities related to ring-based dirty page tracking: KVM_CAP_DIRTY_LOG_RING and KVM_CAP_DIRTY_LOG_RING_ACQ_REL. Both are supported by x86. However, arm64 supports KVM_CAP_DIRTY_LOG_RING_ACQ_REL only when the feature is supported on arm64. The userspace doesn't have to enable the advertised capability, meaning KVM_CAP_DIRTY_LOG_RING can be enabled on arm64 by userspace and it's wrong. Fix it by double checking if the capability has been advertised prior to enabling it. It's rejected to enable the capability if it hasn't been advertised. Fixes: 17601bfed909 ("KVM: Add KVM_CAP_DIRTY_LOG_RING_ACQ_REL capability and config option") Reported-by: Sean Christopherson <seanjc@google.com> Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Gavin Shan <gshan@redhat.com> --- virt/kvm/kvm_main.c | 3 +++ 1 file changed, 3 insertions(+)