George Dunlap
2006-Jun-01 20:17 UTC
[Xen-devel] [PATCH] Make xentrace hypercall a bit more sane
xentrace, setsize and the hypervisor don''t seem to be on the same page. If tracing is not enabled, the hypercall will only allow TBUF_SET_SIZE and TBUF_ENABLE. However, set_size calls TBUF_GET_INFO, and xentrace wants to call TBUF_SET_EVT_MASK and TBUF_SET_CPU_MASK before calling TBUF_ENABLE. I don''t see any reason not to call SET_*_MASK and GET_INFO if tracing is not enabled. If the buffer hasn''t been allocated yet, GET_INFO should just return something invalid in the mfn field. Anyone calling should check this value. Comments? -George _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Rob Gardner
2006-Jun-01 20:24 UTC
Re: [Xen-devel] [PATCH] Make xentrace hypercall a bit more sane
George Dunlap wrote:> xentrace, setsize and the hypervisor don''t seem to be on the same > page. If tracing is not enabled, the hypercall will only allow > TBUF_SET_SIZE and TBUF_ENABLE. However, set_size calls TBUF_GET_INFO, > and xentrace wants to call TBUF_SET_EVT_MASK and TBUF_SET_CPU_MASK > before calling TBUF_ENABLE. > > I don''t see any reason not to call SET_*_MASK and GET_INFO if tracing > is not enabled. If the buffer hasn''t been allocated yet, GET_INFO > should just return something invalid in the mfn field. Anyone calling > should check this value. >Sounds benign enough. I never liked the behavior of disallowing the get_info call. Rob _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel