+++ /dev/null
-
-
-Xen port notes
-
-Mathieu Desnoyers, April 2006
-
-Useful files :
-
-common/trace.c
-include/xen/trace.h and the dom0 op in include/public/dom0_ops.h
-
-alloc buffer (alloc_trace_bufs) :
-alloc_xenheap_pages
-
-Shared buffer between dom0 and hypervisor :
-share_xen_page_with_privileged_guests
-
-
-
-trace_create / trace_destroy :
-
-call xen hooks from dom0 to allocate a new buffer, get the newly allocated
-struct trace pointer.
-Share struct traces with dom0 to have offset and consumed counts.
-Share the buffers with dom0 too.
-
-Create a new "xen" channel.
-
-
-Create 4 new xen facilities (see include/public/trace.h) :
-xen_sched (grep TRC_SCHED)
- sched_dom_add
- sched_dom_rem
- sched_sleep
- sched_wake
- sched_yield
- sched_block
- sched_shutdown
- sched_ctl
- sched_switch
- sched_s_timer_fn
- sched_t_timer_fn
- sched_dom_timer_fn
- sched_dom_timer_fn
- sched_switch_infprev
- sched_switch_infnext
-xen_dom0op (grep TRC_DOM0OP)
- dom0op_enter_base
- dom0op_leave_base
-xen_vmx (grep TRC_VMX)
- vmx_vmexit
- vmx_vmentry
- vmx_timer_intr
- vmx_int
- vmx_io
-xen_mem (grep TRC_MEM)
- mem_page_grant_map
- mem_page_grant_unmap
- mem_page_grant_transfer
-
-
-How to share xen pages efficiently ?
-Pages allocated in xen heap, the shared with dom0.
-
-How buffers are accessed in dom0 ?
-directly from pointers to buffers contained in get_info control information.
-
-do_dom0_op
-
-tbufcontrol -> control info
- int tb_control(dom0_tbufcontrol_t *tbc)
-
-DOM0_TBUF_GET_INFO buffer_mfn __pa(t_bufs[0]) >> PAGE_SHIFT;
-
-
-create trace :
-
-in :
-trace name
-buffer size
-return : 0 success, 1 failure
-do :
-alloc buffer xen
-share with dom0
-
-destroy trace :
-in :
-trace name
-do : unshare buffer / free.
-
-
-start/stop :
-tb_control that will update the control structure.
-in : trace name
-start : put active to 1 + inc. nb_active traces
-stop : put active to 0 + dec nb_active traces.
-return : 0 success, 1 failure.
-
-consume :
-in : trace name
-tb_control that will update the consumed count.
-in : old count.
-return : 0 success, 1 failure (pushed).
-
-get_info :
-tb_control that returns a fresh copy of trace control info.
-
-
-
-NOTE 8-11-2006
-
-Xen 3.0.3
-Only one init of buffers (cannot change buffer size)
-tbc->buffer_mfn = opt_tbuf_size ? virt_to_mfn(per_cpu(t_bufs, 0)) : 0;
-/* Convert between Xen-heap virtual addresses and machine frame numbers. */
-#define virt_to_mfn(va) (virt_to_maddr(va) >> PAGE_SHIFT)
-
-struct t_buf *tbufs_mapped;
-
- tbufs_mapped = xc_map_foreign_range(xc_handle, DOMID_XEN,
- size * num, PROT_READ | PROT_WRITE,
- tbufs_mfn);
-
-int fd = open("/proc/xen/privcmd", O_RDWR);
-
-/* sleep for this long (milliseconds) between checking the trace buffers */
-#define POLL_SLEEP_MILLIS 100
-
-
-netfront.c
-xenbus_alloc_evtchn
-bind_evtchn_to_irqhandler
-
-
-virq :
-
-include/public/xen.h VIRQ_TBUF
- /* G. (DOM0) Trace buffer has records available. */
-
-trace_notify_guest : send_guest_global_virq(dom0, VIRQ_TBUF);
-
-see arch/i386/oprofile/xenoprof.c
-bind_virq
-
-
-