[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 3/4] xen: introduce an event channel for buffered io event notifications
From: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> Use the newly introduced HVM_PARAM_BUFIOREQ_EVTCHN to receive notifications for buffered io events. After the first notification is received leave the event channel masked and setup a timer to process the rest of the batch. Once we have completed processing the batch, unmask the event channel and delete the timer. Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> --- xen-all.c | 38 ++++++++++++++++++++++++++++++++------ 1 files changed, 32 insertions(+), 6 deletions(-) diff --git a/xen-all.c b/xen-all.c index b5e28ab..b28d7e7 100644 --- a/xen-all.c +++ b/xen-all.c @@ -70,6 +70,8 @@ typedef struct XenIOState { QEMUTimer *buffered_io_timer; /* the evtchn port for polling the notification, */ evtchn_port_t *ioreq_local_port; + /* evtchn local port for buffered io */ + evtchn_port_t bufioreq_local_port; /* the evtchn fd for polling */ XenEvtchn xce_handle; /* which vcpu we are serving */ @@ -516,6 +518,12 @@ static ioreq_t *cpu_get_ioreq(XenIOState *state) evtchn_port_t port; port = xc_evtchn_pending(state->xce_handle); + if (port == state->bufioreq_local_port) { + qemu_mod_timer(state->buffered_io_timer, + BUFFER_IO_MAX_DELAY + qemu_get_clock_ms(rt_clock)); + return NULL; + } + if (port != -1) { for (i = 0; i < smp_cpus; i++) { if (state->ioreq_local_port[i] == port) { @@ -664,16 +672,18 @@ static void handle_ioreq(ioreq_t *req) } } -static void handle_buffered_iopage(XenIOState *state) +static int handle_buffered_iopage(XenIOState *state) { buf_ioreq_t *buf_req = NULL; ioreq_t req; int qw; if (!state->buffered_io_page) { - return; + return 0; } + memset(&req, 0x00, sizeof(req)); + while (state->buffered_io_page->read_pointer != state->buffered_io_page->write_pointer) { buf_req = &state->buffered_io_page->buf_ioreq[ state->buffered_io_page->read_pointer % IOREQ_BUFFER_SLOT_NUM]; @@ -698,15 +708,21 @@ static void handle_buffered_iopage(XenIOState *state) xen_mb(); state->buffered_io_page->read_pointer += qw ? 2 : 1; } + + return req.count; } static void handle_buffered_io(void *opaque) { XenIOState *state = opaque; - handle_buffered_iopage(state); - qemu_mod_timer(state->buffered_io_timer, - BUFFER_IO_MAX_DELAY + qemu_get_clock_ms(rt_clock)); + if (handle_buffered_iopage(state)) { + qemu_mod_timer(state->buffered_io_timer, + BUFFER_IO_MAX_DELAY + qemu_get_clock_ms(rt_clock)); + } else { + qemu_del_timer(state->buffered_io_timer); + xc_evtchn_unmask(state->xce_handle, state->bufioreq_local_port); + } } static void cpu_handle_ioreq(void *opaque) @@ -836,7 +852,6 @@ static void xen_main_loop_prepare(XenIOState *state) state->buffered_io_timer = qemu_new_timer_ms(rt_clock, handle_buffered_io, state); - qemu_mod_timer(state->buffered_io_timer, qemu_get_clock_ms(rt_clock)); if (evtchn_fd != -1) { qemu_set_fd_handler(evtchn_fd, cpu_handle_ioreq, NULL, state); @@ -888,6 +903,7 @@ int xen_hvm_init(void) { int i, rc; unsigned long ioreq_pfn; + unsigned long bufioreq_evtchn; XenIOState *state; state = g_malloc0(sizeof (XenIOState)); @@ -937,6 +953,16 @@ int xen_hvm_init(void) state->ioreq_local_port[i] = rc; } + xc_get_hvm_param(xen_xc, xen_domid, HVM_PARAM_BUFIOREQ_EVTCHN, + &bufioreq_evtchn); + rc = xc_evtchn_bind_interdomain(state->xce_handle, xen_domid, + (uint32_t)bufioreq_evtchn); + if (rc == -1) { + fprintf(stderr, "bind interdomain ioctl error %d\n", errno); + return -1; + } + state->bufioreq_local_port = rc; + /* Init RAM management */ xen_map_cache_init(); xen_ram_init(ram_size); -- 1.7.2.3 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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