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[src/trunk]: src/sys/arch/xen/xen Implement feature-rx-copy support in xennet...
details: https://anonhg.NetBSD.org/src/rev/8993bf71429c
branches: trunk
changeset: 758089:8993bf71429c
user: jym <jym%NetBSD.org@localhost>
date: Sun Oct 17 17:10:44 2010 +0000
description:
Implement feature-rx-copy support in xennet (domU network frontend).
Instead of flipping pages back and forth between dom0 and domU for the
network RX queue, feature-rx-copy tells frontend to use content copy
instead.
This is the only mode supported by the dom0 Linux pv_ops backend. NetBSD
domU and dom0 can still fall back to flipping, when needed.
Copy is supposed to be faster than flipping, as it does not require
MMU manipulation and TLB shootdowns.
Based on patch provided by Hideki ONO. Thanks!
See also http://mail-index.netbsd.org/port-xen/2010/09/24/msg006265.html
and http://mail-index.netbsd.org/port-xen/2010/10/16/msg006312.html
ok bouyer@.
XXX will ask for a pull-up after 5.1 is branched.
diffstat:
sys/arch/xen/xen/if_xennet_xenbus.c | 287 +++++++++++++++++++++++------------
1 files changed, 184 insertions(+), 103 deletions(-)
diffs (truncated from 387 to 300 lines):
diff -r ffa3c0cf7df5 -r 8993bf71429c sys/arch/xen/xen/if_xennet_xenbus.c
--- a/sys/arch/xen/xen/if_xennet_xenbus.c Sun Oct 17 16:13:56 2010 +0000
+++ b/sys/arch/xen/xen/if_xennet_xenbus.c Sun Oct 17 17:10:44 2010 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: if_xennet_xenbus.c,v 1.44 2010/10/16 00:20:05 jym Exp $ */
+/* $NetBSD: if_xennet_xenbus.c,v 1.45 2010/10/17 17:10:44 jym Exp $ */
/*
* Copyright (c) 2006 Manuel Bouyer.
@@ -85,7 +85,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_xennet_xenbus.c,v 1.44 2010/10/16 00:20:05 jym Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_xennet_xenbus.c,v 1.45 2010/10/17 17:10:44 jym Exp $");
#include "opt_xen.h"
#include "opt_nfs_boot.h"
@@ -199,6 +199,9 @@
#define BEST_DISCONNECTED 1
#define BEST_CONNECTED 2
#define BEST_SUSPENDED 3
+ unsigned long sc_rx_feature;
+#define FEATURE_RX_FLIP 0
+#define FEATURE_RX_COPY 1
#if NRND > 0
rndsource_element_t sc_rnd_source;
#endif
@@ -430,6 +433,7 @@
{
struct xennet_xenbus_softc *sc = p;
struct xenbus_transaction *xbt;
+ unsigned long rx_copy;
int error;
netif_tx_sring_t *tx_ring;
netif_rx_sring_t *rx_ring;
@@ -439,7 +443,6 @@
sc->sc_tx_ring_gntref = GRANT_INVALID_REF;
sc->sc_rx_ring_gntref = GRANT_INVALID_REF;
-
/* setup device: alloc event channel and shared rings */
tx_ring = (void *)uvm_km_alloc(kernel_map, PAGE_SIZE, 0,
UVM_KMF_WIRED | UVM_KMF_ZERO);
@@ -469,6 +472,19 @@
event_set_handler(sc->sc_evtchn, &xennet_handler, sc,
IPL_NET, device_xname(sc->sc_dev));
+ error = xenbus_read_ul(NULL, sc->sc_xbusd->xbusd_otherend,
+ "feature-rx-copy", &rx_copy, 10);
+ if (error)
+ rx_copy = 0; /* default value if key is absent */
+
+ if (rx_copy == 1) {
+ aprint_normal_dev(sc->sc_dev, "using RX copy mode\n");
+ sc->sc_rx_feature = FEATURE_RX_COPY;
+ } else {
+ aprint_normal_dev(sc->sc_dev, "using RX flip mode\n");
+ sc->sc_rx_feature = FEATURE_RX_FLIP;
+ }
+
again:
xbt = xenbus_transaction_start();
if (xbt == NULL)
@@ -486,6 +502,12 @@
goto abort_transaction;
}
error = xenbus_printf(xbt, sc->sc_xbusd->xbusd_path,
+ "request-rx-copy", "%lu", rx_copy);
+ if (error) {
+ errmsg = "writing request-rx-copy";
+ goto abort_transaction;
+ }
+ error = xenbus_printf(xbt, sc->sc_xbusd->xbusd_path,
"feature-rx-notify", "%u", 1);
if (error) {
errmsg = "writing feature-rx-notify";
@@ -553,9 +575,11 @@
RING_IDX i;
struct xennet_rxreq *req;
struct xen_memory_reservation reservation;
- int s1, s2;
+ int s1, s2, otherend_id;
paddr_t pfn;
+ otherend_id = sc->sc_xbusd->xbusd_otherend_id;
+
s1 = splnet();
for (i = 0; sc->sc_free_rxreql != 0; i++) {
req = SLIST_FIRST(&sc->sc_rxreq_head);
@@ -563,53 +587,80 @@
KASSERT(req == &sc->sc_rxreqs[req->rxreq_id]);
RING_GET_REQUEST(&sc->sc_rx_ring, req_prod + i)->id =
req->rxreq_id;
- if (xengnt_grant_transfer(sc->sc_xbusd->xbusd_otherend_id,
- &req->rxreq_gntref) != 0) {
+
+ switch (sc->sc_rx_feature) {
+ case FEATURE_RX_COPY:
+ if (xengnt_grant_access(otherend_id,
+ xpmap_ptom_masked(req->rxreq_pa),
+ 0, &req->rxreq_gntref) != 0) {
+ goto out_loop;
+ }
break;
+ case FEATURE_RX_FLIP:
+ if (xengnt_grant_transfer(otherend_id,
+ &req->rxreq_gntref) != 0) {
+ goto out_loop;
+ }
+ break;
+ default:
+ panic("%s: unsupported RX feature mode: %ld\n",
+ __func__, sc->sc_rx_feature);
}
+
RING_GET_REQUEST(&sc->sc_rx_ring, req_prod + i)->gref =
req->rxreq_gntref;
SLIST_REMOVE_HEAD(&sc->sc_rxreq_head, rxreq_next);
sc->sc_free_rxreql--;
- /* unmap the page */
- MULTI_update_va_mapping(&rx_mcl[i], req->rxreq_va, 0, 0);
- /*
- * Remove this page from pseudo phys map before
- * passing back to Xen.
- */
- pfn = (req->rxreq_pa - XPMAP_OFFSET) >> PAGE_SHIFT;
- xennet_pages[i] = xpmap_phys_to_machine_mapping[pfn];
- xpmap_phys_to_machine_mapping[pfn] = INVALID_P2M_ENTRY;
+ if (sc->sc_rx_feature == FEATURE_RX_FLIP) {
+ /* unmap the page */
+ MULTI_update_va_mapping(&rx_mcl[i],
+ req->rxreq_va, 0, 0);
+ /*
+ * Remove this page from pseudo phys map before
+ * passing back to Xen.
+ */
+ pfn = (req->rxreq_pa - XPMAP_OFFSET) >> PAGE_SHIFT;
+ xennet_pages[i] = xpmap_phys_to_machine_mapping[pfn];
+ xpmap_phys_to_machine_mapping[pfn] = INVALID_P2M_ENTRY;
+ }
}
+
+out_loop:
if (i == 0) {
splx(s1);
return;
}
- /* also make sure to flush all TLB entries */
- rx_mcl[i-1].args[MULTI_UVMFLAGS_INDEX] = UVMF_TLB_FLUSH|UVMF_ALL;
- /*
- * We may have allocated buffers which have entries
- * outstanding in the page update queue -- make sure we flush
- * those first!
- */
- s2 = splvm();
- xpq_flush_queue();
- splx(s2);
- /* now decrease reservation */
- xenguest_handle(reservation.extent_start) = xennet_pages;
- reservation.nr_extents = i;
- reservation.extent_order = 0;
- reservation.address_bits = 0;
- reservation.domid = DOMID_SELF;
- rx_mcl[i].op = __HYPERVISOR_memory_op;
- rx_mcl[i].args[0] = XENMEM_decrease_reservation;
- rx_mcl[i].args[1] = (unsigned long)&reservation;
- HYPERVISOR_multicall(rx_mcl, i+1);
- if (__predict_false(rx_mcl[i].result != i)) {
- panic("xennet_alloc_rx_buffer: XENMEM_decrease_reservation");
+
+ if (sc->sc_rx_feature == FEATURE_RX_FLIP) {
+ /* also make sure to flush all TLB entries */
+ rx_mcl[i-1].args[MULTI_UVMFLAGS_INDEX] =
+ UVMF_TLB_FLUSH | UVMF_ALL;
+ /*
+ * We may have allocated buffers which have entries
+ * outstanding in the page update queue -- make sure we flush
+ * those first!
+ */
+ s2 = splvm();
+ xpq_flush_queue();
+ splx(s2);
+ /* now decrease reservation */
+ xenguest_handle(reservation.extent_start) = xennet_pages;
+ reservation.nr_extents = i;
+ reservation.extent_order = 0;
+ reservation.address_bits = 0;
+ reservation.domid = DOMID_SELF;
+ rx_mcl[i].op = __HYPERVISOR_memory_op;
+ rx_mcl[i].args[0] = XENMEM_decrease_reservation;
+ rx_mcl[i].args[1] = (unsigned long)&reservation;
+ HYPERVISOR_multicall(rx_mcl, i+1);
+ if (__predict_false(rx_mcl[i].result != i)) {
+ panic("xennet_alloc_rx_buffer: "
+ "XENMEM_decrease_reservation");
+ }
}
+
sc->sc_rx_ring.req_prod_pvt = req_prod + i;
RING_PUSH_REQUESTS(&sc->sc_rx_ring);
@@ -652,44 +703,57 @@
SLIST_INSERT_HEAD(&sc->sc_rxreq_head, rxreq,
rxreq_next);
sc->sc_free_rxreql++;
- ma = xengnt_revoke_transfer(rxreq->rxreq_gntref);
- rxreq->rxreq_gntref = GRANT_INVALID_REF;
- if (ma == 0) {
- u_long pfn;
- struct xen_memory_reservation xenres;
- /*
- * transfer not complete, we lost the page.
- * Get one from hypervisor
- */
- xenguest_handle(xenres.extent_start) = &pfn;
- xenres.nr_extents = 1;
- xenres.extent_order = 0;
- xenres.address_bits = 31;
- xenres.domid = DOMID_SELF;
- if (HYPERVISOR_memory_op(
- XENMEM_increase_reservation, &xenres) < 0) {
- panic("xennet_free_rx_buffer: "
- "can't get memory back");
+
+ switch (sc->sc_rx_feature) {
+ case FEATURE_RX_COPY:
+ xengnt_revoke_access(rxreq->rxreq_gntref);
+ rxreq->rxreq_gntref = GRANT_INVALID_REF;
+ break;
+ case FEATURE_RX_FLIP:
+ ma = xengnt_revoke_transfer(
+ rxreq->rxreq_gntref);
+ rxreq->rxreq_gntref = GRANT_INVALID_REF;
+ if (ma == 0) {
+ u_long pfn;
+ struct xen_memory_reservation xenres;
+ /*
+ * transfer not complete, we lost the page.
+ * Get one from hypervisor
+ */
+ xenguest_handle(xenres.extent_start) = &pfn;
+ xenres.nr_extents = 1;
+ xenres.extent_order = 0;
+ xenres.address_bits = 31;
+ xenres.domid = DOMID_SELF;
+ if (HYPERVISOR_memory_op(
+ XENMEM_increase_reservation, &xenres) < 0) {
+ panic("xennet_free_rx_buffer: "
+ "can't get memory back");
+ }
+ ma = pfn;
+ KASSERT(ma != 0);
}
- ma = pfn;
- KASSERT(ma != 0);
+ pa = rxreq->rxreq_pa;
+ va = rxreq->rxreq_va;
+ /* remap the page */
+ mmu[0].ptr = (ma << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE;
+ mmu[0].val = ((pa - XPMAP_OFFSET) >> PAGE_SHIFT);
+ MULTI_update_va_mapping(&mcl[0], va,
+ (ma << PAGE_SHIFT) | PG_V | PG_KW,
+ UVMF_TLB_FLUSH|UVMF_ALL);
+ xpmap_phys_to_machine_mapping[
+ (pa - XPMAP_OFFSET) >> PAGE_SHIFT] = ma;
+ mcl[1].op = __HYPERVISOR_mmu_update;
+ mcl[1].args[0] = (unsigned long)mmu;
+ mcl[1].args[1] = 1;
+ mcl[1].args[2] = 0;
+ mcl[1].args[3] = DOMID_SELF;
+ HYPERVISOR_multicall(mcl, 2);
+ break;
+ default:
+ panic("%s: unsupported RX feature mode: %ld\n",
+ __func__, sc->sc_rx_feature);
}
- pa = rxreq->rxreq_pa;
- va = rxreq->rxreq_va;
- /* remap the page */
- mmu[0].ptr = (ma << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE;
- mmu[0].val = ((pa - XPMAP_OFFSET) >> PAGE_SHIFT);
- MULTI_update_va_mapping(&mcl[0], va,
- (ma << PAGE_SHIFT) | PG_V | PG_KW,
- UVMF_TLB_FLUSH|UVMF_ALL);
- xpmap_phys_to_machine_mapping[
- (pa - XPMAP_OFFSET) >> PAGE_SHIFT] = ma;
- mcl[1].op = __HYPERVISOR_mmu_update;
- mcl[1].args[0] = (unsigned long)mmu;
- mcl[1].args[1] = 1;
- mcl[1].args[2] = 0;
- mcl[1].args[3] = DOMID_SELF;
- HYPERVISOR_multicall(mcl, 2);
}
}
@@ -820,41 +884,58 @@
req = &sc->sc_rxreqs[rx->id];
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