# HG changeset patch
# User awilliam@xxxxxxxxxxx
# Node ID 0fff4c07af186f6772060a4b3b40a05329c598fb
# Parent f662f98d594b65e1698c5da241312f1ae136b975
[IA64] Fix network issue on VTI domain
Clean up event wait sequence in io emulation path, as a critical
fix to a severe issue where VTI domain may fall into block state
when doing bulk network transfer.
Signed-off-by Kevin Tian <kevin.tian@xxxxxxxxx>
---
xen/arch/ia64/vmx/vmx_support.c | 64 +++++++++++++---------------------------
1 files changed, 22 insertions(+), 42 deletions(-)
diff -r f662f98d594b -r 0fff4c07af18 xen/arch/ia64/vmx/vmx_support.c
--- a/xen/arch/ia64/vmx/vmx_support.c Mon Jun 05 14:28:39 2006 -0600
+++ b/xen/arch/ia64/vmx/vmx_support.c Tue Jun 06 09:01:38 2006 -0600
@@ -32,7 +32,8 @@
* when emulation code is waiting for I/O completion by blocking,
* other events like DM interrupt, VBD, etc. may come and unblock
* current exection flow. So we have to prepare for re-block if unblocked
- * by non I/O completion event.
+ * by non I/O completion event. After io emulation is done, re-enable
+ * pending indicaion if other ports are pending
*/
void vmx_wait_io(void)
{
@@ -40,39 +41,25 @@ void vmx_wait_io(void)
struct domain *d = v->domain;
int port = iopacket_port(v);
- do {
- if (!test_bit(port,
- &d->shared_info->evtchn_pending[0]))
- do_sched_op_compat(SCHEDOP_block, 0);
+ for (;;) {
+ if (test_and_clear_bit(0, &v->vcpu_info->evtchn_upcall_pending) &&
+ test_and_clear_bit(port / BITS_PER_LONG,
+ &v->vcpu_info->evtchn_pending_sel) &&
+ test_and_clear_bit(port, &d->shared_info->evtchn_pending[0]))
+ vmx_io_assist(v);
- /* Unblocked when some event is coming. Clear pending indication
- * immediately if deciding to go for io assist
- */
- if (test_and_clear_bit(port,
- &d->shared_info->evtchn_pending[0])) {
- clear_bit(port/BITS_PER_LONG, &v->vcpu_info->evtchn_pending_sel);
- clear_bit(0, &v->vcpu_info->evtchn_upcall_pending);
- vmx_io_assist(v);
- }
+ if (!test_bit(ARCH_VMX_IO_WAIT, &v->arch.arch_vmx.flags))
+ break;
+ do_sched_op_compat(SCHEDOP_block, 0);
+ }
- if (test_bit(ARCH_VMX_IO_WAIT, &v->arch.arch_vmx.flags)) {
- /*
- * Latest event is not I/O completion, so clear corresponding
- * selector and pending indication, to allow real event coming
- */
- clear_bit(0, &v->vcpu_info->evtchn_upcall_pending);
+ /* re-enable indication if other pending events */
+ if (d->shared_info->evtchn_pending[port / BITS_PER_LONG])
+ set_bit(port / BITS_PER_LONG, &v->vcpu_info->evtchn_pending_sel);
- /* Here atually one window is leaved before selector is cleared.
- * However this window only delay the indication to coming event,
- * nothing losed. Next loop will check I/O channel to fix this
- * window.
- */
- clear_bit(port/BITS_PER_LONG, &v->vcpu_info->evtchn_pending_sel);
- }
- else
- break;
- } while (test_bit(ARCH_VMX_IO_WAIT, &v->arch.arch_vmx.flags));
+ if (&v->vcpu_info->evtchn_pending_sel)
+ set_bit(0, &v->vcpu_info->evtchn_upcall_pending);
}
/*
@@ -110,8 +97,7 @@ void vmx_io_assist(struct vcpu *v)
p->state = STATE_INVALID;
clear_bit(ARCH_VMX_IO_WAIT, &v->arch.arch_vmx.flags);
- } else
- return; /* Spurous event? */
+ }
}
/*
@@ -131,21 +117,15 @@ void vmx_intr_assist(struct vcpu *v)
unsigned long *pend_irr);
int port = iopacket_port(v);
+ if (test_bit(port, &d->shared_info->evtchn_pending[0]) ||
+ test_bit(ARCH_VMX_IO_WAIT, &v->arch.arch_vmx.flags))
+ vmx_wait_io();
+
/* I/O emulation is atomic, so it's impossible to see execution flow
* out of vmx_wait_io, when guest is still waiting for response.
*/
if (test_bit(ARCH_VMX_IO_WAIT, &v->arch.arch_vmx.flags))
panic_domain(vcpu_regs(v),"!!!Bad resume to guest before I/O emulation
is done.\n");
-
- /* Clear indicator specific to interrupt delivered from DM */
- if (test_and_clear_bit(port,
- &d->shared_info->evtchn_pending[0])) {
- if (!d->shared_info->evtchn_pending[port/BITS_PER_LONG])
- clear_bit(port/BITS_PER_LONG, &v->vcpu_info->evtchn_pending_sel);
-
- if (!v->vcpu_info->evtchn_pending_sel)
- clear_bit(0, &v->vcpu_info->evtchn_upcall_pending);
- }
/* Even without event pending, we still need to sync pending bits
* between DM and vlsapic. The reason is that interrupt delivery
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