XENMEM_add_to_physmap hypercall on HVM is SMP-unsafe
and may cause a xen crash.
Actually I've met:
(XEN) ia64_fault, vector=0x18, ifa=0xe0000165c98814f0, iip=0xf0000000040a1b80,
ipsr=0x0000121008226010, isr=0x0000008000000030
(XEN) General Exception: IA-64 Reserved Register/Field fault (data access).
...
(XEN) ****************************************
(XEN) Panic on CPU 2:
(XEN) Fault in Xen.
(XEN) ****************************************
This patch fixes it.
Signed-off-by: Kouya Shimura <kouya@xxxxxxxxxxxxxx>
diff -r 08f77df14cba xen/arch/ia64/xen/vhpt.c
--- a/xen/arch/ia64/xen/vhpt.c Wed Jul 02 11:30:37 2008 +0900
+++ b/xen/arch/ia64/xen/vhpt.c Fri Jul 04 09:35:32 2008 +0900
@@ -243,37 +243,34 @@
}
}
+static void __vmx_vcpu_flush_vtlb_all(void *arg)
+{
+ struct vcpu *v = arg;
+
+ BUG_ON(vcpu_runnable(v) || v->is_running);
+ thash_purge_all(v);
+}
+
// SMP: we can't assume v == current, vcpu might move to another physical cpu.
// So memory barrier is necessary.
// if we can guranttee that vcpu can run on only this physical cpu
// (e.g. vcpu == current), smp_mb() is unnecessary.
void vcpu_flush_vtlb_all(struct vcpu *v)
{
- if (VMX_DOMAIN(v)) {
- /* This code may be call for remapping shared_info and
- grant_table share page from guest_physmap_remove_page()
- in arch_memory_op() XENMEM_add_to_physmap to realize
- PV-on-HVM feature. */
- /* FIXME: This is not SMP-safe yet about p2m table */
- /* Purge vTLB for VT-i domain */
- thash_purge_all(v);
- }
- else {
- /* First VCPU tlb. */
- vcpu_purge_tr_entry(&PSCBX(v,dtlb));
- vcpu_purge_tr_entry(&PSCBX(v,itlb));
- smp_mb();
+ /* First VCPU tlb. */
+ vcpu_purge_tr_entry(&PSCBX(v,dtlb));
+ vcpu_purge_tr_entry(&PSCBX(v,itlb));
+ smp_mb();
- /* Then VHPT. */
- if (HAS_PERVCPU_VHPT(v->domain))
- vcpu_vhpt_flush(v);
- else
- local_vhpt_flush();
- smp_mb();
+ /* Then VHPT. */
+ if (HAS_PERVCPU_VHPT(v->domain))
+ vcpu_vhpt_flush(v);
+ else
+ local_vhpt_flush();
+ smp_mb();
- /* Then mTLB. */
- local_flush_tlb_all();
- }
+ /* Then mTLB. */
+ local_flush_tlb_all();
/* We could clear bit in d->domain_dirty_cpumask only if domain d in
not running on this processor. There is currently no easy way to
@@ -296,6 +293,30 @@
for_each_vcpu(d, v) {
if (!v->is_initialised)
continue;
+
+ if (VMX_DOMAIN(v)) {
+ /*
+ * This code may be call for remapping shared_info
+ * and grant_table from guest_physmap_remove_page()
+ * in arch_memory_op() XENMEM_add_to_physmap to realize
+ * PV-on-HVM feature.
+ */
+
+ if (v == current) {
+ /* Purge vTLB for VT-i domain */
+ thash_purge_all(v);
+ continue;
+ }
+
+ vcpu_pause(v);
+ if (v->processor == cpu)
+ thash_purge_all(v);
+ else
+ smp_call_function_single(v->processor,
+ __vmx_vcpu_flush_vtlb_all, v, 1, 1);
+ vcpu_unpause(v);
+ continue;
+ }
if (v->processor == cpu)
vcpu_flush_vtlb_all(v);
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