On 8/9/2016 12:29 AM, Jan Beulich wrote:
On 12.07.16 at 11:02, <yu.c.zh...@linux.intel.com> wrote:
@@ -5512,6 +5513,12 @@ static int hvmop_set_mem_type(
if ( rc )
goto out;
+ if ( t == p2m_ram_rw && memtype[a.hvmmem_type] == p2m_ioreq_server )
+ p2m->ioreq.entry_count++;
+
+ if ( t == p2m_ioreq_server && memtype[a.hvmmem_type] == p2m_ram_rw )
+ p2m->ioreq.entry_count--;
+
These (and others below) happen, afaict, outside of any lock, which
can't be right.
How about we make this entry_count as atomic_t and use atomic_inc/dec
instead?
@@ -5530,11 +5537,13 @@ static int hvmop_set_mem_type(
}
static int hvmop_map_mem_type_to_ioreq_server(
- XEN_GUEST_HANDLE_PARAM(xen_hvm_map_mem_type_to_ioreq_server_t) uop)
+ XEN_GUEST_HANDLE_PARAM(xen_hvm_map_mem_type_to_ioreq_server_t) uop,
+ unsigned long *iter)
{
xen_hvm_map_mem_type_to_ioreq_server_t op;
struct domain *d;
int rc;
+ unsigned long gfn = *iter;
if ( copy_from_guest(&op, uop, 1) )
return -EFAULT;
@@ -5559,7 +5568,42 @@ static int hvmop_map_mem_type_to_ioreq_server(
if ( rc != 0 )
goto out;
- rc = hvm_map_mem_type_to_ioreq_server(d, op.id, op.type, op.flags);
+ if ( gfn == 0 || op.flags != 0 )
+ rc = hvm_map_mem_type_to_ioreq_server(d, op.id, op.type, op.flags);
Couldn't you omit the right side of the || in the if()?
Oh right, it is redundant. Thanks! :-)
+ /*
+ * Iterate p2m table when an ioreq server unmaps from p2m_ioreq_server,
+ * and reset the remaining p2m_ioreq_server entries back to p2m_ram_rw.
+ */
+ if ( op.flags == 0 && rc == 0 )
+ {
+ struct p2m_domain *p2m = p2m_get_hostp2m(d);
+
+ while ( gfn <= p2m->max_mapped_pfn )
+ {
+ p2m_type_t t;
+
+ if ( p2m->ioreq.entry_count == 0 )
+ break;
Perhaps better to be moved up into the while() expression?
OK. Another thing is maybe we can use _atomic_read() to get value of
entry_count if
the counter is defined as atomic_t?
+ get_gfn_unshare(d, gfn, &t);
+
+ if ( (t == p2m_ioreq_server) &&
+ !(p2m_change_type_one(d, gfn, t, p2m_ram_rw)) )
Stray parentheses.
Got it. Thanks!
+ p2m->ioreq.entry_count--;
+
+ put_gfn(d, gfn);
+
+ /* Check for continuation if it's not the last iteration. */
+ if ( ++gfn <= p2m->max_mapped_pfn &&
+ !(gfn & HVMOP_op_mask) &&
+ hypercall_preempt_check() )
+ {
+ rc = -ERESTART;
+ goto out;
I think you need to write gfn back to *iter.
Yes, thanks for pointing out.
Yu
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