Hi,
I'm trying to enable a VNIF driver module in an unmodified Redhat
EL3 kernel.
Now, it can work, but after some network communication, the guest kernel
will crash when running some command like ifconfig, tcpdump, ttcp.
For different applications, they are at the different place. but each
time, it is same.
for example, with ifconfig, it is in sock_create():
if ((i = net_families[family]->create(sock, protocol)) < 0)
the net_families[family] is a illegal point, net_families is 0xc03180a0
one problem is I use kernel 2.6.10 as the xen0, Redhat EL3 is 2.4.21
kernel, the backend net driver skb->head is page aligned, but in
netfront.c it is not, like 0xcxxxx800. so I did a workround as following
patch, can this cause problem?
@@ -353,18 +359,20 @@
* ourself and for other kernel subsystems.
*/
batch_target = np->rx_target - (req_prod - np->rx_resp_cons);
- if (unlikely((skb = alloc_xen_skb(dev->mtu + RX_HEADROOM)) ==
NULL))
+ if ( unlikely((skb = alloc_xen_skb(dev->mtu + RX_HEADROOM +
1500)) == NULL) )
break;
__skb_queue_tail(&np->rx_batch, skb);
}
Another main code I did is the do_update_va_mapping hypercall.
I wrote a new implement for unmodified guest domain.
see the patch. anyone can see the problem in it?
(some commented code are what I've ever tried but still same result)
Index: arch/x86/mm.c
===================================================================
--- arch/x86/mm.c (revision 512)
+++ arch/x86/mm.c (working copy)
@@ -1707,7 +1757,14 @@
break;
}
- if ( unlikely(__copy_from_user(&req, ureqs, sizeof(req)) != 0) )
+ if(VMX_DOMAIN(current)){
+ vbdprintk("copy form guest\n");
+ rc = copy_from_guest(&req, ureqs, sizeof(req));
+ }
+ else {
+ rc = __copy_from_user(&req, ureqs, sizeof(req));
+ }
+ if ( unlikely((rc) != 0) )
{
MEM_LOG("Bad __copy_from_user");
rc = -EFAULT;
@@ -1716,7 +1773,7 @@
cmd = req.ptr & (sizeof(l1_pgentry_t)-1);
pfn = req.ptr >> PAGE_SHIFT;
-
+ vbdprintk("req.ptr, cmd, pfn:%x, %x, %x\n", req.ptr, cmd, pfn);
okay = 0;
switch ( cmd )
@@ -1911,7 +1968,92 @@
return rc;
}
+void shadow_map_l1_into_current_l2(unsigned long va);
+int do_update_vmx_va_mapping(unsigned long va,
+ unsigned long val,
+ unsigned long flags)
+{
+ struct exec_domain *ed = current;
+ struct domain *d = ed->domain;
+ int err = 0;
+ unsigned int cpu = ed->processor;
+ unsigned long deferred_ops;
+ unsigned long gpa;
+ unsigned long sval = 0;
+ vnifprintk("do_update_va_mapping, va:%p, val:%p, flags:%d\n", va,
val, flags);
+ vnifprintk("shadow_mode:%x\n", d->arch.shadow_mode);
+
+ LOCK_BIGLOCK(d);
+
+// cleanup_writable_pagetable(d);
+
+ /*
+ * XXX When we make this support 4MB superpages we should also deal
with
+ * the case of updating L2 entries.
+ */
+
+#if 0
+ gval = val ? ((va - KERNEL_PAGE_OFFSET) & PAGE_MASK) |
+ (val & ~PAGE_MASK) : 0;
+#endif
+
+ gpa = gva_to_gpa(va);
+ if(gpa) {
+ if(val)
+ set_phystomachine(gpa >> PAGE_SHIFT,
+ val >> PAGE_SHIFT);
+ else
+ set_phystomachine(gpa >> PAGE_SHIFT, ~0UL);
+ }
+
+#if 0
+ if ( unlikely(!mod_vmx_l1_entry(va, mk_l1_pgentry(gval))) ) {
+ printk("mod l1 error\n");
+ err = -EINVAL;
+ }
+#endif
+
+ sval = val;
+
+ if((va >> 16) == 0xc031)
+ printk("c031 va:%p\n", va);
+
+ vnifprintk("shadow_mode_enabled:%p, %p\n", val, sval);
+
+ if ( unlikely(__put_user(sval, ((unsigned long *)(
+
&shadow_linear_pg_table[l1_linear_offset(va)])))) )
+ {
+ printk("put_user shadow error:%p %p\n", va, sval,val);
+ printk("spgd:%p\n",
ed->arch.shadow_vtable[va>>L2_PAGETABLE_SHIFT]);
+
+ shadow_map_l1_into_current_l2(va);
+ if(__put_user(sval, ((unsigned long *)(
+ &shadow_linear_pg_table[l1_linear_offset(va)]))))
+ printk("still put_user shadow error:%p %p\n", va, val);
+
+ check_pagetable(d, ed->arch.guest_table, "va"); /* debug */
+ }
+
+ deferred_ops = percpu_info[cpu].deferred_ops;
+ percpu_info[cpu].deferred_ops = 0;
+
+ if ( unlikely(deferred_ops & DOP_FLUSH_TLB) ||
+ unlikely(flags & UVMF_FLUSH_TLB) )
+ local_flush_tlb();
+ else if ( unlikely(flags & UVMF_INVLPG) )
+ __flush_tlb_one(va);
+
+ if ( unlikely(deferred_ops & DOP_RELOAD_LDT) )
+ (void)map_ldt_shadow_page(0);
+
+ UNLOCK_BIGLOCK(d);
+
+ vnifprintk("exit va mapping\n");
+ return err;
+
+}
+
int do_update_va_mapping(unsigned long va,
unsigned long val,
unsigned long flags)
@@ -1924,6 +2066,11 @@
perfc_incrc(calls_to_update_va);
+ if(unlikely(VMX_DOMAIN(ed))) {
+ return do_update_vmx_va_mapping(va, val, flags);
+ }
+
+
if ( unlikely(!__addr_ok(va)) )
return -EINVAL;
@@ -1949,6 +2096,7 @@
l1pte_propagate_from_guest(d, &val, &sval);
+ vnifprintk("shadow_mode_enabled:%p, %p\n", val, sval);
if ( unlikely(__put_user(sval, ((unsigned long *)(
&shadow_linear_pg_table[l1_linear_offset(va)])))) )
{
@@ -2975,3 +3123,5 @@
}
#endif
+
+
Index: include/asm-x86/mm.h
===================================================================
--- include/asm-x86/mm.h (revision 512)
+++ include/asm-x86/mm.h (working copy)
@@ -150,6 +150,9 @@
free_domheap_page(page);
}
+#ifndef vnifprintk
+#define vnifprintk(_a...)
+#endif
static inline int get_page(struct pfn_info *page,
struct domain *domain)
@@ -252,6 +255,21 @@
mfn = l1_pgentry_to_phys(pte) >> PAGE_SHIFT;
return mfn;
}
+
+static inline unsigned long set_phystomachine(unsigned long pfn,
unsigned long ma)
+{
+ l1_pgentry_t pte;
+ if (__get_user(l1_pgentry_val(pte), (__phys_to_machine_mapping +
pfn))) {
+ return 0;
+ }
+ l1_pgentry_val(pte) = (__pa(ma) & PAGE_MASK) | (l1_pgentry_val(pte)
& ~PAGE_MASK);
+ l1_pgentry_val(pte) = ma << PAGE_SHIFT;
+ if(__put_user(l1_pgentry_val(pte), (__phys_to_machine_mapping +
pfn))) {
+ return 0;
+ }
+ return ma;
+}
+
#define set_machinetophys(_mfn, _pfn) machine_to_phys_mapping[(_mfn)]
= (_pfn)
#define DEFAULT_GDT_ENTRIES (LAST_RESERVED_GDT_ENTRY+1)
-------------------
Ling Xiaofeng(Daniel)
Intel China Software Center.
xfling@xxxxxxxxxxxxxxxxxxxxx
Opinions are my own and don’t represent those of my employer
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