Sorry I forgot the last qref before building. I found missing this rcu_unlock
before sending, but wrongly changed as pt_dom == d. I changed that when found
build error but forgot qref.
Attached is the new one, please have a look.
Thanks
Yunhong Jiang
Currently MMU_PT_UPDATE_RESERVE_AD support only update page table for current
domain. This patch add support for foreign domain also.
Signed-off-by: Jiang, Yunhong <yunhong.jiang@xxxxxxxxx>
diff -r 9a74617c4a28 xen/arch/x86/mm.c
--- a/xen/arch/x86/mm.c Tue Jun 30 01:44:30 2009 +0800
+++ b/xen/arch/x86/mm.c Tue Jun 30 19:02:38 2009 +0800
@@ -110,6 +110,7 @@
#include <asm/hypercall.h>
#include <asm/shared.h>
#include <public/memory.h>
+#include <public/sched.h>
#include <xsm/xsm.h>
#include <xen/trace.h>
@@ -2999,8 +3000,9 @@ int do_mmu_update(
unsigned long gpfn, gmfn, mfn;
struct page_info *page;
int rc = 0, okay = 1, i = 0;
- unsigned int cmd, done = 0;
- struct domain *d = current->domain;
+ unsigned int cmd, done = 0, pt_dom;
+ struct domain *d = current->domain, *pt_owner = NULL;
+ struct vcpu *v = current;
struct domain_mmap_cache mapcache;
if ( unlikely(count & MMU_UPDATE_PREEMPTED) )
@@ -3018,7 +3020,28 @@ int do_mmu_update(
goto out;
}
- if ( !set_foreigndom(foreigndom) )
+ pt_dom = foreigndom >> 16;
+ if (pt_dom)
+ {
+ /* the page table belongs to foreign domain */
+ pt_owner = rcu_lock_domain_by_id(pt_dom - 1);
+ if (!pt_owner )
+ {
+ rc = -EINVAL;
+ goto out;
+ }
+ if( !IS_PRIV_FOR(d, pt_owner) )
+ {
+ rc = -ESRCH;
+ goto out;
+ }
+ if (pt_owner == d)
+ rcu_unlock_domain(pt_owner);
+ v = pt_owner->vcpu[0];
+ } else
+ pt_owner = d;
+
+ if ( !set_foreigndom(foreigndom & 0xFFFFU) )
{
rc = -ESRCH;
goto out;
@@ -3059,9 +3082,9 @@ int do_mmu_update(
req.ptr -= cmd;
gmfn = req.ptr >> PAGE_SHIFT;
- mfn = gmfn_to_mfn(d, gmfn);
-
- if ( unlikely(!get_page_from_pagenr(mfn, d)) )
+ mfn = gmfn_to_mfn(pt_owner, gmfn);
+
+ if ( unlikely(!get_page_from_pagenr(mfn, pt_owner)) )
{
MEM_LOG("Could not get page for normal update");
break;
@@ -3080,24 +3103,21 @@ int do_mmu_update(
{
l1_pgentry_t l1e = l1e_from_intpte(req.val);
okay = mod_l1_entry(va, l1e, mfn,
- cmd == MMU_PT_UPDATE_PRESERVE_AD,
- current);
+ cmd == MMU_PT_UPDATE_PRESERVE_AD, v);
}
break;
case PGT_l2_page_table:
{
l2_pgentry_t l2e = l2e_from_intpte(req.val);
okay = mod_l2_entry(va, l2e, mfn,
- cmd == MMU_PT_UPDATE_PRESERVE_AD,
- current);
+ cmd == MMU_PT_UPDATE_PRESERVE_AD, v);
}
break;
case PGT_l3_page_table:
{
l3_pgentry_t l3e = l3e_from_intpte(req.val);
rc = mod_l3_entry(va, l3e, mfn,
- cmd == MMU_PT_UPDATE_PRESERVE_AD, 1,
- current);
+ cmd == MMU_PT_UPDATE_PRESERVE_AD, 1, v);
okay = !rc;
}
break;
@@ -3106,8 +3126,7 @@ int do_mmu_update(
{
l4_pgentry_t l4e = l4e_from_intpte(req.val);
rc = mod_l4_entry(va, l4e, mfn,
- cmd == MMU_PT_UPDATE_PRESERVE_AD, 1,
- current);
+ cmd == MMU_PT_UPDATE_PRESERVE_AD, 1, v);
okay = !rc;
}
break;
@@ -3115,7 +3134,7 @@ int do_mmu_update(
case PGT_writable_page:
perfc_incr(writable_mmu_updates);
okay = paging_write_guest_entry(
- current, va, req.val, _mfn(mfn));
+ v, va, req.val, _mfn(mfn));
break;
}
page_unlock(page);
@@ -3126,7 +3145,7 @@ int do_mmu_update(
{
perfc_incr(writable_mmu_updates);
okay = paging_write_guest_entry(
- current, va, req.val, _mfn(mfn));
+ v, va, req.val, _mfn(mfn));
put_page_type(page);
}
@@ -3191,6 +3210,9 @@ int do_mmu_update(
perfc_add(num_page_updates, i);
out:
+ if (pt_owner && (pt_owner != d))
+ rcu_unlock_domain(pt_owner);
+
/* Add incremental work we have done to the @done output parameter. */
if ( unlikely(!guest_handle_is_null(pdone)) )
{
diff -r 9a74617c4a28 xen/include/public/xen.h
--- a/xen/include/public/xen.h Tue Jun 30 01:44:30 2009 +0800
+++ b/xen/include/public/xen.h Tue Jun 30 01:44:33 2009 +0800
@@ -166,10 +166,14 @@ DEFINE_XEN_GUEST_HANDLE(xen_pfn_t);
* ptr[1:0] specifies the appropriate MMU_* command.
*
* ptr[1:0] == MMU_NORMAL_PT_UPDATE:
- * Updates an entry in a page table. If updating an L1 table, and the new
+ * Updates an entry in a page table.
+ * The page table can be owned by current domain, or a foreign domain. If
+ * the page table belongs to a foreign domain, it should be specified in
+ * upper 16 bits in FD
+ * If updating an L1 table, and the new
* table entry is valid/present, the mapped frame must belong to the FD, if
- * an FD has been specified. If attempting to map an I/O page then the
- * caller assumes the privilege of the FD.
+ * an foreign domain specified in lower 16 btis in FD. If attempting to map
+ * an I/O page then the caller assumes the privilege of the FD.
* FD == DOMID_IO: Permit /only/ I/O mappings, at the priv level of the caller.
* FD == DOMID_XEN: Map restricted areas of Xen's heap space.
* ptr[:2] -- Machine address of the page-table entry to modify.
Keir Fraser wrote:
> This doesn't even build. You compare a pointer with an integer.
>
> -- Keir
>
> On 30/06/2009 08:58, "Jiang, Yunhong" <yunhong.jiang@xxxxxxxxx> wrote:
>
>> Keir, this is the updated version, please have a look on it.
>>
>> Thanks
>> Yunhong Jiang
>>
>> Currently MMU_PT_UPDATE_RESERVE_AD support only update page table
>> for current domain. This patch add support for foreign domain also.
>>
>> Signed-off-by: Jiang, Yunhong <yunhong.jiang@xxxxxxxxx>
>>
>> diff -r 9a74617c4a28 xen/arch/x86/mm.c
>> --- a/xen/arch/x86/mm.c Tue Jun 30 01:44:30 2009 +0800
>> +++ b/xen/arch/x86/mm.c Tue Jun 30 01:51:15 2009 +0800 @@ -110,6
>> +110,7 @@ #include <asm/hypercall.h>
>> #include <asm/shared.h>
>> #include <public/memory.h>
>> +#include <public/sched.h>
>> #include <xsm/xsm.h>
>> #include <xen/trace.h>
>>
>> @@ -2999,8 +3000,9 @@ int do_mmu_update(
>> unsigned long gpfn, gmfn, mfn;
>> struct page_info *page;
>> int rc = 0, okay = 1, i = 0;
>> - unsigned int cmd, done = 0;
>> - struct domain *d = current->domain;
>> + unsigned int cmd, done = 0, pt_dom;
>> + struct domain *d = current->domain, *pt_owner = NULL;
>> + struct vcpu *v = current;
>> struct domain_mmap_cache mapcache;
>>
>> if ( unlikely(count & MMU_UPDATE_PREEMPTED) )
>> @@ -3018,7 +3020,28 @@ int do_mmu_update(
>> goto out;
>> }
>>
>> - if ( !set_foreigndom(foreigndom) )
>> + pt_dom = foreigndom >> 16;
>> + if (pt_dom)
>> + {
>> + /* the page table belongs to foreign domain */
>> + pt_owner = rcu_lock_domain_by_id(pt_dom - 1); + if
>> (!pt_owner ) + {
>> + rc = -EINVAL;
>> + goto out;
>> + }
>> + if( !IS_PRIV_FOR(d, pt_owner) )
>> + {
>> + rc = -ESRCH;
>> + goto out;
>> + }
>> + if (pt_dom == d)
>> + rcu_unlock_domain(pt_owner);
>> + v = pt_owner->vcpu[0];
>> + } else
>> + pt_owner = d;
>> +
>> + if ( !set_foreigndom(foreigndom & 0xFFFFU) )
>> {
>> rc = -ESRCH;
>> goto out;
>> @@ -3059,9 +3082,9 @@ int do_mmu_update(
>>
>> req.ptr -= cmd;
>> gmfn = req.ptr >> PAGE_SHIFT;
>> - mfn = gmfn_to_mfn(d, gmfn);
>> -
>> - if ( unlikely(!get_page_from_pagenr(mfn, d)) )
>> + mfn = gmfn_to_mfn(pt_owner, gmfn);
>> +
>> + if ( unlikely(!get_page_from_pagenr(mfn, pt_owner)) )
>> { MEM_LOG("Could not get page for normal update");
>> break; @@ -3080,24 +3103,21 @@ int do_mmu_update(
>> {
>> l1_pgentry_t l1e = l1e_from_intpte(req.val);
>> okay = mod_l1_entry(va, l1e, mfn,
>> - cmd ==
>> MMU_PT_UPDATE_PRESERVE_AD,
>> - current);
>> + cmd ==
>> MMU_PT_UPDATE_PRESERVE_AD, v); }
>> break; case PGT_l2_page_table:
>> {
>> l2_pgentry_t l2e = l2e_from_intpte(req.val);
>> okay = mod_l2_entry(va, l2e, mfn,
>> - cmd ==
>> MMU_PT_UPDATE_PRESERVE_AD,
>> - current);
>> + cmd ==
>> MMU_PT_UPDATE_PRESERVE_AD, v); }
>> break; case PGT_l3_page_table:
>> {
>> l3_pgentry_t l3e = l3e_from_intpte(req.val);
>> rc = mod_l3_entry(va, l3e, mfn,
>> - cmd ==
>> MMU_PT_UPDATE_PRESERVE_AD, 1,
>> - current);
>> + cmd ==
>> MMU_PT_UPDATE_PRESERVE_AD, 1, v); okay = !rc;
>> }
>> break;
>> @@ -3106,8 +3126,7 @@ int do_mmu_update(
>> {
>> l4_pgentry_t l4e = l4e_from_intpte(req.val);
>> rc = mod_l4_entry(va, l4e, mfn,
>> - cmd ==
>> MMU_PT_UPDATE_PRESERVE_AD, 1,
>> - current);
>> + cmd ==
>> MMU_PT_UPDATE_PRESERVE_AD, 1, v); okay = !rc;
>> }
>> break;
>> @@ -3115,7 +3134,7 @@ int do_mmu_update(
>> case PGT_writable_page:
>> perfc_incr(writable_mmu_updates);
>> okay = paging_write_guest_entry(
>> - current, va, req.val, _mfn(mfn));
>> + v, va, req.val, _mfn(mfn));
>> break; }
>> page_unlock(page);
>> @@ -3126,7 +3145,7 @@ int do_mmu_update(
>> {
>> perfc_incr(writable_mmu_updates);
>> okay = paging_write_guest_entry(
>> - current, va, req.val, _mfn(mfn));
>> + v, va, req.val, _mfn(mfn));
>> put_page_type(page);
>> }
>>
>> @@ -3191,6 +3210,9 @@ int do_mmu_update(
>> perfc_add(num_page_updates, i);
>>
>> out:
>> + if (pt_owner && (pt_owner != d))
>> + rcu_unlock_domain(pt_owner);
>> +
>> /* Add incremental work we have done to the @done output
>> parameter. */ if ( unlikely(!guest_handle_is_null(pdone)) )
>> {
>> diff -r 9a74617c4a28 xen/include/public/xen.h
>> --- a/xen/include/public/xen.h Tue Jun 30 01:44:30 2009 +0800
>> +++ b/xen/include/public/xen.h Tue Jun 30 01:44:33 2009 +0800
>> @@ -166,10 +166,14 @@ DEFINE_XEN_GUEST_HANDLE(xen_pfn_t);
>> * ptr[1:0] specifies the appropriate MMU_* command. *
>> * ptr[1:0] == MMU_NORMAL_PT_UPDATE:
>> - * Updates an entry in a page table. If updating an L1 table, and
>> the new + * Updates an entry in a page table.
>> + * The page table can be owned by current domain, or a foreign
>> domain. If + * the page table belongs to a foreign domain, it should
>> be specified in + * upper 16 bits in FD + * If updating an L1 table,
>> and the new * table entry is valid/present, the mapped frame must
>> belong to the FD, if
>> - * an FD has been specified. If attempting to map an I/O page then
>> the
>> - * caller assumes the privilege of the FD.
>> + * an foreign domain specified in lower 16 btis in FD. If
>> attempting to map + * an I/O page then the caller assumes the
>> privilege of the FD.
>> * FD == DOMID_IO: Permit /only/ I/O mappings, at the priv level of
>> the caller.
>> * FD == DOMID_XEN: Map restricted areas of Xen's heap space.
>> * ptr[:2] -- Machine address of the page-table entry to modify.
>>
>>
>> Keir Fraser wrote:
>>> On 01/06/2009 10:35, "Jiang, Yunhong"
> <yunhong.jiang@xxxxxxxxx> wrote:
>>>
>>>> I think I missed this logic, I just make sure the domain is
>>>> suspended, but seems be wrong because a suspended domain can still
>>>> be killed and relinquish resources. So I will add this logic and
>>>> resend the patch.
>>>>
>>>> But I'm not sure if we need make sure the guest is suspended/paused
>>>> during these functions, as exchange a page or pte in flight may
>>>> cause trouble. Or we can leave it to user space tools, since this
>>>> situation will not damage xen HV itself.
>>>
>>> The HV should not bother to do the suspend check. It is a
>>> higher-level problem which should be checked by the tools.
>>>
>>> -- Keir
pt_update_v2.patch
Description: pt_update_v2.patch
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