From: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
To: gleb@redhat.com
Cc: avi.kivity@gmail.com, mtosatti@redhat.com, pbonzini@redhat.com,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Subject: [PATCH v3 15/15] KVM: MMU: use rcu functions to access the pointer
Date: Wed, 23 Oct 2013 21:29:33 +0800 [thread overview]
Message-ID: <1382534973-13197-16-git-send-email-xiaoguangrong@linux.vnet.ibm.com> (raw)
In-Reply-To: <1382534973-13197-1-git-send-email-xiaoguangrong@linux.vnet.ibm.com>
Use rcu_assign_pointer() to update all the pointer in desc
and use rcu_dereference() to lockless read the pointer
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
---
arch/x86/kvm/mmu.c | 46 ++++++++++++++++++++++++++++------------------
1 file changed, 28 insertions(+), 18 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 3e4b941..68dac26 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -937,12 +937,23 @@ static void pte_list_desc_ctor(void *p)
desc->more = NULL;
}
+#define rcu_assign_pte_list(pte_list_p, value) \
+ rcu_assign_pointer(*(unsigned long __rcu **)(pte_list_p), \
+ (unsigned long *)(value))
+
+#define rcu_assign_desc_more(morep, value) \
+ rcu_assign_pointer(*(unsigned long __rcu **)&morep, \
+ (unsigned long *)value)
+
+#define rcu_assign_spte(sptep, value) \
+ rcu_assign_pointer(*(u64 __rcu **)&sptep, (u64 *)value)
+
static void desc_mark_nulls(unsigned long *pte_list, struct pte_list_desc *desc)
{
unsigned long marker;
marker = (unsigned long)pte_list | 1UL;
- desc->more = (struct pte_list_desc *)marker;
+ rcu_assign_desc_more(desc->more, (struct pte_list_desc *)marker);
}
static bool desc_is_a_nulls(struct pte_list_desc *desc)
@@ -999,10 +1010,6 @@ static int count_spte_number(struct pte_list_desc *desc)
return first_free + desc_num * PTE_LIST_EXT;
}
-#define rcu_assign_pte_list(pte_list_p, value) \
- rcu_assign_pointer(*(unsigned long __rcu **)(pte_list_p), \
- (unsigned long *)(value))
-
/*
* Pte mapping structures:
*
@@ -1029,8 +1036,8 @@ static int pte_list_add(struct kvm_vcpu *vcpu, u64 *spte,
if (!(*pte_list & 1)) {
rmap_printk("pte_list_add: %p %llx 1->many\n", spte, *spte);
desc = mmu_alloc_pte_list_desc(vcpu);
- desc->sptes[0] = (u64 *)*pte_list;
- desc->sptes[1] = spte;
+ rcu_assign_spte(desc->sptes[0], *pte_list);
+ rcu_assign_spte(desc->sptes[1], spte);
desc_mark_nulls(pte_list, desc);
rcu_assign_pte_list(pte_list, (unsigned long)desc | 1);
return 1;
@@ -1043,13 +1050,13 @@ static int pte_list_add(struct kvm_vcpu *vcpu, u64 *spte,
if (desc->sptes[PTE_LIST_EXT - 1]) {
struct pte_list_desc *new_desc;
new_desc = mmu_alloc_pte_list_desc(vcpu);
- new_desc->more = desc;
+ rcu_assign_desc_more(new_desc->more, desc);
desc = new_desc;
rcu_assign_pte_list(pte_list, (unsigned long)desc | 1);
}
free_pos = find_first_free(desc);
- desc->sptes[free_pos] = spte;
+ rcu_assign_spte(desc->sptes[free_pos], spte);
return count_spte_number(desc) - 1;
}
@@ -1067,8 +1074,8 @@ pte_list_desc_remove_entry(unsigned long *pte_list,
* Move the entry from the first desc to this position we want
* to remove.
*/
- desc->sptes[i] = first_desc->sptes[last_used];
- first_desc->sptes[last_used] = NULL;
+ rcu_assign_spte(desc->sptes[i], first_desc->sptes[last_used]);
+ rcu_assign_spte(first_desc->sptes[last_used], NULL);
/* No valid entry in this desc, we can free this desc now. */
if (!first_desc->sptes[0]) {
@@ -1080,7 +1087,7 @@ pte_list_desc_remove_entry(unsigned long *pte_list,
WARN_ON(desc_is_a_nulls(next_desc));
mmu_free_pte_list_desc(first_desc);
- *pte_list = (unsigned long)next_desc | 1ul;
+ rcu_assign_pte_list(pte_list, (unsigned long)next_desc | 1ul);
return;
}
@@ -1089,8 +1096,8 @@ pte_list_desc_remove_entry(unsigned long *pte_list,
* then the desc can be freed.
*/
if (!first_desc->sptes[1] && desc_is_a_nulls(first_desc->more)) {
- *pte_list = (unsigned long)first_desc->sptes[0];
- first_desc->sptes[0] = NULL;
+ rcu_assign_pte_list(pte_list, first_desc->sptes[0]);
+ rcu_assign_spte(first_desc->sptes[0], NULL);
mmu_free_pte_list_desc(first_desc);
}
}
@@ -1112,7 +1119,7 @@ static void pte_list_remove(u64 *spte, unsigned long *pte_list)
pr_err("pte_list_remove: %p 1->BUG\n", spte);
BUG();
}
- *pte_list = 0;
+ rcu_assign_pte_list(pte_list, 0);
return;
}
@@ -1184,9 +1191,12 @@ restart:
* used in the rmap when a spte is removed. Otherwise the
* moved entry will be missed.
*/
- for (i = PTE_LIST_EXT - 1; i >= 0; i--)
- if (desc->sptes[i])
- fn(desc->sptes[i]);
+ for (i = PTE_LIST_EXT - 1; i >= 0; i--) {
+ u64 *sptep = rcu_dereference(desc->sptes[i]);
+
+ if (sptep)
+ fn(sptep);
+ }
desc = rcu_dereference(desc->more);
--
1.8.1.4
next prev parent reply other threads:[~2013-10-23 13:30 UTC|newest]
Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-23 13:29 [PATCH v3 00/15] KVM: MMU: locklessly write-protect Xiao Guangrong
2013-10-23 13:29 ` [PATCH v3 01/15] KVM: MMU: properly check last spte in fast_page_fault() Xiao Guangrong
2013-11-12 0:25 ` Marcelo Tosatti
2013-10-23 13:29 ` [PATCH v3 02/15] KVM: MMU: lazily drop large spte Xiao Guangrong
2013-11-12 22:44 ` Marcelo Tosatti
2013-10-23 13:29 ` [PATCH v3 03/15] KVM: MMU: flush tlb if the spte can be locklessly modified Xiao Guangrong
2013-11-13 0:10 ` Marcelo Tosatti
2013-10-23 13:29 ` [PATCH v3 04/15] KVM: MMU: flush tlb out of mmu lock when write-protect the sptes Xiao Guangrong
2013-11-14 0:36 ` Marcelo Tosatti
2013-11-14 5:15 ` Xiao Guangrong
2013-11-14 18:39 ` Marcelo Tosatti
2013-11-15 7:09 ` Xiao Guangrong
2013-11-19 0:19 ` Marcelo Tosatti
2013-10-23 13:29 ` [PATCH v3 05/15] KVM: MMU: update spte and add it into rmap before dirty log Xiao Guangrong
2013-11-15 0:08 ` Marcelo Tosatti
2013-10-23 13:29 ` [PATCH v3 06/15] KVM: MMU: redesign the algorithm of pte_list Xiao Guangrong
2013-11-19 0:48 ` Marcelo Tosatti
2013-10-23 13:29 ` [PATCH v3 07/15] KVM: MMU: introduce nulls desc Xiao Guangrong
2013-11-22 19:14 ` Marcelo Tosatti
2013-11-25 6:11 ` Xiao Guangrong
2013-11-25 6:29 ` Xiao Guangrong
2013-11-25 18:12 ` Marcelo Tosatti
2013-11-26 3:21 ` Xiao Guangrong
2013-11-26 10:12 ` Gleb Natapov
2013-11-26 19:31 ` Marcelo Tosatti
2013-11-28 8:53 ` Xiao Guangrong
2013-12-03 7:10 ` Xiao Guangrong
2013-12-05 13:50 ` Marcelo Tosatti
2013-12-05 15:30 ` Xiao Guangrong
2013-12-06 0:15 ` Marcelo Tosatti
2013-12-06 0:22 ` Marcelo Tosatti
2013-12-10 6:58 ` Xiao Guangrong
2013-11-25 10:19 ` Gleb Natapov
2013-11-25 10:25 ` Xiao Guangrong
2013-11-25 12:48 ` Avi Kivity
2013-11-25 14:23 ` Marcelo Tosatti
2013-11-25 14:29 ` Gleb Natapov
2013-11-25 18:06 ` Marcelo Tosatti
2013-11-26 3:10 ` Xiao Guangrong
2013-11-26 10:15 ` Gleb Natapov
2013-11-26 19:58 ` Marcelo Tosatti
2013-11-28 8:32 ` Xiao Guangrong
2013-11-25 14:08 ` Marcelo Tosatti
2013-11-26 3:02 ` Xiao Guangrong
2013-11-25 9:31 ` Peter Zijlstra
2013-11-25 10:59 ` Xiao Guangrong
2013-11-25 11:05 ` Peter Zijlstra
2013-11-25 11:29 ` Peter Zijlstra
2013-10-23 13:29 ` [PATCH v3 08/15] KVM: MMU: introduce pte-list lockless walker Xiao Guangrong
2013-10-23 13:29 ` [PATCH v3 09/15] KVM: MMU: initialize the pointers in pte_list_desc properly Xiao Guangrong
2013-10-23 13:29 ` [PATCH v3 10/15] KVM: MMU: allocate shadow pages from slab Xiao Guangrong
2013-10-24 9:19 ` Gleb Natapov
2013-10-24 9:29 ` Xiao Guangrong
2013-10-24 9:52 ` Gleb Natapov
2013-10-24 10:10 ` Xiao Guangrong
2013-10-24 10:39 ` Gleb Natapov
2013-10-24 11:01 ` Xiao Guangrong
2013-10-24 12:32 ` Gleb Natapov
2013-10-28 3:16 ` Xiao Guangrong
2013-10-23 13:29 ` [PATCH v3 11/15] KVM: MMU: locklessly access shadow page under rcu protection Xiao Guangrong
2013-10-23 13:29 ` [PATCH v3 12/15] KVM: MMU: check last spte with unawareness of mapping level Xiao Guangrong
2013-10-23 13:29 ` [PATCH v3 13/15] KVM: MMU: locklessly write-protect the page Xiao Guangrong
2013-10-24 9:17 ` Gleb Natapov
2013-10-24 9:24 ` Xiao Guangrong
2013-10-24 9:32 ` Gleb Natapov
2013-10-23 13:29 ` [PATCH v3 14/15] KVM: MMU: clean up spte_write_protect Xiao Guangrong
2013-10-23 13:29 ` Xiao Guangrong [this message]
2013-11-03 12:29 ` [PATCH v3 00/15] KVM: MMU: locklessly write-protect Gleb Natapov
2013-11-11 5:33 ` Xiao Guangrong
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