# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1236766161 0
# Node ID e6b7b747d122c6640a52b50a562bb44d457ee815
# Parent 07042b677ba4bfa5523fdd6bc34180724835934c
passthrough: fix some spinlock issues in vmsi
Apart from efficiency, I hasten to fix the assertion failure.
- acquire pcidevs_lock before calling pt_irq_xxx_bind_vtd
- allocate msixtbl_entry beforehand
- check return value from domain_spin_lock_irq_desc()
- typo: spin_unlock(&irq_desc->lock) ->
- spin_unlock_irq(&irq_desc->lock)
- acquire msixtbl_list_lock with irq_disabled
Signed-off-by: Kouya Shimura <kouya@xxxxxxxxxxxxxx>
---
xen/arch/x86/domctl.c | 8 ++++++
xen/arch/x86/hvm/vmsi.c | 56 ++++++++++++++++++++++++++++--------------------
2 files changed, 41 insertions(+), 23 deletions(-)
diff -r 07042b677ba4 -r e6b7b747d122 xen/arch/x86/domctl.c
--- a/xen/arch/x86/domctl.c Wed Mar 11 10:08:31 2009 +0000
+++ b/xen/arch/x86/domctl.c Wed Mar 11 10:09:21 2009 +0000
@@ -764,7 +764,11 @@ long arch_do_domctl(
ret = -ESRCH;
if ( iommu_enabled )
+ {
+ spin_lock(&pcidevs_lock);
ret = pt_irq_create_bind_vtd(d, bind);
+ spin_unlock(&pcidevs_lock);
+ }
if ( ret < 0 )
gdprintk(XENLOG_ERR, "pt_irq_create_bind failed!\n");
@@ -783,7 +787,11 @@ long arch_do_domctl(
break;
bind = &(domctl->u.bind_pt_irq);
if ( iommu_enabled )
+ {
+ spin_lock(&pcidevs_lock);
ret = pt_irq_destroy_bind_vtd(d, bind);
+ spin_unlock(&pcidevs_lock);
+ }
if ( ret < 0 )
gdprintk(XENLOG_ERR, "pt_irq_destroy_bind failed!\n");
rcu_unlock_domain(d);
diff -r 07042b677ba4 -r e6b7b747d122 xen/arch/x86/hvm/vmsi.c
--- a/xen/arch/x86/hvm/vmsi.c Wed Mar 11 10:08:31 2009 +0000
+++ b/xen/arch/x86/hvm/vmsi.c Wed Mar 11 10:09:21 2009 +0000
@@ -336,16 +336,12 @@ struct hvm_mmio_handler msixtbl_mmio_han
.write_handler = msixtbl_write
};
-static struct msixtbl_entry *add_msixtbl_entry(struct domain *d,
- struct pci_dev *pdev,
- uint64_t gtable)
-{
- struct msixtbl_entry *entry;
+static void add_msixtbl_entry(struct domain *d,
+ struct pci_dev *pdev,
+ uint64_t gtable,
+ struct msixtbl_entry *entry)
+{
u32 len;
-
- entry = xmalloc(struct msixtbl_entry);
- if ( !entry )
- return NULL;
memset(entry, 0, sizeof(struct msixtbl_entry));
@@ -359,8 +355,6 @@ static struct msixtbl_entry *add_msixtbl
entry->gtable = (unsigned long) gtable;
list_add_rcu(&entry->list, &d->arch.hvm_domain.msixtbl_list);
-
- return entry;
}
static void free_msixtbl_entry(struct rcu_head *rcu)
@@ -383,12 +377,25 @@ int msixtbl_pt_register(struct domain *d
irq_desc_t *irq_desc;
struct msi_desc *msi_desc;
struct pci_dev *pdev;
- struct msixtbl_entry *entry;
+ struct msixtbl_entry *entry, *new_entry;
int r = -EINVAL;
ASSERT(spin_is_locked(&pcidevs_lock));
+ /*
+ * xmalloc() with irq_disabled causes the failure of check_lock()
+ * for xenpool->lock. So we allocate an entry beforehand.
+ */
+ new_entry = xmalloc(struct msixtbl_entry);
+ if ( !new_entry )
+ return -ENOMEM;
+
irq_desc = domain_spin_lock_irq_desc(d, pirq, NULL);
+ if ( !irq_desc )
+ {
+ xfree(new_entry);
+ return r;
+ }
if ( irq_desc->handler != &pci_msi_type )
goto out;
@@ -405,12 +412,9 @@ int msixtbl_pt_register(struct domain *d
if ( pdev == entry->pdev )
goto found;
- entry = add_msixtbl_entry(d, pdev, gtable);
- if ( !entry )
- {
- spin_unlock(&d->arch.hvm_domain.msixtbl_list_lock);
- goto out;
- }
+ entry = new_entry;
+ new_entry = NULL;
+ add_msixtbl_entry(d, pdev, gtable, entry);
found:
atomic_inc(&entry->refcnt);
@@ -419,8 +423,8 @@ found:
out:
spin_unlock_irq(&irq_desc->lock);
+ xfree(new_entry);
return r;
-
}
void msixtbl_pt_unregister(struct domain *d, int pirq)
@@ -433,6 +437,8 @@ void msixtbl_pt_unregister(struct domain
ASSERT(spin_is_locked(&pcidevs_lock));
irq_desc = domain_spin_lock_irq_desc(d, pirq, NULL);
+ if ( !irq_desc )
+ return;
if ( irq_desc->handler != &pci_msi_type )
goto out;
@@ -453,7 +459,7 @@ void msixtbl_pt_unregister(struct domain
out:
- spin_unlock(&irq_desc->lock);
+ spin_unlock_irq(&irq_desc->lock);
return;
found:
@@ -461,13 +467,16 @@ found:
del_msixtbl_entry(entry);
spin_unlock(&d->arch.hvm_domain.msixtbl_list_lock);
- spin_unlock(&irq_desc->lock);
+ spin_unlock_irq(&irq_desc->lock);
}
void msixtbl_pt_cleanup(struct domain *d, int pirq)
{
struct msixtbl_entry *entry, *temp;
-
+ unsigned long flags;
+
+ /* msixtbl_list_lock must be acquired with irq_disabled for check_lock() */
+ local_irq_save(flags);
spin_lock(&d->arch.hvm_domain.msixtbl_list_lock);
list_for_each_entry_safe( entry, temp,
@@ -475,4 +484,5 @@ void msixtbl_pt_cleanup(struct domain *d
del_msixtbl_entry(entry);
spin_unlock(&d->arch.hvm_domain.msixtbl_list_lock);
-}
+ local_irq_restore(flags);
+}
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