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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [RFC PATCH 01/10] xen: pci: add per-domain pci list lock
domain->pdevs_lock protects access to domain->pdev_list.
As this, it should be used when we are adding, removing on enumerating
PCI devices assigned to a domain.
This enables more granular locking instead of one huge pcidevs_lock that
locks entire PCI subsystem. Please note that pcidevs_lock() is still
used, we are going to remove it in subsequent patches.
Signed-off-by: Volodymyr Babchuk <volodymyr_babchuk@xxxxxxxx>
---
xen/common/domain.c | 1 +
xen/drivers/passthrough/amd/iommu_cmd.c | 4 ++-
xen/drivers/passthrough/amd/pci_amd_iommu.c | 7 ++++-
xen/drivers/passthrough/pci.c | 29 ++++++++++++++++++++-
xen/drivers/passthrough/vtd/iommu.c | 9 +++++--
xen/drivers/vpci/header.c | 3 +++
xen/drivers/vpci/msi.c | 7 ++++-
xen/drivers/vpci/vpci.c | 4 +--
xen/include/xen/pci.h | 2 +-
xen/include/xen/sched.h | 1 +
10 files changed, 58 insertions(+), 9 deletions(-)
diff --git a/xen/common/domain.c b/xen/common/domain.c
index 7062393e37..4611141b87 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -618,6 +618,7 @@ struct domain *domain_create(domid_t domid,
#ifdef CONFIG_HAS_PCI
INIT_LIST_HEAD(&d->pdev_list);
+ spin_lock_init(&d->pdevs_lock);
#endif
/* All error paths can depend on the above setup. */
diff --git a/xen/drivers/passthrough/amd/iommu_cmd.c
b/xen/drivers/passthrough/amd/iommu_cmd.c
index 40ddf366bb..47c45398d4 100644
--- a/xen/drivers/passthrough/amd/iommu_cmd.c
+++ b/xen/drivers/passthrough/amd/iommu_cmd.c
@@ -308,11 +308,12 @@ void amd_iommu_flush_iotlb(u8 devfn, const struct pci_dev
*pdev,
flush_command_buffer(iommu, iommu_dev_iotlb_timeout);
}
-static void amd_iommu_flush_all_iotlbs(const struct domain *d, daddr_t daddr,
+static void amd_iommu_flush_all_iotlbs(struct domain *d, daddr_t daddr,
unsigned int order)
{
struct pci_dev *pdev;
+ spin_lock(&d->pdevs_lock);
for_each_pdev( d, pdev )
{
u8 devfn = pdev->devfn;
@@ -323,6 +324,7 @@ static void amd_iommu_flush_all_iotlbs(const struct domain
*d, daddr_t daddr,
} while ( devfn != pdev->devfn &&
PCI_SLOT(devfn) == PCI_SLOT(pdev->devfn) );
}
+ spin_unlock(&d->pdevs_lock);
}
/* Flush iommu cache after p2m changes. */
diff --git a/xen/drivers/passthrough/amd/pci_amd_iommu.c
b/xen/drivers/passthrough/amd/pci_amd_iommu.c
index 4ba8e764b2..64c016491d 100644
--- a/xen/drivers/passthrough/amd/pci_amd_iommu.c
+++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c
@@ -96,20 +96,25 @@ static int __must_check allocate_domain_resources(struct
domain *d)
return rc;
}
-static bool any_pdev_behind_iommu(const struct domain *d,
+static bool any_pdev_behind_iommu(struct domain *d,
const struct pci_dev *exclude,
const struct amd_iommu *iommu)
{
const struct pci_dev *pdev;
+ spin_lock(&d->pdevs_lock);
for_each_pdev ( d, pdev )
{
if ( pdev == exclude )
continue;
if ( find_iommu_for_device(pdev->seg, pdev->sbdf.bdf) == iommu )
+ {
+ spin_unlock(&d->pdevs_lock);
return true;
+ }
}
+ spin_unlock(&d->pdevs_lock);
return false;
}
diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
index cdaf5c247f..4366f8f965 100644
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -523,7 +523,9 @@ static void __init _pci_hide_device(struct pci_dev *pdev)
if ( pdev->domain )
return;
pdev->domain = dom_xen;
+ spin_lock(&dom_xen->pdevs_lock);
list_add(&pdev->domain_list, &dom_xen->pdev_list);
+ spin_unlock(&dom_xen->pdevs_lock);
}
int __init pci_hide_device(unsigned int seg, unsigned int bus,
@@ -595,7 +597,7 @@ struct pci_dev *pci_get_real_pdev(pci_sbdf_t sbdf)
return pdev;
}
-struct pci_dev *pci_get_pdev(const struct domain *d, pci_sbdf_t sbdf)
+struct pci_dev *pci_get_pdev(struct domain *d, pci_sbdf_t sbdf)
{
struct pci_dev *pdev;
@@ -620,9 +622,16 @@ struct pci_dev *pci_get_pdev(const struct domain *d,
pci_sbdf_t sbdf)
return pdev;
}
else
+ {
+ spin_lock(&d->pdevs_lock);
list_for_each_entry ( pdev, &d->pdev_list, domain_list )
if ( pdev->sbdf.bdf == sbdf.bdf )
+ {
+ spin_unlock(&d->pdevs_lock);
return pdev;
+ }
+ spin_unlock(&d->pdevs_lock);
+ }
return NULL;
}
@@ -817,7 +826,9 @@ int pci_add_device(u16 seg, u8 bus, u8 devfn,
if ( !pdev->domain )
{
pdev->domain = hardware_domain;
+ spin_lock(&hardware_domain->pdevs_lock);
list_add(&pdev->domain_list, &hardware_domain->pdev_list);
+ spin_unlock(&hardware_domain->pdevs_lock);
/*
* For devices not discovered by Xen during boot, add vPCI handlers
@@ -827,7 +838,9 @@ int pci_add_device(u16 seg, u8 bus, u8 devfn,
if ( ret )
{
printk(XENLOG_ERR "Setup of vPCI failed: %d\n", ret);
+ spin_lock(&pdev->domain->pdevs_lock);
list_del(&pdev->domain_list);
+ spin_unlock(&pdev->domain->pdevs_lock);
pdev->domain = NULL;
goto out;
}
@@ -835,7 +848,9 @@ int pci_add_device(u16 seg, u8 bus, u8 devfn,
if ( ret )
{
vpci_remove_device(pdev);
+ spin_lock(&pdev->domain->pdevs_lock);
list_del(&pdev->domain_list);
+ spin_unlock(&pdev->domain->pdevs_lock);
pdev->domain = NULL;
goto out;
}
@@ -885,7 +900,11 @@ int pci_remove_device(u16 seg, u8 bus, u8 devfn)
pci_cleanup_msi(pdev);
ret = iommu_remove_device(pdev);
if ( pdev->domain )
+ {
+ spin_lock(&pdev->domain->pdevs_lock);
list_del(&pdev->domain_list);
+ spin_unlock(&pdev->domain->pdevs_lock);
+ }
printk(XENLOG_DEBUG "PCI remove device %pp\n", &pdev->sbdf);
free_pdev(pseg, pdev);
break;
@@ -967,12 +986,14 @@ int pci_release_devices(struct domain *d)
pcidevs_unlock();
return ret;
}
+ spin_lock(&d->pdevs_lock);
list_for_each_entry_safe ( pdev, tmp, &d->pdev_list, domain_list )
{
bus = pdev->bus;
devfn = pdev->devfn;
ret = deassign_device(d, pdev->seg, bus, devfn) ?: ret;
}
+ spin_unlock(&d->pdevs_lock);
pcidevs_unlock();
return ret;
@@ -1194,7 +1215,9 @@ static int __hwdom_init cf_check _setup_hwdom_pci_devices(
if ( !pdev->domain )
{
pdev->domain = ctxt->d;
+ spin_lock(&pdev->domain->pdevs_lock);
list_add(&pdev->domain_list, &ctxt->d->pdev_list);
+ spin_unlock(&pdev->domain->pdevs_lock);
setup_one_hwdom_device(ctxt, pdev);
}
else if ( pdev->domain == dom_xen )
@@ -1556,6 +1579,7 @@ static int iommu_get_device_group(
return group_id;
pcidevs_lock();
+ spin_lock(&d->pdevs_lock);
for_each_pdev( d, pdev )
{
unsigned int b = pdev->bus;
@@ -1571,6 +1595,7 @@ static int iommu_get_device_group(
if ( sdev_id < 0 )
{
pcidevs_unlock();
+ spin_unlock(&d->pdevs_lock);
return sdev_id;
}
@@ -1581,6 +1606,7 @@ static int iommu_get_device_group(
if ( unlikely(copy_to_guest_offset(buf, i, &bdf, 1)) )
{
pcidevs_unlock();
+ spin_unlock(&d->pdevs_lock);
return -EFAULT;
}
i++;
@@ -1588,6 +1614,7 @@ static int iommu_get_device_group(
}
pcidevs_unlock();
+ spin_unlock(&d->pdevs_lock);
return i;
}
diff --git a/xen/drivers/passthrough/vtd/iommu.c
b/xen/drivers/passthrough/vtd/iommu.c
index 62e143125d..fff1442265 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -183,12 +183,13 @@ static void cleanup_domid_map(domid_t domid, struct
vtd_iommu *iommu)
}
}
-static bool any_pdev_behind_iommu(const struct domain *d,
+static bool any_pdev_behind_iommu(struct domain *d,
const struct pci_dev *exclude,
const struct vtd_iommu *iommu)
{
const struct pci_dev *pdev;
+ spin_lock(&d->pdevs_lock);
for_each_pdev ( d, pdev )
{
const struct acpi_drhd_unit *drhd;
@@ -198,8 +199,12 @@ static bool any_pdev_behind_iommu(const struct domain *d,
drhd = acpi_find_matched_drhd_unit(pdev);
if ( drhd && drhd->iommu == iommu )
+ {
+ spin_unlock(&d->pdevs_lock);
return true;
+ }
}
+ spin_unlock(&d->pdevs_lock);
return false;
}
@@ -208,7 +213,7 @@ static bool any_pdev_behind_iommu(const struct domain *d,
* If no other devices under the same iommu owned by this domain,
* clear iommu in iommu_bitmap and clear domain_id in domid_bitmap.
*/
-static void check_cleanup_domid_map(const struct domain *d,
+static void check_cleanup_domid_map(struct domain *d,
const struct pci_dev *exclude,
struct vtd_iommu *iommu)
{
diff --git a/xen/drivers/vpci/header.c b/xen/drivers/vpci/header.c
index a1c928a0d2..a59aa7ad0b 100644
--- a/xen/drivers/vpci/header.c
+++ b/xen/drivers/vpci/header.c
@@ -267,6 +267,7 @@ static int modify_bars(const struct pci_dev *pdev, uint16_t
cmd, bool rom_only)
* Check for overlaps with other BARs. Note that only BARs that are
* currently mapped (enabled) are checked for overlaps.
*/
+ spin_lock(&pdev->domain->pdevs_lock);
for_each_pdev ( pdev->domain, tmp )
{
if ( tmp == pdev )
@@ -306,11 +307,13 @@ static int modify_bars(const struct pci_dev *pdev,
uint16_t cmd, bool rom_only)
printk(XENLOG_G_WARNING "Failed to remove [%lx, %lx]: %d\n",
start, end, rc);
rangeset_destroy(mem);
+ spin_unlock( &pdev->domain->pdevs_lock);
return rc;
}
}
}
+ spin_unlock( &pdev->domain->pdevs_lock);
ASSERT(dev);
if ( system_state < SYS_STATE_active )
diff --git a/xen/drivers/vpci/msi.c b/xen/drivers/vpci/msi.c
index 8f2b59e61a..8969c335b0 100644
--- a/xen/drivers/vpci/msi.c
+++ b/xen/drivers/vpci/msi.c
@@ -265,7 +265,7 @@ REGISTER_VPCI_INIT(init_msi, VPCI_PRIORITY_LOW);
void vpci_dump_msi(void)
{
- const struct domain *d;
+ struct domain *d;
rcu_read_lock(&domlist_read_lock);
for_each_domain ( d )
@@ -277,6 +277,9 @@ void vpci_dump_msi(void)
printk("vPCI MSI/MSI-X d%d\n", d->domain_id);
+ if ( !spin_trylock(&d->pdevs_lock) )
+ continue;
+
for_each_pdev ( d, pdev )
{
const struct vpci_msi *msi;
@@ -326,6 +329,8 @@ void vpci_dump_msi(void)
spin_unlock(&pdev->vpci->lock);
process_pending_softirqs();
}
+ spin_unlock(&d->pdevs_lock);
+
}
rcu_read_unlock(&domlist_read_lock);
}
diff --git a/xen/drivers/vpci/vpci.c b/xen/drivers/vpci/vpci.c
index 3467c0de86..7d1f9fd438 100644
--- a/xen/drivers/vpci/vpci.c
+++ b/xen/drivers/vpci/vpci.c
@@ -312,7 +312,7 @@ static uint32_t merge_result(uint32_t data, uint32_t new,
unsigned int size,
uint32_t vpci_read(pci_sbdf_t sbdf, unsigned int reg, unsigned int size)
{
- const struct domain *d = current->domain;
+ struct domain *d = current->domain;
const struct pci_dev *pdev;
const struct vpci_register *r;
unsigned int data_offset = 0;
@@ -415,7 +415,7 @@ static void vpci_write_helper(const struct pci_dev *pdev,
void vpci_write(pci_sbdf_t sbdf, unsigned int reg, unsigned int size,
uint32_t data)
{
- const struct domain *d = current->domain;
+ struct domain *d = current->domain;
const struct pci_dev *pdev;
const struct vpci_register *r;
unsigned int data_offset = 0;
diff --git a/xen/include/xen/pci.h b/xen/include/xen/pci.h
index 5975ca2f30..19047b4b20 100644
--- a/xen/include/xen/pci.h
+++ b/xen/include/xen/pci.h
@@ -177,7 +177,7 @@ int pci_add_device(u16 seg, u8 bus, u8 devfn,
int pci_remove_device(u16 seg, u8 bus, u8 devfn);
int pci_ro_device(int seg, int bus, int devfn);
int pci_hide_device(unsigned int seg, unsigned int bus, unsigned int devfn);
-struct pci_dev *pci_get_pdev(const struct domain *d, pci_sbdf_t sbdf);
+struct pci_dev *pci_get_pdev(struct domain *d, pci_sbdf_t sbdf);
struct pci_dev *pci_get_real_pdev(pci_sbdf_t sbdf);
void pci_check_disable_device(u16 seg, u8 bus, u8 devfn);
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 1cf629e7ec..0775228ba9 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -457,6 +457,7 @@ struct domain
#ifdef CONFIG_HAS_PCI
struct list_head pdev_list;
+ spinlock_t pdevs_lock;
#endif
#ifdef CONFIG_HAS_PASSTHROUGH
--
2.36.1
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