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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen master] IOMMU: make page table deallocation preemptible
commit cedfdd43a9798e535a05690bb6f01394490d26bb
Author: Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Tue Jan 7 16:01:14 2014 +0100
Commit: Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Jan 7 16:01:14 2014 +0100
IOMMU: make page table deallocation preemptible
This too can take an arbitrary amount of time.
In fact, the bulk of the work is being moved to a tasklet, as handling
the necessary preemption logic in line seems close to impossible given
that the teardown may also be invoked on error paths.
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Acked-by: Xiantao Zhang <xiantao.zhang@xxxxxxxxx>
---
xen/drivers/passthrough/amd/pci_amd_iommu.c | 15 +++++++-
xen/drivers/passthrough/iommu.c | 51 ++++++++++++++++++--------
xen/drivers/passthrough/vtd/iommu.c | 18 ++++++++--
xen/include/xen/iommu.h | 5 +++
4 files changed, 68 insertions(+), 21 deletions(-)
diff --git a/xen/drivers/passthrough/amd/pci_amd_iommu.c
b/xen/drivers/passthrough/amd/pci_amd_iommu.c
index 7241aad..c26aabc 100644
--- a/xen/drivers/passthrough/amd/pci_amd_iommu.c
+++ b/xen/drivers/passthrough/amd/pci_amd_iommu.c
@@ -405,11 +405,21 @@ static int amd_iommu_assign_device(struct domain *d, u8
devfn,
return reassign_device(dom0, d, devfn, pdev);
}
-static void deallocate_next_page_table(struct page_info* pg, int level)
+static void deallocate_next_page_table(struct page_info *pg, int level)
+{
+ PFN_ORDER(pg) = level;
+ spin_lock(&iommu_pt_cleanup_lock);
+ page_list_add_tail(pg, &iommu_pt_cleanup_list);
+ spin_unlock(&iommu_pt_cleanup_lock);
+}
+
+static void deallocate_page_table(struct page_info *pg)
{
void *table_vaddr, *pde;
u64 next_table_maddr;
- int index, next_level;
+ unsigned int index, level = PFN_ORDER(pg), next_level;
+
+ PFN_ORDER(pg) = 0;
if ( level <= 1 )
{
@@ -599,6 +609,7 @@ const struct iommu_ops amd_iommu_ops = {
.teardown = amd_iommu_domain_destroy,
.map_page = amd_iommu_map_page,
.unmap_page = amd_iommu_unmap_page,
+ .free_page_table = deallocate_page_table,
.reassign_device = reassign_device,
.get_device_group_id = amd_iommu_group_id,
.update_ire_from_apic = amd_iommu_ioapic_update_ire,
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index e3b84f4..19b0e23 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -58,6 +58,10 @@ bool_t __read_mostly amd_iommu_perdev_intremap = 1;
DEFINE_PER_CPU(bool_t, iommu_dont_flush_iotlb);
+DEFINE_SPINLOCK(iommu_pt_cleanup_lock);
+PAGE_LIST_HEAD(iommu_pt_cleanup_list);
+static struct tasklet iommu_pt_cleanup_tasklet;
+
static struct keyhandler iommu_p2m_table = {
.diagnostic = 0,
.u.fn = iommu_dump_p2m_table,
@@ -251,6 +255,15 @@ int iommu_remove_device(struct pci_dev *pdev)
return hd->platform_ops->remove_device(pdev->devfn, pdev);
}
+static void iommu_teardown(struct domain *d)
+{
+ const struct hvm_iommu *hd = domain_hvm_iommu(d);
+
+ d->need_iommu = 0;
+ hd->platform_ops->teardown(d);
+ tasklet_schedule(&iommu_pt_cleanup_tasklet);
+}
+
/*
* If the device isn't owned by dom0, it means it already
* has been assigned to other domain, or it doesn't exist.
@@ -325,10 +338,7 @@ static int assign_device(struct domain *d, u16 seg, u8
bus, u8 devfn)
done:
if ( !has_arch_pdevs(d) && need_iommu(d) )
- {
- d->need_iommu = 0;
- hd->platform_ops->teardown(d);
- }
+ iommu_teardown(d);
spin_unlock(&pcidevs_lock);
return rc;
@@ -393,10 +403,7 @@ static int iommu_populate_page_table(struct domain *d)
if ( !rc )
iommu_iotlb_flush_all(d);
else if ( rc != -ERESTART )
- {
- d->need_iommu = 0;
- hd->platform_ops->teardown(d);
- }
+ iommu_teardown(d);
return rc;
}
@@ -413,10 +420,7 @@ void iommu_domain_destroy(struct domain *d)
return;
if ( need_iommu(d) )
- {
- d->need_iommu = 0;
- hd->platform_ops->teardown(d);
- }
+ iommu_teardown(d);
list_for_each_safe ( ioport_list, tmp, &hd->g2m_ioport_list )
{
@@ -454,6 +458,23 @@ int iommu_unmap_page(struct domain *d, unsigned long gfn)
return hd->platform_ops->unmap_page(d, gfn);
}
+static void iommu_free_pagetables(unsigned long unused)
+{
+ do {
+ struct page_info *pg;
+
+ spin_lock(&iommu_pt_cleanup_lock);
+ pg = page_list_remove_head(&iommu_pt_cleanup_list);
+ spin_unlock(&iommu_pt_cleanup_lock);
+ if ( !pg )
+ return;
+ iommu_get_ops()->free_page_table(pg);
+ } while ( !softirq_pending(smp_processor_id()) );
+
+ tasklet_schedule_on_cpu(&iommu_pt_cleanup_tasklet,
+ cpumask_cycle(smp_processor_id(),
&cpu_online_map));
+}
+
void iommu_iotlb_flush(struct domain *d, unsigned long gfn, unsigned int
page_count)
{
struct hvm_iommu *hd = domain_hvm_iommu(d);
@@ -516,10 +537,7 @@ int deassign_device(struct domain *d, u16 seg, u8 bus, u8
devfn)
pdev->fault.count = 0;
if ( !has_arch_pdevs(d) && need_iommu(d) )
- {
- d->need_iommu = 0;
- hd->platform_ops->teardown(d);
- }
+ iommu_teardown(d);
return ret;
}
@@ -558,6 +576,7 @@ int __init iommu_setup(void)
iommu_passthrough ? "Passthrough" :
iommu_dom0_strict ? "Strict" : "Relaxed");
printk("Interrupt remapping %sabled\n", iommu_intremap ? "en" : "dis");
+ tasklet_init(&iommu_pt_cleanup_tasklet, iommu_free_pagetables, 0);
}
return rc;
diff --git a/xen/drivers/passthrough/vtd/iommu.c
b/xen/drivers/passthrough/vtd/iommu.c
index b6b48e2..5f10034 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -668,13 +668,24 @@ static void dma_pte_clear_one(struct domain *domain, u64
addr)
static void iommu_free_pagetable(u64 pt_maddr, int level)
{
- int i;
- struct dma_pte *pt_vaddr, *pte;
- int next_level = level - 1;
+ struct page_info *pg = maddr_to_page(pt_maddr);
if ( pt_maddr == 0 )
return;
+ PFN_ORDER(pg) = level;
+ spin_lock(&iommu_pt_cleanup_lock);
+ page_list_add_tail(pg, &iommu_pt_cleanup_list);
+ spin_unlock(&iommu_pt_cleanup_lock);
+}
+
+static void iommu_free_page_table(struct page_info *pg)
+{
+ unsigned int i, next_level = PFN_ORDER(pg) - 1;
+ u64 pt_maddr = page_to_maddr(pg);
+ struct dma_pte *pt_vaddr, *pte;
+
+ PFN_ORDER(pg) = 0;
pt_vaddr = (struct dma_pte *)map_vtd_domain_page(pt_maddr);
for ( i = 0; i < PTE_NUM; i++ )
@@ -2430,6 +2441,7 @@ const struct iommu_ops intel_iommu_ops = {
.teardown = iommu_domain_teardown,
.map_page = intel_iommu_map_page,
.unmap_page = intel_iommu_unmap_page,
+ .free_page_table = iommu_free_page_table,
.reassign_device = reassign_device_ownership,
.get_device_group_id = intel_iommu_group_id,
.update_ire_from_apic = io_apic_write_remap_rte,
diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
index 6f0ff9d..8bb0a1d 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -88,6 +88,7 @@ bool_t pt_irq_need_timer(uint32_t flags);
struct msi_desc;
struct msi_msg;
+struct page_info;
struct iommu_ops {
int (*init)(struct domain *d);
@@ -100,6 +101,7 @@ struct iommu_ops {
int (*map_page)(struct domain *d, unsigned long gfn, unsigned long mfn,
unsigned int flags);
int (*unmap_page)(struct domain *d, unsigned long gfn);
+ void (*free_page_table)(struct page_info *);
int (*reassign_device)(struct domain *s, struct domain *t,
u8 devfn, struct pci_dev *);
int (*get_device_group_id)(u16 seg, u8 bus, u8 devfn);
@@ -151,4 +153,7 @@ int adjust_vtd_irq_affinities(void);
*/
DECLARE_PER_CPU(bool_t, iommu_dont_flush_iotlb);
+extern struct spinlock iommu_pt_cleanup_lock;
+extern struct page_list_head iommu_pt_cleanup_list;
+
#endif /* _IOMMU_H_ */
--
generated by git-patchbot for /home/xen/git/xen.git#master
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