[PATCH v4 6/6] VT-d: support the device IOTLB

From: Yu Zhao
Date: Mon Mar 23 2009 - 04:01:18 EST


Enable the device IOTLB (i.e. ATS) for both the bare metal and KVM
environments.

Signed-off-by: Yu Zhao <yu.zhao@xxxxxxxxx>
---
drivers/pci/intel-iommu.c | 99 +++++++++++++++++++++++++++++++++++++++++-
include/linux/intel-iommu.h | 1 +
2 files changed, 97 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index 3145368..799bbe5 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -127,6 +127,7 @@ static inline void context_set_fault_enable(struct context_entry *context)
}

#define CONTEXT_TT_MULTI_LEVEL 0
+#define CONTEXT_TT_DEV_IOTLB 1

static inline void context_set_translation_type(struct context_entry *context,
unsigned long value)
@@ -242,6 +243,7 @@ struct device_domain_info {
struct list_head global; /* link to global list */
u8 bus; /* PCI bus numer */
u8 devfn; /* PCI devfn number */
+ struct intel_iommu *iommu; /* IOMMU used by this device */
struct pci_dev *dev; /* it's NULL for PCIE-to-PCI bridge */
struct dmar_domain *domain; /* pointer to domain */
};
@@ -924,6 +926,80 @@ static int __iommu_flush_iotlb(struct intel_iommu *iommu, u16 did,
return 0;
}

+static struct device_domain_info *
+iommu_support_dev_iotlb(struct dmar_domain *domain, u8 bus, u8 devfn)
+{
+ int found = 0;
+ unsigned long flags;
+ struct device_domain_info *info;
+ struct intel_iommu *iommu = device_to_iommu(bus, devfn);
+
+ if (!ecap_dev_iotlb_support(iommu->ecap))
+ return NULL;
+
+ if (!iommu->qi)
+ return NULL;
+
+ spin_lock_irqsave(&device_domain_lock, flags);
+ list_for_each_entry(info, &domain->devices, link)
+ if (info->bus == bus && info->devfn == devfn) {
+ found = 1;
+ break;
+ }
+ spin_unlock_irqrestore(&device_domain_lock, flags);
+
+ if (!found || !info->dev)
+ return NULL;
+
+ if (!pci_find_ext_capability(info->dev, PCI_EXT_CAP_ID_ATS))
+ return NULL;
+
+ if (!dmar_find_matched_atsr_unit(info->dev))
+ return NULL;
+
+ info->iommu = iommu;
+
+ return info;
+}
+
+static void iommu_enable_dev_iotlb(struct device_domain_info *info)
+{
+ if (!info)
+ return;
+
+ pci_enable_ats(info->dev, VTD_PAGE_SHIFT);
+}
+
+static void iommu_disable_dev_iotlb(struct device_domain_info *info)
+{
+ if (!info->dev || !pci_ats_enabled(info->dev))
+ return;
+
+ pci_disable_ats(info->dev);
+}
+
+static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
+ u64 addr, unsigned mask)
+{
+ int rc;
+ u16 sid, qdep;
+ unsigned long flags;
+ struct device_domain_info *info;
+
+ spin_lock_irqsave(&device_domain_lock, flags);
+ list_for_each_entry(info, &domain->devices, link) {
+ if (!info->dev || !pci_ats_enabled(info->dev))
+ continue;
+
+ sid = info->bus << 8 | info->devfn;
+ qdep = pci_ats_queue_depth(info->dev);
+ rc = qi_flush_dev_iotlb(info->iommu, sid, qdep, addr, mask);
+ if (rc)
+ dev_err(&info->dev->dev, "flush IOTLB failed\n");
+ }
+ spin_unlock_irqrestore(&device_domain_lock, flags);
+}
+
static int iommu_flush_iotlb_psi(struct intel_iommu *iommu, u16 did,
u64 addr, unsigned int pages, int non_present_entry_flush)
{
@@ -947,6 +1023,9 @@ static int iommu_flush_iotlb_psi(struct intel_iommu *iommu, u16 did,
rc = iommu->flush.flush_iotlb(iommu, did, addr, mask,
DMA_TLB_PSI_FLUSH,
non_present_entry_flush);
+ if (!rc && !non_present_entry_flush)
+ iommu_flush_dev_iotlb(iommu->domains[did], addr, mask);
+
return rc;
}

@@ -1471,6 +1550,7 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
unsigned long ndomains;
int id;
int agaw;
+ struct device_domain_info *info;

pr_debug("Set context mapping for %02x:%02x.%d\n",
bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
@@ -1536,7 +1616,9 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
context_set_domain_id(context, id);
context_set_address_width(context, iommu->agaw);
context_set_address_root(context, virt_to_phys(pgd));
- context_set_translation_type(context, CONTEXT_TT_MULTI_LEVEL);
+ info = iommu_support_dev_iotlb(domain, bus, devfn);
+ context_set_translation_type(context,
+ info ? CONTEXT_TT_DEV_IOTLB : CONTEXT_TT_MULTI_LEVEL);
context_set_fault_enable(context);
context_set_present(context);
domain_flush_cache(domain, context, sizeof(*context));
@@ -1549,6 +1631,8 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
else
iommu->flush.flush_iotlb(iommu, 0, 0, 0, DMA_TLB_DSI_FLUSH, 0);

+ iommu_enable_dev_iotlb(info);
+
spin_unlock_irqrestore(&iommu->lock, flags);

spin_lock_irqsave(&domain->iommu_lock, flags);
@@ -1689,6 +1773,7 @@ static void domain_remove_dev_info(struct dmar_domain *domain)
info->dev->dev.archdata.iommu = NULL;
spin_unlock_irqrestore(&device_domain_lock, flags);

+ iommu_disable_dev_iotlb(info);
iommu = device_to_iommu(info->bus, info->devfn);
iommu_detach_dev(iommu, info->bus, info->devfn);
free_devinfo_mem(info);
@@ -2306,8 +2391,14 @@ static void flush_unmaps(void)
iommu->flush.flush_iotlb(iommu, 0, 0, 0,
DMA_TLB_GLOBAL_FLUSH, 0);
for (j = 0; j < deferred_flush[i].next; j++) {
- __free_iova(&deferred_flush[i].domain[j]->iovad,
- deferred_flush[i].iova[j]);
+ unsigned long mask;
+ struct iova *iova = deferred_flush[i].iova[j];
+
+ mask = (iova->pfn_hi - iova->pfn_lo + 1) << PAGE_SHIFT;
+ mask = ilog2(mask >> VTD_PAGE_SHIFT);
+ iommu_flush_dev_iotlb(deferred_flush[i].domain[j],
+ iova->pfn_lo << PAGE_SHIFT, mask);
+ __free_iova(&deferred_flush[i].domain[j]->iovad, iova);
}
deferred_flush[i].next = 0;
}
@@ -2794,6 +2885,7 @@ static void vm_domain_remove_one_dev_info(struct dmar_domain *domain,
info->dev->dev.archdata.iommu = NULL;
spin_unlock_irqrestore(&device_domain_lock, flags);

+ iommu_disable_dev_iotlb(info);
iommu_detach_dev(iommu, info->bus, info->devfn);
free_devinfo_mem(info);

@@ -2842,6 +2934,7 @@ static void vm_domain_remove_all_dev_info(struct dmar_domain *domain)

spin_unlock_irqrestore(&device_domain_lock, flags1);

+ iommu_disable_dev_iotlb(info);
iommu = device_to_iommu(info->bus, info->devfn);
iommu_detach_dev(iommu, info->bus, info->devfn);

diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index a32b3db..e182286 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -123,6 +123,7 @@ static inline void dmar_writeq(void __iomem *addr, u64 val)
#define ecap_qis(e) ((e) & 0x2)
#define ecap_eim_support(e) ((e >> 4) & 0x1)
#define ecap_ir_support(e) ((e >> 3) & 0x1)
+#define ecap_dev_iotlb_support(e) (((e) >> 2) & 0x1)
#define ecap_max_handle_mask(e) ((e >> 20) & 0xf)


--
1.5.6.4

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