[Patch Part3 V4 05/21] iommu/vt-d: Allocate dynamic domain id for virtual domains only

Jiang Liu
2014-07-11T06:22:42Z

Check the same domain id is allocated for si_domain on each IOMMU,
otherwise the IOTLB flush for si_domain will fail.

Now the rules to allocate and manage domain id are:
1) For normal and static identity domains, domain id is allocated
when creating domain structure. And this id will be written into
context entry.
2) For virtual machine domain, a virtual id is allocated when creating
domain. And when binding virtual machine domain to an iommu, a real
domain id is allocated on demand and this domain id will be written
into context entry. So domain->id for virtual machine domain may be
different from the domain id written into context entry(used by
hardware).

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
drivers/iommu/intel-iommu.c | 47 ++++++++++++++++++++++++-------------------
1 file changed, 26 insertions(+), 21 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index eae9b0d8bc60..968e3d32e305 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -1549,15 +1549,27 @@ static int iommu_attach_domain(struct dmar_domain *domain,

spin_lock_irqsave(&iommu->lock, flags);
num = __iommu_attach_domain(domain, iommu);
+ spin_unlock_irqrestore(&iommu->lock, flags);
if (num < 0)
pr_err("IOMMU: no free domain ids\n");
- else
- domain->id = num;
- spin_unlock_irqrestore(&iommu->lock, flags);

return num;
}

+static int iommu_attach_vm_domain(struct dmar_domain *domain,
+ struct intel_iommu *iommu)
+{
+ int num;
+ unsigned long ndomains;
+
+ ndomains = cap_ndoms(iommu->cap);
+ for_each_set_bit(num, iommu->domain_ids, ndomains)
+ if (iommu->domains[num] == domain)
+ return num;
+
+ return __iommu_attach_domain(domain, iommu);
+}
+
static void iommu_detach_domain(struct dmar_domain *domain,
struct intel_iommu *iommu)
{
@@ -1764,8 +1776,6 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
struct context_entry *context;
unsigned long flags;
struct dma_pte *pgd;
- unsigned long num;
- unsigned long ndomains;
int id;
int agaw;
struct device_domain_info *info = NULL;
@@ -1790,20 +1800,8 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
pgd = domain->pgd;

if (domain_type_is_vm_or_si(domain)) {
- int found = 0;
-
- /* find an available domain id for this device in iommu */
- ndomains = cap_ndoms(iommu->cap);
- for_each_set_bit(num, iommu->domain_ids, ndomains) {
- if (iommu->domains[num] == domain) {
- id = num;
- found = 1;
- break;
- }
- }
-
- if (found == 0) {
- id = __iommu_attach_domain(domain, iommu);
+ if (domain_type_is_vm(domain)) {
+ id = iommu_attach_vm_domain(domain, iommu);
if (id < 0) {
spin_unlock_irqrestore(&iommu->lock, flags);
pr_err("IOMMU: no free domain ids\n");
@@ -2257,8 +2255,8 @@ static struct dmar_domain *get_domain_for_dev(struct device *dev, int gaw)
domain = alloc_domain(0);
if (!domain)
return NULL;
-
- if (iommu_attach_domain(domain, iommu) < 0) {
+ domain->id = iommu_attach_domain(domain, iommu);
+ if (domain->id < 0) {
free_domain_mem(domain);
return NULL;
}
@@ -2428,6 +2426,7 @@ static int __init si_domain_init(int hw)
struct dmar_drhd_unit *drhd;
struct intel_iommu *iommu;
int nid, ret = 0;
+ bool first = true;

si_domain = alloc_domain(DOMAIN_FLAG_STATIC_IDENTITY);
if (!si_domain)
@@ -2438,6 +2437,12 @@ static int __init si_domain_init(int hw)
if (ret < 0) {
domain_exit(si_domain);
return -EFAULT;
+ } else if (first) {
+ si_domain->id = ret;
+ first = false;
+ } else if (si_domain->id != ret) {
+ domain_exit(si_domain);
+ return -EFAULT;
}
domain_attach_iommu(si_domain, iommu);
}
--
1.7.10.4