[Patch Part3 V4 13/21] iommu/vt-d: Fix issue in computing domain's iommu_snooping flag

Jiang Liu
2014-07-11T06:17:59Z

IOMMU units may dynamically attached to/detached from domains,
so we should scan all active IOMMU units when computing iommu_snooping
flag for a domain instead of only scanning IOMMU units associated
with the domain.

Also check snooping and superpage capabilities when hot-adding DMAR units.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
drivers/iommu/intel-iommu.c | 42 ++++++++++++++++++++++++------------------
1 file changed, 24 insertions(+), 18 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index cd1ba24c766a..58cc2b75d7ae 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -633,50 +633,56 @@ static void domain_update_iommu_coherency(struct dmar_domain *domain)
rcu_read_unlock();
}

-static void domain_update_iommu_snooping(struct dmar_domain *domain)
+static int domain_update_iommu_snooping(struct intel_iommu *skip)
{
- int i;
-
- domain->iommu_snooping = 1;
+ struct dmar_drhd_unit *drhd;
+ struct intel_iommu *iommu;
+ int ret = 1;

- for_each_set_bit(i, domain->iommu_bmp, g_num_of_iommus) {
- if (!ecap_sc_support(g_iommus[i]->ecap)) {
- domain->iommu_snooping = 0;
- break;
+ rcu_read_lock();
+ for_each_active_iommu(iommu, drhd) {
+ if (iommu != skip) {
+ if (!ecap_sc_support(iommu->ecap)) {
+ ret = 0;
+ break;
+ }
}
}
+ rcu_read_unlock();
+
+ return ret;
}

-static void domain_update_iommu_superpage(struct dmar_domain *domain)
+static int domain_update_iommu_superpage(struct intel_iommu *skip)
{
struct dmar_drhd_unit *drhd;
- struct intel_iommu *iommu = NULL;
+ struct intel_iommu *iommu;
int mask = 0xf;

if (!intel_iommu_superpage) {
- domain->iommu_superpage = 0;
- return;
+ return 0;
}

/* set iommu_superpage to the smallest common denominator */
rcu_read_lock();
for_each_active_iommu(iommu, drhd) {
- mask &= cap_super_page_val(iommu->cap);
- if (!mask) {
- break;
+ if (iommu != skip) {
+ mask &= cap_super_page_val(iommu->cap);
+ if (!mask)
+ break;
}
}
rcu_read_unlock();

- domain->iommu_superpage = fls(mask);
+ return fls(mask);
}

/* Some capabilities may be different across iommus */
static void domain_update_iommu_cap(struct dmar_domain *domain)
{
domain_update_iommu_coherency(domain);
- domain_update_iommu_snooping(domain);
- domain_update_iommu_superpage(domain);
+ domain->iommu_snooping = domain_update_iommu_snooping(NULL);
+ domain->iommu_superpage = domain_update_iommu_superpage(NULL);
}

static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn)
--
1.7.10.4