On Mon, 2015-04-27 at 15:27 +0800, [email protected] wrote: > commit 18436afdc11a00ac881990b454cfb2eae81d6003 iommu/vt-d: Allow > RMRR on graphics devices too > > cause kernel panic with Z77+vt-d and kernel parameters: > intel_iommu=igfx_off iommu=pt > the panic path is: > dev_prepare_static_identity_mapping() > domain_add_dev_info() > dmar_insert_dev_info() > find_domain() > info = dev->archdata.iommu; > if (info) > -> return info->domain; > > igfx_off cause <igfx@0:2.0>.archdata.iommu assigned to > DUMMY_DEVICE_DOMAIN_INFO. > Above patch cause iommu_should_identity_map() return 1, and attempt > to setup identity mapping for igfx.
Can you try this please?
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 68d43be..2ffe589 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -696,6 +696,11 @@ static inline struct context_entry
*iommu_context_addr(struct intel_iommu *iommu
return &context[devfn];
}
+static int iommu_dummy(struct device *dev)
+{
+ return dev->archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO;
+}
+
static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8
*devfn)
{
struct dmar_drhd_unit *drhd = NULL;
@@ -705,6 +710,9 @@ static struct intel_iommu *device_to_iommu(struct device
*dev, u8 *bus, u8 *devf
u16 segment = 0;
int i;
+ if (iommu_dummy(dev))
+ return NULL;
+
if (dev_is_pci(dev)) {
pdev = to_pci_dev(dev);
segment = pci_domain_nr(pdev->bus);
@@ -2969,11 +2977,6 @@ static inline struct dmar_domain
*get_valid_domain_for_dev(struct device *dev)
return __get_valid_domain_for_dev(dev);
}
-static int iommu_dummy(struct device *dev)
-{
- return dev->archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO;
-}
-
/* Check if the dev needs to go through non-identity map and unmap process.*/
static int iommu_no_mapping(struct device *dev)
{
--
David Woodhouse Open Source Technology Centre
[email protected] Intel Corporation
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