diff options
| author | Lu Baolu <baolu.lu@linux.intel.com> | 2019-09-06 14:14:49 +0800 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2019-09-11 12:34:29 +0200 |
| commit | e5e04d051979dbd636a99099b7a595093c50a4bc (patch) | |
| tree | 02c641871e285fea720da12bd1420bc865ccae83 /drivers/iommu | |
| parent | 3fc1ca00653db6371585e3c21c4b873b2f20e60a (diff) | |
iommu/vt-d: Check whether device requires bounce buffer
This adds a helper to check whether a device needs to
use bounce buffer. It also provides a boot time option
to disable the bounce buffer. Users can use this to
prevent the iommu driver from using the bounce buffer
for performance gain.
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Xu Pengfei <pengfei.xu@intel.com>
Tested-by: Mika Westerberg <mika.westerberg@intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/intel-iommu.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 12d094d08c0a..ce6baabc9dcc 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -360,6 +360,7 @@ static int dmar_forcedac; static int intel_iommu_strict; static int intel_iommu_superpage = 1; static int iommu_identity_mapping; +static int intel_no_bounce; #define IDENTMAP_ALL 1 #define IDENTMAP_GFX 2 @@ -373,6 +374,9 @@ EXPORT_SYMBOL_GPL(intel_iommu_gfx_mapped); static DEFINE_SPINLOCK(device_domain_lock); static LIST_HEAD(device_domain_list); +#define device_needs_bounce(d) (!intel_no_bounce && dev_is_pci(d) && \ + to_pci_dev(d)->untrusted) + /* * Iterate over elements in device_domain_list and call the specified * callback @fn against each element. @@ -455,6 +459,9 @@ static int __init intel_iommu_setup(char *str) printk(KERN_INFO "Intel-IOMMU: not forcing on after tboot. This could expose security risk for tboot\n"); intel_iommu_tboot_noforce = 1; + } else if (!strncmp(str, "nobounce", 8)) { + pr_info("Intel-IOMMU: No bounce buffer. This could expose security risks of DMA attacks\n"); + intel_no_bounce = 1; } str += strcspn(str, ","); |