Hi Yi,
On 12/20/19 7:44 PM, Liu, Yi L wrote:
From: Lu Baolu [mailto:baolu.lu@xxxxxxxxxxxxxxx]
Sent: Thursday, December 19, 2019 11:17 AM
To: Joerg Roedel <joro@xxxxxxxxxx>; David Woodhouse <dwmw2@xxxxxxxxxxxxx>;
Alex Williamson <alex.williamson@xxxxxxxxxx>
Subject: [PATCH v4 4/7] iommu/vt-d: Setup pasid entries for iova over first level
Intel VT-d in scalable mode supports two types of page tables for IOVA translation:
first level and second level. The IOMMU driver can choose one from both for IOVA
translation according to the use case. This sets up the pasid entry if a domain is
selected to use the first-level page table for iova translation.
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
drivers/iommu/intel-iommu.c | 48 +++++++++++++++++++++++++++++++++++--
include/linux/intel-iommu.h | 16 ++++++++-----
2 files changed, 56 insertions(+), 8 deletions(-)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index
2b5a47584baf..f0813997dea2 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -571,6 +571,11 @@ static inline int domain_type_is_si(struct dmar_domain
*domain)
return domain->flags & DOMAIN_FLAG_STATIC_IDENTITY; }
+static inline bool domain_use_first_level(struct dmar_domain *domain) {
+ return domain->flags & DOMAIN_FLAG_USE_FIRST_LEVEL; }
+
static inline int domain_pfn_supported(struct dmar_domain *domain,
unsigned long pfn)
{
@@ -2288,6 +2293,8 @@ static int __domain_mapping(struct dmar_domain
*domain, unsigned long iov_pfn,
return -EINVAL;
prot &= DMA_PTE_READ | DMA_PTE_WRITE | DMA_PTE_SNP;
+ if (domain_use_first_level(domain))
+ prot |= DMA_FL_PTE_PRESENT | DMA_FL_PTE_XD;
if (!sg) {
sg_res = nr_pages;
@@ -2515,6 +2522,36 @@ dmar_search_domain_by_dev_info(int segment, int bus,
int devfn)
return NULL;
}
+static int domain_setup_first_level(struct intel_iommu *iommu,
+ struct dmar_domain *domain,
+ struct device *dev,
+ int pasid)
+{
+ int flags = PASID_FLAG_SUPERVISOR_MODE;
Hi Baolu,
Could you explain a bit why PASID_FLAG_SUPERVISOR_MODE is
required?
This flag indicates a PASID which can be used for access to kernel
addresses (static 1:1 only). Otherwise, DMA requests requesting
supervisor level privilege level will be blocked.
Regards,
Yi Liu
Best regards,
baolu
