+Will
Please consider this patch for v5.10.
Best regards,
baolu
On 2020/11/10 15:19, Zhenzhong Duan wrote:
"intel_iommu=off" command line is used to disable iommu but iommu is force
enabled in a tboot system for security reason.
However for better performance on high speed network device, a new option
"intel_iommu=tboot_noforce" is introduced to disable the force on.
By default kernel should panic if iommu init fail in tboot for security
reason, but it's unnecessory if we use "intel_iommu=tboot_noforce,off".
Fix the code setting force_on and move intel_iommu_tboot_noforce
from tboot code to intel iommu code.
Fixes: 7304e8f28bb2 ("iommu/vt-d: Correctly disable Intel IOMMU force on")
Signed-off-by: Zhenzhong Duan <zhenzhong.d...@gmail.com>
---
v2: move ckeck of intel_iommu_tboot_noforce into iommu code per Baolu.
arch/x86/kernel/tboot.c | 3 ---
drivers/iommu/intel/iommu.c | 5 +++--
include/linux/intel-iommu.h | 1 -
3 files changed, 3 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index 992fb14..420be87 100644
--- a/arch/x86/kernel/tboot.c
+++ b/arch/x86/kernel/tboot.c
@@ -514,9 +514,6 @@ int tboot_force_iommu(void)
if (!tboot_enabled())
return 0;
- if (intel_iommu_tboot_noforce)
- return 1;
-
if (no_iommu || swiotlb || dmar_disabled)
pr_warn("Forcing Intel-IOMMU to enabled\n");
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 1b1ca63..4d9b298 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -179,7 +179,7 @@ static inline unsigned long virt_to_dma_pfn(void *p)
* (used when kernel is launched w/ TXT)
*/
static int force_on = 0;
-int intel_iommu_tboot_noforce;
+static int intel_iommu_tboot_noforce;
static int no_platform_optin;
#define ROOT_ENTRY_NR (VTD_PAGE_SIZE/sizeof(struct root_entry))
@@ -4885,7 +4885,8 @@ int __init intel_iommu_init(void)
* Intel IOMMU is required for a TXT/tboot launch or platform
* opt in, so enforce that.
*/
- force_on = tboot_force_iommu() || platform_optin_force_iommu();
+ force_on = (!intel_iommu_tboot_noforce && tboot_force_iommu()) ||
+ platform_optin_force_iommu();
if (iommu_init_mempool()) {
if (force_on)
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index fbf5b3e..d956987 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -798,7 +798,6 @@ struct context_entry *iommu_context_addr(struct intel_iommu
*iommu, u8 bus,
extern int iommu_calculate_max_sagaw(struct intel_iommu *iommu);
extern int dmar_disabled;
extern int intel_iommu_enabled;
-extern int intel_iommu_tboot_noforce;
extern int intel_iommu_gfx_mapped;
#else
static inline int iommu_calculate_agaw(struct intel_iommu *iommu)
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