AMD IOMMU: add parameter to disable device isolation
Impact: add a new AMD IOMMU kernel command line parameter
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 9fa6508..b56ee02 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -295,6 +295,8 @@
isolate - enable device isolation (each device, as far
as possible, will get its own protection
domain)
+ share - put every device behind one IOMMU into the
+ same protection domain
fullflush - enable flushing of IO/TLB entries when
they are unmapped. Otherwise they are
flushed before they will be reused, which
diff --git a/arch/x86/kernel/amd_iommu_init.c b/arch/x86/kernel/amd_iommu_init.c
index 0cdcda3..838a2e1 100644
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -1213,6 +1213,8 @@
for (; *str; ++str) {
if (strncmp(str, "isolate", 7) == 0)
amd_iommu_isolate = 1;
+ if (strncmp(str, "share", 5) == 0)
+ amd_iommu_isolate = 0;
if (strncmp(str, "fullflush", 11) == 0)
amd_iommu_unmap_flush = true;
}