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 9fa6508892c287ce68e5449c894ae2fab2c7bbf9..b56ee02d251488235426559a11fbf0b4b957796a 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -295,6 +295,8 @@ and is between 256 and 4096 characters. It is defined in the file
                        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 0cdcda35a05fbcd01d6d4b32f6ba935f6e9d7cb4..838a2e1d5bb297bd048ed3d44bdf0b60ee090f7f 100644 (file)
--- a/arch/x86/kernel/amd_iommu_init.c
+++ b/arch/x86/kernel/amd_iommu_init.c
@@ -1213,6 +1213,8 @@ static int __init parse_amd_iommu_options(char *str)
        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;
        }