fix #4707: add override parameter for RMRR relaxation

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
(cherry picked from commit 1acfcad2f3)
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
This commit is contained in:
Fabian Grünbichler 2023-09-05 14:31:04 +02:00 committed by Thomas Lamprecht
parent db0095a49a
commit 31a20e1eb0

View File

@ -0,0 +1,35 @@
From: kiler129 <grzegorz@noflash.pl>
allow opt-in to allow pass-through on broken hardware..
adapted from https://github.com/kiler129/relax-intel-rmrr , licensed under MIT or GPL 2.0+
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -297,6 +297,7 @@
static int dmar_map_ipu = 1;
static int intel_iommu_superpage = 1;
static int iommu_identity_mapping;
+static int intel_relaxable_rmrr = 0;
static int iommu_skip_te_disable;
#define IDENTMAP_GFX 2
@@ -358,6 +359,9 @@
} else if (!strncmp(str, "tboot_noforce", 13)) {
pr_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, "relax_rmrr", 10)) {
+ pr_info("Intel-IOMMU: assuming all RMRRs are relaxable. This can lead to instability or data loss\n");
+ intel_relaxable_rmrr = 1;
} else {
pr_notice("Unknown option - '%s'\n", str);
}
@@ -2538,7 +2542,7 @@
return false;
pdev = to_pci_dev(dev);
- if (IS_USB_DEVICE(pdev) || IS_GFX_DEVICE(pdev))
+ if (intel_relaxable_rmrr || IS_USB_DEVICE(pdev) || IS_GFX_DEVICE(pdev))
return true;
else
return false;