Re: [PATCH v2 2/2] iommu/vt-d: skip invalid RMRR entries

From: Barret Rhoden
Date: Wed Jan 08 2020 - 12:35:47 EST


On 1/7/20 8:27 PM, Lu Baolu wrote:
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index a8bb458845bc..32c3c6338a3d 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4315,13 +4315,25 @@ static void __init init_iommu_pm_ops(void)
 static inline void init_iommu_pm_ops(void) {}
 #endif /* CONFIG_PM */
+static int rmrr_validity_check(struct acpi_dmar_reserved_memory *rmrr)
+{
+ÂÂÂ if ((rmrr->base_address & PAGE_MASK) ||
+ÂÂÂÂÂÂÂ (rmrr->end_address <= rmrr->base_address) ||
+ÂÂÂÂÂÂÂ ((rmrr->end_address - rmrr->base_address + 1) & PAGE_MASK)) {
+ÂÂÂÂÂÂÂ pr_err(FW_BUG "Broken RMRR base: %#018Lx end: %#018Lx\n",
+ÂÂÂÂÂÂÂÂÂÂÂÂÂÂ rmrr->base_address, rmrr->end_address);

Since you will WARN_TAINT below, do you still want an error message
here?

I'm fine either way.

I put it in since arch_rmrr_sanity_check() also has a pr_err():

pr_err(FW_BUG "No firmware reserved region can cover this RMRR
[%#018Lx-%#018Lx], contact BIOS vendor for fixes\n",
start, end - 1);

Thanks,

Barret