From 7cef33471a35c6973ddad2926e9e88c52e9e1c1b Mon Sep 17 00:00:00 2001 From: "Li, Zhen-Hua" Date: Mon, 20 May 2013 15:57:32 +0800 Subject: [PATCH] iommu/vt-d: DMAR reporting table needs at least one DRHD In intel vt-d spec , chapter 8.1 , DMA Remapping Reporting Structure. In the end of the table, it says: Remapping Structures[] - A list of structures. The list will contain one or more DMA Remapping Hardware Unit Definition (DRHD) structures, and zero or more Reserved Memory Region Reporting (RMRR) and Root Port ATS Capability Reporting (ATSR) structures. These structures are described below. So, there should be at least one DRHD structure in DMA Remapping reporting table. If there is no DRHD found, a warning is necessary. Signed-off-by: Li, Zhen-Hua Signed-off-by: Joerg Roedel --- drivers/iommu/dmar.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c index a7967ceb79e6..785675a56a10 100644 --- a/drivers/iommu/dmar.c +++ b/drivers/iommu/dmar.c @@ -309,6 +309,7 @@ parse_dmar_table(void) struct acpi_table_dmar *dmar; struct acpi_dmar_header *entry_header; int ret = 0; + int drhd_count = 0; /* * Do it again, earlier dmar_tbl mapping could be mapped with @@ -347,6 +348,7 @@ parse_dmar_table(void) switch (entry_header->type) { case ACPI_DMAR_TYPE_HARDWARE_UNIT: + drhd_count++; ret = dmar_parse_one_drhd(entry_header); break; case ACPI_DMAR_TYPE_RESERVED_MEMORY: @@ -371,6 +373,8 @@ parse_dmar_table(void) entry_header = ((void *)entry_header + entry_header->length); } + if (drhd_count == 0) + pr_warn(FW_BUG "No DRHD structure found in DMAR table\n"); return ret; } -- GitLab