From 5786827f47a0721bb997ad3f653d2b843ba3fd76 Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Wed, 19 Jun 2024 13:12:43 -0700 Subject: [PATCH] hw/arm/virt-acpi-build: Fix id_count in build_iort_id_mapping It's observed that Linux kernel booting with the VM reports a "conflicting mapping for input ID" FW_BUG. The IORT doc defines "Number of IDs" to be "the number of IDs in the range minus one", while virt-acpi-build.c simply stores the number of IDs in the id_count without the "minus one". Meanwhile, some of the callers pass in a 0xFFFF following the spec. So, this is a mismatch between the function and its callers. Fix build_iort_id_mapping() by internally subtracting one from the pass-in @id_count. Accordingly make sure that all existing callers pass in a value without the "minus one", i.e. change all 0xFFFFs to 0x10000s. Also, add a few lines of comments to highlight this change along with the referencing document for this build_iort_id_mapping(). Fixes: 42e0f050e3a5 ("hw/arm/virt-acpi-build: Add IORT support to bypass SMMUv3") Suggested-by: Michael S. Tsirkin Reviewed-by: Eric Auger Signed-off-by: Nicolin Chen Message-Id: <20240619201243.936819-1-nicolinc@nvidia.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/arm/virt-acpi-build.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c index 102e2da934..e10cad86dd 100644 --- a/hw/arm/virt-acpi-build.c +++ b/hw/arm/virt-acpi-build.c @@ -209,12 +209,19 @@ static void acpi_dsdt_add_tpm(Aml *scope, VirtMachineState *vms) #define ROOT_COMPLEX_ENTRY_SIZE 36 #define IORT_NODE_OFFSET 48 +/* + * Append an ID mapping entry as described by "Table 4 ID mapping format" in + * "IO Remapping Table System Software on ARM Platforms", Chapter 3. + * Document number: ARM DEN 0049E.f, Apr 2024 + * + * Note that @id_count gets internally subtracted by one, following the spec. + */ static void build_iort_id_mapping(GArray *table_data, uint32_t input_base, uint32_t id_count, uint32_t out_ref) { - /* Table 4 ID mapping format */ build_append_int_noprefix(table_data, input_base, 4); /* Input base */ - build_append_int_noprefix(table_data, id_count, 4); /* Number of IDs */ + /* Number of IDs - The number of IDs in the range minus one */ + build_append_int_noprefix(table_data, id_count - 1, 4); build_append_int_noprefix(table_data, input_base, 4); /* Output base */ build_append_int_noprefix(table_data, out_ref, 4); /* Output Reference */ /* Flags */ @@ -305,8 +312,8 @@ build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms) } /* Append the last RC -> ITS ID mapping */ - if (next_range.input_base < 0xFFFF) { - next_range.id_count = 0xFFFF - next_range.input_base; + if (next_range.input_base < 0x10000) { + next_range.id_count = 0x10000 - next_range.input_base; g_array_append_val(its_idmaps, next_range); } @@ -365,7 +372,7 @@ build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms) build_append_int_noprefix(table_data, 0, 4); /* output IORT node is the ITS group node (the first node) */ - build_iort_id_mapping(table_data, 0, 0xFFFF, IORT_NODE_OFFSET); + build_iort_id_mapping(table_data, 0, 0x10000, IORT_NODE_OFFSET); } /* Table 17 Root Complex Node */ @@ -418,7 +425,7 @@ build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms) } } else { /* output IORT node is the ITS group node (the first node) */ - build_iort_id_mapping(table_data, 0, 0xFFFF, IORT_NODE_OFFSET); + build_iort_id_mapping(table_data, 0, 0x10000, IORT_NODE_OFFSET); } acpi_table_end(linker, &table);