From 099f2df2e6b0ec1b0f1d4e518f730594a66661a8 Mon Sep 17 00:00:00 2001 From: Andrew Jones Date: Wed, 20 Oct 2021 22:21:22 +0800 Subject: hw/acpi/aml-build: Add PPTT table Add the Processor Properties Topology Table (PPTT) used to describe CPU topology information to ACPI guests. Note, a DT-boot Linux guest with a non-flat CPU topology will see socket and core IDs being sequential integers starting from zero, which is different from ACPI-boot Linux guest, e.g. with -smp 4,sockets=2,cores=2,threads=1 a DT boot produces: cpu: 0 package_id: 0 core_id: 0 cpu: 1 package_id: 0 core_id: 1 cpu: 2 package_id: 1 core_id: 0 cpu: 3 package_id: 1 core_id: 1 an ACPI boot produces: cpu: 0 package_id: 36 core_id: 0 cpu: 1 package_id: 36 core_id: 1 cpu: 2 package_id: 96 core_id: 2 cpu: 3 package_id: 96 core_id: 3 This is due to several reasons: 1) DT cpu nodes do not have an equivalent field to what the PPTT ACPI Processor ID must be, i.e. something equal to the MADT CPU UID or equal to the UID of an ACPI processor container. In both ACPI cases those are platform dependant IDs assigned by the vendor. 2) While QEMU is the vendor for a guest, if the topology specifies SMT (> 1 thread), then, with ACPI, it is impossible to assign a core-id the same value as a package-id, thus it is not possible to have package-id=0 and core-id=0. This is because package and core containers must be in the same ACPI namespace and therefore must have unique UIDs. 3) ACPI processor containers are not mandatorily required for PPTT tables to be used and, due to the limitations of which IDs are selected described above in (2), they are not helpful for QEMU, so we don't build them with this patch. In the absence of them, Linux assigns its own unique IDs. The maintainers have chosen not to use counters from zero, but rather ACPI table offsets, which explains why the numbers are so much larger than with DT. 4) When there is no SMT (threads=1) the core IDs for ACPI boot guests match the logical CPU IDs, because these IDs must be equal to the MADT CPU UID (as no processor containers are present), and QEMU uses the logical CPU ID for these MADT IDs. So in summary, with QEMU as the vendor for the guests, we simply use sequential integers starting from zero for the non-leaf nodes but with ID-valid flag unset, so that guest will ignore them and use table offsets as unique container IDs. And we use logical CPU IDs for the leaf nodes with the ID-valid flag set, which will be consistent with MADT. Currently the implementation of PPTT generation complies with ACPI specification 5.2.29 (Revision 6.3). The 6.3 spec can be found at: https://uefi.org/sites/default/files/resources/ACPI_6_3_May16.pdf Reviewed-by: Eric Auger Co-developed-by: Yanan Wang Signed-off-by: Andrew Jones Signed-off-by: Yanan Wang Reviewed-by: Michael S. Tsirkin Message-Id: <20211020142125.7516-6-wangyanan55@huawei.com> Signed-off-by: Richard Henderson --- hw/acpi/aml-build.c | 59 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) (limited to 'hw/acpi') diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c index 5195324..b3b3310 100644 --- a/hw/acpi/aml-build.c +++ b/hw/acpi/aml-build.c @@ -1994,6 +1994,65 @@ static void build_processor_hierarchy_node(GArray *tbl, uint32_t flags, } } +/* + * ACPI spec, Revision 6.3 + * 5.2.29 Processor Properties Topology Table (PPTT) + */ +void build_pptt(GArray *table_data, BIOSLinker *linker, MachineState *ms, + const char *oem_id, const char *oem_table_id) +{ + int pptt_start = table_data->len; + int uid = 0; + int socket; + AcpiTable table = { .sig = "PPTT", .rev = 2, + .oem_id = oem_id, .oem_table_id = oem_table_id }; + + acpi_table_begin(&table, table_data); + + for (socket = 0; socket < ms->smp.sockets; socket++) { + uint32_t socket_offset = table_data->len - pptt_start; + int core; + + build_processor_hierarchy_node( + table_data, + /* + * Physical package - represents the boundary + * of a physical package + */ + (1 << 0), + 0, socket, NULL, 0); + + for (core = 0; core < ms->smp.cores; core++) { + uint32_t core_offset = table_data->len - pptt_start; + int thread; + + if (ms->smp.threads > 1) { + build_processor_hierarchy_node( + table_data, + (0 << 0), /* not a physical package */ + socket_offset, core, NULL, 0); + + for (thread = 0; thread < ms->smp.threads; thread++) { + build_processor_hierarchy_node( + table_data, + (1 << 1) | /* ACPI Processor ID valid */ + (1 << 2) | /* Processor is a Thread */ + (1 << 3), /* Node is a Leaf */ + core_offset, uid++, NULL, 0); + } + } else { + build_processor_hierarchy_node( + table_data, + (1 << 1) | /* ACPI Processor ID valid */ + (1 << 3), /* Node is a Leaf */ + socket_offset, uid++, NULL, 0); + } + } + } + + acpi_table_end(linker, &table); +} + /* build rev1/rev3/rev5.1 FADT */ void build_fadt(GArray *tbl, BIOSLinker *linker, const AcpiFadtData *f, const char *oem_id, const char *oem_table_id) -- cgit v1.1