Message ID | 20211020142125.7516-6-wangyanan55@huawei.com |
---|---|
State | New |
Headers | show |
Series | hw/arm/virt: Introduce cpu topology support | expand |
Hi Yanan, On 10/20/21 4:21 PM, Yanan Wang wrote: > From: Andrew Jones <drjones@redhat.com> > > 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 > > Signed-off-by: Andrew Jones <drjones@redhat.com> > Co-developed-by: Yanan Wang <wangyanan55@huawei.com> > Signed-off-by: Yanan Wang <wangyanan55@huawei.com> > Reviewed-by: Michael S. Tsirkin <mst@redhat.com> > --- > hw/acpi/aml-build.c | 59 +++++++++++++++++++++++++++++++++++++ > include/hw/acpi/aml-build.h | 3 ++ > 2 files changed, 62 insertions(+) > > diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c > index 5195324585..b3b3310df3 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) > diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h > index 3cf6f2c1b9..8346003a22 100644 > --- a/include/hw/acpi/aml-build.h > +++ b/include/hw/acpi/aml-build.h > @@ -489,6 +489,9 @@ void build_srat_memory(GArray *table_data, uint64_t base, > void build_slit(GArray *table_data, BIOSLinker *linker, MachineState *ms, > const char *oem_id, const char *oem_table_id); > > +void build_pptt(GArray *table_data, BIOSLinker *linker, MachineState *ms, > + const char *oem_id, const char *oem_table_id); > + > void build_fadt(GArray *tbl, BIOSLinker *linker, const AcpiFadtData *f, > const char *oem_id, const char *oem_table_id); > > Reviewed-by: Eric Auger <eric.auger@redhat.com> Thanks Eric
diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c index 5195324585..b3b3310df3 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) diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h index 3cf6f2c1b9..8346003a22 100644 --- a/include/hw/acpi/aml-build.h +++ b/include/hw/acpi/aml-build.h @@ -489,6 +489,9 @@ void build_srat_memory(GArray *table_data, uint64_t base, void build_slit(GArray *table_data, BIOSLinker *linker, MachineState *ms, const char *oem_id, const char *oem_table_id); +void build_pptt(GArray *table_data, BIOSLinker *linker, MachineState *ms, + const char *oem_id, const char *oem_table_id); + void build_fadt(GArray *tbl, BIOSLinker *linker, const AcpiFadtData *f, const char *oem_id, const char *oem_table_id);