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powerpc/spapr: Add host threads parameter to ibm,get_system_parameter

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The ibm,get_system_parameter rtas call is used by the guest to retrieve
data relating to certain parameters of the system. The SPLPAR
characteristics option (token 20) is used to determine characteristics of
the environment in which the lpar will run.

It may be useful for a guest to know the number of physical host threads
present on the underlying system where it is being run. Add the
characteristic "HostThrs" to the SPLPAR Characteristics
ibm,get_system_parameter rtas call to expose this information to a
guest. Add a n_host_threads property to the processor class which is
then used to retrieve this information and define it for POWER8 and
POWER9. Other processors will default to 0 and the charateristic won't
be added.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>

Message-Id: <20190827045751.22123-1-sjitindarsingh@gmail.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Suraj Jitindar Singh 2019-08-27 14:57:51 +10:00 committed by David Gibson
parent 00eaad2e29
commit 289af4ac99
3 changed files with 18 additions and 0 deletions
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15
hw/ppc/spapr_rtas.c
View File

@ -266,6 +266,7 @@ static void rtas_ibm_get_system_parameter(PowerPCCPU *cpu,
target_ulong args, target_ulong args,
uint32_t nret, target_ulong rets) uint32_t nret, target_ulong rets)
{ {
PowerPCCPUClass *pcc = POWERPC_CPU_GET_CLASS(cpu);
MachineState *ms = MACHINE(qdev_get_machine()); MachineState *ms = MACHINE(qdev_get_machine());
unsigned int max_cpus = ms->smp.max_cpus; unsigned int max_cpus = ms->smp.max_cpus;
target_ulong parameter = rtas_ld(args, 0); target_ulong parameter = rtas_ld(args, 0);
@ -283,6 +284,20 @@ static void rtas_ibm_get_system_parameter(PowerPCCPU *cpu,
current_machine->ram_size / MiB, current_machine->ram_size / MiB,
ms->smp.cpus, ms->smp.cpus,
max_cpus); max_cpus);
if (pcc->n_host_threads > 0) {
char *hostthr_val, *old = param_val;
/*
* Add HostThrs property. This property is not present in PAPR but
* is expected by some guests to communicate the number of physical
* host threads per core on the system so that they can scale
* information which varies based on the thread configuration.
*/
hostthr_val = g_strdup_printf(",HostThrs=%d", pcc->n_host_threads);
param_val = g_strconcat(param_val, hostthr_val, NULL);
g_free(hostthr_val);
g_free(old);
}
ret = sysparm_st(buffer, length, param_val, strlen(param_val) + 1); ret = sysparm_st(buffer, length, param_val, strlen(param_val) + 1);
g_free(param_val); g_free(param_val);
break; break;

1
target/ppc/cpu-qom.h
View File

@ -191,6 +191,7 @@ typedef struct PowerPCCPUClass {
const PPCHash64Options *hash64_opts; const PPCHash64Options *hash64_opts;
struct ppc_radix_page_info *radix_page_info; struct ppc_radix_page_info *radix_page_info;
uint32_t lrg_decr_bits; uint32_t lrg_decr_bits;
int n_host_threads;
void (*init_proc)(CPUPPCState *env); void (*init_proc)(CPUPPCState *env);
int (*check_pow)(CPUPPCState *env); int (*check_pow)(CPUPPCState *env);
int (*handle_mmu_fault)(PowerPCCPU *cpu, vaddr eaddr, int rwx, int mmu_idx); int (*handle_mmu_fault)(PowerPCCPU *cpu, vaddr eaddr, int rwx, int mmu_idx);

2
target/ppc/translate_init.inc.c
View File

@ -8770,6 +8770,7 @@ POWERPC_FAMILY(POWER8)(ObjectClass *oc, void *data)
pcc->handle_mmu_fault = ppc_hash64_handle_mmu_fault; pcc->handle_mmu_fault = ppc_hash64_handle_mmu_fault;
pcc->hash64_opts = &ppc_hash64_opts_POWER7; pcc->hash64_opts = &ppc_hash64_opts_POWER7;
pcc->lrg_decr_bits = 32; pcc->lrg_decr_bits = 32;
pcc->n_host_threads = 8;
#endif #endif
pcc->excp_model = POWERPC_EXCP_POWER8; pcc->excp_model = POWERPC_EXCP_POWER8;
pcc->bus_model = PPC_FLAGS_INPUT_POWER7; pcc->bus_model = PPC_FLAGS_INPUT_POWER7;
@ -8981,6 +8982,7 @@ POWERPC_FAMILY(POWER9)(ObjectClass *oc, void *data)
pcc->hash64_opts = &ppc_hash64_opts_POWER7; pcc->hash64_opts = &ppc_hash64_opts_POWER7;
pcc->radix_page_info = &POWER9_radix_page_info; pcc->radix_page_info = &POWER9_radix_page_info;
pcc->lrg_decr_bits = 56; pcc->lrg_decr_bits = 56;
pcc->n_host_threads = 4;
#endif #endif
pcc->excp_model = POWERPC_EXCP_POWER9; pcc->excp_model = POWERPC_EXCP_POWER9;
pcc->bus_model = PPC_FLAGS_INPUT_POWER9; pcc->bus_model = PPC_FLAGS_INPUT_POWER9;