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[PULL 06/28] spapr: Set VSMT to smp_threads by default
From: |
David Gibson |
Subject: |
[PULL 06/28] spapr: Set VSMT to smp_threads by default |
Date: |
Thu, 24 Oct 2019 19:17:51 +1100 |
From: Greg Kurz <address@hidden>
Support for setting VSMT is available in KVM since linux-4.13. Most distros
that support KVM on POWER already have it. It thus seem reasonable enough
to have the default machine to set VSMT to smp_threads.
This brings contiguous VCPU ids and thus brings their upper bound down to
the machine's max_cpus. This is especially useful for XIVE KVM devices,
which may thus allocate only one VP descriptor per VCPU.
Signed-off-by: Greg Kurz <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: David Gibson <address@hidden>
---
hw/ppc/spapr.c | 7 ++++++-
include/hw/ppc/spapr.h | 1 +
2 files changed, 7 insertions(+), 1 deletion(-)
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 4eb97d3a9b..428b834f30 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -2496,6 +2496,7 @@ static CPUArchId *spapr_find_cpu_slot(MachineState *ms,
uint32_t id, int *idx)
static void spapr_set_vsmt_mode(SpaprMachineState *spapr, Error **errp)
{
MachineState *ms = MACHINE(spapr);
+ SpaprMachineClass *smc = SPAPR_MACHINE_GET_CLASS(spapr);
Error *local_err = NULL;
bool vsmt_user = !!spapr->vsmt;
int kvm_smt = kvmppc_smt_threads();
@@ -2522,7 +2523,7 @@ static void spapr_set_vsmt_mode(SpaprMachineState *spapr,
Error **errp)
goto out;
}
/* In this case, spapr->vsmt has been set by the command line */
- } else {
+ } else if (!smc->smp_threads_vsmt) {
/*
* Default VSMT value is tricky, because we need it to be as
* consistent as possible (for migration), but this requires
@@ -2531,6 +2532,8 @@ static void spapr_set_vsmt_mode(SpaprMachineState *spapr,
Error **errp)
* overwhelmingly common case in production systems.
*/
spapr->vsmt = MAX(8, smp_threads);
+ } else {
+ spapr->vsmt = smp_threads;
}
/* KVM: If necessary, set the SMT mode: */
@@ -4438,6 +4441,7 @@ static void spapr_machine_class_init(ObjectClass *oc,
void *data)
smc->irq = &spapr_irq_dual;
smc->dr_phb_enabled = true;
smc->linux_pci_probe = true;
+ smc->smp_threads_vsmt = true;
}
static const TypeInfo spapr_machine_info = {
@@ -4505,6 +4509,7 @@ static void spapr_machine_4_1_class_options(MachineClass
*mc)
spapr_machine_4_2_class_options(mc);
smc->linux_pci_probe = false;
+ smc->smp_threads_vsmt = false;
compat_props_add(mc->compat_props, hw_compat_4_1, hw_compat_4_1_len);
compat_props_add(mc->compat_props, compat, G_N_ELEMENTS(compat));
}
diff --git a/include/hw/ppc/spapr.h b/include/hw/ppc/spapr.h
index cbd1a4c9f3..2009eb64f9 100644
--- a/include/hw/ppc/spapr.h
+++ b/include/hw/ppc/spapr.h
@@ -122,6 +122,7 @@ struct SpaprMachineClass {
bool broken_host_serial_model; /* present real host info to the guest */
bool pre_4_1_migration; /* don't migrate hpt-max-page-size */
bool linux_pci_probe;
+ bool smp_threads_vsmt; /* set VSMT to smp_threads by default */
void (*phb_placement)(SpaprMachineState *spapr, uint32_t index,
uint64_t *buid, hwaddr *pio,
--
2.21.0
- [PULL 10/28] spapr: Formalize notion of active interrupt controller, (continued)
- [PULL 10/28] spapr: Formalize notion of active interrupt controller, David Gibson, 2019/10/24
- [PULL 08/28] spapr, xics, xive: Move cpu_intc_create from SpaprIrq to SpaprInterruptController, David Gibson, 2019/10/24
- [PULL 23/28] spapr_cpu_core: Implement DeviceClass::reset, David Gibson, 2019/10/24
- [PULL 09/28] spapr, xics, xive: Move irq claim and free from SpaprIrq to SpaprInterruptController, David Gibson, 2019/10/24
- [PULL 18/28] spapr: Remove SpaprIrq::nr_msis, David Gibson, 2019/10/24
- [PULL 27/28] ppc/pnv: Fix naming of routines realizing the CPUs, David Gibson, 2019/10/24
- [PULL 28/28] spapr/xive: Set the OS CAM line at reset, David Gibson, 2019/10/24
- [PULL 13/28] spapr, xics, xive: Move dt_populate from SpaprIrq to SpaprInterruptController, David Gibson, 2019/10/24
- [PULL 12/28] spapr, xics, xive: Move print_info from SpaprIrq to SpaprInterruptController, David Gibson, 2019/10/24
- [PULL 17/28] spapr, xics, xive: Move SpaprIrq::post_load hook to backends, David Gibson, 2019/10/24
- [PULL 06/28] spapr: Set VSMT to smp_threads by default,
David Gibson <=
- [PULL 22/28] spapr: move CPU reset after presenter creation, David Gibson, 2019/10/24
- [PULL 15/28] spapr: Remove SpaprIrq::init_kvm hook, David Gibson, 2019/10/24
- [PULL 14/28] spapr, xics, xive: Match signatures for XICS and XIVE KVM connect routines, David Gibson, 2019/10/24
- [PULL 25/28] ppc/pnv: Add a PnvChip pointer to PnvCore, David Gibson, 2019/10/24
- [PULL 24/28] ppc/pnv: Introduce a PnvCore reset handler, David Gibson, 2019/10/24
- [PULL 16/28] spapr, xics, xive: Move SpaprIrq::reset hook logic into activate/deactivate, David Gibson, 2019/10/24
- [PULL 26/28] ppc: Reset the interrupt presenter from the CPU reset handler, David Gibson, 2019/10/24
- [PULL 19/28] spapr: Move SpaprIrq::nr_xirqs to SpaprMachineClass, David Gibson, 2019/10/24
- [PULL 20/28] pseries: Update SLOF firmware image, David Gibson, 2019/10/24
- Re: [PULL 00/28] ppc-for-4.2 queue 20191024, Peter Maydell, 2019/10/24