[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-ppc] [PULL 10/14] spapr: consolidate the VCPU id numbering logic i
From: |
David Gibson |
Subject: |
[Qemu-ppc] [PULL 10/14] spapr: consolidate the VCPU id numbering logic in a single place |
Date: |
Fri, 16 Feb 2018 21:06:13 +1100 |
From: Greg Kurz <address@hidden>
Several places in the code need to calculate a VCPU id:
(cpu_index / smp_threads) * spapr->vsmt + cpu_index % smp_threads
(core_id / smp_threads) * spapr->vsmt (1 user)
index * spapr->vsmt (2 users)
or guess that the VCPU id of a given VCPU is the first thread of a virtual
core:
index % spapr->vsmt != 0
Even if the numbering logic isn't that complex, it is rather fragile to
have these assumptions open-coded in several places. FWIW this was
proved with recent issues related to VSMT.
This patch moves the VCPU id formula to a single function to be called
everywhere the code needs to compute one. It also adds an helper to
guess if a VCPU is the first thread of a VCORE.
Signed-off-by: Greg Kurz <address@hidden>
[dwg: Rename spapr_is_vcore() to spapr_is_thread0_in_vcore() for clarity]
Signed-off-by: David Gibson <address@hidden>
---
hw/ppc/spapr.c | 30 +++++++++++++++++++++++-------
1 file changed, 23 insertions(+), 7 deletions(-)
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index 18ebc058ac..83c9d66dd5 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -99,6 +99,21 @@
#define PHANDLE_XICP 0x00001111
+/* These two functions implement the VCPU id numbering: one to compute them
+ * all and one to identify thread 0 of a VCORE. Any change to the first one
+ * is likely to have an impact on the second one, so let's keep them close.
+ */
+static int spapr_vcpu_id(sPAPRMachineState *spapr, int cpu_index)
+{
+ return
+ (cpu_index / smp_threads) * spapr->vsmt + cpu_index % smp_threads;
+}
+static bool spapr_is_thread0_in_vcore(sPAPRMachineState *spapr,
+ PowerPCCPU *cpu)
+{
+ return spapr_get_vcpu_id(cpu) % spapr->vsmt == 0;
+}
+
static ICSState *spapr_ics_create(sPAPRMachineState *spapr,
const char *type_ics,
int nr_irqs, Error **errp)
@@ -345,7 +360,7 @@ static int spapr_fixup_cpu_dt(void *fdt, sPAPRMachineState
*spapr)
int index = spapr_get_vcpu_id(cpu);
int compat_smt = MIN(smp_threads, ppc_compat_max_vthreads(cpu));
- if (index % spapr->vsmt != 0) {
+ if (!spapr_is_thread0_in_vcore(spapr, cpu)) {
continue;
}
@@ -630,7 +645,7 @@ static void spapr_populate_cpus_dt_node(void *fdt,
sPAPRMachineState *spapr)
DeviceClass *dc = DEVICE_GET_CLASS(cs);
int offset;
- if (index % spapr->vsmt != 0) {
+ if (!spapr_is_thread0_in_vcore(spapr, cpu)) {
continue;
}
@@ -2251,7 +2266,7 @@ static void spapr_init_cpus(sPAPRMachineState *spapr)
if (mc->has_hotpluggable_cpus) {
spapr_dr_connector_new(OBJECT(spapr), TYPE_SPAPR_DRC_CPU,
- (core_id / smp_threads) * spapr->vsmt);
+ spapr_vcpu_id(spapr, core_id));
}
if (i < boot_cores_nr) {
@@ -3293,7 +3308,8 @@ void spapr_core_unplug_request(HotplugHandler
*hotplug_dev, DeviceState *dev,
return;
}
- drc = spapr_drc_by_id(TYPE_SPAPR_DRC_CPU, index * spapr->vsmt);
+ drc = spapr_drc_by_id(TYPE_SPAPR_DRC_CPU,
+ spapr_vcpu_id(spapr, cc->core_id));
g_assert(drc);
spapr_drc_detach(drc);
@@ -3322,7 +3338,8 @@ static void spapr_core_plug(HotplugHandler *hotplug_dev,
DeviceState *dev,
cc->core_id);
return;
}
- drc = spapr_drc_by_id(TYPE_SPAPR_DRC_CPU, index * spapr->vsmt);
+ drc = spapr_drc_by_id(TYPE_SPAPR_DRC_CPU,
+ spapr_vcpu_id(spapr, cc->core_id));
g_assert(drc || !mc->has_hotpluggable_cpus);
@@ -3807,8 +3824,7 @@ void spapr_set_vcpu_id(PowerPCCPU *cpu, int cpu_index,
Error **errp)
sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
int vcpu_id;
- vcpu_id =
- (cpu_index / smp_threads) * spapr->vsmt + cpu_index % smp_threads;
+ vcpu_id = spapr_vcpu_id(spapr, cpu_index);
if (kvm_enabled() && !kvm_vcpu_id_is_valid(vcpu_id)) {
error_setg(errp, "Can't create CPU with id %d in KVM", vcpu_id);
--
2.14.3
- [Qemu-ppc] [PULL 00/14] ppc-for-2.12 queue 20180216, David Gibson, 2018/02/16
- [Qemu-ppc] [PULL 06/14] ppc/spapr-caps: Change migration macro to take full spapr-cap name, David Gibson, 2018/02/16
- [Qemu-ppc] [PULL 04/14] hw/ppc/spapr_hcall: set htab_shift after kvmppc_resize_hpt_commit, David Gibson, 2018/02/16
- [Qemu-ppc] [PULL 13/14] ppc/spapr-caps: Disallow setting workaround for spapr-cap-ibs, David Gibson, 2018/02/16
- [Qemu-ppc] [PULL 08/14] spapr: move VCPU calculation to core machine code, David Gibson, 2018/02/16
- [Qemu-ppc] [PULL 09/14] spapr: rename spapr_vcpu_id() to spapr_get_vcpu_id(), David Gibson, 2018/02/16
- [Qemu-ppc] [PULL 02/14] ppc: move CUDAState and other CUDA-related definitions into separate cuda.h file, David Gibson, 2018/02/16
- [Qemu-ppc] [PULL 12/14] target/ppc: convert to TranslatorOps, David Gibson, 2018/02/16
- [Qemu-ppc] [PULL 10/14] spapr: consolidate the VCPU id numbering logic in a single place,
David Gibson <=
- [Qemu-ppc] [PULL 03/14] cuda: convert to trace-events, David Gibson, 2018/02/16
- [Qemu-ppc] [PULL 07/14] spapr: use spapr->vsmt to compute VCPU ids, David Gibson, 2018/02/16
- [Qemu-ppc] [PULL 05/14] hw/char: remove legacy interface escc_init(), David Gibson, 2018/02/16
- [Qemu-ppc] [PULL 11/14] target/ppc: convert to DisasContextBase, David Gibson, 2018/02/16
- [Qemu-ppc] [PULL 01/14] cuda: convert to use the shared mos6522 device, David Gibson, 2018/02/16
- [Qemu-ppc] [PULL 14/14] ppc4xx: Add device models found in PPC440 core SoCs, David Gibson, 2018/02/16
- Re: [Qemu-ppc] [PULL 00/14] ppc-for-2.12 queue 20180216, Peter Maydell, 2018/02/16