| Message ID | 1502337500-5718-1-git-send-email-tianyu.lan@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Aug 09, 2017 at 11:58:20PM -0400, Lan Tianyu wrote: > Intel Xeon phi chip will support 352 logical threads. For HPC > usage case, it will create a huge VM with vcpus number as same as host > cpus. This patch is to increase max vcpu number to 352. There is this ioctl called KVM_CAP_MAX_VCPUS. Why not use that? Oh wait, this is generic code. Perhaps there is a way to make this more abstract? Where this information is provided via an function to which various accelerators register? > > Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> > --- > hw/i386/pc_q35.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c > index 169a214..5e93749 100644 > --- a/hw/i386/pc_q35.c > +++ b/hw/i386/pc_q35.c > @@ -299,7 +299,7 @@ static void pc_q35_machine_options(MachineClass *m) > m->default_display = "std"; > m->no_floppy = 1; > m->has_dynamic_sysbus = true; > - m->max_cpus = 288; > + m->max_cpus = 352; > } > > static void pc_q35_2_10_machine_options(MachineClass *m) > -- > 1.8.3.1 > >
On Thu, Aug 10, 2017 at 02:08:38PM -0400, Konrad Rzeszutek Wilk wrote: > On Wed, Aug 09, 2017 at 11:58:20PM -0400, Lan Tianyu wrote: > > Intel Xeon phi chip will support 352 logical threads. For HPC > > usage case, it will create a huge VM with vcpus number as same as host > > cpus. This patch is to increase max vcpu number to 352. > > There is this ioctl called KVM_CAP_MAX_VCPUS. Why not use that? > > Oh wait, this is generic code. Perhaps there is a way to make > this more abstract? Where this information is provided via > an function to which various accelerators register? We already check KVM_CAP_MAX_VCPUS, see kvm-all.c:kvm_init(). MachineClass::max_cpus is a limit defined at compile time, based on the limitations of the existing QEMU machine/device code.
diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c index 169a214..5e93749 100644 --- a/hw/i386/pc_q35.c +++ b/hw/i386/pc_q35.c @@ -299,7 +299,7 @@ static void pc_q35_machine_options(MachineClass *m) m->default_display = "std"; m->no_floppy = 1; m->has_dynamic_sysbus = true; - m->max_cpus = 288; + m->max_cpus = 352; } static void pc_q35_2_10_machine_options(MachineClass *m)
Intel Xeon phi chip will support 352 logical threads. For HPC usage case, it will create a huge VM with vcpus number as same as host cpus. This patch is to increase max vcpu number to 352. Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> --- hw/i386/pc_q35.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)