Re: [PATCH] KVM: PPC: Book3S HV: Tunable to configure maximum # of vCPUs per VM

2019-09-12 Thread David Gibson
On Wed, Sep 11, 2019 at 12:25:24PM +0200, Greg Kurz wrote: > On Wed, 11 Sep 2019 12:30:48 +1000 > David Gibson wrote: > > > On Tue, Sep 10, 2019 at 06:49:34PM +0200, Greg Kurz wrote: > > > Each vCPU of a VM allocates a XIVE VP in OPAL which is associated with > > > 8 event queue (EQ) descriptors,

Re: [PATCH] KVM: PPC: Book3S HV: Tunable to configure maximum # of vCPUs per VM

2019-09-11 Thread Greg Kurz
On Wed, 11 Sep 2019 12:30:48 +1000 David Gibson wrote: > On Tue, Sep 10, 2019 at 06:49:34PM +0200, Greg Kurz wrote: > > Each vCPU of a VM allocates a XIVE VP in OPAL which is associated with > > 8 event queue (EQ) descriptors, one for each priority. A POWER9 socket > > can handle a maximum of 1M

Re: [PATCH] KVM: PPC: Book3S HV: Tunable to configure maximum # of vCPUs per VM

2019-09-10 Thread David Gibson
On Tue, Sep 10, 2019 at 06:49:34PM +0200, Greg Kurz wrote: > Each vCPU of a VM allocates a XIVE VP in OPAL which is associated with > 8 event queue (EQ) descriptors, one for each priority. A POWER9 socket > can handle a maximum of 1M event queues. > > The powernv platform allocates NR_CPUS (== 204

[PATCH] KVM: PPC: Book3S HV: Tunable to configure maximum # of vCPUs per VM

2019-09-10 Thread Greg Kurz
Each vCPU of a VM allocates a XIVE VP in OPAL which is associated with 8 event queue (EQ) descriptors, one for each priority. A POWER9 socket can handle a maximum of 1M event queues. The powernv platform allocates NR_CPUS (== 2048) VPs for the hypervisor, and each XIVE KVM device allocates KVM_MAX