KVM: PPC: Book3S HV: XIVE: Allow userspace to set the # of VPs

Add a new attribute to both XIVE and XICS-on-XIVE KVM devices so that
userspace can tell how many interrupt servers it needs. If a VM needs
less than the current default of KVM_MAX_VCPUS (2048), we can allocate
less VPs in OPAL. Combined with a core stride (VSMT) that matches the
number of guest threads per core, this may substantially increases the
number of VMs that can run concurrently with an in-kernel XIVE device.

Since the legacy XIVE KVM device is exposed to userspace through the
XICS KVM API, a new attribute group is added to it for this purpose.
While here, fix the syntax of the existing KVM_DEV_XICS_GRP_SOURCES
in the XICS documentation.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This commit is contained in:
Greg Kurz
2019-09-27 13:54:07 +02:00
committed by Paul Mackerras
parent 062cfab706
commit efe5ddcae4
5 changed files with 36 additions and 2 deletions

View File

@@ -667,6 +667,8 @@ struct kvm_ppc_cpu_char {
/* PPC64 eXternal Interrupt Controller Specification */
#define KVM_DEV_XICS_GRP_SOURCES 1 /* 64-bit source attributes */
#define KVM_DEV_XICS_GRP_CTRL 2
#define KVM_DEV_XICS_NR_SERVERS 1
/* Layout of 64-bit source attribute values */
#define KVM_XICS_DESTINATION_SHIFT 0
@@ -683,6 +685,7 @@ struct kvm_ppc_cpu_char {
#define KVM_DEV_XIVE_GRP_CTRL 1
#define KVM_DEV_XIVE_RESET 1
#define KVM_DEV_XIVE_EQ_SYNC 2
#define KVM_DEV_XIVE_NR_SERVERS 3
#define KVM_DEV_XIVE_GRP_SOURCE 2 /* 64-bit source identifier */
#define KVM_DEV_XIVE_GRP_SOURCE_CONFIG 3 /* 64-bit source identifier */
#define KVM_DEV_XIVE_GRP_EQ_CONFIG 4 /* 64-bit EQ identifier */