Currently the max number of VCPUs usable along with the KVM GICv3
device is limited to 123. The rationale is a single redistributor
region was supported and this latter was set to [0x80A0000, 0x9000000]
within the guest physical address space, surrounded with DIST and UART
MMIO regions.
[1] now allows to register several redistributor regions.
So this series overcomes the max 123 vcpu limitation by registering
a new redistributor region located just after the VIRT_MEM RAM region.
This second redistributor region has a capacity of 512 redistributors.
The max supported VCPUs in non accelerated mode is not modified.
Best Regards
Eric
Host Kernel dependencies:
[1] [PATCH v6 00/12] KVM: arm/arm64: Allow multiple GICv3 redistributor
regions
https://github.com/eauger/linux/tree/v4.17-rc2-rdist-regions-v6
This QEMU series can be found at:
https://github.com/eauger/qemu/tree/v2.12.0-rdist_regions-rfc-v3
Previous version:
https://github.com/eauger/qemu/tree/v2.12.0-rdist_regions-rfc-v2
History:
v2 -> v3:
- Added the last patch defining 3.0 machine type and setting
max_cpus to 512
- redistributor region total count exactly matching the number
of requested vcpus
- added missing return in arm_gic_realize
- checked redist region capacity versus #vcpus earlier in
gicv3_init_irqs_and_mmio
- use GICV3_REDIST_SIZE
- Changed the 2d region size to 64MB
v1 -> v2:
- Do not use KVM_MAX_VCPUS anymore
- In case the multiple redistributor region capability is not
supported by the host kernel, the GICv3 device realize() fails
with a hint for the end-user.
- use properties to set the redistributor region count
- sysbus_mmio_map is kept in virt and machine init done notifier
mechanism is used with an address fixup addition.
- I have not yet extended the second redist region as Peter suggested.
We can easily add another 3th region later on if requested. But
if mandated, I will fix that in next release.
Eric Auger (8):
linux-headers: Partial update for KVM/ARM multiple redistributor
region registration
target/arm: Allow KVM device address overwriting
hw/intc/arm_gicv3: Introduce redist-region-count array property
hw/intc/arm_gicv3_kvm: Get prepared to handle multiple redist regions
hw/arm/virt: GICv3 DT node with one or two redistributor regions
hw/arm/virt-acpi-build: Advertise one or two GICR structures
hw/arm/virt: Register two redistributor regions when necessary
hw/arm/virt: Add virt-3.0 machine type supporting up to 512 vcpus
hw/arm/virt-acpi-build.c | 9 ++++
hw/arm/virt.c | 88 ++++++++++++++++++++++++++++++++------
hw/intc/arm_gic_kvm.c | 4 +-
hw/intc/arm_gicv3.c | 12 +++++-
hw/intc/arm_gicv3_common.c | 38 +++++++++++++---
hw/intc/arm_gicv3_its_kvm.c | 2 +-
hw/intc/arm_gicv3_kvm.c | 40 +++++++++++++++--
include/hw/arm/virt.h | 14 ++++++
include/hw/intc/arm_gicv3_common.h | 8 +++-
linux-headers/asm-arm/kvm.h | 1 +
linux-headers/asm-arm64/kvm.h | 1 +
target/arm/kvm.c | 10 ++++-
target/arm/kvm_arm.h | 3 +-
13 files changed, 200 insertions(+), 30 deletions(-)
--
2.5.5
