[PATCH v6 0/4] KVM: arm64: Errata management for VM Live migration
Shameer Kolothum
shameerali.kolothum.thodi at huawei.com
Wed Feb 5 05:22:18 PST 2025
Hi,
v5 --> v6
https://lore.kernel.org/kvmarm/20250124151732.6072-1-shameerali.kolothum.thodi@huawei.com/
-Addressed comments from Oliver,
-Changed version to 32 bit to match SMCCC_VERSION
-Don't advertise pKVM hypercalls to guests.
-Moved hypercall invocation to kvm_guest.c
This can be sanity tested by the Qemu branch here,
https://github.com/hisilicon/qemu/tree/v9.0-nv-rfcv4-vcpu-model-v2-target-cpu-errata
(branch based on Eric's/Connie's NV + custom CPU series)
Eg: to specify target impl CPUs,
-machine virt,.., x-target-impl-cpus=0xMIDR1:0xREVIDR1-0xMIDR2:REVIDR2
Please take a look and let me know your feedback.
Thanks,
Shameer
v4 --> v5
https://lore.kernel.org/kvmarm/20241218105345.73472-1-shameerali.kolothum.thodi@huawei.com/
-Addressed comments from Marc,
-Added an hypercall to retrieve version and number of supported target
impl CPUs.
-Added a check for KVM hypercall services availability.
-Removed R-by tags from Connie & Sebastian as patches 2 & 4 are now
changed a bit. Please take another look.
v3 --> v4(Minor updates)
https://lore.kernel.org/kvmarm/20241209115311.40496-1-shameerali.kolothum.thodi@huawei.com/
-Changed MIDR/REVIDR to 64 bits based on feedback from Connie
and Marc(Patch #3).
-Added R-by tags from Sebastian (Thanks!).
RFC v2 --> v3
https://lore.kernel.org/kvmarm/20241024094012.29452-1-shameerali.kolothum.thodi@huawei.com/
-Addressed comments from Oliver(Thanks!).
-Using implementation CPUs MIDR/REVIDR when it is set for
_midr_range() functions(Patch 1 & 3)
-New hypercall for retrieving implementation CPUs(Patch #2).
-Dropped RFC.
RFC v1 --> RFCv2:
https://lore.kernel.org/kvmarm/20241011075053.80540-1-shameerali.kolothum.thodi@huawei.com/
-Introduced hypercalls to retrieve target CPUs info from user space VMM.
see patch #1 for details.
-Patch #2 uses the hypercall to retrieve the target CPU info if any.
-Use the target CPUs MIDR/REVIDR in errata enablement. See patch #3.
Background from v1:
On ARM64 platforms most of the errata workarounds are based on CPU
MIDR/REVIDR values and a number of these workarounds need to be
implemented by the Guest kernel as well. This creates a problem when
Guest needs to be migrated to a platform that differs in these
MIDR/REVIDR values even if the VMM can come up with a common minimum
feature list for the Guest using the recently introduced "Writable
ID registers" support.
(This is roughly based on a discussion I had with Marc and Oliver
at KVM forum. Marc outlined his idea for a solution and this is an
attempt to implement it. Thanks to both and I take all the blame
if this is nowhere near what is intended/required)
Shameer Kolothum (4):
arm64: Modify _midr_range() functions to read MIDR/REVIDR internally
KVM: arm64: Introduce hypercall support for retrieving target
implementations
KVM: arm64: Report all the KVM/arm64-specific hypercalls
arm64: paravirt: Enable errata based on implementation CPUs
Documentation/virt/kvm/arm/hypercalls.rst | 59 +++++++++++++++++++++
arch/arm64/include/asm/cputype.h | 50 ++++++++++++------
arch/arm64/include/asm/hypervisor.h | 1 +
arch/arm64/include/asm/mmu.h | 3 +-
arch/arm64/kernel/cpu_errata.c | 37 +++++++++----
arch/arm64/kernel/cpufeature.c | 8 +--
arch/arm64/kernel/image-vars.h | 2 +
arch/arm64/kernel/proton-pack.c | 17 +++---
arch/arm64/kvm/hypercalls.c | 6 ++-
arch/arm64/kvm/vgic/vgic-v3.c | 2 +-
drivers/clocksource/arm_arch_timer.c | 2 +-
drivers/firmware/smccc/kvm_guest.c | 63 +++++++++++++++++++++++
include/linux/arm-smccc.h | 15 ++++++
13 files changed, 223 insertions(+), 42 deletions(-)
--
2.47.0
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