[RFC,v2,00/10] Support disable/enable CPU features for AArch64

Message

Peng Liang Sept. 17, 2020, 12:14 p.m. UTC

QEMU does not support disable/enable CPU features in AArch64 for now.
This patch series add support for CPU features in AArch64.

Firstly, we change the isar struct in ARMCPU to an array for
convenience.  Secondly, we add support to configure CPU feautres in
AArch64 and make sure that the ID registers can be synchronized to KVM
so that guest can read the value we configure.  Thirdly, we add a
mechanism to solve the dependency relationship of some CPU features.
Last, we add a KVM_CAP_ARM_CPU_FEATURE to check whether KVM supports to
set CPU features in AArch64.

Also export CPU features to the result of qmp query-cpu-model-expansion
so that libvirt can get the supported CPU features.

Update the ID fields to ARMv8.6 and add some CPU features according to
the new ID fields.

With related KVM patch set[1], we can disable/enable CPU features in
AArch64.

[1] https://patchwork.kernel.org/patch/11782361/

v1 -> v2:
 - adjust the order of patches
 - only expose AArch64 features which are exposed by kernel via /proc/cpuinfo
 - add check for conflict CPU features set by user
 - split the change in linux-headers/linux/kvm.h

Peng Liang (10):
  linux-header: Introduce KVM_CAP_ARM_CPU_FEATURE
  target/arm: Update ID fields
  target/arm: only set ID_PFR1_EL1.GIC for AArch32 guest
  target/arm: convert isar regs to array
  target/arm: Introduce kvm_arm_cpu_feature_supported
  target/arm: register CPU features for property
  target/arm: Allow ID registers to synchronize to KVM
  target/arm: Introduce user_mask to indicate whether the feature is set
    explicitly
  target/arm: introduce CPU feature dependency mechanism
  target/arm: Add CPU features to query-cpu-model-expansion

 linux-headers/linux/kvm.h |   1 +
 target/arm/cpu.h          | 243 +++++++++--------
 target/arm/internals.h    |  15 +-
 target/arm/kvm_arm.h      |  10 +
 hw/intc/armv7m_nvic.c     |  28 +-
 target/arm/cpu.c          | 555 ++++++++++++++++++++++++++++++--------
 target/arm/cpu64.c        | 174 ++++++------
 target/arm/cpu_tcg.c      | 250 ++++++++---------
 target/arm/helper.c       | 102 ++++---
 target/arm/kvm.c          |  38 +++
 target/arm/kvm64.c        |  86 +++---
 target/arm/monitor.c      |   4 +
 12 files changed, 976 insertions(+), 530 deletions(-)