[v2,00/16] KVM: Add Xen hypercall and shared info pages

Message

David Woodhouse Dec. 6, 2020, 11:03 a.m. UTC

Reviving the first section (so far) of a patch set that Joao posted as 
RFC last year:

https://lore.kernel.org/kvm/[e-mail]/

This adds basic hypercall interception support, and adds support for
timekeeping and runstate-related shared info regions.

I've updated and reworked the original a bit, including (in my v1):
 • Support for 32-bit guests
 • 64-bit second support in wallclock
 • Time counters for runnable/blocked states in runstate support
 • Self-tests
 • Fixed Viridian coexistence
 • No new KVM_CAP_XEN_xxx, just more bits returned by KVM_CAP_XEN_HVM

v2: 
 • Remember the RCU read-critical sections on using the shared info pages
 • Fix 32-bit build of compat structures (which we use there too)
 • Use RUNSTATE_blocked as initial state not RUNSTATE_runnable
 • Include documentation, add cosmetic KVM_XEN_HVM_CONFIG_HYPERCALL_MSR

David Woodhouse (7):
      KVM: Fix arguments to kvm_{un,}map_gfn()
      KVM: x86/xen: Fix coexistence of Xen and Hyper-V hypercalls
      KVM: x86/xen: latch long_mode when hypercall page is set up
      KVM: x86/xen: add definitions of compat_shared_info, compat_vcpu_info
      xen: add wc_sec_hi to struct shared_info
      KVM: x86: declare Xen HVM shared info capability and add test case
      KVM: Add documentation for Xen hypercall and shared_info updates

Joao Martins (9):
      KVM: x86/xen: fix Xen hypercall page msr handling
      KVM: x86/xen: intercept xen hypercalls if enabled
      KVM: x86/xen: add KVM_XEN_HVM_SET_ATTR/KVM_XEN_HVM_GET_ATTR
      KVM: x86/xen: register shared_info page
      KVM: x86/xen: setup pvclock updates
      KVM: x86/xen: update wallclock region
      KVM: x86/xen: register vcpu info
      KVM: x86/xen: register vcpu time info region
      KVM: x86/xen: register runstate info

 Documentation/virt/kvm/api.rst                       | 119 ++++++++++++++++++++++++++++++++++
 arch/x86/include/asm/kvm_host.h                      |  23 +++++++
 arch/x86/include/asm/xen/interface.h                 |   3 +
 arch/x86/kvm/Makefile                                |   2 +-
 arch/x86/kvm/hyperv.c                                |  40 ++++++++----
 arch/x86/kvm/trace.h                                 |  36 +++++++++++
 arch/x86/kvm/x86.c                                   | 110 ++++++++++++++++++++------------
 arch/x86/kvm/x86.h                                   |   1 +
 arch/x86/kvm/xen.c                                   | 557 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 arch/x86/kvm/xen.h                                   |  83 ++++++++++++++++++++++++
 include/linux/kvm_host.h                             |  34 +++++-----
 include/uapi/linux/kvm.h                             |  48 ++++++++++++++
 include/xen/interface/xen.h                          |   4 +-
 tools/testing/selftests/kvm/Makefile                 |   2 +
 tools/testing/selftests/kvm/lib/kvm_util.c           |   1 +
 tools/testing/selftests/kvm/x86_64/xen_shinfo_test.c | 187 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 tools/testing/selftests/kvm/x86_64/xen_vmcall_test.c | 150 +++++++++++++++++++++++++++++++++++++++++++
 virt/kvm/kvm_main.c                                  |   8 +--
 18 files changed, 1335 insertions(+), 73 deletions(-)