Re: [PATCH v11 0/7] x86/kvm/hyper-v: add support for synthetic debugger

[Paolo Bonzini <pbonzini@redhat.com>]

On 07/05/20 05:01, Jon Doron wrote:
> Paolo was this merged in or by any chance in the queue?

No, I'll get to it today.

Paolo

> Thanks,
> -- Jon.
> 
> On 24/04/2020, Jon Doron wrote:
>> Add support for the synthetic debugger interface of hyper-v, the
>> synthetic debugger has 2 modes.
>> 1. Use a set of MSRs to send/recv information (undocumented so it's not
>>   going to the hyperv-tlfs.h)
>> 2. Use hypercalls
>>
>> The first mode is based the following MSRs:
>> 1. Control/Status MSRs which either asks for a send/recv .
>> 2. Send/Recv MSRs each holds GPA where the send/recv buffers are.
>> 3. Pending MSR, holds a GPA to a PAGE that simply has a boolean that
>>   indicates if there is data pending to issue a recv VMEXIT.
>>
>> The first mode implementation is to simply exit to user-space when
>> either the control MSR or the pending MSR are being set.
>> Then it's up-to userspace to implement the rest of the logic of
>> sending/recving.
>>
>> In the second mode instead of using MSRs KNet will simply issue
>> Hypercalls with the information to send/recv, in this mode the data
>> being transferred is UDP encapsulated, unlike in the previous mode in
>> which you get just the data to send.
>>
>> The new hypercalls will exit to userspace which will be incharge of
>> re-encapsulating if needed the UDP packets to be sent.
>>
>> There is an issue though in which KDNet does not respect the hypercall
>> page and simply issues vmcall/vmmcall instructions depending on the cpu
>> type expecting them to be handled as it a real hypercall was issued.
>>
>> It's important to note that part of this feature has been subject to be
>> removed in future versions of Windows, which is why some of the
>> defintions will not be present the the TLFS but in the kvm hyperv header
>> instead.
>>
>> v11:
>> Fixed all reviewed by and rebased on latest origin/master
>>
>> Jon Doron (6):
>>  x86/kvm/hyper-v: Explicitly align hcall param for kvm_hyperv_exit
>>  x86/kvm/hyper-v: Simplify addition for custom cpuid leafs
>>  x86/hyper-v: Add synthetic debugger definitions
>>  x86/kvm/hyper-v: Add support for synthetic debugger capability
>>  x86/kvm/hyper-v: enable hypercalls without hypercall page with syndbg
>>  x86/kvm/hyper-v: Add support for synthetic debugger via hypercalls
>>
>> Vitaly Kuznetsov (1):
>>  KVM: selftests: update hyperv_cpuid with SynDBG tests
>>
>> Documentation/virt/kvm/api.rst                |  18 ++
>> arch/x86/include/asm/hyperv-tlfs.h            |   6 +
>> arch/x86/include/asm/kvm_host.h               |  14 +
>> arch/x86/kvm/hyperv.c                         | 242 ++++++++++++++++--
>> arch/x86/kvm/hyperv.h                         |  33 +++
>> arch/x86/kvm/trace.h                          |  51 ++++
>> arch/x86/kvm/x86.c                            |  13 +
>> include/uapi/linux/kvm.h                      |  13 +
>> .../selftests/kvm/x86_64/hyperv_cpuid.c       | 143 +++++++----
>> 9 files changed, 468 insertions(+), 65 deletions(-)
>>
>> -- 
>> 2.24.1
>>
>