Re: [PATCH V3 0/4] KVM/x86/hyper-V: Introduce PV guest address space mapping flush support

[Paolo Bonzini]

On 20/07/2018 05:58, KY Srinivasan wrote:
> 
> 
>> -----Original Message-----
>> From: Tianyu Lan
>> Sent: Thursday, July 19, 2018 1:40 AM
>> Cc: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>; devel@xxxxxxxxxxxxxxxxxxxxxx;
>> Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>; hpa@xxxxxxxxx;
>> kvm@xxxxxxxxxxxxxxx; KY Srinivasan <kys@xxxxxxxxxxxxx>; linux-
>> kernel@xxxxxxxxxxxxxxx; mingo@xxxxxxxxxx; pbonzini@xxxxxxxxxx;
>> rkrcmar@xxxxxxxxxx; Stephen Hemminger <sthemmin@xxxxxxxxxxxxx>;
>> tglx@xxxxxxxxxxxxx; x86@xxxxxxxxxx; Michael Kelley (EOSG)
>> <Michael.H.Kelley@xxxxxxxxxxxxx>; vkuznets@xxxxxxxxxx
>> Subject: [PATCH V3 0/4] KVM/x86/hyper-V: Introduce PV guest address
>> space mapping flush support
>>
>> Hyper-V provides a para-virtualization hypercall
>> HvFlushGuestPhysicalAddressSpace
>> to flush nested VM address space mapping in l1 hypervisor and it's to reduce
>> overhead
>> of flushing ept tlb among vcpus. The tradition way is to send IPIs to all
>> affected
>> vcpus and executes INVEPT on each vcpus. It will trigger several vmexits for
>> IPI and
>> INVEPT emulation. The pv hypercall can help to flush specified ept table on all
>> vcpus
>> via one single hypercall.
>>
>> Change since v2:
>>        - Make ept_pointers_match as tristate "check", "match" and "mismatch".
>>        Set "check" in vmx_set_cr3(), check all ept table pointers in
>> hv_remote_flush_tlb()
>>        and call hypercall when all ept pointers are same.
>>        - Rename kvm_arch_hv_flush_remote_tlb with
>> kvm_arch_flush_remote_tlb and
>>        Rename kvm_x86_ops->hv_tlb_remote_flush with kvm_x86_ops-
>>> tlb_remote_flush
>>        - Fix issue that ignore updating tlbs_dirty during calling
>> kvm_arch_flush_remote_tlbs()
>>        - Merge patch "KVM/VMX: Add identical ept table pointer check" and
>>        patch "KVM/x86: Add tlb_remote_flush callback support for vmx"
>>
>> Change since v1:
>>        - Fix compilation error for non-x86 platform.
>>        - Use ept_pointers_match to check condition of identical ept
>>             table pointer and get ept pointer from struct vcpu_vmx->ept_pointer.
>>        - Add hyperv_nested_flush_guest_mapping ftrace support
>>
>>
>>
>> Lan Tianyu (4):
>>   X86/Hyper-V: Add flush HvFlushGuestPhysicalAddressSpace hypercall
>>     support
>>   X86/Hyper-V: Add hyperv_nested_flush_guest_mapping ftrace support
>>   KVM: Add tlb remote flush callback in kvm_x86_ops.
>>   KVM/x86: Add tlb_remote_flush callback support for vmx
>>
>>  arch/x86/hyperv/Makefile            |  2 +-
>>  arch/x86/hyperv/nested.c            | 67
>> ++++++++++++++++++++++++++++++++++
>>  arch/x86/include/asm/hyperv-tlfs.h  |  8 +++++
>>  arch/x86/include/asm/kvm_host.h     | 11 ++++++
>>  arch/x86/include/asm/mshyperv.h     |  2 ++
>>  arch/x86/include/asm/trace/hyperv.h | 14 ++++++++
>>  arch/x86/kvm/vmx.c                  | 72
>> ++++++++++++++++++++++++++++++++++++-
>>  include/linux/kvm_host.h            |  7 ++++
>>  virt/kvm/kvm_main.c                 |  3 +-
>>  9 files changed, 183 insertions(+), 3 deletions(-)
>>  create mode 100644 arch/x86/hyperv/nested.c
> 
> Acked-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>

Queued, thanks!

Paolo