On Wed, Mar 4, 2020 at 4:00 PM Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> wrote:
>
> Jon Doron <arilou@xxxxxxxxx> writes:
>
> > There is another mode for the synthetic debugger which uses hypercalls
> > to send/recv network data instead of the MSR interface.
> >
> > This interface is much slower and less recommended since you might get
> > a lot of VMExits while KDVM polling for new packets to recv, rather
> > than simply checking the pending page to see if there is data avialble
> > and then request.
> >
> > Signed-off-by: Jon Doron <arilou@xxxxxxxxx>
> > ---
> > arch/x86/include/asm/hyperv-tlfs.h | 5 +++++
> > arch/x86/kvm/hyperv.c | 11 +++++++++++
> > 2 files changed, 16 insertions(+)
> >
> > diff --git a/arch/x86/include/asm/hyperv-tlfs.h b/arch/x86/include/asm/hyperv-tlfs.h
> > index 8efdf974c23f..4fa6bf3732a6 100644
> > --- a/arch/x86/include/asm/hyperv-tlfs.h
> > +++ b/arch/x86/include/asm/hyperv-tlfs.h
> > @@ -283,6 +283,8 @@
> > #define HV_X64_MSR_SYNDBG_PENDING_BUFFER 0x400000F5
> > #define HV_X64_MSR_SYNDBG_OPTIONS 0x400000FF
> >
> > +#define HV_X64_SYNDBG_OPTION_USE_HCALLS BIT(2)
> > +
>
> BIT(2) of what? :-) Also, you don't seem to use this define anywhere.
>
Will use it now :) and it's a syndbg MSR option bit
> > /* Hyper-V guest crash notification MSR's */
> > #define HV_X64_MSR_CRASH_P0 0x40000100
> > #define HV_X64_MSR_CRASH_P1 0x40000101
> > @@ -392,6 +394,9 @@ struct hv_tsc_emulation_status {
> > #define HVCALL_SEND_IPI_EX 0x0015
> > #define HVCALL_POST_MESSAGE 0x005c
> > #define HVCALL_SIGNAL_EVENT 0x005d
> > +#define HVCALL_POST_DEBUG_DATA 0x0069
> > +#define HVCALL_RETRIEVE_DEBUG_DATA 0x006a
> > +#define HVCALL_RESET_DEBUG_SESSION 0x006b
> > #define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE 0x00af
> > #define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_LIST 0x00b0
> >
> > diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
> > index 7ec962d433af..593e0f3f4dba 100644
> > --- a/arch/x86/kvm/hyperv.c
> > +++ b/arch/x86/kvm/hyperv.c
> > @@ -1794,6 +1794,17 @@ int kvm_hv_hypercall(struct kvm_vcpu *vcpu)
> > }
> > ret = kvm_hv_send_ipi(vcpu, ingpa, outgpa, true, false);
> > break;
> > + case HVCALL_POST_DEBUG_DATA:
> > + case HVCALL_RETRIEVE_DEBUG_DATA:
> > + case HVCALL_RESET_DEBUG_SESSION:
> > + vcpu->run->exit_reason = KVM_EXIT_HYPERV;
> > + vcpu->run->hyperv.type = KVM_EXIT_HYPERV_HCALL;
> > + vcpu->run->hyperv.u.hcall.input = param;
> > + vcpu->run->hyperv.u.hcall.params[0] = ingpa;
> > + vcpu->run->hyperv.u.hcall.params[1] = outgpa;
> > + vcpu->arch.complete_userspace_io =
> > + kvm_hv_hypercall_complete_userspace;
> > + return 0;
> > default:
> > ret = HV_STATUS_INVALID_HYPERCALL_CODE;
> > break;
>
> --
> Vitaly
>
