[PATCH v8 5/5] x86/kvm/hyper-v: Add support for synthetic debugger via hypercalls
From: Jon Doron <hidden>
Date: 2020-03-19 06:38:59
Also in:
kvm
Subsystem:
kernel virtual machine for x86 (kvm/x86), kvm x86 hyper-v (kvm/hyper-v), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Sean Christopherson, Paolo Bonzini, Vitaly Kuznetsov, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
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 <redacted> --- arch/x86/kvm/hyperv.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 64f267f10049..0c3d2224dfad 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c@@ -1829,6 +1829,34 @@ 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: + if (unlikely(fast)) { + ret = HV_STATUS_INVALID_PARAMETER; + break; + } + fallthrough; + case HVCALL_RESET_DEBUG_SESSION: { + struct kvm_hv_syndbg *syndbg = vcpu_to_hv_syndbg(vcpu); + + if (!syndbg->active) { + ret = HV_STATUS_INVALID_HYPERCALL_CODE; + break; + } + + if (!(syndbg->options & HV_X64_SYNDBG_OPTION_USE_HCALLS)) { + ret = HV_STATUS_OPERATION_DENIED; + break; + } + 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;
--
2.24.1