| Message ID | d8b438b6be78b4dbeea5c2a0ecaddfc06bfea43c.1699368322.git.isaku.yamahata@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | KVM TDX basic feature support | expand |
On Tue, Nov 7, 2023 at 6:58 AM <isaku.yamahata@intel.com> wrote: > > From: Isaku Yamahata <isaku.yamahata@intel.com> > > Wire up TDX PV port IO hypercall to the KVM backend function. > > Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> > Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> > --- > arch/x86/kvm/vmx/tdx.c | 57 ++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 57 insertions(+) > > diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c > index 4e48989d364f..d4b09255ad32 100644 > --- a/arch/x86/kvm/vmx/tdx.c > +++ b/arch/x86/kvm/vmx/tdx.c > @@ -1140,6 +1140,61 @@ static int tdx_emulate_hlt(struct kvm_vcpu *vcpu) > return kvm_emulate_halt_noskip(vcpu); > } > > +static int tdx_complete_pio_in(struct kvm_vcpu *vcpu) > +{ > + struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt; > + unsigned long val = 0; > + int ret; > + > + WARN_ON_ONCE(vcpu->arch.pio.count != 1); > + > + ret = ctxt->ops->pio_in_emulated(ctxt, vcpu->arch.pio.size, > + vcpu->arch.pio.port, &val, 1); > + WARN_ON_ONCE(!ret); > + > + tdvmcall_set_return_code(vcpu, TDG_VP_VMCALL_SUCCESS); > + tdvmcall_set_return_val(vcpu, val); > + > + return 1; > +} > + > +static int tdx_emulate_io(struct kvm_vcpu *vcpu) > +{ > + struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt; > + unsigned long val = 0; > + unsigned int port; > + int size, ret; > + bool write; > + > + ++vcpu->stat.io_exits; > + > + size = tdvmcall_a0_read(vcpu); > + write = tdvmcall_a1_read(vcpu); > + port = tdvmcall_a2_read(vcpu); > + > + if (size != 1 && size != 2 && size != 4) { > + tdvmcall_set_return_code(vcpu, TDG_VP_VMCALL_INVALID_OPERAND); > + return 1; > + } > + > + if (write) { > + val = tdvmcall_a3_read(vcpu); > + ret = ctxt->ops->pio_out_emulated(ctxt, size, port, &val, 1); > + > + /* No need for a complete_userspace_io callback. */ > + vcpu->arch.pio.count = 0; > + } else { > + ret = ctxt->ops->pio_in_emulated(ctxt, size, port, &val, 1); > + if (!ret) > + vcpu->arch.complete_userspace_io = tdx_complete_pio_in; > + else > + tdvmcall_set_return_val(vcpu, val); > + } > + if (ret) > + tdvmcall_set_return_code(vcpu, TDG_VP_VMCALL_SUCCESS); In the case of a write operation that needs to exit to userspace, pio_out_emulated is going to return 0 which means that the return code is never set by tdx_emulate_io. The reason this code is working now is because r10 is already set to 0 by the guest as part of the call to tdvmcall and never gets written by the host. > + return ret; > +} > + > static int handle_tdvmcall(struct kvm_vcpu *vcpu) > { > if (tdvmcall_exit_type(vcpu)) > @@ -1150,6 +1205,8 @@ static int handle_tdvmcall(struct kvm_vcpu *vcpu) > return tdx_emulate_cpuid(vcpu); > case EXIT_REASON_HLT: > return tdx_emulate_hlt(vcpu); > + case EXIT_REASON_IO_INSTRUCTION: > + return tdx_emulate_io(vcpu); > default: > break; > } > -- > 2.25.1 >
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index 4e48989d364f..d4b09255ad32 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -1140,6 +1140,61 @@ static int tdx_emulate_hlt(struct kvm_vcpu *vcpu) return kvm_emulate_halt_noskip(vcpu); } +static int tdx_complete_pio_in(struct kvm_vcpu *vcpu) +{ + struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt; + unsigned long val = 0; + int ret; + + WARN_ON_ONCE(vcpu->arch.pio.count != 1); + + ret = ctxt->ops->pio_in_emulated(ctxt, vcpu->arch.pio.size, + vcpu->arch.pio.port, &val, 1); + WARN_ON_ONCE(!ret); + + tdvmcall_set_return_code(vcpu, TDG_VP_VMCALL_SUCCESS); + tdvmcall_set_return_val(vcpu, val); + + return 1; +} + +static int tdx_emulate_io(struct kvm_vcpu *vcpu) +{ + struct x86_emulate_ctxt *ctxt = vcpu->arch.emulate_ctxt; + unsigned long val = 0; + unsigned int port; + int size, ret; + bool write; + + ++vcpu->stat.io_exits; + + size = tdvmcall_a0_read(vcpu); + write = tdvmcall_a1_read(vcpu); + port = tdvmcall_a2_read(vcpu); + + if (size != 1 && size != 2 && size != 4) { + tdvmcall_set_return_code(vcpu, TDG_VP_VMCALL_INVALID_OPERAND); + return 1; + } + + if (write) { + val = tdvmcall_a3_read(vcpu); + ret = ctxt->ops->pio_out_emulated(ctxt, size, port, &val, 1); + + /* No need for a complete_userspace_io callback. */ + vcpu->arch.pio.count = 0; + } else { + ret = ctxt->ops->pio_in_emulated(ctxt, size, port, &val, 1); + if (!ret) + vcpu->arch.complete_userspace_io = tdx_complete_pio_in; + else + tdvmcall_set_return_val(vcpu, val); + } + if (ret) + tdvmcall_set_return_code(vcpu, TDG_VP_VMCALL_SUCCESS); + return ret; +} + static int handle_tdvmcall(struct kvm_vcpu *vcpu) { if (tdvmcall_exit_type(vcpu)) @@ -1150,6 +1205,8 @@ static int handle_tdvmcall(struct kvm_vcpu *vcpu) return tdx_emulate_cpuid(vcpu); case EXIT_REASON_HLT: return tdx_emulate_hlt(vcpu); + case EXIT_REASON_IO_INSTRUCTION: + return tdx_emulate_io(vcpu); default: break; }