On Tue, 26 Jun 2018 11:22:26 +0200 Marc-André Lureau <marcandre.lur...@gmail.com> wrote:
> On Thu, Jun 21, 2018 at 4:33 PM, Igor Mammedov <imamm...@redhat.com> wrote: > > On Thu, 21 Jun 2018 15:24:44 +0200 > > Marc-André Lureau <marcandre.lur...@gmail.com> wrote: > > > >> Hi > >> > >> On Thu, Jun 21, 2018 at 3:02 PM, Igor Mammedov <imamm...@redhat.com> > >> wrote: > >> > On Tue, 15 May 2018 14:14:33 +0200 > >> > Marc-André Lureau <marcandre.lur...@redhat.com> wrote: > >> > > >> >> This allows to pass the last failing test from the Windows HLK TPM 2.0 > >> >> TCG PPI 1.3 tests. > >> >> > >> >> The interface is described in the "TCG Platform Reset Attack > >> >> Mitigation Specification", chapter 6 "ACPI _DSM Function". Whether or > >> >> not we should have a real implementation remains an open question to > >> >> me. > >> > might it cause security issues? > >> > >> Good question. If the guest assumes success of this operation perhaps. > >> I'll check the spec. > >> > >> > What are implications of faking it and how hard it's to implement thing > >> > per spec? > >> > >> Laszlo answerd that in "[Qemu-devel] investigating TPM for > >> OVMF-on-QEMU" 2f2b) TCG Memory Clear Interface > > I get that it's optional, but we probably shouldn't advertise/fake > > feature if it's not supported. > > As said in the commit message, the objective was to pass the Windows > HLK test. If we don't want to advertize a fake interface, I am fine > droping this patch. We'll have to revisit with Laszlo the work needed > in the firmware to support it. I think it would be safer to drop this patch. > > > >> > >> > > >> > > >> >> Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com> > >> >> --- > >> >> hw/i386/acpi-build.c | 9 +++++++++ > >> >> 1 file changed, 9 insertions(+) > >> >> > >> >> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c > >> >> index 95be4f0710..392a1e50bd 100644 > >> >> --- a/hw/i386/acpi-build.c > >> >> +++ b/hw/i386/acpi-build.c > >> >> @@ -2072,6 +2072,15 @@ build_tpm_ppi(Aml *dev) > >> >> aml_append(ifctx, aml_return(aml_buffer(1, zerobyte))); > >> >> } > >> >> aml_append(method, ifctx); > >> >> + > >> >> + /* dummy MOR Memory Clear for the sake of WLK PPI test */ > >> >> + ifctx = aml_if( > >> >> + aml_equal(aml_arg(0), > >> >> + > >> >> aml_touuid("376054ED-CC13-4675-901C-4756D7F2D45D"))); > >> >> + { > >> >> + aml_append(ifctx, aml_return(aml_int(0))); > >> >> + } > >> >> + aml_append(method, ifctx); > >> >> } > >> >> aml_append(dev, method); > >> >> } > >> > > >> > > >> > >> > >> > > > > >