Xiaoyao Li <xiaoyao.li@xxxxxxxxx> writes: > From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx> > > Three sha384 hash values, mrconfigid, mrowner and mrownerconfig, of a TD > can be provided for TDX attestation. Detailed meaning of them can be > found: https://lore.kernel.org/qemu-devel/31d6dbc1-f453-4cef-ab08-4813f4e0ff92@xxxxxxxxx/ > > Allow user to specify those values via property mrconfigid, mrowner and > mrownerconfig. They are all in base64 format. > > example > -object tdx-guest, \ > mrconfigid=ASNFZ4mrze8BI0VniavN7wEjRWeJq83vASNFZ4mrze8BI0VniavN7wEjRWeJq83v,\ > mrowner=ASNFZ4mrze8BI0VniavN7wEjRWeJq83vASNFZ4mrze8BI0VniavN7wEjRWeJq83v,\ > mrownerconfig=ASNFZ4mrze8BI0VniavN7wEjRWeJq83vASNFZ4mrze8BI0VniavN7wEjRWeJq83v > > Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx> > Co-developed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx> > Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx> > > --- > Changes in v5: > - refine the description of QAPI properties and add description of > default value when not specified; > > Changes in v4: > - describe more of there fields in qom.json > - free the old value before set new value to avoid memory leak in > _setter(); (Daniel) > > Changes in v3: > - use base64 encoding instread of hex-string; > --- > qapi/qom.json | 17 ++++++++- > target/i386/kvm/tdx.c | 87 +++++++++++++++++++++++++++++++++++++++++++ > target/i386/kvm/tdx.h | 3 ++ > 3 files changed, 106 insertions(+), 1 deletion(-) > > diff --git a/qapi/qom.json b/qapi/qom.json > index 89ed89b9b46e..cac875349a3a 100644 > --- a/qapi/qom.json > +++ b/qapi/qom.json > @@ -905,10 +905,25 @@ > # pages. Some guest OS (e.g., Linux TD guest) may require this to > # be set, otherwise they refuse to boot. > # > +# @mrconfigid: ID for non-owner-defined configuration of the guest TD, > +# e.g., run-time or OS configuration (base64 encoded SHA384 digest). > +# (A default value 0 of SHA384 is used when absent). Suggest to drop the parenthesis in the last sentence. @mrconfigid is a string, so the default value can't be 0. Actually, it's not just any string, but a base64 encoded SHA384 digest, which means it must be exactly 96 hex digits. So it can't be "0", either. It could be "000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000". More on this below. > +# > +# @mrowner: ID for the guest TD’s owner (base64 encoded SHA384 digest). > +# (A default value 0 of SHA384 is used when absent). > +# > +# @mrownerconfig: ID for owner-defined configuration of the guest TD, > +# e.g., specific to the workload rather than the run-time or OS > +# (base64 encoded SHA384 digest). (A default value 0 of SHA384 is > +# used when absent). > +# > # Since: 9.0 > ## > { 'struct': 'TdxGuestProperties', > - 'data': { '*sept-ve-disable': 'bool' } } > + 'data': { '*sept-ve-disable': 'bool', > + '*mrconfigid': 'str', > + '*mrowner': 'str', > + '*mrownerconfig': 'str' } } > > ## > # @ThreadContextProperties: > diff --git a/target/i386/kvm/tdx.c b/target/i386/kvm/tdx.c > index d0ad4f57b5d0..4ce2f1d082ce 100644 > --- a/target/i386/kvm/tdx.c > +++ b/target/i386/kvm/tdx.c > @@ -13,6 +13,7 @@ > > #include "qemu/osdep.h" > #include "qemu/error-report.h" > +#include "qemu/base64.h" > #include "qapi/error.h" > #include "qom/object_interfaces.h" > #include "standard-headers/asm-x86/kvm_para.h" > @@ -516,6 +517,7 @@ int tdx_pre_create_vcpu(CPUState *cpu, Error **errp) > X86CPU *x86cpu = X86_CPU(cpu); > CPUX86State *env = &x86cpu->env; > g_autofree struct kvm_tdx_init_vm *init_vm = NULL; > + size_t data_len; > int r = 0; > > object_property_set_bool(OBJECT(cpu), "pmu", false, &error_abort); > @@ -528,6 +530,38 @@ int tdx_pre_create_vcpu(CPUState *cpu, Error **errp) > init_vm = g_malloc0(sizeof(struct kvm_tdx_init_vm) + > sizeof(struct kvm_cpuid_entry2) * KVM_MAX_CPUID_ENTRIES); > > +#define SHA384_DIGEST_SIZE 48 > + > + if (tdx_guest->mrconfigid) { > + g_autofree uint8_t *data = qbase64_decode(tdx_guest->mrconfigid, > + strlen(tdx_guest->mrconfigid), &data_len, errp); > + if (!data || data_len != SHA384_DIGEST_SIZE) { > + error_setg(errp, "TDX: failed to decode mrconfigid"); > + return -1; > + } > + memcpy(init_vm->mrconfigid, data, data_len); > + } When @mrconfigid is absent, the property remains null, and this conditional is not executed. init_vm->mrconfigid[], an array of 6 __u64, remains all zero. How does the kernel treat that? > + > + if (tdx_guest->mrowner) { > + g_autofree uint8_t *data = qbase64_decode(tdx_guest->mrowner, > + strlen(tdx_guest->mrowner), &data_len, errp); > + if (!data || data_len != SHA384_DIGEST_SIZE) { > + error_setg(errp, "TDX: failed to decode mrowner"); > + return -1; > + } > + memcpy(init_vm->mrowner, data, data_len); > + } > + > + if (tdx_guest->mrownerconfig) { > + g_autofree uint8_t *data = qbase64_decode(tdx_guest->mrownerconfig, > + strlen(tdx_guest->mrownerconfig), &data_len, errp); > + if (!data || data_len != SHA384_DIGEST_SIZE) { > + error_setg(errp, "TDX: failed to decode mrownerconfig"); > + return -1; > + } > + memcpy(init_vm->mrownerconfig, data, data_len); > + } > + > r = kvm_vm_enable_cap(kvm_state, KVM_CAP_MAX_VCPUS, 0, ms->smp.cpus); > if (r < 0) { > error_setg(errp, "Unable to set MAX VCPUS to %d", ms->smp.cpus); [...]
