Re: [libvirt][PATCH RESEND v12 6/6] qemu: Add command-line to generate SGX EPC memory backend

On 5/18/22 09:59, Haibin Huang wrote: > From: Lin Yang <lin.a.yang(a)intel.com&gt; > > According to the result parsing from xml, add the argument of > SGX EPC memory backend into QEMU command line: > > #qemu-system-x86_64 \ > ...... \ > -object memory-backend-epc,id=memepc0,size=64M,prealloc=on \ > -object memory-backend-epc,id=memepc1,size=28M \ > -machine sgx-epc.0.memdev=memepc0,sgx-epc.1.memdev=memepc1 > > Signed-off-by: Lin Yang <lin.a.yang(a)intel.com&gt; > Signed-off-by: Haibin Huang <haibin.huang(a)intel.com&gt; > --- > src/qemu/qemu_alias.c | 3 +- > src/qemu/qemu_command.c | 53 +++++++++++++++++-- > .../sgx-epc.x86_64-6.2.0.args | 37 +++++++++++++ > tests/qemuxml2argvtest.c | 2 + > 4 files changed, 90 insertions(+), 5 deletions(-) > create mode 100644 tests/qemuxml2argvdata/sgx-epc.x86_64-6.2.0.args > > diff --git a/src/qemu/qemu_alias.c b/src/qemu/qemu_alias.c > index e5a946cbed..03c79bcf0e 100644 > --- a/src/qemu/qemu_alias.c > +++ b/src/qemu/qemu_alias.c > @@ -467,7 +467,8 @@ qemuDeviceMemoryGetAliasID(virDomainDef *def, > * valid */ > if (!oldAlias && > mem->model != VIR_DOMAIN_MEMORY_MODEL_VIRTIO_PMEM && > - mem->model != VIR_DOMAIN_MEMORY_MODEL_VIRTIO_MEM) > + mem->model != VIR_DOMAIN_MEMORY_MODEL_VIRTIO_MEM && > + mem->model != VIR_DOMAIN_MEMORY_MODEL_SGX_EPC) > return mem->info.addr.dimm.slot; > > for (i = 0; i < def->nmems; i++) { > diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c > index 4807b137b6..9c83f0e168 100644 > --- a/src/qemu/qemu_command.c > +++ b/src/qemu/qemu_command.c > @@ -3774,6 +3774,10 @@ qemuBuildMemoryBackendProps(virJSONValue **backendProps, > if (systemMemory) > disableCanonicalPath = true; > > + } else if (mem->model == VIR_DOMAIN_MEMORY_MODEL_SGX_EPC) { > + backendType = "memory-backend-epc"; > + if (!priv->memPrealloc) > + prealloc = true; > } else if (useHugepage || mem->nvdimmPath || memAccess || > def->mem.source == VIR_DOMAIN_MEMORY_SOURCE_FILE) { > > @@ -3934,6 +3938,11 @@ qemuBuildMemoryBackendProps(virJSONValue **backendProps, > _("this qemu doesn't support the " > "memory-backend-memfd object")); > return -1; > + } else if (STREQ(backendType, "memory-backend-epc") && > + !virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_SGX_EPC)) { > + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", > + _("this qemu doesn't support the memory-backend-epc object")); > + return -1; > } > > rc = 0; > @@ -6979,6 +6988,7 @@ qemuBuildMachineCommandLine(virCommand *cmd, > virCPUDef *cpu = def->cpu; > g_auto(virBuffer) buf = VIR_BUFFER_INITIALIZER; > size_t i; > + int epcNum = 0; > > virCommandAddArg(cmd, "-machine"); > virBufferAdd(&buf, def->os.machine, -1); > @@ -7199,6 +7209,25 @@ qemuBuildMachineCommandLine(virCommand *cmd, > virBufferAddLit(&buf, ",graphics=off"); > } > > + /* add sgx epc memory to -machine parameter */ > + for (i = 0; i < def->nmems; i++) { > + switch ((virDomainMemoryModel) def->mems[i]->model) { > + case VIR_DOMAIN_MEMORY_MODEL_SGX_EPC: > + virBufferAsprintf(&buf, ",sgx-epc.%d.memdev=mem%s", epcNum++, > + def->mems[i]->info.alias); So there really isn't any better way to specify sgx-epc than through -M? This way libvirt loses capability to set th device @id attribute which means we have to jump through hoops (like in your patch 2/6) when the @id value is expected. I vaguely pointing this out earlier (but maybe I just thought about pointing it out and never did - it's been a while since I've reviewed these patches), but I don't know what the consensus was.