[libvirt][PATCH v7 2/5] qemu: Add command-line to generate SGX EPC memory backend

[Daniel P. Berrangé]

On Wed, Sep 08, 2021 at 09:15:55AM +0800, Haibin Huang wrote:
> From: Lin Yang <lin.a.yang at intel.com>
> 
> 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=mem1,size=64M,prealloc=on \
>         -object memory-backend-epc,id=mem2,size=28M \
>         -M sgx-epc.0.memdev=mem1,sgx-epc.1.memdev=mem2
> ---
>  src/qemu/qemu_alias.c   |  3 ++-
>  src/qemu/qemu_command.c | 38 ++++++++++++++++++++++++++++++++++----
>  src/qemu/qemu_domain.c  |  9 ++++++++-
>  3 files changed, 44 insertions(+), 6 deletions(-)
> 
> diff --git a/src/qemu/qemu_alias.c b/src/qemu/qemu_alias.c
> index 5990fc5f87..53eb30b81f 100644
> --- a/src/qemu/qemu_alias.c
> +++ b/src/qemu/qemu_alias.c
> @@ -476,7 +476,8 @@ qemuDeviceMemoryGetAliasID(virDomainDef *def,
>      int maxidx = 0;
>  
>      /* virtio-pmem goes onto PCI bus and thus DIMM address is not valid */
> -    if (!oldAlias && mem->model != VIR_DOMAIN_MEMORY_MODEL_VIRTIO_PMEM)
> +    if (!oldAlias && mem->model != VIR_DOMAIN_MEMORY_MODEL_VIRTIO_PMEM &&
> +        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 24572d03d7..11bce51e82 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -3117,6 +3117,10 @@ 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 {
>          backendType = "memory-backend-ram";
>      }
> @@ -7565,6 +7569,8 @@ qemuBuildMemoryDeviceCommandLine(virCommand *cmd,
>                                   qemuDomainObjPrivate *priv)
>  {
>      size_t i;
> +    g_auto(virBuffer) epcBuf = VIR_BUFFER_INITIALIZER;
> +    int epcNum = 0;
>  
>      /* memory hotplug requires NUMA to be enabled - we already checked
>       * that memory devices are present only when NUMA is */
> @@ -7578,12 +7584,36 @@ qemuBuildMemoryDeviceCommandLine(virCommand *cmd,
>          virCommandAddArg(cmd, "-object");
>          virCommandAddArgBuffer(cmd, &buf);
>  
> -        if (!(dimmStr = qemuBuildMemoryDeviceStr(def, def->mems[i], priv->qemuCaps)))
> -            return -1;
> +        switch ((virDomainMemoryModel) def->mems[i]->model) {
> +        case VIR_DOMAIN_MEMORY_MODEL_NVDIMM:
> +        case VIR_DOMAIN_MEMORY_MODEL_DIMM:
> +        case VIR_DOMAIN_MEMORY_MODEL_VIRTIO_PMEM:
> +            if (!(dimmStr = qemuBuildMemoryDeviceStr(def, def->mems[i], priv->qemuCaps)))
> +                return -1;
> +
> +            virCommandAddArgList(cmd, "-device", dimmStr, NULL);
> +
> +            VIR_FREE(dimmStr);
> +            break;
> +
> +        case VIR_DOMAIN_MEMORY_MODEL_SGX_EPC:
> +            if (virBufferUse(&epcBuf) > 0)
> +                virBufferAddChar(&epcBuf, ',');
>  
> -        virCommandAddArgList(cmd, "-device", dimmStr, NULL);
> +            virBufferAsprintf(&epcBuf, "sgx-epc.%d.memdev=%s", epcNum++,
> +                              g_strdup_printf("mem%s", def->mems[i]->info.alias));
> +
> +            break;

The 'case VIR_DOMAIN_MEMORY_MODEL_SGX_EPC' block ends here, but



> +
> +        case VIR_DOMAIN_MEMORY_MODEL_NONE:
> +        case VIR_DOMAIN_MEMORY_MODEL_LAST:
> +            break;
> +        }
> +    }
>  
> -        VIR_FREE(dimmStr);
> +    if (virBufferUse(&epcBuf) > 0) {
> +        virCommandAddArg(cmd, "-M");
> +        virCommandAddArgBuffer(cmd, &epcBuf);

This is EPC specific code.

Since you put the virCommandAddArgList() call inside the switch()
for the other memory model types, I think this virCommandAddArgBuffer
for EPC should be inside the switch too.

>      }
>  
>      return 0;

Regards,
Daniel
-- 
|: https://berrange.com      -o-    https://www.flickr.com/photos/dberrange :|
|: https://libvirt.org         -o-            https://fstop138.berrange.com :|
|: https://entangle-photo.org    -o-    https://www.instagram.com/dberrange :|