RE: [libvirt][PATCH v4 2/4] qemu: Add command-line to generate SGX EPC memory backend
-----Original Message-----
From: Tim Wiederhake <twiederh(a)redhat.com>
Sent: Monday, July 5, 2021 7:32 PM
To: Huang, Haibin <haibin.huang(a)intel.com>
Cc: libvir-list(a)redhat.com; Ding, Jian-feng <jian-feng.ding(a)intel.com>; Yang,
Lin A <lin.a.yang(a)intel.com>; Lu, Lianhao <lianhao.lu(a)intel.com>
Subject: Re: [libvirt][PATCH v4 2/4] qemu: Add command-line to generate
SGX EPC memory backend
On Thu, 2021-07-01 at 20:10 +0800, Haibin Huang wrote:
> From: Lin Yang <lin.a.yang(a)intel.com>
>
> According to the result parsing from xml, add the argument of SGX EPC
> memory backend into QEMU command line:
>
> -object memory-backend-epc,id=mem1,size=<epc_size>K,prealloc \
> -sgx-epc id=epc1,memdev=mem1
> ---
> src/qemu/qemu_command.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c
index
> 01812cd39b..2c3785886c 100644
> --- a/src/qemu/qemu_command.c
> +++ b/src/qemu/qemu_command.c
> @@ -9869,6 +9869,27 @@ qemuBuildVsockCommandLine(virCommandPtr
cmd,
> }
>
>
> +static int
> +qemuBuildSGXCommandLine(virCommandPtr cmd, virDomainSGXDefPtr
sgx) {
> + g_auto(virBuffer) buf = VIR_BUFFER_INITIALIZER;
> +
> + if (!sgx)
> + return 0;
> +
> + VIR_DEBUG("sgx->epc_size=%lluKiB", sgx->epc_size);
> +
> + virBufferAsprintf(&buf, "memory-backend-
> epc,id=mem1,size=%lluK,prealloc", sgx->epc_size);
> + virCommandAddArg(cmd, "-object");
> + virCommandAddArgBuffer(cmd, &buf);
virCommandAddArgFormat?
[Haibin] ok, I will change to virCommandAddArgFormat
> +
> + virCommandAddArg(cmd, "-sgx-epc");
> + virCommandAddArg(cmd, "id=epc1,memdev=mem1");
> +
> + return 0;
> +}
> +
> +
> /*
> * Constructs a argv suitable for launching qemu with config defined
> * for a given virtual machine.
> @@ -10154,6 +10175,9 @@ qemuBuildCommandLine(virQEMUDriverPtr
driver,
> cfg->logTimestamp)
> virCommandAddArgList(cmd, "-msg", "timestamp=on",
NULL);
>
> + if (qemuBuildSGXCommandLine(cmd, def->sgx) < 0)
> + return NULL;
> +
Personal opinion: I would not add this to the end of the function, but place it
next to the call to "qemuBuildSEVCommandLine(...)". Or replace the call to
qemuBuildSEVCommandLine() with a "qemuBuildSecurityCommandLine()",
which in turn calls qemuBuild{SEV,SGX}CommandLine().
[Haibin] ok, good point.
Regards,
Tim
> return g_steal_pointer(&cmd);
> }
>