The device is created by the machine based on the sgx-epc property.
It should not be created by users.
Reported-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Since there is no fill_device_info() callback support, and when we
execute "info memory-devices" command in the monitor, the segfault
will be found.
This patch will add this callback support and "info memory-devices"
will show sgx epc memory exposed to guest. The result as below:
qemu) info memory-devices
Memory device [sgx-epc]: ""
memaddr: 0x180000000
size: 29360128
memdev: /objects/mem1
Memory device [sgx-epc]: ""
memaddr: 0x181c00000
size: 10485760
memdev: /objects/mem2
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <20210719112136.57018-33-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Because SGX EPC is enumerated through CPUID, EPC "devices" need to be
realized prior to realizing the vCPUs themselves, i.e. long before
generic devices are parsed and realized. From a virtualization
perspective, the CPUID aspect also means that EPC sections cannot be
hotplugged without paravirtualizing the guest kernel (hardware does
not support hotplugging as EPC sections must be locked down during
pre-boot to provide EPC's security properties).
So even though EPC sections could be realized through the generic
-devices command, they need to be created much earlier for them to
actually be usable by the guest. Place all EPC sections in a
contiguous block, somewhat arbitrarily starting after RAM above 4g.
Ensuring EPC is in a contiguous region simplifies calculations, e.g.
device memory base, PCI hole, etc..., allows dynamic calculation of the
total EPC size, e.g. exposing EPC to guests does not require -maxmem,
and last but not least allows all of EPC to be enumerated in a single
ACPI entry, which is expected by some kernels, e.g. Windows 7 and 8.
The new compound properties command for sgx like below:
......
-object memory-backend-epc,id=mem1,size=28M,prealloc=on \
-object memory-backend-epc,id=mem2,size=10M \
-M sgx-epc.0.memdev=mem1,sgx-epc.1.memdev=mem2
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <20210719112136.57018-6-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
SGX EPC is enumerated through CPUID, i.e. EPC "devices" need to be
realized prior to realizing the vCPUs themselves, which occurs long
before generic devices are parsed and realized. Because of this,
do not allow 'sgx-epc' devices to be instantiated after vCPUS have
been created.
The 'sgx-epc' device is essentially a placholder at this time, it will
be fully implemented in a future patch along with a dedicated command
to create 'sgx-epc' devices.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <20210719112136.57018-5-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
