Re: [Qemu-devel] [PATCH v6 00/23] x86: Secure Encrypted Virtualization (AMD)

[Brijesh Singh]

On 2/6/18 9:51 AM, Bruce Rogers wrote:
>>>> On 1/29/2018 at 10:41 AM, <address@hidden> wrote:
>> This patch series provides support for AMD's new Secure Encrypted 
>> Virtualization (SEV) feature.
>>
>> SEV is an extension to the AMD‑V architecture which supports running
>> multiple VMs under the control of a hypervisor. The SEV feature allows
>> the memory contents of a virtual machine (VM) to be transparently encrypted
>> with a key unique to the guest VM. The memory controller contains a
>> high performance encryption engine which can be programmed with multiple
>> keys for use by a different VMs in the system. The programming and
>> management of these keys is handled by the AMD Secure Processor firmware
>> which exposes a commands for these tasks.
>>
>> The KVM SEV patch series introduced a new ioctl (KVM_MEMORY_ENCRYPTION_OP)
>> which is used by qemu to issue the SEV commands to assist performing
>> common hypervisor activities such as a launching, running, snapshooting,
>> migration and debugging guests.
>>
> As for the reported failure to build on non-x86 hosts, eg:
> ...
>   LINK    i386-softmmu/qemu-system-i386
> target/i386/helper.o: In function `get_me_mask':
> /var/tmp/patchew-tester-tmp-hek3vjny/src/target/i386/helper.c:735: undefined 
> reference to `kvm_arch_get_supported_cpuid'
> target/i386/monitor.o: In function `get_me_mask':
> /var/tmp/patchew-tester-tmp-hek3vjny/src/target/i386/monitor.c:71: undefined 
> reference to `kvm_arch_get_supported_cpuid'
>
> ... I've looked at that a bit and find that in target/i386/kvm-stub.c, if we 
> get rid of
> the #ifndef __OPTIMIZE__ it then builds ok. I'm not sure if the guarding done 
> there
> with the check for  __OPTIMIZE__ is a relic that no longer applies given how 
> qemu
> currently builds, but at least it's something to look at.

Thanks for looking Bruce.

I have reworked code a bit and that should fix this build error. I will
be posting patches soon for review.

> Bruce
>