f9cecb3c50
The idea that no parameter would ever be necessary when enabling SEV or SEV-ES for a VM was decidedly optimistic. The first source of variability that was encountered is the desired set of VMSA features, as that affects the measurement of the VM's initial state and cannot be changed arbitrarily by the hypervisor. This series adds all the APIs that are needed to customize the features, with room for future enhancements: - a new /dev/kvm device attribute to retrieve the set of supported features (right now, only debug swap) - a new sub-operation for KVM_MEM_ENCRYPT_OP that can take a struct, replacing the existing KVM_SEV_INIT and KVM_SEV_ES_INIT It then puts the new op to work by including the VMSA features as a field of the The existing KVM_SEV_INIT and KVM_SEV_ES_INIT use the full set of supported VMSA features for backwards compatibility; but I am considering also making them use zero as the feature mask, and will gladly adjust the patches if so requested. In order to avoid creating *two* new KVM_MEM_ENCRYPT_OPs, I decided that I could as well make SEV and SEV-ES use VM types. This allows SEV-SNP to reuse the KVM_SEV_INIT2 ioctl. And while at it, KVM_SEV_INIT2 also includes two bugfixes. First of all, SEV-ES VM, when created with the new VM type instead of KVM_SEV_ES_INIT, reject KVM_GET_REGS/KVM_SET_REGS and friends on the vCPU file descriptor once the VMSA has been encrypted... which is how the API should have always behaved. Second, they also synchronize the FPU and AVX state. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.