Confidential VMs(CVMs) need to execute hypercall instruction as per the CPU type. Normally KVM emulates the vmcall/vmmcall instruction by patching the guest code at runtime. Such a guest memory manipulation by KVM is not allowed with CVMs and is also undesirable in general.
This series adds support of executing hypercall as per the host cpu type queried using cpuid instruction. CPU vendor type is stored early during selftest setup and guest setup to be reused later.
Changes in v4: 1) Incoporated suggestions from Sean - * Added APIs to query host cpu type * Shared the host cpu type with guests to avoid querying the cpu type again * Modified kvm_hypercall to execute vmcall/vmmcall according to host cpu type. 2) Dropped the separate API for kvm_hypercall.
v3: https://lore.kernel.org/lkml/20221222230458.3828342-1-vannapurve@google.com/
Vishal Annapurve (4): KVM: selftests: x86: use this_cpu_* helpers KVM: selftests: x86: Add variables to store cpu type KVM: sefltests: x86: Replace is_*cpu with is_host_*cpu KVM: selftests: x86: Invoke kvm hypercall as per host cpu
.../selftests/kvm/include/x86_64/processor.h | 26 ++++++++++- .../selftests/kvm/lib/x86_64/processor.c | 44 ++++++++++--------- .../selftests/kvm/x86_64/fix_hypercall_test.c | 4 +- .../selftests/kvm/x86_64/mmio_warning_test.c | 2 +- .../kvm/x86_64/pmu_event_filter_test.c | 4 +- .../vmx_exception_with_invalid_guest_state.c | 2 +- 6 files changed, 54 insertions(+), 28 deletions(-)