The KVM_SYSTEM_EVENT_NDATA_VALID mechanism that was introduced contextually with KVM_SYSTEM_EVENT_SEV_TERM is not a good match for ARM and RISC-V, which want to communicate information even for existing KVM_SYSTEM_EVENT_* constants. Userspace is not ready to filter out bit 31 of type, and fails to process the KVM_EXIT_SYSTEM_EVENT exit. Therefore, tie the availability of ndata to a system capability; if the capability is present, ndata is always valid, so patch 1 makes x86 always initialize it. Then patches 2 and 3 fix ARM and RISC-V compilation and patch 4 enables the capability. Only compiled on x86, waiting for acks. Paolo Paolo Bonzini (4): KVM: x86: always initialize system_event.ndata KVM: ARM: replace system_event.flags with ndata and data[0] KVM: RISC-V: replace system_event.flags with ndata and data[0] KVM: tell userspace that system_event.ndata is valid Documentation/virt/kvm/api.rst | 29 +++++++++++++++------------ arch/arm64/kvm/psci.c | 3 ++- arch/riscv/include/asm/kvm_vcpu_sbi.h | 2 +- arch/riscv/kvm/vcpu_sbi.c | 5 +++-- arch/riscv/kvm/vcpu_sbi_replace.c | 4 ++-- arch/riscv/kvm/vcpu_sbi_v01.c | 2 +- arch/x86/kvm/svm/sev.c | 3 +-- arch/x86/kvm/x86.c | 2 ++ include/uapi/linux/kvm.h | 2 +- virt/kvm/kvm_main.c | 1 + 10 files changed, 30 insertions(+), 23 deletions(-) -- 2.31.1
