[PATCH 0/4] KVM: fix KVM_EXIT_SYSTEM_EVENT mess

Paolo Bonzini
2022-04-21T18:05:04Z

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(-)

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2.31.1