Fix an x86 bug where KVM overwrites vcpu->srcu_idx and can leak an SRCU lock due to unlocking the wrong index, ultimately causing a hang if/when KVM attempts to synchronize. Switch RISC-V to the generic vcpu->srcu_idx, for reasons unknown it has its own copy and ignores the generic one. Add helpers with rudimentary detection of illegal vcpu->srcu_idx usage, the x86 bug would have been incredibly painful to debug had I not known what to look for (found by a selftest with very specific behavior... that we recently modified with respect to SRCU). Non-x86 changes are compile tested only. Sean Christopherson (3): KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io() KVM: RISC-V: Use kvm_vcpu.srcu_idx, drop RISC-V's unnecessary copy KVM: Add helpers to wrap vcpu->srcu_idx and yell if it's abused arch/powerpc/kvm/book3s_64_mmu_radix.c | 9 ++++--- arch/powerpc/kvm/book3s_hv_nested.c | 16 ++++++------ arch/powerpc/kvm/book3s_rtas.c | 4 +-- arch/powerpc/kvm/powerpc.c | 4 +-- arch/riscv/include/asm/kvm_host.h | 3 --- arch/riscv/kvm/vcpu.c | 16 ++++++------ arch/riscv/kvm/vcpu_exit.c | 4 +-- arch/s390/kvm/interrupt.c | 4 +-- arch/s390/kvm/kvm-s390.c | 8 +++--- arch/s390/kvm/vsie.c | 4 +-- arch/x86/kvm/x86.c | 35 +++++++++++--------------- include/linux/kvm_host.h | 24 +++++++++++++++++- 12 files changed, 72 insertions(+), 59 deletions(-) base-commit: 150866cd0ec871c765181d145aa0912628289c8a -- 2.36.0.rc0.470.gd361397f0d-goog
