• Nicholas Piggin's avatar
    KVM: PPC: Book3S HV: Handle host system reset in guest mode · 6de6638b
    Nicholas Piggin authored
    If the host takes a system reset interrupt while a guest is running,
    the CPU must exit the guest before processing the host exception
    handler.
    
    After this patch, taking a sysrq+x with a CPU running in a guest
    gives a trace like this:
    
       cpu 0x27: Vector: 100 (System Reset) at [c000000fdf5776f0]
           pc: c008000010158b80: kvmppc_run_core+0x16b8/0x1ad0 [kvm_hv]
           lr: c008000010158b80: kvmppc_run_core+0x16b8/0x1ad0 [kvm_hv]
           sp: c000000fdf577850
          msr: 9000000002803033
         current = 0xc000000fdf4b1e00
         paca    = 0xc00000000fd4d680	 softe: 3	 irq_happened: 0x01
           pid   = 6608, comm = qemu-system-ppc
       Linux version 4.14.0-rc7-01489-g47e1893a404a-dirty #26 SMP
       [c000000fdf577a00] c008000010159dd4 kvmppc_vcpu_run_hv+0x3dc/0x12d0 [kvm_hv]
       [c000000fdf577b30] c0080000100a537c kvmppc_vcpu_run+0x44/0x60 [kvm]
       [c000000fdf577b60] c0080000100a1ae0 kvm_arch_vcpu_ioctl_run+0x118/0x310 [kvm]
       [c000000fdf577c00] c008000010093e98 kvm_vcpu_ioctl+0x530/0x7c0 [kvm]
       [c000000fdf577d50] c000000000357bf8 do_vfs_ioctl+0xd8/0x8c0
       [c000000fdf577df0] c000000000358448 SyS_ioctl+0x68/0x100
       [c000000fdf577e30] c00000000000b220 system_call+0x58/0x6c
       --- Exception: c01 (System Call) at 00007fff76868df0
       SP (7fff7069baf0) is in userspace
    
    Fixes: e36d0a2e ("powerpc/powernv: Implement NMI IPI with OPAL_SIGNAL_SYSTEM_RESET")
    Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
    Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
    6de6638b
hw_irq.h 4.98 KB