• Paul Mackerras's avatar
    KVM: PPC: Book3S HV: Flush TLB on secondary radix threads · 70ea13f6
    Paul Mackerras authored
    When running on POWER9 with kvm_hv.indep_threads_mode = N and the host
    in SMT1 mode, KVM will run guest VCPUs on offline secondary threads.
    If those guests are in radix mode, we fail to load the LPID and flush
    the TLB if necessary, leading to the guest crashing with an
    unsupported MMU fault.  This arises from commit 9a4506e1 ("KVM:
    PPC: Book3S HV: Make radix handle process scoped LPID flush in C,
    with relocation on", 2018-05-17), which didn't consider the case
    where indep_threads_mode = N.
    
    For simplicity, this makes the real-mode guest entry path flush the
    TLB in the same place for both radix and hash guests, as we did before
    9a4506e1, though the code is now C code rather than assembly code.
    We also have the radix TLB flush open-coded rather than calling
    radix__local_flush_tlb_lpid_guest(), because the TLB flush can be
    called in real mode, and in real mode we don't want to invoke the
    tracepoint code.
    
    Fixes: 9a4506e1 ("KVM: PPC: Book3S HV: Make radix handle process scoped LPID flush in C, with relocation on")
    Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
    70ea13f6
book3s_hv.c 143 KB