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| author | Simon Guo <wei.guo.simon@gmail.com> | 2018-05-23 15:01:55 +0800 |
|---|---|---|
| committer | Paul Mackerras <paulus@ozlabs.org> | 2018-06-01 10:29:42 +1000 |
| commit | 36383a0862b68fc14b63dd6c93c64f1f82b6e8a9 (patch) | |
| tree | 2ebf34d92549e0ef2f75678124c3b77429b73824 | |
| parent | 401a89e9375c011de4e3271d50f27648b734a7cb (diff) | |
| download | linux-36383a0862b68fc14b63dd6c93c64f1f82b6e8a9.tar.gz | |
KVM: PPC: Book3S PR: Avoid changing TS bits when exiting guest
PR KVM host usually runs with TM enabled in its host MSR value, and with non-transactional TS value. When a guest with TM active traps into PR KVM host, the rfid at the tail of kvmppc_interrupt_pr() will try to switch TS bits from S0 (Suspended & TM disabled) to N1 (Non-transactional & TM enabled). That will leads to TM Bad Thing interrupt. This patch manually sets target TS bits unchanged to avoid this exception. Signed-off-by: Simon Guo <wei.guo.simon@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
| -rw-r--r-- | arch/powerpc/kvm/book3s_segment.S | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S index 93a180ceefad..98ccc7ec5d48 100644 --- a/arch/powerpc/kvm/book3s_segment.S +++ b/arch/powerpc/kvm/book3s_segment.S @@ -383,6 +383,19 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) */ PPC_LL r6, HSTATE_HOST_MSR(r13) +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + /* + * We don't want to change MSR[TS] bits via rfi here. + * The actual TM handling logic will be in host with + * recovered DR/IR bits after HSTATE_VMHANDLER. + * And MSR_TM can be enabled in HOST_MSR so rfid may + * not suppress this change and can lead to exception. + * Manually set MSR to prevent TS state change here. + */ + mfmsr r7 + rldicl r7, r7, 64 - MSR_TS_S_LG, 62 + rldimi r6, r7, MSR_TS_S_LG, 63 - MSR_TS_T_LG +#endif PPC_LL r8, HSTATE_VMHANDLER(r13) #ifdef CONFIG_PPC64 |