diff options
Diffstat (limited to 'arch/powerpc/kernel/idle_book3s.S')
| -rw-r--r-- | arch/powerpc/kernel/idle_book3s.S | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S index bd739fed26e3..0d8712a835d2 100644 --- a/arch/powerpc/kernel/idle_book3s.S +++ b/arch/powerpc/kernel/idle_book3s.S @@ -163,12 +163,6 @@ _GLOBAL(pnv_powersave_common) std r9,_MSR(r1) std r1,PACAR1(r13) -#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE - /* Tell KVM we're entering idle */ - li r4,KVM_HWTHREAD_IN_IDLE - stb r4,HSTATE_HWTHREAD_STATE(r13) -#endif - /* * Go to real mode to do the nap, as required by the architecture. * Also, we need to be in real mode before setting hwthread_state, @@ -185,6 +179,26 @@ _GLOBAL(pnv_powersave_common) .globl pnv_enter_arch207_idle_mode pnv_enter_arch207_idle_mode: +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + /* Tell KVM we're entering idle */ + li r4,KVM_HWTHREAD_IN_IDLE + /******************************************************/ + /* N O T E W E L L ! ! ! N O T E W E L L */ + /* The following store to HSTATE_HWTHREAD_STATE(r13) */ + /* MUST occur in real mode, i.e. with the MMU off, */ + /* and the MMU must stay off until we clear this flag */ + /* and test HSTATE_HWTHREAD_REQ(r13) in the system */ + /* reset interrupt vector in exceptions-64s.S. */ + /* The reason is that another thread can switch the */ + /* MMU to a guest context whenever this flag is set */ + /* to KVM_HWTHREAD_IN_IDLE, and if the MMU was on, */ + /* that would potentially cause this thread to start */ + /* executing instructions from guest memory in */ + /* hypervisor mode, leading to a host crash or data */ + /* corruption, or worse. */ + /******************************************************/ + stb r4,HSTATE_HWTHREAD_STATE(r13) +#endif stb r3,PACA_THREAD_IDLE_STATE(r13) cmpwi cr3,r3,PNV_THREAD_SLEEP bge cr3,2f @@ -250,6 +264,12 @@ enter_winkle: * r3 - requested stop state */ power_enter_stop: +#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE + /* Tell KVM we're entering idle */ + li r4,KVM_HWTHREAD_IN_IDLE + /* DO THIS IN REAL MODE! See comment above. */ + stb r4,HSTATE_HWTHREAD_STATE(r13) +#endif /* * Check if the requested state is a deep idle state. */ |