On Sun, Aug 13, 2017 at 11:33:44AM +1000, Nicholas Piggin wrote: > The "lppaca" is a structure registered with the hypervisor. This > is unnecessary when running on non-virtualised platforms. One field > from the lppaca (pmcregs_in_use) is also used by the host, so move > the host part out into the paca (lppaca field is still updated in > guest mode).
There is an error in the patch, see below... > diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S > b/arch/powerpc/kvm/book3s_hv_rmhandlers.S > index c52184a8efdf..b838348e3a2b 100644 > --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S > +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S > @@ -99,8 +99,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) > mtspr SPRN_SPRG_VDSO_WRITE,r3 > > /* Reload the host's PMU registers */ > - ld r3, PACALPPACAPTR(r13) /* is the host using the PMU? */ > - lbz r4, LPPACA_PMCINUSE(r3) > + lbz r4, PACA_PMCINUSE(r13) /* is the host using the PMU? */ > cmpwi r4, 0 > beq 23f /* skip if not */ > BEGIN_FTR_SECTION > @@ -1671,7 +1670,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) > mtspr SPRN_MMCRA, r7 > isync > beq 21f /* if no VPA, save PMU stuff anyway */ > - lbz r7, LPPACA_PMCINUSE(r8) > + lbz r7, PACA_PMCINUSE(r13) We really do need to check the guest's flag not the host's here, since we're deciding whether to save the PMU state to the vcpu struct. Paul.
