On Fri, 4 Sep 2020 10:56:31 -0300 Daniel Henrique Barboza <danielhb...@gmail.com> wrote:
> The current implementation of h_home_node_associativity hard codes > the values of associativity domains of the vcpus. Let's make > it consider the values already initialized in spapr->numa_assoc_array, > via the spapr_numa_get_vcpu_assoc() helper. > > We want to set it and forget it, and for that we also need to > assert that we don't overflow the registers of the hypercall. > From R4 to R9 we can squeeze in 12 associativity domains for > vcpus, so let's assert that VCPU_ASSOC_SIZE -1 isn't greater > than that. > > Signed-off-by: Daniel Henrique Barboza <danielhb...@gmail.com> > --- > hw/ppc/spapr_numa.c | 41 +++++++++++++++++++++++++++++++++-------- > 1 file changed, 33 insertions(+), 8 deletions(-) > > diff --git a/hw/ppc/spapr_numa.c b/hw/ppc/spapr_numa.c > index 674d2ee86d..07eb921737 100644 > --- a/hw/ppc/spapr_numa.c > +++ b/hw/ppc/spapr_numa.c > @@ -178,10 +178,11 @@ static target_ulong > h_home_node_associativity(PowerPCCPU *cpu, > target_ulong opcode, > target_ulong *args) > { > + g_autofree uint32_t *vcpu_assoc = NULL; > target_ulong flags = args[0]; > target_ulong procno = args[1]; > PowerPCCPU *tcpu; > - int idx; > + int idx, assoc_idx; > > /* only support procno from H_REGISTER_VPA */ > if (flags != 0x1) { > @@ -193,16 +194,40 @@ static target_ulong > h_home_node_associativity(PowerPCCPU *cpu, > return H_P2; > } > > - /* sequence is the same as in the "ibm,associativity" property */ > + /* > + * Given that we want to be flexible with the sizes and indexes, > + * we must consider that there is a hard limit of how many > + * associativities domain we can fit in R4 up to R9, which would be > + * 12 associativity domains for vcpus. Assert and bail if that's > + * not the case. > + */ > + G_STATIC_ASSERT((VCPU_ASSOC_SIZE - 1) <= 12); > + > + vcpu_assoc = spapr_numa_get_vcpu_assoc(spapr, tcpu); > + /* assoc_idx starts at 1 to skip associativity size */ > + assoc_idx = 1; > > - idx = 0; > #define ASSOCIATIVITY(a, b) (((uint64_t)(a) << 32) | \ > ((uint64_t)(b) & 0xffffffff)) > - args[idx++] = ASSOCIATIVITY(0, 0); > - args[idx++] = ASSOCIATIVITY(0, tcpu->node_id); > - args[idx++] = ASSOCIATIVITY(procno, -1); > - for ( ; idx < 6; idx++) { > - args[idx] = -1; > + > + for (idx = 0; idx < 6; idx++) { > + int32_t a, b; > + > + /* > + * vcpu_assoc[] will contain the associativity domains for tcpu, > + * including tcpu->node_id and procno, meaning that we don't > + * need to use these variables here. > + * > + * We'll read 2 values at a time to fill up the ASSOCIATIVITY() > + * macro. The ternary will fill the remaining registers with -1 > + * after we went through vcpu_assoc[]. > + */ > + a = assoc_idx < VCPU_ASSOC_SIZE ? > + be32_to_cpu(vcpu_assoc[assoc_idx++]) : -1; > + b = assoc_idx < VCPU_ASSOC_SIZE ? > + be32_to_cpu(vcpu_assoc[assoc_idx++]) : -1; > + > + args[idx] = ASSOCIATIVITY(a, b); > } > #undef ASSOCIATIVITY > Much clearer with the comment. Reviewed-by: Greg Kurz <gr...@kaod.org>