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 -- 2.26.2