pseries: Correctly create ibm,segment-page-sizes property
PATCH v2 2/2 pseries: Correctly create ibm,segment-page-sizes property
The core tcg/kvm code for ppc64 now has at least the outline capability to support pagesizes beyond the standard 4k and 16MB. The CPUState is initialized with information advertising the available pagesizes and their correct encodings, and under the right KVM setup this will be populated with page sizes beyond the standard.
Obviously guests can't use the extra page sizes unless they know they're present. For the pseries machine, at least, there is a defined method for conveying exactly this information, the "ibm-segment-page-sizes" property in the guest device tree.
This patch generates this property using the supported page size information that's already in the CPUState.
---
v2: - Passes checkpatch
- Removed unrelated bits that were folded into the previous patch
Note: I kept the pointer arithmetic, which is the right way to
do these things :-)
The chances to have a separate "len" variable get out of sync vs. the various *(p++) are higher than getting that wrong, besides pointer arithmetic in C is pretty standard stuff.
hw/spapr.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 43 insertions(+), 0 deletions(-)
hw/spapr.c +43 -0
@@ -149,6 +149,40 @@ static int spapr_set_associativity(void *fdt, sPAPREnvironment *spapr)return ret; } + +static size_t create_page_sizes_prop (CPUPPCState *env,uint32_t *prop, +size_t maxsize) +{ +size_t maxcells = maxsize /sizeof (uint32_t ); +int i, j, count; +uint32_t *p = prop; + +for (i =0 ; i <PPC_PAGE_SIZES_MAX_SZ ; i++) { +struct ppc_one_seg_page_size *sps = &env->sps.sps[i]; + +if (!sps->page_shift) { +break ; + } +for (count =0 ; count <PPC_PAGE_SIZES_MAX_SZ ; count++) { +if (sps->enc[count].page_shift ==0 ) { +break ; + } + } +if ((p - prop) >= (maxcells -3 - count *2 )) { +break ; + } + *(p++) =cpu_to_be32 (sps->page_shift); + *(p++) =cpu_to_be32 (sps->slb_enc); + *(p++) =cpu_to_be32 (count); +for (j =0 ; j < count; j++) { + *(p++) =cpu_to_be32 (sps->enc[j].page_shift); + *(p++) =cpu_to_be32 (sps->enc[j].pte_enc); + } + } + +return (p - prop) *sizeof (uint32_t ); +} + static void *spapr_create_fdt_skel(const char *cpu_model, target_phys_addr_t rma_size, target_phys_addr_t initrd_base,
@@ -304,6 +338,8 @@ static void *spapr_create_fdt_skel(const char *cpu_model, 0xffffffff, 0xffffffff};uint32_t tbfreq =kvm_enabled () ?kvmppc_get_tbfreq () :TIMEBASE_FREQ ;uint32_t cpufreq =kvm_enabled () ?kvmppc_get_clockfreq () :1000000000 ; +uint32_t page_sizes_prop[64 ]; +size_t page_sizes_prop_size;if ((index % smt) !=0 ) {continue ;
@@ -368,6 +404,13 @@ static void *spapr_create_fdt_skel(const char *cpu_model,_FDT ((fdt_property_cell (fdt,"ibm,dfp" ,1 ))); } + page_sizes_prop_size =create_page_sizes_prop (env, page_sizes_prop, +sizeof (page_sizes_prop)); +if (page_sizes_prop_size) { +_FDT ((fdt_property (fdt,"ibm,segment-page-sizes" , + page_sizes_prop, page_sizes_prop_size))); + } +_FDT ((fdt_end_node (fdt))); }