From cd6a9bb6e977864b1b7ec21b983fa0678b4b82e9 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Wed, 27 Jan 2016 11:52:57 +1100 Subject: [PATCH] target-ppc: Rework SLB page size lookup Currently, the ppc_hash64_page_shift() function looks up a page size based on information in an SLB entry. It open codes the bit translation for existing CPUs, however different CPU models can have different SLB encodings. We already store those in the 'sps' table in CPUPPCState, but we don't currently enforce that that actually matches the logic in ppc_hash64_page_shift. This patch reworks lookup of page size from SLB in several ways: * ppc_store_slb() will now fail (triggering an illegal instruction exception) if given a bad SLB page size encoding * On success ppc_store_slb() stores a pointer to the relevant entry in the page size table in the SLB entry. This is looked up directly from the published table of page size encodings, so can't get out ot sync. * ppc_hash64_htab_lookup() and others now use this precached page size information rather than decoding the SLB values * Now that callers have easy access to the page_shift, ppc_hash64_pte_raddr() amounts to just a deposit64(), so remove it and have the callers use deposit64() directly. Signed-off-by: David Gibson Acked-by: Benjamin Herrenschmidt Reviewed-by: Alexander Graf --- target-ppc/cpu.h | 1 + target-ppc/machine.c | 20 +++++++++++ target-ppc/mmu-hash64.c | 74 +++++++++++++++++++---------------------- 3 files changed, 56 insertions(+), 39 deletions(-) diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h index 2bc96b4fa7..082039006f 100644 --- a/target-ppc/cpu.h +++ b/target-ppc/cpu.h @@ -419,6 +419,7 @@ typedef struct ppc_slb_t ppc_slb_t; struct ppc_slb_t { uint64_t esid; uint64_t vsid; + const struct ppc_one_seg_page_size *sps; }; #define MAX_SLB_ENTRIES 64 diff --git a/target-ppc/machine.c b/target-ppc/machine.c index 8cabc77883..692121e983 100644 --- a/target-ppc/machine.c +++ b/target-ppc/machine.c @@ -3,6 +3,7 @@ #include "hw/boards.h" #include "sysemu/kvm.h" #include "helper_regs.h" +#include "mmu-hash64.h" static int cpu_load_old(QEMUFile *f, void *opaque, int version_id) { @@ -353,11 +354,30 @@ static bool slb_needed(void *opaque) return (cpu->env.mmu_model & POWERPC_MMU_64); } +static int slb_post_load(void *opaque, int version_id) +{ + PowerPCCPU *cpu = opaque; + CPUPPCState *env = &cpu->env; + int i; + + /* We've pulled in the raw esid and vsid values from the migration + * stream, but we need to recompute the page size pointers */ + for (i = 0; i < env->slb_nr; i++) { + if (ppc_store_slb(cpu, i, env->slb[i].esid, env->slb[i].vsid) < 0) { + /* Migration source had bad values in its SLB */ + return -1; + } + } + + return 0; +} + static const VMStateDescription vmstate_slb = { .name = "cpu/slb", .version_id = 1, .minimum_version_id = 1, .needed = slb_needed, + .post_load = slb_post_load, .fields = (VMStateField[]) { VMSTATE_INT32_EQUAL(env.slb_nr, PowerPCCPU), VMSTATE_SLB_ARRAY(env.slb, PowerPCCPU, MAX_SLB_ENTRIES), diff --git a/target-ppc/mmu-hash64.c b/target-ppc/mmu-hash64.c index 788725c460..9ad02f3a8f 100644 --- a/target-ppc/mmu-hash64.c +++ b/target-ppc/mmu-hash64.c @@ -20,6 +20,7 @@ #include "qemu/osdep.h" #include "cpu.h" #include "exec/helper-proto.h" +#include "qemu/error-report.h" #include "sysemu/kvm.h" #include "kvm_ppc.h" #include "mmu-hash64.h" @@ -141,6 +142,8 @@ int ppc_store_slb(PowerPCCPU *cpu, target_ulong slot, { CPUPPCState *env = &cpu->env; ppc_slb_t *slb = &env->slb[slot]; + const struct ppc_one_seg_page_size *sps = NULL; + int i; if (slot >= env->slb_nr) { return -1; /* Bad slot number */ @@ -155,8 +158,29 @@ int ppc_store_slb(PowerPCCPU *cpu, target_ulong slot, return -1; /* 1T segment on MMU that doesn't support it */ } + for (i = 0; i < PPC_PAGE_SIZES_MAX_SZ; i++) { + const struct ppc_one_seg_page_size *sps1 = &env->sps.sps[i]; + + if (!sps1->page_shift) { + break; + } + + if ((vsid & SLB_VSID_LLP_MASK) == sps1->slb_enc) { + sps = sps1; + break; + } + } + + if (!sps) { + error_report("Bad page size encoding in SLB store: slot "TARGET_FMT_lu + " esid 0x"TARGET_FMT_lx" vsid 0x"TARGET_FMT_lx, + slot, esid, vsid); + return -1; + } + slb->esid = esid; slb->vsid = vsid; + slb->sps = sps; LOG_SLB("%s: %d " TARGET_FMT_lx " - " TARGET_FMT_lx " => %016" PRIx64 " %016" PRIx64 "\n", __func__, slot, esid, vsid, @@ -395,24 +419,6 @@ static hwaddr ppc_hash64_pteg_search(PowerPCCPU *cpu, hwaddr hash, return -1; } -static uint64_t ppc_hash64_page_shift(ppc_slb_t *slb) -{ - uint64_t epnshift; - - /* Page size according to the SLB, which we use to generate the - * EPN for hash table lookup.. When we implement more recent MMU - * extensions this might be different from the actual page size - * encoded in the PTE */ - if ((slb->vsid & SLB_VSID_LLP_MASK) == SLB_VSID_4K) { - epnshift = TARGET_PAGE_BITS; - } else if ((slb->vsid & SLB_VSID_LLP_MASK) == SLB_VSID_64K) { - epnshift = TARGET_PAGE_BITS_64K; - } else { - epnshift = TARGET_PAGE_BITS_16M; - } - return epnshift; -} - static hwaddr ppc_hash64_htab_lookup(PowerPCCPU *cpu, ppc_slb_t *slb, target_ulong eaddr, ppc_hash_pte64_t *pte) @@ -420,21 +426,24 @@ static hwaddr ppc_hash64_htab_lookup(PowerPCCPU *cpu, CPUPPCState *env = &cpu->env; hwaddr pte_offset; hwaddr hash; - uint64_t vsid, epnshift, epnmask, epn, ptem; + uint64_t vsid, epnmask, epn, ptem; + + /* The SLB store path should prevent any bad page size encodings + * getting in there, so: */ + assert(slb->sps); - epnshift = ppc_hash64_page_shift(slb); - epnmask = ~((1ULL << epnshift) - 1); + epnmask = ~((1ULL << slb->sps->page_shift) - 1); if (slb->vsid & SLB_VSID_B) { /* 1TB segment */ vsid = (slb->vsid & SLB_VSID_VSID) >> SLB_VSID_SHIFT_1T; epn = (eaddr & ~SEGMENT_MASK_1T) & epnmask; - hash = vsid ^ (vsid << 25) ^ (epn >> epnshift); + hash = vsid ^ (vsid << 25) ^ (epn >> slb->sps->page_shift); } else { /* 256M segment */ vsid = (slb->vsid & SLB_VSID_VSID) >> SLB_VSID_SHIFT; epn = (eaddr & ~SEGMENT_MASK_256M) & epnmask; - hash = vsid ^ (epn >> epnshift); + hash = vsid ^ (epn >> slb->sps->page_shift); } ptem = (slb->vsid & SLB_VSID_PTEM) | ((epn >> 16) & HPTE64_V_AVPN); @@ -466,20 +475,6 @@ static hwaddr ppc_hash64_htab_lookup(PowerPCCPU *cpu, return pte_offset; } -static hwaddr ppc_hash64_pte_raddr(ppc_slb_t *slb, ppc_hash_pte64_t pte, - target_ulong eaddr) -{ - hwaddr mask; - int target_page_bits; - hwaddr rpn = pte.pte1 & HPTE64_R_RPN; - /* - * We support 4K, 64K and 16M now - */ - target_page_bits = ppc_hash64_page_shift(slb); - mask = (1ULL << target_page_bits) - 1; - return (rpn & ~mask) | (eaddr & mask); -} - int ppc_hash64_handle_mmu_fault(PowerPCCPU *cpu, target_ulong eaddr, int rwx, int mmu_idx) { @@ -601,7 +596,7 @@ int ppc_hash64_handle_mmu_fault(PowerPCCPU *cpu, target_ulong eaddr, /* 7. Determine the real address from the PTE */ - raddr = ppc_hash64_pte_raddr(slb, pte, eaddr); + raddr = deposit64(pte.pte1 & HPTE64_R_RPN, 0, slb->sps->page_shift, eaddr); tlb_set_page(cs, eaddr & TARGET_PAGE_MASK, raddr & TARGET_PAGE_MASK, prot, mmu_idx, TARGET_PAGE_SIZE); @@ -631,7 +626,8 @@ hwaddr ppc_hash64_get_phys_page_debug(PowerPCCPU *cpu, target_ulong addr) return -1; } - return ppc_hash64_pte_raddr(slb, pte, addr) & TARGET_PAGE_MASK; + return deposit64(pte.pte1 & HPTE64_R_RPN, 0, slb->sps->page_shift, addr) + & TARGET_PAGE_MASK; } void ppc_hash64_store_hpte(PowerPCCPU *cpu, -- GitLab