diff options
Diffstat (limited to 'arch/powerpc/kvm/book3s_64_mmu_hv.c')
-rw-r--r-- | arch/powerpc/kvm/book3s_64_mmu_hv.c | 228 |
1 files changed, 218 insertions, 10 deletions
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index b904c40a17bc..2d31519b8637 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -34,8 +34,6 @@ #include <asm/ppc-opcode.h> #include <asm/cputable.h> -#define VRMA_VSID 0x1ffffffUL /* 1TB VSID reserved for VRMA */ - /* POWER7 has 10-bit LPIDs, PPC970 has 6-bit LPIDs */ #define MAX_LPID_970 63 #define NR_LPIDS (LPID_RSVD + 1) @@ -298,16 +296,18 @@ long kvmppc_virtmode_h_enter(struct kvm_vcpu *vcpu, unsigned long flags, if (!psize) return H_PARAMETER; + pteh &= ~(HPTE_V_HVLOCK | HPTE_V_ABSENT | HPTE_V_VALID); + /* Find the memslot (if any) for this address */ gpa = (ptel & HPTE_R_RPN) & ~(psize - 1); gfn = gpa >> PAGE_SHIFT; memslot = gfn_to_memslot(kvm, gfn); - if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) - return H_PARAMETER; - if (!slot_is_aligned(memslot, psize)) - return H_PARAMETER; - if (kvmppc_get_guest_page(kvm, gfn, memslot, psize) < 0) - return H_PARAMETER; + if (memslot && !(memslot->flags & KVM_MEMSLOT_INVALID)) { + if (!slot_is_aligned(memslot, psize)) + return H_PARAMETER; + if (kvmppc_get_guest_page(kvm, gfn, memslot, psize) < 0) + return H_PARAMETER; + } preempt_disable(); ret = kvmppc_h_enter(vcpu, flags, pte_index, pteh, ptel); @@ -321,10 +321,218 @@ long kvmppc_virtmode_h_enter(struct kvm_vcpu *vcpu, unsigned long flags, } +static struct kvmppc_slb *kvmppc_mmu_book3s_hv_find_slbe(struct kvm_vcpu *vcpu, + gva_t eaddr) +{ + u64 mask; + int i; + + for (i = 0; i < vcpu->arch.slb_nr; i++) { + if (!(vcpu->arch.slb[i].orige & SLB_ESID_V)) + continue; + + if (vcpu->arch.slb[i].origv & SLB_VSID_B_1T) + mask = ESID_MASK_1T; + else + mask = ESID_MASK; + + if (((vcpu->arch.slb[i].orige ^ eaddr) & mask) == 0) + return &vcpu->arch.slb[i]; + } + return NULL; +} + +static unsigned long kvmppc_mmu_get_real_addr(unsigned long v, unsigned long r, + unsigned long ea) +{ + unsigned long ra_mask; + + ra_mask = hpte_page_size(v, r) - 1; + return (r & HPTE_R_RPN & ~ra_mask) | (ea & ra_mask); +} + static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, - struct kvmppc_pte *gpte, bool data) + struct kvmppc_pte *gpte, bool data) { - return -ENOENT; + struct kvm *kvm = vcpu->kvm; + struct kvmppc_slb *slbe; + unsigned long slb_v; + unsigned long pp, key; + unsigned long v, gr; + unsigned long *hptep; + int index; + int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR); + + /* Get SLB entry */ + if (virtmode) { + slbe = kvmppc_mmu_book3s_hv_find_slbe(vcpu, eaddr); + if (!slbe) + return -EINVAL; + slb_v = slbe->origv; + } else { + /* real mode access */ + slb_v = vcpu->kvm->arch.vrma_slb_v; + } + + /* Find the HPTE in the hash table */ + index = kvmppc_hv_find_lock_hpte(kvm, eaddr, slb_v, + HPTE_V_VALID | HPTE_V_ABSENT); + if (index < 0) + return -ENOENT; + hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4)); + v = hptep[0] & ~HPTE_V_HVLOCK; + gr = kvm->arch.revmap[index].guest_rpte; + + /* Unlock the HPTE */ + asm volatile("lwsync" : : : "memory"); + hptep[0] = v; + + gpte->eaddr = eaddr; + gpte->vpage = ((v & HPTE_V_AVPN) << 4) | ((eaddr >> 12) & 0xfff); + + /* Get PP bits and key for permission check */ + pp = gr & (HPTE_R_PP0 | HPTE_R_PP); + key = (vcpu->arch.shregs.msr & MSR_PR) ? SLB_VSID_KP : SLB_VSID_KS; + key &= slb_v; + + /* Calculate permissions */ + gpte->may_read = hpte_read_permission(pp, key); + gpte->may_write = hpte_write_permission(pp, key); + gpte->may_execute = gpte->may_read && !(gr & (HPTE_R_N | HPTE_R_G)); + + /* Storage key permission check for POWER7 */ + if (data && virtmode && cpu_has_feature(CPU_FTR_ARCH_206)) { + int amrfield = hpte_get_skey_perm(gr, vcpu->arch.amr); + if (amrfield & 1) + gpte->may_read = 0; + if (amrfield & 2) + gpte->may_write = 0; + } + + /* Get the guest physical address */ + gpte->raddr = kvmppc_mmu_get_real_addr(v, gr, eaddr); + return 0; +} + +/* + * Quick test for whether an instruction is a load or a store. + * If the instruction is a load or a store, then this will indicate + * which it is, at least on server processors. (Embedded processors + * have some external PID instructions that don't follow the rule + * embodied here.) If the instruction isn't a load or store, then + * this doesn't return anything useful. + */ +static int instruction_is_store(unsigned int instr) +{ + unsigned int mask; + + mask = 0x10000000; + if ((instr & 0xfc000000) == 0x7c000000) + mask = 0x100; /* major opcode 31 */ + return (instr & mask) != 0; +} + +static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu, + unsigned long gpa, int is_store) +{ + int ret; + u32 last_inst; + unsigned long srr0 = kvmppc_get_pc(vcpu); + + /* We try to load the last instruction. We don't let + * emulate_instruction do it as it doesn't check what + * kvmppc_ld returns. + * If we fail, we just return to the guest and try executing it again. + */ + if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) { + ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false); + if (ret != EMULATE_DONE || last_inst == KVM_INST_FETCH_FAILED) + return RESUME_GUEST; + vcpu->arch.last_inst = last_inst; + } + + /* + * WARNING: We do not know for sure whether the instruction we just + * read from memory is the same that caused the fault in the first + * place. If the instruction we read is neither an load or a store, + * then it can't access memory, so we don't need to worry about + * enforcing access permissions. So, assuming it is a load or + * store, we just check that its direction (load or store) is + * consistent with the original fault, since that's what we + * checked the access permissions against. If there is a mismatch + * we just return and retry the instruction. + */ + + if (instruction_is_store(vcpu->arch.last_inst) != !!is_store) + return RESUME_GUEST; + + /* + * Emulated accesses are emulated by looking at the hash for + * translation once, then performing the access later. The + * translation could be invalidated in the meantime in which + * point performing the subsequent memory access on the old + * physical address could possibly be a security hole for the + * guest (but not the host). + * + * This is less of an issue for MMIO stores since they aren't + * globally visible. It could be an issue for MMIO loads to + * a certain extent but we'll ignore it for now. + */ + + vcpu->arch.paddr_accessed = gpa; + return kvmppc_emulate_mmio(run, vcpu); +} + +int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu, + unsigned long ea, unsigned long dsisr) +{ + struct kvm *kvm = vcpu->kvm; + unsigned long *hptep, hpte[3]; + unsigned long psize; + unsigned long gfn; + struct kvm_memory_slot *memslot; + struct revmap_entry *rev; + long index; + + /* + * Real-mode code has already searched the HPT and found the + * entry we're interested in. Lock the entry and check that + * it hasn't changed. If it has, just return and re-execute the + * instruction. + */ + if (ea != vcpu->arch.pgfault_addr) + return RESUME_GUEST; + index = vcpu->arch.pgfault_index; + hptep = (unsigned long *)(kvm->arch.hpt_virt + (index << 4)); + rev = &kvm->arch.revmap[index]; + preempt_disable(); + while (!try_lock_hpte(hptep, HPTE_V_HVLOCK)) + cpu_relax(); + hpte[0] = hptep[0] & ~HPTE_V_HVLOCK; + hpte[1] = hptep[1]; + hpte[2] = rev->guest_rpte; + asm volatile("lwsync" : : : "memory"); + hptep[0] = hpte[0]; + preempt_enable(); + + if (hpte[0] != vcpu->arch.pgfault_hpte[0] || + hpte[1] != vcpu->arch.pgfault_hpte[1]) + return RESUME_GUEST; + + /* Translate the logical address and get the page */ + psize = hpte_page_size(hpte[0], hpte[1]); + gfn = hpte_rpn(hpte[2], psize); + memslot = gfn_to_memslot(kvm, gfn); + + /* No memslot means it's an emulated MMIO region */ + if (!memslot || (memslot->flags & KVM_MEMSLOT_INVALID)) { + unsigned long gpa = (gfn << PAGE_SHIFT) | (ea & (psize - 1)); + return kvmppc_hv_emulate_mmio(run, vcpu, gpa, + dsisr & DSISR_ISSTORE); + } + + /* should never get here otherwise */ + return -EFAULT; } void *kvmppc_pin_guest_page(struct kvm *kvm, unsigned long gpa, |