diff options
Diffstat (limited to 'arch/mips/kvm')
| -rw-r--r-- | arch/mips/kvm/vz.c | 242 |
1 files changed, 241 insertions, 1 deletions
diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c index 97e7a788bf4a..f32c1ab3f724 100644 --- a/arch/mips/kvm/vz.c +++ b/arch/mips/kvm/vz.c @@ -412,6 +412,117 @@ static void kvm_vz_save_timer(struct kvm_vcpu *vcpu) } /** + * is_eva_access() - Find whether an instruction is an EVA memory accessor. + * @inst: 32-bit instruction encoding. + * + * Finds whether @inst encodes an EVA memory access instruction, which would + * indicate that emulation of it should access the user mode address space + * instead of the kernel mode address space. This matters for MUSUK segments + * which are TLB mapped for user mode but unmapped for kernel mode. + * + * Returns: Whether @inst encodes an EVA accessor instruction. + */ +static bool is_eva_access(union mips_instruction inst) +{ + if (inst.spec3_format.opcode != spec3_op) + return false; + + switch (inst.spec3_format.func) { + case lwle_op: + case lwre_op: + case cachee_op: + case sbe_op: + case she_op: + case sce_op: + case swe_op: + case swle_op: + case swre_op: + case prefe_op: + case lbue_op: + case lhue_op: + case lbe_op: + case lhe_op: + case lle_op: + case lwe_op: + return true; + default: + return false; + } +} + +/** + * is_eva_am_mapped() - Find whether an access mode is mapped. + * @vcpu: KVM VCPU state. + * @am: 3-bit encoded access mode. + * @eu: Segment becomes unmapped and uncached when Status.ERL=1. + * + * Decode @am to find whether it encodes a mapped segment for the current VCPU + * state. Where necessary @eu and the actual instruction causing the fault are + * taken into account to make the decision. + * + * Returns: Whether the VCPU faulted on a TLB mapped address. + */ +static bool is_eva_am_mapped(struct kvm_vcpu *vcpu, unsigned int am, bool eu) +{ + u32 am_lookup; + int err; + + /* + * Interpret access control mode. We assume address errors will already + * have been caught by the guest, leaving us with: + * AM UM SM KM 31..24 23..16 + * UK 0 000 Unm 0 0 + * MK 1 001 TLB 1 + * MSK 2 010 TLB TLB 1 + * MUSK 3 011 TLB TLB TLB 1 + * MUSUK 4 100 TLB TLB Unm 0 1 + * USK 5 101 Unm Unm 0 0 + * - 6 110 0 0 + * UUSK 7 111 Unm Unm Unm 0 0 + * + * We shift a magic value by AM across the sign bit to find if always + * TLB mapped, and if not shift by 8 again to find if it depends on KM. + */ + am_lookup = 0x70080000 << am; + if ((s32)am_lookup < 0) { + /* + * MK, MSK, MUSK + * Always TLB mapped, unless SegCtl.EU && ERL + */ + if (!eu || !(read_gc0_status() & ST0_ERL)) + return true; + } else { + am_lookup <<= 8; + if ((s32)am_lookup < 0) { + union mips_instruction inst; + unsigned int status; + u32 *opc; + + /* + * MUSUK + * TLB mapped if not in kernel mode + */ + status = read_gc0_status(); + if (!(status & (ST0_EXL | ST0_ERL)) && + (status & ST0_KSU)) + return true; + /* + * EVA access instructions in kernel + * mode access user address space. + */ + opc = (u32 *)vcpu->arch.pc; + if (vcpu->arch.host_cp0_cause & CAUSEF_BD) + opc += 1; + err = kvm_get_badinstr(opc, vcpu, &inst.word); + if (!err && is_eva_access(inst)) + return true; + } + } + + return false; +} + +/** * kvm_vz_gva_to_gpa() - Convert valid GVA to GPA. * @vcpu: KVM VCPU state. * @gva: Guest virtual address to convert. @@ -427,10 +538,58 @@ static int kvm_vz_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva, unsigned long *gpa) { u32 gva32 = gva; + unsigned long segctl; if ((long)gva == (s32)gva32) { /* Handle canonical 32-bit virtual address */ - if ((s32)gva32 < (s32)0xc0000000) { + if (cpu_guest_has_segments) { + unsigned long mask, pa; + + switch (gva32 >> 29) { + case 0: + case 1: /* CFG5 (1GB) */ + segctl = read_gc0_segctl2() >> 16; + mask = (unsigned long)0xfc0000000ull; + break; + case 2: + case 3: /* CFG4 (1GB) */ + segctl = read_gc0_segctl2(); + mask = (unsigned long)0xfc0000000ull; + break; + case 4: /* CFG3 (512MB) */ + segctl = read_gc0_segctl1() >> 16; + mask = (unsigned long)0xfe0000000ull; + break; + case 5: /* CFG2 (512MB) */ + segctl = read_gc0_segctl1(); + mask = (unsigned long)0xfe0000000ull; + break; + case 6: /* CFG1 (512MB) */ + segctl = read_gc0_segctl0() >> 16; + mask = (unsigned long)0xfe0000000ull; + break; + case 7: /* CFG0 (512MB) */ + segctl = read_gc0_segctl0(); + mask = (unsigned long)0xfe0000000ull; + break; + default: + /* + * GCC 4.9 isn't smart enough to figure out that + * segctl and mask are always initialised. + */ + unreachable(); + } + + if (is_eva_am_mapped(vcpu, (segctl >> 4) & 0x7, + segctl & 0x0008)) + goto tlb_mapped; + + /* Unmapped, find guest physical address */ + pa = (segctl << 20) & mask; + pa |= gva32 & ~mask; + *gpa = pa; + return 0; + } else if ((s32)gva32 < (s32)0xc0000000) { /* legacy unmapped KSeg0 or KSeg1 */ *gpa = gva32 & 0x1fffffff; return 0; @@ -438,6 +597,20 @@ static int kvm_vz_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva, #ifdef CONFIG_64BIT } else if ((gva & 0xc000000000000000) == 0x8000000000000000) { /* XKPHYS */ + if (cpu_guest_has_segments) { + /* + * Each of the 8 regions can be overridden by SegCtl2.XR + * to use SegCtl1.XAM. + */ + segctl = read_gc0_segctl2(); + if (segctl & (1ull << (56 + ((gva >> 59) & 0x7)))) { + segctl = read_gc0_segctl1(); + if (is_eva_am_mapped(vcpu, (segctl >> 59) & 0x7, + 0)) + goto tlb_mapped; + } + + } /* * Traditionally fully unmapped. * Bits 61:59 specify the CCA, which we can just mask off here. @@ -449,6 +622,7 @@ static int kvm_vz_gva_to_gpa(struct kvm_vcpu *vcpu, unsigned long gva, #endif } +tlb_mapped: return kvm_vz_guest_tlb_lookup(vcpu, gva, gpa); } @@ -1212,6 +1386,12 @@ static u64 kvm_vz_get_one_regs_contextconfig[] = { #endif }; +static u64 kvm_vz_get_one_regs_segments[] = { + KVM_REG_MIPS_CP0_SEGCTL0, + KVM_REG_MIPS_CP0_SEGCTL1, + KVM_REG_MIPS_CP0_SEGCTL2, +}; + static u64 kvm_vz_get_one_regs_kscratch[] = { KVM_REG_MIPS_CP0_KSCRATCH1, KVM_REG_MIPS_CP0_KSCRATCH2, @@ -1234,6 +1414,8 @@ static unsigned long kvm_vz_num_regs(struct kvm_vcpu *vcpu) ++ret; if (cpu_guest_has_contextconfig) ret += ARRAY_SIZE(kvm_vz_get_one_regs_contextconfig); + if (cpu_guest_has_segments) + ret += ARRAY_SIZE(kvm_vz_get_one_regs_segments); ret += __arch_hweight8(cpu_data[0].guest.kscratch_mask); return ret; @@ -1273,6 +1455,12 @@ static int kvm_vz_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices) return -EFAULT; indices += ARRAY_SIZE(kvm_vz_get_one_regs_contextconfig); } + if (cpu_guest_has_segments) { + if (copy_to_user(indices, kvm_vz_get_one_regs_segments, + sizeof(kvm_vz_get_one_regs_segments))) + return -EFAULT; + indices += ARRAY_SIZE(kvm_vz_get_one_regs_segments); + } for (i = 0; i < 6; ++i) { if (!cpu_guest_has_kscr(i + 2)) continue; @@ -1361,6 +1549,21 @@ static int kvm_vz_get_one_reg(struct kvm_vcpu *vcpu, case KVM_REG_MIPS_CP0_PAGEGRAIN: *v = (long)read_gc0_pagegrain(); break; + case KVM_REG_MIPS_CP0_SEGCTL0: + if (!cpu_guest_has_segments) + return -EINVAL; + *v = read_gc0_segctl0(); + break; + case KVM_REG_MIPS_CP0_SEGCTL1: + if (!cpu_guest_has_segments) + return -EINVAL; + *v = read_gc0_segctl1(); + break; + case KVM_REG_MIPS_CP0_SEGCTL2: + if (!cpu_guest_has_segments) + return -EINVAL; + *v = read_gc0_segctl2(); + break; case KVM_REG_MIPS_CP0_WIRED: *v = (long)read_gc0_wired(); break; @@ -1528,6 +1731,21 @@ static int kvm_vz_set_one_reg(struct kvm_vcpu *vcpu, case KVM_REG_MIPS_CP0_PAGEGRAIN: write_gc0_pagegrain(v); break; + case KVM_REG_MIPS_CP0_SEGCTL0: + if (!cpu_guest_has_segments) + return -EINVAL; + write_gc0_segctl0(v); + break; + case KVM_REG_MIPS_CP0_SEGCTL1: + if (!cpu_guest_has_segments) + return -EINVAL; + write_gc0_segctl1(v); + break; + case KVM_REG_MIPS_CP0_SEGCTL2: + if (!cpu_guest_has_segments) + return -EINVAL; + write_gc0_segctl2(v); + break; case KVM_REG_MIPS_CP0_WIRED: change_gc0_wired(MIPSR6_WIRED_WIRED, v); break; @@ -1955,6 +2173,12 @@ static int kvm_vz_vcpu_load(struct kvm_vcpu *vcpu, int cpu) if (cpu_guest_has_badinstrp) kvm_restore_gc0_badinstrp(cop0); + if (cpu_guest_has_segments) { + kvm_restore_gc0_segctl0(cop0); + kvm_restore_gc0_segctl1(cop0); + kvm_restore_gc0_segctl2(cop0); + } + /* restore Root.GuestCtl2 from unused Guest guestctl2 register */ if (cpu_has_guestctl2) write_c0_guestctl2( @@ -2038,6 +2262,12 @@ static int kvm_vz_vcpu_put(struct kvm_vcpu *vcpu, int cpu) if (cpu_guest_has_badinstrp) kvm_save_gc0_badinstrp(cop0); + if (cpu_guest_has_segments) { + kvm_save_gc0_segctl0(cop0); + kvm_save_gc0_segctl1(cop0); + kvm_save_gc0_segctl2(cop0); + } + kvm_vz_save_timer(vcpu); /* save Root.GuestCtl2 in unused Guest guestctl2 register */ @@ -2356,6 +2586,16 @@ static int kvm_vz_vcpu_setup(struct kvm_vcpu *vcpu) #endif } + /* Implementation dependent, use the legacy layout */ + if (cpu_guest_has_segments) { + /* SegCtl0, SegCtl1, SegCtl2 */ + kvm_write_sw_gc0_segctl0(cop0, 0x00200010); + kvm_write_sw_gc0_segctl1(cop0, 0x00000002 | + (_page_cachable_default >> _CACHE_SHIFT) << + (16 + MIPS_SEGCFG_C_SHIFT)); + kvm_write_sw_gc0_segctl2(cop0, 0x00380438); + } + /* start with no pending virtual guest interrupts */ if (cpu_has_guestctl2) cop0->reg[MIPS_CP0_GUESTCTL2][MIPS_CP0_GUESTCTL2_SEL] = 0; |