1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright 2017 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> 4 */ 5 6 #include <linux/kvm_host.h> 7 8 #include <asm/kvm_ppc.h> 9 #include <asm/kvm_book3s.h> 10 #include <asm/kvm_book3s_64.h> 11 #include <asm/reg.h> 12 #include <asm/ppc-opcode.h> 13 14 /* 15 * This handles the cases where the guest is in real suspend mode 16 * and we want to get back to the guest without dooming the transaction. 17 * The caller has checked that the guest is in real-suspend mode 18 * (MSR[TS] = S and the fake-suspend flag is not set). 19 */ 20 int kvmhv_p9_tm_emulation_early(struct kvm_vcpu *vcpu) 21 { 22 u32 instr = vcpu->arch.emul_inst; 23 u64 newmsr, msr, bescr; 24 int rs; 25 26 /* 27 * rfid, rfebb, and mtmsrd encode bit 31 = 0 since it's a reserved bit 28 * in these instructions, so masking bit 31 out doesn't change these 29 * instructions. For the tsr. instruction if bit 31 = 0 then it is per 30 * ISA an invalid form, however P9 UM, in section 4.6.10 Book II Invalid 31 * Forms, informs specifically that ignoring bit 31 is an acceptable way 32 * to handle TM-related invalid forms that have bit 31 = 0. Moreover, 33 * for emulation purposes both forms (w/ and wo/ bit 31 set) can 34 * generate a softpatch interrupt. Hence both forms are handled below 35 * for tsr. to make them behave the same way. 36 */ 37 switch (instr & PO_XOP_OPCODE_MASK) { 38 case PPC_INST_RFID: 39 /* XXX do we need to check for PR=0 here? */ 40 newmsr = vcpu->arch.shregs.srr1; 41 /* should only get here for Sx -> T1 transition */ 42 if (!(MSR_TM_TRANSACTIONAL(newmsr) && (newmsr & MSR_TM))) 43 return 0; 44 newmsr = sanitize_msr(newmsr); 45 vcpu->arch.shregs.msr = newmsr; 46 vcpu->arch.cfar = vcpu->arch.regs.nip - 4; 47 vcpu->arch.regs.nip = vcpu->arch.shregs.srr0; 48 return 1; 49 50 case PPC_INST_RFEBB: 51 /* check for PR=1 and arch 2.06 bit set in PCR */ 52 msr = vcpu->arch.shregs.msr; 53 if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206)) 54 return 0; 55 /* check EBB facility is available */ 56 if (!(vcpu->arch.hfscr & HFSCR_EBB) || 57 ((msr & MSR_PR) && !(mfspr(SPRN_FSCR) & FSCR_EBB))) 58 return 0; 59 bescr = mfspr(SPRN_BESCR); 60 /* expect to see a S->T transition requested */ 61 if (((bescr >> 30) & 3) != 2) 62 return 0; 63 bescr &= ~BESCR_GE; 64 if (instr & (1 << 11)) 65 bescr |= BESCR_GE; 66 mtspr(SPRN_BESCR, bescr); 67 msr = (msr & ~MSR_TS_MASK) | MSR_TS_T; 68 vcpu->arch.shregs.msr = msr; 69 vcpu->arch.cfar = vcpu->arch.regs.nip - 4; 70 vcpu->arch.regs.nip = mfspr(SPRN_EBBRR); 71 return 1; 72 73 case PPC_INST_MTMSRD: 74 /* XXX do we need to check for PR=0 here? */ 75 rs = (instr >> 21) & 0x1f; 76 newmsr = kvmppc_get_gpr(vcpu, rs); 77 msr = vcpu->arch.shregs.msr; 78 /* check this is a Sx -> T1 transition */ 79 if (!(MSR_TM_TRANSACTIONAL(newmsr) && (newmsr & MSR_TM))) 80 return 0; 81 /* mtmsrd doesn't change LE */ 82 newmsr = (newmsr & ~MSR_LE) | (msr & MSR_LE); 83 newmsr = sanitize_msr(newmsr); 84 vcpu->arch.shregs.msr = newmsr; 85 return 1; 86 87 /* ignore bit 31, see comment above */ 88 case (PPC_INST_TSR & PO_XOP_OPCODE_MASK): 89 /* we know the MSR has the TS field = S (0b01) here */ 90 msr = vcpu->arch.shregs.msr; 91 /* check for PR=1 and arch 2.06 bit set in PCR */ 92 if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206)) 93 return 0; 94 /* check for TM disabled in the HFSCR or MSR */ 95 if (!(vcpu->arch.hfscr & HFSCR_TM) || !(msr & MSR_TM)) 96 return 0; 97 /* L=1 => tresume => set TS to T (0b10) */ 98 if (instr & (1 << 21)) 99 vcpu->arch.shregs.msr = (msr & ~MSR_TS_MASK) | MSR_TS_T; 100 /* Set CR0 to 0b0010 */ 101 vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) | 102 0x20000000; 103 return 1; 104 } 105 106 return 0; 107 } 108 109 /* 110 * This is called when we are returning to a guest in TM transactional 111 * state. We roll the guest state back to the checkpointed state. 112 */ 113 void kvmhv_emulate_tm_rollback(struct kvm_vcpu *vcpu) 114 { 115 vcpu->arch.shregs.msr &= ~MSR_TS_MASK; /* go to N state */ 116 vcpu->arch.regs.nip = vcpu->arch.tfhar; 117 copy_from_checkpoint(vcpu); 118 vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) | 0xa0000000; 119 } 120