1 /* 2 * Copyright 2017 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License, version 2, as 6 * published by the Free Software Foundation. 7 */ 8 9 #include <linux/kvm_host.h> 10 11 #include <asm/kvm_ppc.h> 12 #include <asm/kvm_book3s.h> 13 #include <asm/kvm_book3s_64.h> 14 #include <asm/reg.h> 15 #include <asm/ppc-opcode.h> 16 17 /* 18 * This handles the cases where the guest is in real suspend mode 19 * and we want to get back to the guest without dooming the transaction. 20 * The caller has checked that the guest is in real-suspend mode 21 * (MSR[TS] = S and the fake-suspend flag is not set). 22 */ 23 int kvmhv_p9_tm_emulation_early(struct kvm_vcpu *vcpu) 24 { 25 u32 instr = vcpu->arch.emul_inst; 26 u64 newmsr, msr, bescr; 27 int rs; 28 29 switch (instr & 0xfc0007ff) { 30 case PPC_INST_RFID: 31 /* XXX do we need to check for PR=0 here? */ 32 newmsr = vcpu->arch.shregs.srr1; 33 /* should only get here for Sx -> T1 transition */ 34 if (!(MSR_TM_TRANSACTIONAL(newmsr) && (newmsr & MSR_TM))) 35 return 0; 36 newmsr = sanitize_msr(newmsr); 37 vcpu->arch.shregs.msr = newmsr; 38 vcpu->arch.cfar = vcpu->arch.pc - 4; 39 vcpu->arch.pc = vcpu->arch.shregs.srr0; 40 return 1; 41 42 case PPC_INST_RFEBB: 43 /* check for PR=1 and arch 2.06 bit set in PCR */ 44 msr = vcpu->arch.shregs.msr; 45 if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206)) 46 return 0; 47 /* check EBB facility is available */ 48 if (!(vcpu->arch.hfscr & HFSCR_EBB) || 49 ((msr & MSR_PR) && !(mfspr(SPRN_FSCR) & FSCR_EBB))) 50 return 0; 51 bescr = mfspr(SPRN_BESCR); 52 /* expect to see a S->T transition requested */ 53 if (((bescr >> 30) & 3) != 2) 54 return 0; 55 bescr &= ~BESCR_GE; 56 if (instr & (1 << 11)) 57 bescr |= BESCR_GE; 58 mtspr(SPRN_BESCR, bescr); 59 msr = (msr & ~MSR_TS_MASK) | MSR_TS_T; 60 vcpu->arch.shregs.msr = msr; 61 vcpu->arch.cfar = vcpu->arch.pc - 4; 62 vcpu->arch.pc = mfspr(SPRN_EBBRR); 63 return 1; 64 65 case PPC_INST_MTMSRD: 66 /* XXX do we need to check for PR=0 here? */ 67 rs = (instr >> 21) & 0x1f; 68 newmsr = kvmppc_get_gpr(vcpu, rs); 69 msr = vcpu->arch.shregs.msr; 70 /* check this is a Sx -> T1 transition */ 71 if (!(MSR_TM_TRANSACTIONAL(newmsr) && (newmsr & MSR_TM))) 72 return 0; 73 /* mtmsrd doesn't change LE */ 74 newmsr = (newmsr & ~MSR_LE) | (msr & MSR_LE); 75 newmsr = sanitize_msr(newmsr); 76 vcpu->arch.shregs.msr = newmsr; 77 return 1; 78 79 case PPC_INST_TSR: 80 /* we know the MSR has the TS field = S (0b01) here */ 81 msr = vcpu->arch.shregs.msr; 82 /* check for PR=1 and arch 2.06 bit set in PCR */ 83 if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206)) 84 return 0; 85 /* check for TM disabled in the HFSCR or MSR */ 86 if (!(vcpu->arch.hfscr & HFSCR_TM) || !(msr & MSR_TM)) 87 return 0; 88 /* L=1 => tresume => set TS to T (0b10) */ 89 if (instr & (1 << 21)) 90 vcpu->arch.shregs.msr = (msr & ~MSR_TS_MASK) | MSR_TS_T; 91 /* Set CR0 to 0b0010 */ 92 vcpu->arch.cr = (vcpu->arch.cr & 0x0fffffff) | 0x20000000; 93 return 1; 94 } 95 96 return 0; 97 } 98 99 /* 100 * This is called when we are returning to a guest in TM transactional 101 * state. We roll the guest state back to the checkpointed state. 102 */ 103 void kvmhv_emulate_tm_rollback(struct kvm_vcpu *vcpu) 104 { 105 vcpu->arch.shregs.msr &= ~MSR_TS_MASK; /* go to N state */ 106 vcpu->arch.pc = vcpu->arch.tfhar; 107 copy_from_checkpoint(vcpu); 108 vcpu->arch.cr = (vcpu->arch.cr & 0x0fffffff) | 0xa0000000; 109 } 110