/*
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* Copyright 2017 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, version 2, as
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* published by the Free Software Foundation.
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*/
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#include <linux/kvm_host.h>
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#include <asm/kvm_ppc.h>
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#include <asm/kvm_book3s.h>
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#include <asm/kvm_book3s_64.h>
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#include <asm/reg.h>
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#include <asm/ppc-opcode.h>
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/*
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* This handles the cases where the guest is in real suspend mode
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* and we want to get back to the guest without dooming the transaction.
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* The caller has checked that the guest is in real-suspend mode
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* (MSR[TS] = S and the fake-suspend flag is not set).
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*/
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int kvmhv_p9_tm_emulation_early(struct kvm_vcpu *vcpu)
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{
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u32 instr = vcpu->arch.emul_inst;
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u64 newmsr, msr, bescr;
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int rs;
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/*
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* rfid, rfebb, and mtmsrd encode bit 31 = 0 since it's a reserved bit
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* in these instructions, so masking bit 31 out doesn't change these
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* instructions. For the tsr. instruction if bit 31 = 0 then it is per
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* ISA an invalid form, however P9 UM, in section 4.6.10 Book II Invalid
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* Forms, informs specifically that ignoring bit 31 is an acceptable way
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* to handle TM-related invalid forms that have bit 31 = 0. Moreover,
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* for emulation purposes both forms (w/ and wo/ bit 31 set) can
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* generate a softpatch interrupt. Hence both forms are handled below
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* for tsr. to make them behave the same way.
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*/
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switch (instr & PO_XOP_OPCODE_MASK) {
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case PPC_INST_RFID:
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/* XXX do we need to check for PR=0 here? */
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newmsr = vcpu->arch.shregs.srr1;
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/* should only get here for Sx -> T1 transition */
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if (!(MSR_TM_TRANSACTIONAL(newmsr) && (newmsr & MSR_TM)))
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return 0;
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newmsr = sanitize_msr(newmsr);
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vcpu->arch.shregs.msr = newmsr;
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vcpu->arch.cfar = vcpu->arch.regs.nip - 4;
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vcpu->arch.regs.nip = vcpu->arch.shregs.srr0;
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return 1;
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case PPC_INST_RFEBB:
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/* check for PR=1 and arch 2.06 bit set in PCR */
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msr = vcpu->arch.shregs.msr;
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if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206))
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return 0;
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/* check EBB facility is available */
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if (!(vcpu->arch.hfscr & HFSCR_EBB) ||
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((msr & MSR_PR) && !(mfspr(SPRN_FSCR) & FSCR_EBB)))
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return 0;
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bescr = mfspr(SPRN_BESCR);
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/* expect to see a S->T transition requested */
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if (((bescr >> 30) & 3) != 2)
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return 0;
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bescr &= ~BESCR_GE;
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if (instr & (1 << 11))
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bescr |= BESCR_GE;
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mtspr(SPRN_BESCR, bescr);
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msr = (msr & ~MSR_TS_MASK) | MSR_TS_T;
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vcpu->arch.shregs.msr = msr;
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vcpu->arch.cfar = vcpu->arch.regs.nip - 4;
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vcpu->arch.regs.nip = mfspr(SPRN_EBBRR);
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return 1;
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case PPC_INST_MTMSRD:
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/* XXX do we need to check for PR=0 here? */
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rs = (instr >> 21) & 0x1f;
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newmsr = kvmppc_get_gpr(vcpu, rs);
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msr = vcpu->arch.shregs.msr;
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/* check this is a Sx -> T1 transition */
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if (!(MSR_TM_TRANSACTIONAL(newmsr) && (newmsr & MSR_TM)))
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return 0;
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/* mtmsrd doesn't change LE */
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newmsr = (newmsr & ~MSR_LE) | (msr & MSR_LE);
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newmsr = sanitize_msr(newmsr);
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vcpu->arch.shregs.msr = newmsr;
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return 1;
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/* ignore bit 31, see comment above */
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case (PPC_INST_TSR & PO_XOP_OPCODE_MASK):
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/* we know the MSR has the TS field = S (0b01) here */
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msr = vcpu->arch.shregs.msr;
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/* check for PR=1 and arch 2.06 bit set in PCR */
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if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206))
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return 0;
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/* check for TM disabled in the HFSCR or MSR */
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if (!(vcpu->arch.hfscr & HFSCR_TM) || !(msr & MSR_TM))
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return 0;
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/* L=1 => tresume => set TS to T (0b10) */
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if (instr & (1 << 21))
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vcpu->arch.shregs.msr = (msr & ~MSR_TS_MASK) | MSR_TS_T;
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/* Set CR0 to 0b0010 */
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vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) |
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0x20000000;
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return 1;
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}
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return 0;
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}
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/*
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* This is called when we are returning to a guest in TM transactional
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* state. We roll the guest state back to the checkpointed state.
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*/
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void kvmhv_emulate_tm_rollback(struct kvm_vcpu *vcpu)
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{
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vcpu->arch.shregs.msr &= ~MSR_TS_MASK; /* go to N state */
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vcpu->arch.regs.nip = vcpu->arch.tfhar;
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copy_from_checkpoint(vcpu);
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vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) | 0xa0000000;
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}
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