// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright 2017 Paul Mackerras, IBM Corp. <[email protected]>
*/
#include <linux/kvm_host.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/kvm_book3s_64.h>
#include <asm/reg.h>
#include <asm/ppc-opcode.h>
/*
* This handles the cases where the guest is in real suspend mode
* and we want to get back to the guest without dooming the transaction.
* The caller has checked that the guest is in real-suspend mode
* (MSR[TS] = S and the fake-suspend flag is not set).
*/
int kvmhv_p9_tm_emulation_early(struct kvm_vcpu *vcpu)
{
u32 instr = vcpu->arch.emul_inst;
u64 newmsr, msr, bescr;
int rs;
/*
* rfid, rfebb, and mtmsrd encode bit 31 = 0 since it's a reserved bit
* in these instructions, so masking bit 31 out doesn't change these
* instructions. For the tsr. instruction if bit 31 = 0 then it is per
* ISA an invalid form, however P9 UM, in section 4.6.10 Book II Invalid
* Forms, informs specifically that ignoring bit 31 is an acceptable way
* to handle TM-related invalid forms that have bit 31 = 0. Moreover,
* for emulation purposes both forms (w/ and wo/ bit 31 set) can
* generate a softpatch interrupt. Hence both forms are handled below
* for tsr. to make them behave the same way.
*/
switch (instr & PO_XOP_OPCODE_MASK) {
case PPC_INST_RFID:
/* XXX do we need to check for PR=0 here? */
newmsr = vcpu->arch.shregs.srr1;
/* should only get here for Sx -> T1 transition */
if (!(MSR_TM_TRANSACTIONAL(newmsr) && (newmsr & MSR_TM)))
return 0;
newmsr = sanitize_msr(newmsr);
vcpu->arch.shregs.msr = newmsr;
vcpu->arch.cfar = vcpu->arch.regs.nip - 4;
vcpu->arch.regs.nip = vcpu->arch.shregs.srr0;
return 1;
case PPC_INST_RFEBB:
/* check for PR=1 and arch 2.06 bit set in PCR */
msr = vcpu->arch.shregs.msr;
if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206))
return 0;
/* check EBB facility is available */
if (!(vcpu->arch.hfscr & HFSCR_EBB) ||
((msr & MSR_PR) && !(mfspr(SPRN_FSCR) & FSCR_EBB)))
return 0;
bescr = mfspr(SPRN_BESCR);
/* expect to see a S->T transition requested */
if (((bescr >> 30) & 3) != 2)
return 0;
bescr &= ~BESCR_GE;
if (instr & (1 << 11))
bescr |= BESCR_GE;
mtspr(SPRN_BESCR, bescr);
msr = (msr & ~MSR_TS_MASK) | MSR_TS_T;
vcpu->arch.shregs.msr = msr;
vcpu->arch.cfar = vcpu->arch.regs.nip - 4;
vcpu->arch.regs.nip = mfspr(SPRN_EBBRR);
return 1;
case PPC_INST_MTMSRD:
/* XXX do we need to check for PR=0 here? */
rs = (instr >> 21) & 0x1f;
newmsr = kvmppc_get_gpr(vcpu, rs);
msr = vcpu->arch.shregs.msr;
/* check this is a Sx -> T1 transition */
if (!(MSR_TM_TRANSACTIONAL(newmsr) && (newmsr & MSR_TM)))
return 0;
/* mtmsrd doesn't change LE */
newmsr = (newmsr & ~MSR_LE) | (msr & MSR_LE);
newmsr = sanitize_msr(newmsr);
vcpu->arch.shregs.msr = newmsr;
return 1;
/* ignore bit 31, see comment above */
case (PPC_INST_TSR & PO_XOP_OPCODE_MASK):
/* we know the MSR has the TS field = S (0b01) here */
msr = vcpu->arch.shregs.msr;
/* check for PR=1 and arch 2.06 bit set in PCR */
if ((msr & MSR_PR) && (vcpu->arch.vcore->pcr & PCR_ARCH_206))
return 0;
/* check for TM disabled in the HFSCR or MSR */
if (!(vcpu->arch.hfscr & HFSCR_TM) || !(msr & MSR_TM))
return 0;
/* L=1 => tresume => set TS to T (0b10) */
if (instr & (1 << 21))
vcpu->arch.shregs.msr = (msr & ~MSR_TS_MASK) | MSR_TS_T;
/* Set CR0 to 0b0010 */
vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) |
0x20000000;
return 1;
}
return 0;
}
/*
* This is called when we are returning to a guest in TM transactional
* state. We roll the guest state back to the checkpointed state.
*/
void kvmhv_emulate_tm_rollback(struct kvm_vcpu *vcpu)
{
vcpu->arch.shregs.msr &= ~MSR_TS_MASK; /* go to N state */
vcpu->arch.regs.nip = vcpu->arch.tfhar;
copy_from_checkpoint(vcpu);
vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) | 0xa0000000;
}
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