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KVM: PPC: Book3S: Fix CONFIG_TRANSACTIONAL_MEM=n crash

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[ Upstream commit bd31ecf44b ]

When running CPU_FTR_P9_TM_HV_ASSIST, HFSCR[TM] is set for the guest
even if the host has CONFIG_TRANSACTIONAL_MEM=n, which causes it to be
unprepared to handle guest exits while transactional.

Normal guests don't have a problem because the HTM capability will not
be advertised, but a rogue or buggy one could crash the host.

Fixes: 4bb3c7a020 ("KVM: PPC: Book3S HV: Work around transactional memory bugs in POWER9")
Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210716024310.164448-1-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Nicholas Piggin
2021-07-16 12:43:09 +10:00
committed by Greg Kroah-Hartman
parent 30b8302151
commit fcbad8e18d
1 changed files with 2 additions and 0 deletions
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2
arch/powerpc/kvm/book3s_hv.c
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@@ -2366,8 +2366,10 @@ static int kvmppc_core_vcpu_create_hv(struct kvm_vcpu *vcpu)
HFSCR_DSCR | HFSCR_VECVSX | HFSCR_FP | HFSCR_PREFIX; HFSCR_DSCR | HFSCR_VECVSX | HFSCR_FP | HFSCR_PREFIX;
if (cpu_has_feature(CPU_FTR_HVMODE)) { if (cpu_has_feature(CPU_FTR_HVMODE)) {
vcpu->arch.hfscr &= mfspr(SPRN_HFSCR); vcpu->arch.hfscr &= mfspr(SPRN_HFSCR);
#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
if (cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST)) if (cpu_has_feature(CPU_FTR_P9_TM_HV_ASSIST))
vcpu->arch.hfscr |= HFSCR_TM; vcpu->arch.hfscr |= HFSCR_TM;
#endif
} }
if (cpu_has_feature(CPU_FTR_TM_COMP)) if (cpu_has_feature(CPU_FTR_TM_COMP))
vcpu->arch.hfscr |= HFSCR_TM; vcpu->arch.hfscr |= HFSCR_TM;