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| author | Mihai Caraman <mihai.caraman@freescale.com> | 2014-07-23 19:06:21 +0300 |
|---|---|---|
| committer | Alexander Graf <agraf@suse.de> | 2014-07-28 15:23:14 +0200 |
| commit | 51f047261e717b74b226f837a16455994b61ae30 (patch) | |
| tree | e94a57703fed176a72acef425cea442a8395746b /arch/powerpc/kvm/book3s_64_mmu_hv.c | |
| parent | 9a26af64d6bba72c9dfd62cc0cab0e79f8a66d7b (diff) | |
| download | blackbird-op-linux-51f047261e717b74b226f837a16455994b61ae30.tar.gz blackbird-op-linux-51f047261e717b74b226f837a16455994b61ae30.zip | |
KVM: PPC: Allow kvmppc_get_last_inst() to fail
On book3e, guest last instruction is read on the exit path using load
external pid (lwepx) dedicated instruction. This load operation may fail
due to TLB eviction and execute-but-not-read entries.
This patch lay down the path for an alternative solution to read the guest
last instruction, by allowing kvmppc_get_lat_inst() function to fail.
Architecture specific implmentations of kvmppc_load_last_inst() may read
last guest instruction and instruct the emulation layer to re-execute the
guest in case of failure.
Make kvmppc_get_last_inst() definition common between architectures.
Signed-off-by: Mihai Caraman <mihai.caraman@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Diffstat (limited to 'arch/powerpc/kvm/book3s_64_mmu_hv.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_64_mmu_hv.c | 17 |
1 files changed, 5 insertions, 12 deletions
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index 2d154d9319b3..fa944a3abdf0 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -530,21 +530,14 @@ static int instruction_is_store(unsigned int instr) static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu, unsigned long gpa, gva_t ea, int is_store) { - int ret; u32 last_inst; - unsigned long srr0 = kvmppc_get_pc(vcpu); - /* We try to load the last instruction. We don't let - * emulate_instruction do it as it doesn't check what - * kvmppc_ld returns. + /* * If we fail, we just return to the guest and try executing it again. */ - if (vcpu->arch.last_inst == KVM_INST_FETCH_FAILED) { - ret = kvmppc_ld(vcpu, &srr0, sizeof(u32), &last_inst, false); - if (ret != EMULATE_DONE || last_inst == KVM_INST_FETCH_FAILED) - return RESUME_GUEST; - vcpu->arch.last_inst = last_inst; - } + if (kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst) != + EMULATE_DONE) + return RESUME_GUEST; /* * WARNING: We do not know for sure whether the instruction we just @@ -558,7 +551,7 @@ static int kvmppc_hv_emulate_mmio(struct kvm_run *run, struct kvm_vcpu *vcpu, * we just return and retry the instruction. */ - if (instruction_is_store(kvmppc_get_last_inst(vcpu)) != !!is_store) + if (instruction_is_store(last_inst) != !!is_store) return RESUME_GUEST; /* |
