From 916ccadccdcd8a0b7184dce37066a9fb2f9b4195 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Thu, 7 Jun 2018 18:04:37 +1000 Subject: KVM: PPC: Book3S PR: Fix MSR setting when delivering interrupts This makes sure that MSR "partial-function" bits are not transferred to SRR1 when delivering an interrupt. This was causing failures in guests running kernels that include commit f3d96e698ed0 ("powerpc/mm: Overhaul handling of bad page faults", 2017-07-19), which added code to check bits of SRR1 on instruction storage interrupts (ISIs) that indicate a bad page fault. The symptom was that a guest user program that handled a signal and attempted to return from the signal handler would get a SIGBUS signal and die. The code that generated ISIs and some other interrupts would previously set bits in the guest MSR to indicate the interrupt status and then call kvmppc_book3s_queue_irqprio(). This technique no longer works now that kvmppc_inject_interrupt() is masking off those bits. Instead we make kvmppc_core_queue_data_storage() and kvmppc_core_queue_inst_storage() call kvmppc_inject_interrupt() directly, and make sure that all the places that generate ISIs or DSIs call kvmppc_core_queue_{data,inst}_storage instead of kvmppc_book3s_queue_irqprio(). Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s.c | 13 +++++-------- arch/powerpc/kvm/book3s_pr.c | 42 +++++++++++++++++------------------------- 2 files changed, 22 insertions(+), 33 deletions(-) (limited to 'arch') diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index 309c8cf..edaf4720 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -134,7 +134,7 @@ void kvmppc_inject_interrupt(struct kvm_vcpu *vcpu, int vec, u64 flags) { kvmppc_unfixup_split_real(vcpu); kvmppc_set_srr0(vcpu, kvmppc_get_pc(vcpu)); - kvmppc_set_srr1(vcpu, kvmppc_get_msr(vcpu) | flags); + kvmppc_set_srr1(vcpu, (kvmppc_get_msr(vcpu) & ~0x783f0000ul) | flags); kvmppc_set_pc(vcpu, kvmppc_interrupt_offset(vcpu) + vec); vcpu->arch.mmu.reset_msr(vcpu); } @@ -256,18 +256,15 @@ void kvmppc_core_queue_data_storage(struct kvm_vcpu *vcpu, ulong dar, { kvmppc_set_dar(vcpu, dar); kvmppc_set_dsisr(vcpu, flags); - kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_DATA_STORAGE); + kvmppc_inject_interrupt(vcpu, BOOK3S_INTERRUPT_DATA_STORAGE, 0); } -EXPORT_SYMBOL_GPL(kvmppc_core_queue_data_storage); /* used by kvm_hv */ +EXPORT_SYMBOL_GPL(kvmppc_core_queue_data_storage); void kvmppc_core_queue_inst_storage(struct kvm_vcpu *vcpu, ulong flags) { - u64 msr = kvmppc_get_msr(vcpu); - msr &= ~(SRR1_ISI_NOPT | SRR1_ISI_N_OR_G | SRR1_ISI_PROT); - msr |= flags & (SRR1_ISI_NOPT | SRR1_ISI_N_OR_G | SRR1_ISI_PROT); - kvmppc_set_msr_fast(vcpu, msr); - kvmppc_book3s_queue_irqprio(vcpu, BOOK3S_INTERRUPT_INST_STORAGE); + kvmppc_inject_interrupt(vcpu, BOOK3S_INTERRUPT_INST_STORAGE, flags); } +EXPORT_SYMBOL_GPL(kvmppc_core_queue_inst_storage); static int kvmppc_book3s_irqprio_deliver(struct kvm_vcpu *vcpu, unsigned int priority) diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index a356916..e8036dd 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -728,24 +728,20 @@ int kvmppc_handle_pagefault(struct kvm_run *run, struct kvm_vcpu *vcpu, pte.may_execute = !data; } - if (page_found == -ENOENT) { - /* Page not found in guest PTE entries */ - u64 ssrr1 = vcpu->arch.shadow_srr1; - u64 msr = kvmppc_get_msr(vcpu); - kvmppc_set_dar(vcpu, kvmppc_get_fault_dar(vcpu)); - kvmppc_set_dsisr(vcpu, vcpu->arch.fault_dsisr); - kvmppc_set_msr_fast(vcpu, msr | (ssrr1 & 0xf8000000ULL)); - kvmppc_book3s_queue_irqprio(vcpu, vec); - } else if (page_found == -EPERM) { - /* Storage protection */ - u32 dsisr = vcpu->arch.fault_dsisr; - u64 ssrr1 = vcpu->arch.shadow_srr1; - u64 msr = kvmppc_get_msr(vcpu); - kvmppc_set_dar(vcpu, kvmppc_get_fault_dar(vcpu)); - dsisr = (dsisr & ~DSISR_NOHPTE) | DSISR_PROTFAULT; - kvmppc_set_dsisr(vcpu, dsisr); - kvmppc_set_msr_fast(vcpu, msr | (ssrr1 & 0xf8000000ULL)); - kvmppc_book3s_queue_irqprio(vcpu, vec); + if (page_found == -ENOENT || page_found == -EPERM) { + /* Page not found in guest PTE entries, or protection fault */ + u64 flags; + + if (page_found == -EPERM) + flags = DSISR_PROTFAULT; + else + flags = DSISR_NOHPTE; + if (data) { + flags |= vcpu->arch.fault_dsisr & DSISR_ISSTORE; + kvmppc_core_queue_data_storage(vcpu, eaddr, flags); + } else { + kvmppc_core_queue_inst_storage(vcpu, flags); + } } else if (page_found == -EINVAL) { /* Page not found in guest SLB */ kvmppc_set_dar(vcpu, kvmppc_get_fault_dar(vcpu)); @@ -1178,10 +1174,8 @@ int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu, kvmppc_mmu_pte_flush(vcpu, kvmppc_get_pc(vcpu), ~0xFFFUL); r = RESUME_GUEST; } else { - u64 msr = kvmppc_get_msr(vcpu); - msr |= shadow_srr1 & 0x58000000; - kvmppc_set_msr_fast(vcpu, msr); - kvmppc_book3s_queue_irqprio(vcpu, exit_nr); + kvmppc_core_queue_inst_storage(vcpu, + shadow_srr1 & 0x58000000); r = RESUME_GUEST; } break; @@ -1220,9 +1214,7 @@ int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu, r = kvmppc_handle_pagefault(run, vcpu, dar, exit_nr); srcu_read_unlock(&vcpu->kvm->srcu, idx); } else { - kvmppc_set_dar(vcpu, dar); - kvmppc_set_dsisr(vcpu, fault_dsisr); - kvmppc_book3s_queue_irqprio(vcpu, exit_nr); + kvmppc_core_queue_data_storage(vcpu, dar, fault_dsisr); r = RESUME_GUEST; } break; -- cgit v1.1