Commit 916ccadc authored by Paul Mackerras's avatar Paul Mackerras
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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 f3d96e69 ("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: default avatarPaul Mackerras <paulus@ozlabs.org>
parent b71dc519

arch/powerpc/kvm/book3s.c

+5 −8
Original line number Original line Diff line number Diff line
@@ -134,7 +134,7 @@ void kvmppc_inject_interrupt(struct kvm_vcpu *vcpu, int vec, u64 flags) 
{

{

	kvmppc_unfixup_split_real(vcpu);

	kvmppc_unfixup_split_real(vcpu);

	kvmppc_set_srr0(vcpu, kvmppc_get_pc(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);

	kvmppc_set_pc(vcpu, kvmppc_interrupt_offset(vcpu) + vec);

	vcpu->arch.mmu.reset_msr(vcpu);

	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_dar(vcpu, dar);

	kvmppc_set_dsisr(vcpu, flags);

	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)

void kvmppc_core_queue_inst_storage(struct kvm_vcpu *vcpu, ulong flags)

{

{

	u64 msr = kvmppc_get_msr(vcpu);

	kvmppc_inject_interrupt(vcpu, BOOK3S_INTERRUPT_INST_STORAGE, flags);

	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);

}

}

EXPORT_SYMBOL_GPL(kvmppc_core_queue_inst_storage);





static int kvmppc_book3s_irqprio_deliver(struct kvm_vcpu *vcpu,

static int kvmppc_book3s_irqprio_deliver(struct kvm_vcpu *vcpu,

					 unsigned int priority)

					 unsigned int priority)

arch/powerpc/kvm/book3s_pr.c

+17 −25
Original line number Original line Diff line number Diff line
@@ -728,24 +728,20 @@ int kvmppc_handle_pagefault(struct kvm_run *run, struct kvm_vcpu *vcpu, 
		pte.may_execute = !data;

		pte.may_execute = !data;

	}

	}





	if (page_found == -ENOENT) {

	if (page_found == -ENOENT || page_found == -EPERM) {

		/* Page not found in guest PTE entries */

		/* Page not found in guest PTE entries, or protection fault */

		u64 ssrr1 = vcpu->arch.shadow_srr1;

		u64 flags;

		u64 msr = kvmppc_get_msr(vcpu);



		kvmppc_set_dar(vcpu, kvmppc_get_fault_dar(vcpu));

		if (page_found == -EPERM)

		kvmppc_set_dsisr(vcpu, vcpu->arch.fault_dsisr);

			flags = DSISR_PROTFAULT;

		kvmppc_set_msr_fast(vcpu, msr | (ssrr1 & 0xf8000000ULL));

		else

		kvmppc_book3s_queue_irqprio(vcpu, vec);

			flags = DSISR_NOHPTE;

	} else if (page_found == -EPERM) {

		if (data) {

		/* Storage protection */

			flags |= vcpu->arch.fault_dsisr & DSISR_ISSTORE;

		u32 dsisr = vcpu->arch.fault_dsisr;

			kvmppc_core_queue_data_storage(vcpu, eaddr, flags);

		u64 ssrr1 = vcpu->arch.shadow_srr1;

		} else {

		u64 msr = kvmppc_get_msr(vcpu);

			kvmppc_core_queue_inst_storage(vcpu, flags);

		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);

	} else if (page_found == -EINVAL) {

	} else if (page_found == -EINVAL) {

		/* Page not found in guest SLB */

		/* Page not found in guest SLB */

		kvmppc_set_dar(vcpu, kvmppc_get_fault_dar(vcpu));

		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);

			kvmppc_mmu_pte_flush(vcpu, kvmppc_get_pc(vcpu), ~0xFFFUL);

			r = RESUME_GUEST;

			r = RESUME_GUEST;

		} else {

		} else {

			u64 msr = kvmppc_get_msr(vcpu);

			kvmppc_core_queue_inst_storage(vcpu,

			msr |= shadow_srr1 & 0x58000000;

						shadow_srr1 & 0x58000000);

			kvmppc_set_msr_fast(vcpu, msr);

			kvmppc_book3s_queue_irqprio(vcpu, exit_nr);

			r = RESUME_GUEST;

			r = RESUME_GUEST;

		}

		}

		break;

		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);

			r = kvmppc_handle_pagefault(run, vcpu, dar, exit_nr);

			srcu_read_unlock(&vcpu->kvm->srcu, idx);

			srcu_read_unlock(&vcpu->kvm->srcu, idx);

		} else {

		} else {

			kvmppc_set_dar(vcpu, dar);

			kvmppc_core_queue_data_storage(vcpu, dar, fault_dsisr);

			kvmppc_set_dsisr(vcpu, fault_dsisr);

			kvmppc_book3s_queue_irqprio(vcpu, exit_nr);

			r = RESUME_GUEST;

			r = RESUME_GUEST;

		}

		}

		break;

		break;

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