diff options
| author | Fabiano Rosas <farosas@linux.ibm.com> | 2022-01-25 18:56:55 -0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-01-31 13:43:00 +1100 |
| commit | c1c8a66367a35aabbad9bd629b105b9fb49f2c1f (patch) | |
| tree | 75092218759f4803b869bd1f97b799bc546bd7a9 /arch/powerpc/kvm/powerpc.c | |
| parent | 349fbfe9b918e6dea00734f07c0fbaf4c2e2df5e (diff) | |
KVM: PPC: Book3s: mmio: Deliver DSI after emulation failure
MMIO emulation can fail if the guest uses an instruction that we are
not prepared to emulate. Since these instructions can be and most
likely are valid ones, this is (slightly) closer to an access fault
than to an illegal instruction, so deliver a Data Storage interrupt
instead of a Program interrupt.
BookE ignores bad faults, so it will keep using a Program interrupt
because a DSI would cause a fault loop in the guest.
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220125215655.1026224-6-farosas@linux.ibm.com
Diffstat (limited to 'arch/powerpc/kvm/powerpc.c')
| -rw-r--r-- | arch/powerpc/kvm/powerpc.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index acb0d2a4bdb9..82d889db2b6b 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -309,6 +309,28 @@ int kvmppc_emulate_mmio(struct kvm_vcpu *vcpu) kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst); kvm_debug_ratelimited("Guest access to device memory using unsupported instruction (opcode: %#08x)\n", last_inst); + + /* + * Injecting a Data Storage here is a bit more + * accurate since the instruction that caused the + * access could still be a valid one. + */ + if (!IS_ENABLED(CONFIG_BOOKE)) { + ulong dsisr = DSISR_BADACCESS; + + if (vcpu->mmio_is_write) + dsisr |= DSISR_ISSTORE; + + kvmppc_core_queue_data_storage(vcpu, vcpu->arch.vaddr_accessed, dsisr); + } else { + /* + * BookE does not send a SIGBUS on a bad + * fault, so use a Program interrupt instead + * to avoid a fault loop. + */ + kvmppc_core_queue_program(vcpu, 0); + } + r = RESUME_GUEST; break; } |