On Sat, Nov 29, 2014 at 1:28 PM, Christoffer Dall <christoffer.d...@linaro.org> wrote: > On Mon, Nov 24, 2014 at 11:26:51PM +0200, Nikolay Nikolaev wrote: >> On IO memory abort, try to handle the MMIO access thorugh the KVM >> registered read/write callbacks. This is done by invoking the relevant >> kvm_io_bus_* API. >> >> Signed-off-by: Nikolay Nikolaev <n.nikol...@virtualopensystems.com> >> --- >> arch/arm/kvm/mmio.c | 33 +++++++++++++++++++++++++++++++++ >> 1 file changed, 33 insertions(+) >> >> diff --git a/arch/arm/kvm/mmio.c b/arch/arm/kvm/mmio.c >> index 4cb5a93..81230da 100644 >> --- a/arch/arm/kvm/mmio.c >> +++ b/arch/arm/kvm/mmio.c >> @@ -162,6 +162,36 @@ static int decode_hsr(struct kvm_vcpu *vcpu, >> phys_addr_t fault_ipa, >> return 0; >> } >> >> +/** >> + * kvm_handle_mmio - handle an in-kernel MMIO access >> + * @vcpu: pointer to the vcpu performing the access >> + * @run: pointer to the kvm_run structure >> + * @mmio: pointer to the data describing the access >> + * >> + * returns true if the MMIO access has been performed in kernel space, >> + * and false if it needs to be emulated in user space. >> + */ >> +static bool handle_kernel_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run, >> + struct kvm_exit_mmio *mmio) >> +{ >> + int ret; >> + >> + if (mmio->is_write) { >> + ret = kvm_io_bus_write(vcpu, KVM_MMIO_BUS, mmio->phys_addr, >> + mmio->len, &mmio->data); >> + >> + } else { >> + ret = kvm_io_bus_read(vcpu, KVM_MMIO_BUS, mmio->phys_addr, >> + mmio->len, &mmio->data); >> + } >> + if (!ret) { >> + kvm_prepare_mmio(run, mmio); >> + kvm_handle_mmio_return(vcpu, run); >> + } >> + >> + return !ret; >> +} >> + >> int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run, >> phys_addr_t fault_ipa) >> { >> @@ -200,6 +230,9 @@ int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run >> *run, >> if (vgic_handle_mmio(vcpu, run, &mmio)) >> return 1; >> >> + if (handle_kernel_mmio(vcpu, run, &mmio)) >> + return 1; >> + > > Is this stuff always synchronously handled so that the mmio is properly > populated upon handle_kernel_mmio on reads?
If I get it right the kvm_io_bus_ API is intended to work synchronously. Of course it probably depends on how the registered device handles the read/write call. Or maybe I misunderstand your question? Please clarify in that case. regards, Nikolay Nikolaev > > -Christoffer -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html