| Message ID | 1458871508-17279-20-git-send-email-andre.przywara@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Mar 25, 2016 at 02:04:42AM +0000, Andre Przywara wrote: > Signed-off-by: Andre Przywara <andre.przywara@arm.com> > --- > virt/kvm/arm/vgic/vgic_mmio.c | 63 ++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 62 insertions(+), 1 deletion(-) > > diff --git a/virt/kvm/arm/vgic/vgic_mmio.c b/virt/kvm/arm/vgic/vgic_mmio.c > index bfc530c..76657ce 100644 > --- a/virt/kvm/arm/vgic/vgic_mmio.c > +++ b/virt/kvm/arm/vgic/vgic_mmio.c > @@ -410,6 +410,67 @@ static int vgic_mmio_write_priority(struct kvm_vcpu *vcpu, > return 0; > } > > +static int vgic_mmio_read_config(struct kvm_vcpu *vcpu, > + struct kvm_io_device *this, > + gpa_t addr, int len, void *val) > +{ > + struct vgic_io_device *iodev = container_of(this, > + struct vgic_io_device, dev); > + u32 intid = (addr - iodev->base_addr) * 4; > + u32 value = 0; > + int i; > + > + if (iodev->redist_vcpu) > + vcpu = iodev->redist_vcpu; > + > + for (i = 0; i < len * 4; i++) { > + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); > + > + if (irq->config == VGIC_CONFIG_EDGE) > + value |= (2U << (i * 2)); > + } > + > + write_mask32(value, addr & 3, len, val); > + return 0; > +} > + > +static int vgic_mmio_write_config(struct kvm_vcpu *vcpu, > + struct kvm_io_device *this, > + gpa_t addr, int len, const void *val) > +{ > + struct vgic_io_device *iodev = container_of(this, > + struct vgic_io_device, dev); > + u32 intid = (addr - iodev->base_addr) * 4; > + int i; > + > + if (iodev->redist_vcpu) > + vcpu = iodev->redist_vcpu; > + > + for (i = 0; i < len * 4; i++) { > + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); > + > + if (intid + i < 16) > + continue; > + > + /* > + * The spec says that interrupts must be disabled before > + * changing the configuration to avoid UNDEFINED behaviour. > + * Is this sufficient in our case? Do we quickly enough remove > + * the IRQ from the ap_list to safely do the config change? I don't understand the question about 'quickly enough' here. > + * Will even a disabled interrupt in an ap_list cause us > + * headaches if we change the configuration? > + */ I don't think there's any particular problem here, except for my comments below: (there may be some super weirdness if a VCPU is running with some bits of this IRQ in a LR while changing it, but I think we can ignore this case for now - or we can do like with the active state and force an exit). > + spin_lock(&irq->irq_lock); > + if (test_bit(i * 2 + 1, val)) > + irq->config = VGIC_CONFIG_EDGE; > + else > + irq->config = VGIC_CONFIG_LEVEL; I think here you have to sync pending to level | soft_pending, that's a rule we enforce for level triggered interrupts. > + spin_unlock(&irq->irq_lock); > + } > + > + return 0; > +} > + > struct vgic_register_region vgic_v2_dist_registers[] = { > REGISTER_DESC_WITH_LENGTH(GIC_DIST_CTRL, > vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc, 12), > @@ -432,7 +493,7 @@ struct vgic_register_region vgic_v2_dist_registers[] = { > REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_TARGET, > vgic_mmio_read_nyi, vgic_mmio_write_nyi, 8), > REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_CONFIG, > - vgic_mmio_read_nyi, vgic_mmio_write_nyi, 8), > + vgic_mmio_read_config, vgic_mmio_write_config, 2), > REGISTER_DESC_WITH_LENGTH(GIC_DIST_SOFTINT, > vgic_mmio_read_nyi, vgic_mmio_write_nyi, 4), > REGISTER_DESC_WITH_LENGTH(GIC_DIST_SGI_PENDING_CLEAR, > -- > 2.7.3 >
diff --git a/virt/kvm/arm/vgic/vgic_mmio.c b/virt/kvm/arm/vgic/vgic_mmio.c index bfc530c..76657ce 100644 --- a/virt/kvm/arm/vgic/vgic_mmio.c +++ b/virt/kvm/arm/vgic/vgic_mmio.c @@ -410,6 +410,67 @@ static int vgic_mmio_write_priority(struct kvm_vcpu *vcpu, return 0; } +static int vgic_mmio_read_config(struct kvm_vcpu *vcpu, + struct kvm_io_device *this, + gpa_t addr, int len, void *val) +{ + struct vgic_io_device *iodev = container_of(this, + struct vgic_io_device, dev); + u32 intid = (addr - iodev->base_addr) * 4; + u32 value = 0; + int i; + + if (iodev->redist_vcpu) + vcpu = iodev->redist_vcpu; + + for (i = 0; i < len * 4; i++) { + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); + + if (irq->config == VGIC_CONFIG_EDGE) + value |= (2U << (i * 2)); + } + + write_mask32(value, addr & 3, len, val); + return 0; +} + +static int vgic_mmio_write_config(struct kvm_vcpu *vcpu, + struct kvm_io_device *this, + gpa_t addr, int len, const void *val) +{ + struct vgic_io_device *iodev = container_of(this, + struct vgic_io_device, dev); + u32 intid = (addr - iodev->base_addr) * 4; + int i; + + if (iodev->redist_vcpu) + vcpu = iodev->redist_vcpu; + + for (i = 0; i < len * 4; i++) { + struct vgic_irq *irq = vgic_get_irq(vcpu->kvm, vcpu, intid + i); + + if (intid + i < 16) + continue; + + /* + * The spec says that interrupts must be disabled before + * changing the configuration to avoid UNDEFINED behaviour. + * Is this sufficient in our case? Do we quickly enough remove + * the IRQ from the ap_list to safely do the config change? + * Will even a disabled interrupt in an ap_list cause us + * headaches if we change the configuration? + */ + spin_lock(&irq->irq_lock); + if (test_bit(i * 2 + 1, val)) + irq->config = VGIC_CONFIG_EDGE; + else + irq->config = VGIC_CONFIG_LEVEL; + spin_unlock(&irq->irq_lock); + } + + return 0; +} + struct vgic_register_region vgic_v2_dist_registers[] = { REGISTER_DESC_WITH_LENGTH(GIC_DIST_CTRL, vgic_mmio_read_v2_misc, vgic_mmio_write_v2_misc, 12), @@ -432,7 +493,7 @@ struct vgic_register_region vgic_v2_dist_registers[] = { REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_TARGET, vgic_mmio_read_nyi, vgic_mmio_write_nyi, 8), REGISTER_DESC_WITH_BITS_PER_IRQ(GIC_DIST_CONFIG, - vgic_mmio_read_nyi, vgic_mmio_write_nyi, 8), + vgic_mmio_read_config, vgic_mmio_write_config, 2), REGISTER_DESC_WITH_LENGTH(GIC_DIST_SOFTINT, vgic_mmio_read_nyi, vgic_mmio_write_nyi, 4), REGISTER_DESC_WITH_LENGTH(GIC_DIST_SGI_PENDING_CLEAR,
Signed-off-by: Andre Przywara <andre.przywara@arm.com> --- virt/kvm/arm/vgic/vgic_mmio.c | 63 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 62 insertions(+), 1 deletion(-)