[PATCH v3 47/55] KVM: arm/arm64: vgic-new: Add userland GIC CPU interface access
Andre Przywara
andre.przywara at arm.com
Wed May 11 01:24:45 PDT 2016
Hi,
On 09/05/16 18:27, Marc Zyngier wrote:
> On 06/05/16 11:46, Andre Przywara wrote:
>> Using the VMCR accessors we provide access to GIC CPU interface state
>> to userland by wiring it up to the existing userland interface.
>> [Marc: move and make VMCR accessors static, streamline MMIO handlers]
>>
>> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
>> Signed-off-by: Marc Zyngier <marc.zyngier at arm.com>
>> ---
>> Changelog v2 .. v3:
>> - total rework, moving into vgic-mmio-v2.c
>> - move vmcr accessor wrapper functions into this file
>> - use the register description table for CPU i/f registers as well
>> - add RAZ/WI handling for the active priority registers
>> - streamline MMIO handler functions
>>
>> virt/kvm/arm/vgic/vgic-kvm-device.c | 2 +-
>> virt/kvm/arm/vgic/vgic-mmio-v2.c | 104 ++++++++++++++++++++++++++++++++++++
>> virt/kvm/arm/vgic/vgic.h | 2 +
>> 3 files changed, 107 insertions(+), 1 deletion(-)
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c
>> index bb33af8..2122ff2 100644
>> --- a/virt/kvm/arm/vgic/vgic-kvm-device.c
>> +++ b/virt/kvm/arm/vgic/vgic-kvm-device.c
>> @@ -300,7 +300,7 @@ static int vgic_attr_regs_access(struct kvm_device *dev,
>>
>> switch (attr->group) {
>> case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
>> - ret = -EINVAL;
>> + ret = vgic_v2_cpuif_uaccess(vcpu, is_write, addr, reg);
>> break;
>> case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
>> ret = vgic_v2_dist_uaccess(vcpu, is_write, addr, reg);
>> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c
>> index c453e6f..0060539 100644
>> --- a/virt/kvm/arm/vgic/vgic-mmio-v2.c
>> +++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c
>> @@ -206,6 +206,84 @@ static void vgic_mmio_write_sgipends(struct kvm_vcpu *vcpu,
>> }
>> }
>>
>> +static void vgic_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
>> +{
>> + if (kvm_vgic_global_state.type == VGIC_V2)
>> + vgic_v2_set_vmcr(vcpu, vmcr);
>> + else
>> + vgic_v3_set_vmcr(vcpu, vmcr);
>> +}
>> +
>> +static void vgic_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcr)
>> +{
>> + if (kvm_vgic_global_state.type == VGIC_V2)
>> + vgic_v2_get_vmcr(vcpu, vmcr);
>> + else
>> + vgic_v3_get_vmcr(vcpu, vmcr);
>> +}
>> +
>> +#define GICC_ARCH_VERSION_V2 0x2
>> +
>> +/* These are for userland accesses only, there is no guest-facing emulation. */
>> +static unsigned long vgic_mmio_read_vcpuif(struct kvm_vcpu *vcpu,
>> + gpa_t addr, unsigned int len)
>> +{
>> + struct vgic_vmcr vmcr;
>> + u32 val;
>> +
>> + vgic_get_vmcr(vcpu, &vmcr);
>> +
>> + switch (addr & 0xff) {
>> + case GIC_CPU_CTRL:
>> + val = vmcr.ctlr;
>> + break;
>> + case GIC_CPU_PRIMASK:
>> + val = vmcr.pmr;
>> + break;
>> + case GIC_CPU_BINPOINT:
>> + val = vmcr.bpr;
>> + break;
>> + case GIC_CPU_ALIAS_BINPOINT:
>> + val = vmcr.abpr;
>> + break;
>> + case GIC_CPU_IDENT:
>> + val = ((PRODUCT_ID_KVM << 20) |
>> + (GICC_ARCH_VERSION_V2 << 16) |
>> + IMPLEMENTER_ARM);
>> + break;
>> + default:
>> + return 0;
>> + }
>> +
>> + return extract_bytes(val, addr & 3, len);
>> +}
>> +
>> +static void vgic_mmio_write_vcpuif(struct kvm_vcpu *vcpu,
>> + gpa_t addr, unsigned int len,
>> + unsigned long val)
>> +{
>> + struct vgic_vmcr vmcr;
>> +
>> + vgic_get_vmcr(vcpu, &vmcr);
>> +
>> + switch (addr & 0xff) {
>> + case GIC_CPU_CTRL:
>> + vmcr.ctlr = val;
>> + break;
>> + case GIC_CPU_PRIMASK:
>> + vmcr.pmr = val;
>> + break;
>> + case GIC_CPU_BINPOINT:
>> + vmcr.bpr = val;
>> + break;
>> + case GIC_CPU_ALIAS_BINPOINT:
>> + vmcr.abpr = val;
>> + break;
>> + }
>> +
>> + vgic_set_vmcr(vcpu, &vmcr);
>> +}
>> +
>> static const 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),
>> @@ -237,6 +315,21 @@ static const struct vgic_register_region vgic_v2_dist_registers[] = {
>> vgic_mmio_read_sgipend, vgic_mmio_write_sgipends, 16),
>> };
>>
>> +static const struct vgic_register_region vgic_v2_cpu_registers[] = {
>> + REGISTER_DESC_WITH_LENGTH(GIC_CPU_CTRL,
>> + vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4),
>> + REGISTER_DESC_WITH_LENGTH(GIC_CPU_PRIMASK,
>> + vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4),
>> + REGISTER_DESC_WITH_LENGTH(GIC_CPU_BINPOINT,
>> + vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4),
>> + REGISTER_DESC_WITH_LENGTH(GIC_CPU_ALIAS_BINPOINT,
>> + vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4),
>> + REGISTER_DESC_WITH_LENGTH(GIC_CPU_ACTIVEPRIO,
>> + vgic_mmio_read_raz, vgic_mmio_write_wi, 16),
>> + REGISTER_DESC_WITH_LENGTH(GIC_CPU_IDENT,
>> + vgic_mmio_read_vcpuif, vgic_mmio_write_vcpuif, 4),
>> +};
>> +
>> unsigned int vgic_v2_init_dist_iodev(struct vgic_io_device *dev)
>> {
>> dev->regions = vgic_v2_dist_registers;
>> @@ -306,6 +399,17 @@ static int vgic_uaccess(struct kvm_vcpu *vcpu, struct vgic_io_device *dev,
>> return ret;
>> }
>>
>> +int vgic_v2_cpuif_uaccess(struct kvm_vcpu *vcpu, bool is_write,
>> + int offset, u32 *val)
>> +{
>> + struct vgic_io_device dev = {
>> + .regions = vgic_v2_cpu_registers,
>> + .nr_regions = ARRAY_SIZE(vgic_v2_cpu_registers),
>> + };
>> +
>> + return vgic_uaccess(vcpu, &dev, is_write, offset, val);
>> +}
>> +
>> int vgic_v2_dist_uaccess(struct kvm_vcpu *vcpu, bool is_write,
>> int offset, u32 *val)
>> {
>
> And what about this:
>
> +int vgic_v2_has_attr_regs(struct kvm_device *dev, struct kvm_device_attr *attr)
> +{
> + int nr_irqs = dev->kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS;
> + const struct vgic_register_region *regions;
> + gpa_t addr;
> + int nr_regions, i, len;
> +
> + addr = attr->attr & KVM_DEV_ARM_VGIC_OFFSET_MASK;
> +
> + switch (attr->group) {
> + case KVM_DEV_ARM_VGIC_GRP_DIST_REGS:
> + regions = vgic_v2_dist_registers;
> + nr_regions = ARRAY_SIZE(vgic_v2_dist_registers);
> + break;
> + case KVM_DEV_ARM_VGIC_GRP_CPU_REGS:
> + return -ENXIO; /* TODO: describe CPU i/f regs also */
> + default:
> + return -ENXIO;
> + }
>
> This TODO was already in the previous version. Can you please wire it
> and give save/restore a chance to work?
Oh dear, thanks for spotting this. It _was_ in my fix patch, but got
lost during the rebase. Will fix it.
Cheers,
Andre.
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