Hi,
On 12/05/16 19:47, Christoffer Dall wrote:
> On Fri, May 06, 2016 at 11:46:00AM +0100, 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]
>
> does this mean Marc did this and serves as credit or is it a lost
> reminder?
It was meant as credit. I thought that is the usual annotation for this?
>>
>> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
>> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
>> ---
>> 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);
>
> I don't think we allow anything than a full 32-bit aligned accesses
> from userspace - we shouldn't at least.
Indeed - I think userland was always 32-bit only. And since last night
we even enforce this. So potentially there are more extract_bytes()
calls that can go.
Cheers,
Andre.
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