On Fri, May 13, 2016 at 01:23:02PM +0100, Andre Przywara wrote:
> Hi,
>
> On 13/05/16 12:54, Christoffer Dall wrote:
> > On Fri, May 13, 2016 at 11:44:38AM +0100, Andre Przywara wrote:
> >> Hi,
> >>
> >> On 13/05/16 08:53, Christoffer Dall wrote:
> >>> On Thu, May 12, 2016 at 07:52:38PM +0100, Andre Przywara wrote:
> >>>> 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?
> >>>>
> >>>
> >>> I'm not sure if that's the usual way, I read it as a reminder, but it's
> >>> not too important. Mostly wanting to make sure we're not forgetting
> >>> some todo item.
> >>>
> >>>>>>
> >>>>>> 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.
> >>>>
> >>> Right.
> >>
> >> So can I replace every call to extract_bytes() with just a "return val;"
> >> for every register that allows 32-bit accesses only?
> >> I think that's safe now, just checking ...
> >
> > yes, I think the way we do it now, you simply return val (asuming you
> > build that variable at the right offset, even for byte accesses).
>
> ??? If we only have word accesses, then we don't need to care about byte
> accesses? Or do I got something wrong here?
>
Ah right, we're talking about the userspace API here, never mind.
> > The only exception is for 32-bit accesses to 64-bit registers, where you
> > have to return either the upper or lower 32-bits. I think you can still
> > use extract_bytes() there should you be so inclined.
>
> Yeah, in fact GICR_TYPER and GICD_IROUTER are the only users remaining
> afterwards. So I moved the declaration into vgic-mmio-v3.c and renamed
> it to extract_words() on the way.
did you modify it to only work on words and let len specify the length
in words then, or?
> Will send the patch in a minute ...
>
I guess I can comment on it there.
-Christoffer
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