[PATCH v9 05/11] arm/arm64: vgic: Introduce VENG0 and VENG1 fields to vmcr struct

[Auger Eric]

Hi Christoffer,

On 08/12/2016 13:21, Christoffer Dall wrote:
> On Thu, Dec 08, 2016 at 12:52:39PM +0100, Auger Eric wrote:
>> Hi Vijay,
>>
>> On 28/11/2016 15:28, Christoffer Dall wrote:
>>> On Wed, Nov 23, 2016 at 06:31:52PM +0530, vijay.kilari at gmail.com wrote:
>>>> From: Vijaya Kumar K <Vijaya.Kumar at cavium.com>
>>>>
>>>> ICC_VMCR_EL2 supports virtual access to ICC_IGRPEN1_EL1.Enable
>>>> and ICC_IGRPEN0_EL1.Enable fields. Add grpen0 and grpen1 member
>>>> variables to struct vmcr to support read and write of these fields.
>>>>
>>>> Also refactor vgic_set_vmcr and vgic_get_vmcr() code.
>>>> Drop ICH_VMCR_CTLR_SHIFT and ICH_VMCR_CTLR_MASK macros and instead
>>>> use ICH_VMCR_EOI* and ICH_VMCR_CBPR* macros
>>>> .
>>>> Signed-off-by: Vijaya Kumar K <Vijaya.Kumar at cavium.com>
>>>> ---
>>>>  include/linux/irqchip/arm-gic-v3.h |  2 --
>>>>  virt/kvm/arm/vgic/vgic-mmio-v2.c   | 16 ----------------
>>>>  virt/kvm/arm/vgic/vgic-mmio.c      | 16 ++++++++++++++++
>>>>  virt/kvm/arm/vgic/vgic-v3.c        | 22 ++++++++++++++++++++--
>>>>  virt/kvm/arm/vgic/vgic.h           |  5 +++++
>>>>  5 files changed, 41 insertions(+), 20 deletions(-)
>>>>
>>>> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
>>>> index b4f8287..406fc3e 100644
>>>> --- a/include/linux/irqchip/arm-gic-v3.h
>>>> +++ b/include/linux/irqchip/arm-gic-v3.h
>>>> @@ -404,8 +404,6 @@
>>>>  #define ICH_HCR_EN			(1 << 0)
>>>>  #define ICH_HCR_UIE			(1 << 1)
>>>>  
>>>> -#define ICH_VMCR_CTLR_SHIFT		0
>>>> -#define ICH_VMCR_CTLR_MASK		(0x21f << ICH_VMCR_CTLR_SHIFT)
>>>>  #define ICH_VMCR_CBPR_SHIFT		4
>>>>  #define ICH_VMCR_CBPR_MASK		(1 << ICH_VMCR_CBPR_SHIFT)
>>>>  #define ICH_VMCR_EOIM_SHIFT		9
>>>> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v2.c b/virt/kvm/arm/vgic/vgic-mmio-v2.c
>>>> index 2cb04b7..ad353b5 100644
>>>> --- a/virt/kvm/arm/vgic/vgic-mmio-v2.c
>>>> +++ b/virt/kvm/arm/vgic/vgic-mmio-v2.c
>>>> @@ -212,22 +212,6 @@ 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. */
>>>> diff --git a/virt/kvm/arm/vgic/vgic-mmio.c b/virt/kvm/arm/vgic/vgic-mmio.c
>>>> index 0d1bc98..f81e0e5 100644
>>>> --- a/virt/kvm/arm/vgic/vgic-mmio.c
>>>> +++ b/virt/kvm/arm/vgic/vgic-mmio.c
>>>> @@ -416,6 +416,22 @@ int vgic_validate_mmio_region_addr(struct kvm_device *dev,
>>>>  	return -ENXIO;
>>>>  }
>>>>  
>>>> +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);
>>>> +}
>>>> +
>>>> +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);
>>>> +}
>>>> +
>>>>  /*
>>>>   * kvm_mmio_read_buf() returns a value in a format where it can be converted
>>>>   * to a byte array and be directly observed as the guest wanted it to appear
>>>> diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
>>>> index 9f0dae3..a3ff04b 100644
>>>> --- a/virt/kvm/arm/vgic/vgic-v3.c
>>>> +++ b/virt/kvm/arm/vgic/vgic-v3.c
>>>> @@ -175,10 +175,19 @@ void vgic_v3_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
>>>>  {
>>>>  	u32 vmcr;
>>>>  
>>>> -	vmcr  = (vmcrp->ctlr << ICH_VMCR_CTLR_SHIFT) & ICH_VMCR_CTLR_MASK;
>>>> +	/*
>>>> +	 * Ignore the FIQen bit, because GIC emulation always implies
>>>> +	 * SRE=1 which means the vFIQEn bit is also RES1.
>>>> +	 */
>>>> +	vmcr = (vmcrp->ctlr & ICC_CTLR_EL1_EOImode_MASK) >>
>>>> +		ICC_CTLR_EL1_EOImode_SHIFT;
>>>> +	vmcr = (vmcr << ICH_VMCR_EOIM_SHIFT) & ICH_VMCR_EOIM_MASK;
> 
>> I am not able to understand why we use ICC_CTLR _*macros here? Please
>> could you explain it to me? Besides if we want to ignore the FIQen bit
>> can't we change the ICH_VMCR_CTLR_MASK value?
>>
> This first statement is setting the vmcr to the ctlr's bit[1], but
> placed in bit[0], and then the next statement is moving that bit value
> to the corresponding place in the vmcr.  I think this is correct
> (although a little opaque).
Yes the question was more about the semantic of the vmcrp->ctlr field. I
thought it was supposed to store ICH_VMCR_EL2 ctrl bits as they are and
not with a different layout.
> 
> There's also a newer series on the list, just so you know.

Argh OK I missed it. I will check the diffs in the AArch64 related patches.

Thanks

Eric
> 
> Thanks,
> -Christoffer
> 
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