[PATCH v3 07/19] KVM: arm64: ITS: Report the ITE size in GITS_TYPER

[Auger Eric]

Hi,

On 17/03/2017 15:39, Andre Przywara wrote:
> 
> 
> On 06/03/17 11:34, Eric Auger wrote:
>> An ITE size of 8 Bytes is reported to the guest. Combining this
>> information with the number of event IDs the guest wants to support,
>> this latter will be able to allocate each device's ITT with the
>> right size.
>>
>> Signed-off-by: Eric Auger <eric.auger at redhat.com>
>>
>> ---
>>
>> v1 -> v2:
>> - correct ITT_ENTRY_SIZE field
>> - remove ITE_SIZE since all entries become 8 bytes
>> ---
>>  include/linux/irqchip/arm-gic-v3.h | 1 +
>>  virt/kvm/arm/vgic/vgic-its.c       | 5 ++++-
>>  2 files changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
>> index 672cfef..d81f10f 100644
>> --- a/include/linux/irqchip/arm-gic-v3.h
>> +++ b/include/linux/irqchip/arm-gic-v3.h
>> @@ -232,6 +232,7 @@
>>  #define GITS_CTLR_QUIESCENT		(1U << 31)
>>  
>>  #define GITS_TYPER_PLPIS		(1UL << 0)
>> +#define GITS_TYPER_ITT_ENTRY_SIZE_SHIFT	4
>>  #define GITS_TYPER_IDBITS_SHIFT		8
>>  #define GITS_TYPER_DEVBITS_SHIFT	13
>>  #define GITS_TYPER_DEVBITS(r)		((((r) >> GITS_TYPER_DEVBITS_SHIFT) & 0x1f) + 1)
>> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
>> index 6120c6e..6d84508 100644
>> --- a/virt/kvm/arm/vgic/vgic-its.c
>> +++ b/virt/kvm/arm/vgic/vgic-its.c
>> @@ -176,6 +176,8 @@ static struct its_ite *find_ite(struct vgic_its *its, u32 device_id,
>>  
>>  #define GIC_LPI_OFFSET 8192
>>  
>> +#define VITS_ESZ 8
>> +
>>  /*
>>   * Finds and returns a collection in the ITS collection table.
>>   * Must be called with the its_lock mutex held.
>> @@ -399,6 +401,7 @@ static unsigned long vgic_mmio_read_its_typer(struct kvm *kvm,
>>  	 */
>>  	reg |= 0x0f << GITS_TYPER_DEVBITS_SHIFT;
>>  	reg |= 0x0f << GITS_TYPER_IDBITS_SHIFT;
>> +	reg |= (VITS_ESZ - 1) << GITS_TYPER_ITT_ENTRY_SIZE_SHIFT;
>>  
>>  	return extract_bytes(reg, addr & 7, len);
>>  }
>> @@ -1387,7 +1390,7 @@ static int vgic_register_its_iodev(struct kvm *kvm, struct vgic_its *its)
>>  	(GIC_BASER_CACHEABILITY(GITS_BASER, INNER, RaWb)		| \
>>  	 GIC_BASER_CACHEABILITY(GITS_BASER, OUTER, SameAsInner)		| \
>>  	 GIC_BASER_SHAREABILITY(GITS_BASER, InnerShareable)		| \
>> -	 ((8ULL - 1) << GITS_BASER_ENTRY_SIZE_SHIFT)			| \
>> +	 ((u64)(VITS_ESZ - 1) << GITS_BASER_ENTRY_SIZE_SHIFT)		| \
> 
> Nit: wouldn't (VITS_ESZ - 1ULL) save you the cast? 
Yes it does. I took your suggestion.

Or you define
> VITS_ESZ to 8ULL above.
> 
> But apart from that:
> Reviewed-by: Andre Przywara <andre.przywara at arm.com>
Thanks

Eric
> 
> Cheers,
> Andre.
> 
>>  	 GITS_BASER_PAGE_SIZE_64K)
>>  
>>  #define INITIAL_PROPBASER_VALUE						  \
>>