[PATCH v3 16/19] KVM: arm64: ITS: vgic_its_check_id returns the entry's GPA

[eric.auger@redhat.com (Auger Eric)]

Hi Andre,
On 21/03/2017 19:12, Andre Przywara wrote:
> Hi,
> 
> On 06/03/17 11:34, Eric Auger wrote:
>> As vgic_its_check_id() computes the device/collection entry's
>> GPA, let's return it so that new callers can retrieve it easily.
>>
>> Signed-off-by: Eric Auger <eric.auger@redhat.com>
>>
>> ---
>>
>> v2: new
>> ---
>>  virt/kvm/arm/vgic/vgic-its.c | 11 ++++++++---
>>  1 file changed, 8 insertions(+), 3 deletions(-)
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
>> index ad67759..1060125 100644
>> --- a/virt/kvm/arm/vgic/vgic-its.c
>> +++ b/virt/kvm/arm/vgic/vgic-its.c
>> @@ -637,7 +637,8 @@ static int vgic_its_cmd_handle_movi(struct kvm *kvm, struct vgic_its *its,
>>   * is actually valid (covered by a memslot and guest accessible).
>>   * For this we have to read the respective first level entry.
>>   */
>> -static bool vgic_its_check_id(struct vgic_its *its, u64 baser, int id)
>> +static bool vgic_its_check_id(struct vgic_its *its, u64 baser, int id,
>> +			      gpa_t *eaddr)
>>  {
>>  	int l1_tbl_size = GITS_BASER_NR_PAGES(baser) * SZ_64K;
>>  	int index;
>> @@ -657,6 +658,7 @@ static bool vgic_its_check_id(struct vgic_its *its, u64 baser, int id)
>>  		addr = BASER_ADDRESS(baser) + id * esz;
>>  		gfn = addr >> PAGE_SHIFT;
>>  
>> +		*eaddr = addr;
> 
> If you check that eaddr is not NULL before writing to it, you can save
> the dummy variable in the two callers below (which doesn't hurt, but
> does not help readability either).

Done

Thanks

Eric
> 
> Cheers,
> Andre.
> 
>>  		return kvm_is_visible_gfn(its->dev->kvm, gfn);
>>  	}
>>  
>> @@ -689,6 +691,7 @@ static bool vgic_its_check_id(struct vgic_its *its, u64 baser, int id)
>>  	indirect_ptr += index * esz;
>>  	gfn = indirect_ptr >> PAGE_SHIFT;
>>  
>> +	*eaddr = indirect_ptr;
>>  	return kvm_is_visible_gfn(its->dev->kvm, gfn);
>>  }
>>  
>> @@ -697,8 +700,9 @@ static int vgic_its_alloc_collection(struct vgic_its *its,
>>  				     u32 coll_id)
>>  {
>>  	struct its_collection *collection;
>> +	gpa_t eaddr;
>>  
>> -	if (!vgic_its_check_id(its, its->baser_coll_table, coll_id))
>> +	if (!vgic_its_check_id(its, its->baser_coll_table, coll_id, &eaddr))
>>  		return E_ITS_MAPC_COLLECTION_OOR;
>>  
>>  	collection = kzalloc(sizeof(*collection), GFP_KERNEL);
>> @@ -910,8 +914,9 @@ static int vgic_its_cmd_handle_mapd(struct kvm *kvm, struct vgic_its *its,
>>  	size_t size = its_cmd_get_size(its_cmd);
>>  	gpa_t itt_addr = its_cmd_get_ittaddr(its_cmd);
>>  	struct its_device *device;
>> +	gpa_t eaddr;
>>  
>> -	if (!vgic_its_check_id(its, its->baser_device_table, device_id))
>> +	if (!vgic_its_check_id(its, its->baser_device_table, device_id, &eaddr))
>>  		return E_ITS_MAPD_DEVICE_OOR;
>>  
>>  	if (valid && size > VITS_TYPER_IDBITS)
>>