[PATCH v5 11/22] KVM: arm64: vgic-its: Interpret MAPD Size field and check related errors

[Auger Eric]

Hi,
On 27/04/2017 18:25, Christoffer Dall wrote:
> On Fri, Apr 14, 2017 at 12:15:23PM +0200, Eric Auger wrote:
>> Up to now the MAPD's ITT size field has been ignored. It encodes
>> the number of eventid bit minus 1. It should be used to check
>> the eventid when a MAPTI command is issued on a device. Let's
>> store the number of eventid bits in the its_device and do the
>> check on MAPTI. Also make sure the ITT size field does
>> not exceed the GITS_TYPER IDBITS field.
>>
>> Signed-off-by: Eric Auger <eric.auger at redhat.com>
>>
>> ---
>> v4 -> v5:
>> - its_cmd_get_size macro now returns the actual number of eventid bits
>> - use GIC_ENCODE_SZ macro to encode ID_bits
>>
>> v3 -> v4:
>> - VITS_TYPER_IDBITS set to 16 to be homogeneous with VITS_ESZ definition
>>   and correct users
>> - nb_eventid_bits correspond to the actual number of eventid bits
>> ---
>>  include/linux/irqchip/arm-gic-v3.h |  2 ++
>>  virt/kvm/arm/vgic/vgic-its.c       | 15 ++++++++++++++-
>>  2 files changed, 16 insertions(+), 1 deletion(-)
>>
>> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
>> index 54c20bd..0c6798c 100644
>> --- a/include/linux/irqchip/arm-gic-v3.h
>> +++ b/include/linux/irqchip/arm-gic-v3.h
>> @@ -345,9 +345,11 @@
>>  #define E_ITS_INT_UNMAPPED_INTERRUPT		0x010307
>>  #define E_ITS_CLEAR_UNMAPPED_INTERRUPT		0x010507
>>  #define E_ITS_MAPD_DEVICE_OOR			0x010801
>> +#define E_ITS_MAPD_ITTSIZE_OOR			0x010802
>>  #define E_ITS_MAPC_PROCNUM_OOR			0x010902
>>  #define E_ITS_MAPC_COLLECTION_OOR		0x010903
>>  #define E_ITS_MAPTI_UNMAPPED_DEVICE		0x010a04
>> +#define E_ITS_MAPTI_ID_OOR			0x010a05
>>  #define E_ITS_MAPTI_PHYSICALID_OOR		0x010a06
>>  #define E_ITS_INV_UNMAPPED_INTERRUPT		0x010c07
>>  #define E_ITS_INVALL_UNMAPPED_COLLECTION	0x010d09
>> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
>> index 1b5797e..0f3c8f3 100644
>> --- a/virt/kvm/arm/vgic/vgic-its.c
>> +++ b/virt/kvm/arm/vgic/vgic-its.c
>> @@ -105,6 +105,7 @@ struct its_device {
>>  
>>  	/* the head for the list of ITTEs */
>>  	struct list_head itt_head;
>> +	u32 nb_eventid_bits;
> 
> what does nb_ mean?
number ;-)

Eric
> 
>>  	u32 device_id;
>>  };
>>  
>> @@ -191,6 +192,8 @@ static struct its_ite *find_ite(struct vgic_its *its, u32 device_id,
>>  
>>  #define GIC_LPI_OFFSET 8192
>>  
>> +#define VITS_TYPER_IDBITS 16
>> +
>>  /*
>>   * Finds and returns a collection in the ITS collection table.
>>   * Must be called with the its_lock mutex held.
>> @@ -391,7 +394,7 @@ static unsigned long vgic_mmio_read_its_typer(struct kvm *kvm,
>>  	 * DevBits low - as least for the time being.
>>  	 */
>>  	reg |= 0x0f << GITS_TYPER_DEVBITS_SHIFT;
>> -	reg |= 0x0f << GITS_TYPER_IDBITS_SHIFT;
>> +	reg |= GIC_ENCODE_SZ(VITS_TYPER_IDBITS, 5) << GITS_TYPER_IDBITS_SHIFT;
>>  	reg |= GIC_ENCODE_SZ(abi->ite_esz, 4) << GITS_TYPER_ITT_ENTRY_SIZE_SHIFT;
>>  
>>  	return extract_bytes(reg, addr & 7, len);
>> @@ -562,6 +565,7 @@ static u64 its_cmd_mask_field(u64 *its_cmd, int word, int shift, int size)
>>  
>>  #define its_cmd_get_command(cmd)	its_cmd_mask_field(cmd, 0,  0,  8)
>>  #define its_cmd_get_deviceid(cmd)	its_cmd_mask_field(cmd, 0, 32, 32)
>> +#define its_cmd_get_size(cmd)		(its_cmd_mask_field(cmd, 1,  0,  5) + 1)
>>  #define its_cmd_get_id(cmd)		its_cmd_mask_field(cmd, 1,  0, 32)
>>  #define its_cmd_get_physical_id(cmd)	its_cmd_mask_field(cmd, 1, 32, 32)
>>  #define its_cmd_get_collection(cmd)	its_cmd_mask_field(cmd, 2,  0, 16)
>> @@ -752,6 +756,9 @@ static int vgic_its_cmd_handle_mapi(struct kvm *kvm, struct vgic_its *its,
>>  	if (!device)
>>  		return E_ITS_MAPTI_UNMAPPED_DEVICE;
>>  
>> +	if (event_id >= BIT_ULL(device->nb_eventid_bits))
>> +		return E_ITS_MAPTI_ID_OOR;
>> +
>>  	if (its_cmd_get_command(its_cmd) == GITS_CMD_MAPTI)
>>  		lpi_nr = its_cmd_get_physical_id(its_cmd);
>>  	else
>> @@ -832,11 +839,15 @@ static int vgic_its_cmd_handle_mapd(struct kvm *kvm, struct vgic_its *its,
>>  {
>>  	u32 device_id = its_cmd_get_deviceid(its_cmd);
>>  	bool valid = its_cmd_get_validbit(its_cmd);
>> +	u8 nb_eventid_bits = its_cmd_get_size(its_cmd);
>>  	struct its_device *device;
>>  
>>  	if (!vgic_its_check_id(its, its->baser_device_table, device_id))
>>  		return E_ITS_MAPD_DEVICE_OOR;
>>  
>> +	if (valid && nb_eventid_bits > VITS_TYPER_IDBITS)
>> +		return E_ITS_MAPD_ITTSIZE_OOR;
>> +
>>  	device = find_its_device(its, device_id);
>>  
>>  	/*
>> @@ -859,6 +870,8 @@ static int vgic_its_cmd_handle_mapd(struct kvm *kvm, struct vgic_its *its,
>>  		return -ENOMEM;
>>  
>>  	device->device_id = device_id;
>> +	device->nb_eventid_bits = nb_eventid_bits;
>> +
>>  	INIT_LIST_HEAD(&device->itt_head);
>>  
>>  	list_add_tail(&device->dev_list, &its->device_list);
>> -- 
>> 2.5.5
>>
> 
> Otherwise:
> 
> Reviewed-by: Christoffer Dall <cdall at linaro.org>
>