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

Auger Eric
2017-04-27T17:15:34Z

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@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@linaro.org>
>