On Mon, Dec 14, 2015 at 8:01 PM, Jan Viktorin <viktorin at rehivetech.com>
wrote:
> Hello,
>
> this patch set increases the number of warnings for the armv7 build. I
> believe that most of them are false-positives.
>
> virtio_ethdev.c:729, GNU Make + GNU C Compiler (gcc), Priority: Normal
> cast increases required alignment of target type [-Wcast-align]
>
> xstats[count].value = *(uint64_t *)(((char *)rxvq) +
>
> * Can you guarantee this is not an unaligned 64-bit access?
>
> virtio_ethdev.c:747, GNU Make + GNU C Compiler (gcc), Priority: Normal
> cast increases required alignment of target type [-Wcast-align]
>
> ditto...
>
> virtio_pci.c:52, GNU Make + GNU C Compiler (gcc), Priority: Normal
> cast increases required alignment of target type [-Wcast-align]
>
> *(uint32_t *)d = VIRTIO_READ_REG_4(hw, off);
>
> * I think, here we can live with unaligned_uint32_t, don't we?
>
Yes.
> virtio_pci.c:55, GNU Make + GNU C Compiler (gcc), Priority: Normal
> cast increases required alignment of target type [-Wcast-align]
>
> similar...
>
> virtio_pci.c:75, GNU Make + GNU C Compiler (gcc), Priority: Normal
> cast increases required alignment of target type [-Wcast-align]
>
> similar...
>
> virtio_pci.c:78, GNU Make + GNU C Compiler (gcc), Priority: Normal
> cast increases required alignment of target type [-Wcast-align]
>
> similar...
>
> virtio_ring.h:144, GNU Make + GNU C Compiler (gcc), Priority: Normal
> cast increases required alignment of target type [-Wcast-align]
>
> vr->desc = (struct vring_desc *) p;
>
> * What can we do here? Should we annotate vring_desc to be aligned properly?
>
> virtio_ring.h:145, GNU Make + GNU C Compiler (gcc), Priority: Normal
> cast increases required alignment of target type [-Wcast-align]
>
> similar...
>
> virtio_rxtx.c:733, GNU Make + GNU C Compiler (gcc), Priority: Normal
> cast increases required alignment of target type [-Wcast-align]
>
> header = (struct virtio_net_hdr_mrg_rxbuf *)((char *)rxm->buf_addr +
> RTE_PKTMBUF_HEADROOM - hdr_size);
>
> * No idea how to solve this...
>
>
These warnings are in-general virtio-pmd warnings for armv7 case.
Patchset enables virtio feature thus above warning noticed.
I spent 10 min and noticed that most of those warning are types
(uint64_t*) ((char *) ptr + offset). could avoid such warning by
(uint64_t *) (uintptr) ((char*)ptr + offset) where ptr is void *, But
this not the case in virtio code, most of such places ptr is uint8_t,
keeping then void * then typecasting to ((char *)ptr + offset) then
following proposed-way, I guess won't harm functionality and could
keep armv7 happy. And yes they are all look false-positive to me too.
Pasting code a snape which could get rid of above warning for armv7
case. Let me know your feedback, Others thought/comment welcome.
Thanks!
----------------------------------------------------------
diff --git a/drivers/net/virtio/virtio_ethdev.c
b/drivers/net/virtio/virtio_ethdev.c
index 8107aef..7ef4d13 100644
--- a/drivers/net/virtio/virtio_ethdev.c
diff --git a/drivers/net/virtio/virtio_ethdev.c
b/drivers/net/virtio/virtio_ethdev.c
index 8107aef..7ef4d13 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -726,7 +726,7 @@ virtio_dev_xstats_get(struct rte_eth_dev *dev,
struct rte_eth_xstats *xstats,
snprintf(xstats[count].name, sizeof(xstats[count].name),
"rx_q%u_%s", i,
rte_virtio_q_stat_strings[t].name);
- xstats[count].value = *(uint64_t *)(((char *)rxvq) +
+ xstats[count].value = *(uint64_t
*)(uintptr_t)(((char *)rxvq) +
rte_virtio_q_stat_strings[t].offset);
count++;
}
@@ -744,7 +744,7 @@ virtio_dev_xstats_get(struct rte_eth_dev *dev,
struct rte_eth_xstats *xstats,
snprintf(xstats[count].name, sizeof(xstats[count].name),
"tx_q%u_%s", i,
rte_virtio_q_stat_strings[t].name);
- xstats[count].value = *(uint64_t *)(((char *)txvq) +
+ xstats[count].value = *(uint64_t
*)(uintptr_t)(((char *)txvq) +
rte_virtio_q_stat_strings[t].offset);
count++;
}
diff --git a/drivers/net/virtio/virtio_ring.h b/drivers/net/virtio/virtio_ring.h
index 447760a..f2f85b4 100644
--- a/drivers/net/virtio/virtio_ring.h
+++ b/drivers/net/virtio/virtio_ring.h
@@ -141,8 +141,8 @@ vring_init(struct vring *vr, unsigned int num, uint8_t *p,
unsigned long align)
{
vr->num = num;
- vr->desc = (struct vring_desc *) p;
- vr->avail = (struct vring_avail *) (p +
+ vr->desc = (struct vring_desc *) (uintptr_t)p;
+ vr->avail = (struct vring_avail *) ((uintptr_t)p +
num * sizeof(struct vring_desc));
vr->used = (void *)
RTE_ALIGN_CEIL((uintptr_t)(&vr->avail->ring[num]), align);
diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
index 23be1ff..d636e08 100644
--- a/drivers/net/virtio/virtio_rxtx.c
+++ b/drivers/net/virtio/virtio_rxtx.c
@@ -730,7 +730,7 @@ virtio_recv_mergeable_pkts(void *rx_queue,
continue;
}
- header = (struct virtio_net_hdr_mrg_rxbuf *)((char
*)rxm->buf_addr +
+ header = (struct virtio_net_hdr_mrg_rxbuf
*)(uintptr_t)((char *)rxm->buf_addr +
RTE_PKTMBUF_HEADROOM - hdr_size);
seg_num = header->num_buffers;
-----------------------------------------------------------------------------------
> Any other ideas are welcome.
>
> Regards
> Jan
>
> On Mon, 14 Dec 2015 18:30:19 +0530
> Santosh Shukla <sshukla at mvista.com> wrote:
>
>> This patch set add basic infrastrucure to run virtio-net-pci pmd driver for
>> arm64/arm. Tested on ThunderX platfrom. Verified for existing dpdk(s) test
>> applications like:
>> - ovs-dpdk-vhost-user: across the VM's, for the use-cases like guest2guest
>> and
>> Host2Guest
>> - testpmd application: Tested for max virtio-net-pci interface currently
>> supported in kernel i.e. 31 interface.
>>
>> Builds successfully for armv7/v8/thunderX and x86_64/i686 platforms. Made
>> sure
>> that patch changes donot break for x86_64 case. Done similar tests for x86_64
>> too.
>>
>> Patch History:
>> v2:
>> - Removed ifdef arm.. clutter from igb_uio / virtio_ethedev files
>> - Introduced rte_io.h header file in generic/ and arch specifics i.e.. for
>> armv7 --> rte_io_32.h, for armv8 --> rte_io_64.h.
>> - Removed RTE_ARCH_X86 ifdef clutter too and added rte_io.h header which
>> nothing
>> but wraps sys/io.h for x86_64 and i686
>> - Moved all the RTE_ARCH_ARM/64 dependancy for igb_uio case to separate
>> header
>> file named igbuio_ioport_misc.h. Now igb_uio.c will call only three
>> function
>> - igbuio_iomap
>> - igbuio_ioport_register
>> - igbuio_ioport_unregister
>> - Moved ARM/64 specific definition to include/exec-env/rte_virt_ioport.h
>> header
>> - Included virtio_ioport.c/h; has all private and public api required to map
>> iopci bar for non-x86 arch. Tested on thunderX and x86_64 both.
>> Private api includes:
>> - virtio_map_ioport
>> - virtio_set_ioport_addr
>> Public api includes:
>> - virtio_ioport_init
>> - virtio_ioport_unmap
>>
>> - Last patch is the miscllanious format specifier fix identifid for 64bit
>> case
>> during regression.
>>
>>
>> v1:
>> - First patch adds RTE_VIRTIO_INC_VECTOR config, much needed for archs like
>> arm/arm64 as they don't support vectored implementation, also wont able to
>> build.
>> - Second patch is in-general fix for i686.
>> - Third patch is to emulate x86-style of {in,out}[b,w,l] api support for
>> armv7/v8.
>> As virtio-net-pci pmd driver uses those apis for port rd/wr {b,w,l}
>> - Fourth patch to enable VIRTIO_PMD feature in armv7/v8/thunderX config.
>> - Fifth patch to disable iopl syscall, As arm/arm64 linux kernel doesn't
>> support
>> them.
>> - Sixth patch introduces ioport memdevice called /dev/igb_ioport by which
>> virtio
>> pmd driver could able to rd/wr PCI_IOBAR.
>> {applicable for arm/arm64 only, tested for arm64 as of now}
>>
>>
>> Santosh Shukla (13):
>> virtio: Introduce config RTE_VIRTIO_INC_VECTOR
>> config: i686: set RTE_VIRTIO_INC_VECTOR=n
>> rte_io: armv7/v8: Introduce api to emulate x86-style of PCI/ISA
>> ioport access
>> virtio_pci: use rte_io.h for non-x86 arch
>> virtio: change io_base datatype from uint32_t to uint64_type
>> config: armv7/v8: Enable RTE_LIBRTE_VIRTIO_PMD
>> linuxapp: eal: arm: Always return 0 for rte_eal_iopl_init()
>> rte_io: x86: Remove sys/io.h ifdef x86 clutter
>> igb_uio: ioport: map iopci region for armv7/v8
>> include/exec-env: ioport: add rte_virt_ioport header file
>> virtio_ioport: armv7/v8: mmap virtio iopci bar region
>> virtio_ethdev: use virtio_ioport api at device init/close
>> virtio_ethdev : fix format specifier error for 64bit addr case
>>
>> config/common_linuxapp | 1 +
>> config/defconfig_arm-armv7a-linuxapp-gcc | 6 +-
>> config/defconfig_arm64-armv8a-linuxapp-gcc | 6 +-
>> config/defconfig_i686-native-linuxapp-gcc | 1 +
>> config/defconfig_i686-native-linuxapp-icc | 1 +
>> drivers/net/virtio/Makefile | 3 +-
>> drivers/net/virtio/virtio_ethdev.c | 10 +-
>> drivers/net/virtio/virtio_ioport.c | 163
>> ++++++++++++++++++++
>> drivers/net/virtio/virtio_ioport.h | 42 +++++
>> drivers/net/virtio/virtio_pci.h | 6 +-
>> drivers/net/virtio/virtio_rxtx.c | 7 +
>> lib/librte_eal/common/Makefile | 1 +
>> lib/librte_eal/common/include/arch/arm/rte_io.h | 60 +++++++
>> lib/librte_eal/common/include/arch/arm/rte_io_32.h | 155
>> +++++++++++++++++++
>> lib/librte_eal/common/include/arch/arm/rte_io_64.h | 155
>> +++++++++++++++++++
>> lib/librte_eal/common/include/arch/x86/rte_io.h | 42 +++++
>> lib/librte_eal/common/include/generic/rte_io.h | 81 ++++++++++
>> lib/librte_eal/linuxapp/eal/Makefile | 2 +-
>> lib/librte_eal/linuxapp/eal/eal.c | 7 +-
>> .../eal/include/exec-env/rte_virt_ioport.h | 81 ++++++++++
>> lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 8 +-
>> .../linuxapp/igb_uio/igbuio_ioport_misc.h | 133 ++++++++++++++++
>> 22 files changed, 957 insertions(+), 14 deletions(-)
>> create mode 100644 drivers/net/virtio/virtio_ioport.c
>> create mode 100644 drivers/net/virtio/virtio_ioport.h
>> create mode 100644 lib/librte_eal/common/include/arch/arm/rte_io.h
>> create mode 100644 lib/librte_eal/common/include/arch/arm/rte_io_32.h
>> create mode 100644 lib/librte_eal/common/include/arch/arm/rte_io_64.h
>> create mode 100644 lib/librte_eal/common/include/arch/x86/rte_io.h
>> create mode 100644 lib/librte_eal/common/include/generic/rte_io.h
>> create mode 100644
>> lib/librte_eal/linuxapp/eal/include/exec-env/rte_virt_ioport.h
>> create mode 100644 lib/librte_eal/linuxapp/igb_uio/igbuio_ioport_misc.h
>>
>
>
>
> --
> Jan Viktorin E-mail: Viktorin at RehiveTech.com
> System Architect Web: www.RehiveTech.com
> RehiveTech
> Brno, Czech Republic
