[PATCH v4 0/8] Introduce support for RISC-V architecture

[Heinrich Schuchardt]

On 6/8/22 10:41, David Marchand wrote:
> On Tue, May 31, 2022 at 4:14 PM Stanislaw Kardach <kda at semihalf.com> wrote:
>>
>> This patchset adds support for building and running DPDK on 64bit RISC-V
>> architecture. The initial support targets rv64gc (rv64imafdc) ISA and
>> was tested on SiFive Unmatched development board with the Freedom U740
>> SoC running Linux (freedom-u-sdk based kernel).
>> I have tested this codebase using DPDK unit and perf tests as well as
>> test-pmd, l2fwd and l3fwd examples.
>> The NIC attached to the DUT was Intel X520-DA2 which uses ixgbe PMD.
>> On the UIO side, since U740 does not have an IOMMU, I've used igb_uio,
>> uio_pci_generic and vfio-pci noiommu drivers.
>>
>> Functional verification done using meson tests. fast-tests suite passing with
>> the default config.
>>
>> PMD verification done using a Intel x520-DA2 NIC (ixgbe) and the test-pmd
>> application. Packet transfer checked using all UIO drivers available for
>> non-IOMMU platforms: uio_pci_generic, vfio-pci noiommu and igb_uio.
>>
>> The i40e PMD driver is disabled on RISC-V as the rv64gc ISA has no vector
>> operations.
>>
>> RISCV support is currently limited to Linux as the time measurement frequency
>> discovery is tied to reading a device-tree node via procfs.
>>
>> Clang compilation currently not supported due to issues with missing relocation
>> relaxation.
>>
>> Commit 1 introduces EAL and build system support for RISC-V architecture
>>     as well as documentation updates.
>> Commits 2-5 add missing defines and stubs to enable RISC-V operation in
>>     non-EAL parts.
>> Commit 6 adds RISC-V specific cpuflags test.
>> Commits 7-8 add RISC-V build testing to test-meson-builds.sh and github CI.
> 
> Overall, the series lgtm.
> It did not get much reviews, but the porting is straightforward and
> clean enough.
> 
> I'm waiting for some compilation to finish and I will merge it for 22.07-rc1.
> 
> 
> Some comments that will probably require some followup patches for rc2:
> 
> - I removed the known issue about --no-huge from the EAL patch.
> This seems to be a generic issue that does not block the RISC V port
> and can be re-submitted as a separate patch.
> 
> 
> - I had some trouble with finding a right toolchain for test-meson-builds.sh.
> The mentionned toolchains in the cross build guide don't work for me on FC36.
> I managed to cross compile with a Bootlin toolchain, though I had to
> adjust the cross compilation file.
> I'll probably end up compiling my own toolchain later unless you have
> a better idea.

Please, consider building natively too. https://wiki.ubuntu.com/RISC-V 
describes setting setting up a virtual machine.

> 
> At least the compilation in GHA works.
> 
> 
> - The hardcoded pkg-config path in config/riscv/riscv64_linux_gcc does
> not seem generic.
> It is probably not a big issue, but I'd rather move it to a Ubuntu
> specific cross compile meson file.
> WDYT?
> 
> 
> - I adjusted some coding style in some asm and some indentation and
> wording in meson.
> 
> 
> - The cross compilation guide mentions using
> crossbuild-essential-riscv64 for Ubuntu.
> We should switch to it in GHA.
> Though after trying myself, there is an issue in the C++ headers check
> in GHA for some acl header including rte_vect.h.
> Can you have a look?
> 
> 
> - There was a patch from Heinrich about native compilation, can you review it?

[PATCH] Fix RISC-V builds
http://mails.dpdk.org/archives/dev/2022-May/242749.html
relates to PktGen.

Best regards

Heinrich