From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
To: Alejandro Lucero <alejandro.lucero@netronome.com>, dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH v2 4/6] bus/pci: use IOVAs dmak mask check when setting IOVA mode
Date: Fri, 5 Oct 2018 13:18:28 +0100 [thread overview]
Message-ID: <3f0c0853-4ec6-152f-7787-d01f6efd3466@intel.com> (raw)
In-Reply-To: <1538741212-7922-5-git-send-email-alejandro.lucero@netronome.com>
On 05-Oct-18 1:06 PM, Alejandro Lucero wrote:
> Currently the code precludes IOVA mode if IOMMU hardware reports
> less addressing bits than necessary for full virtual memory range.
>
> Although VT-d emulation currently only supports 39 bits, it could
> be iovas for allocated memlory being within that supported range.
^^ memory
> This patch allows IOVA mode in such a case adding a call to
> rte_eal_check_dma_mask using the reported addressing bits by the
> IOMMU hardware.
>
> Indeed, memory initialization code has been modified for using lower
> virtual addresses than those used by the kernel for 64 bits processes
> by default, and therefore memsegs iovas can use 39 bits or less for
> most systems. And this is likely 100% true for VMs.
>
> Signed-off-by: Alejandro Lucero <alejandro.lucero@netronome.com>
> ---
> drivers/bus/pci/linux/pci.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c
> index a871549..5cf78d7 100644
> --- a/drivers/bus/pci/linux/pci.c
> +++ b/drivers/bus/pci/linux/pci.c
> @@ -588,10 +588,8 @@
> fclose(fp);
>
> mgaw = ((vtd_cap_reg & VTD_CAP_MGAW_MASK) >> VTD_CAP_MGAW_SHIFT) + 1;
> - if (mgaw < X86_VA_WIDTH)
> - return false;
>
> - return true;
> + return rte_eal_check_dma_mask(mgaw) == 0 ? true : false;
Still looks weird but OK, no big deal :)
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>
> }
> #elif defined(RTE_ARCH_PPC_64)
> static bool
>
--
Thanks,
Anatoly
next prev parent reply other threads:[~2018-10-05 12:18 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-05 12:06 [dpdk-dev] [PATCH v2 0/6] use IOVAs check based on DMA mask Alejandro Lucero
2018-10-05 12:06 ` [dpdk-dev] [PATCH v2 1/6] mem: add function for checking memsegs IOVAs addresses Alejandro Lucero
2018-10-05 12:15 ` Burakov, Anatoly
2018-10-05 12:19 ` Alejandro Lucero
2018-10-05 12:20 ` Burakov, Anatoly
2018-10-05 12:06 ` [dpdk-dev] [PATCH v2 2/6] mem: use address hint for mapping hugepages Alejandro Lucero
2018-10-05 12:16 ` Burakov, Anatoly
2018-10-05 12:06 ` [dpdk-dev] [PATCH v2 3/6] bus/pci: check iommu addressing limitation just once Alejandro Lucero
2018-10-05 12:16 ` Burakov, Anatoly
2018-10-05 12:06 ` [dpdk-dev] [PATCH v2 4/6] bus/pci: use IOVAs dmak mask check when setting IOVA mode Alejandro Lucero
2018-10-05 12:18 ` Burakov, Anatoly [this message]
2018-10-05 12:06 ` [dpdk-dev] [PATCH v2 5/6] net/nfp: check hugepages IOVAs based on DMA mask Alejandro Lucero
2018-10-05 12:06 ` [dpdk-dev] [PATCH v2 6/6] net/nfp: support IOVA VA mode Alejandro Lucero
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