From: "Eelco Chaudron" <echaudro@redhat.com>
To: "Alejandro Lucero" <alejandro.lucero@netronome.com>
Cc: dev@dpdk.org, stable@dpdk.org, anatoly.burakov@intel.com
Subject: Re: [dpdk-stable] [PATCH v4 2/5] bus/pci: use IOVAs check when setting IOVA mode
Date: Wed, 11 Jul 2018 12:18:25 +0200 [thread overview]
Message-ID: <A36D1731-8E03-424B-8D72-FE765B38A5E5@redhat.com> (raw)
In-Reply-To: <1531243552-7795-3-git-send-email-alejandro.lucero@netronome.com>
On 10 Jul 2018, at 19:25, Alejandro Lucero wrote:
> Although VT-d emulation currently only supports 39 bits, it could
> be iovas being within that supported range. This patch allows
> IOVA mode in such a case.
>
> Indeed, memory initialization code can be 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 system. And this is likely 100% true for VMs.
>
> Applicable to v17.11.3 only.
>
> Signed-off-by: Alejandro Lucero <alejandro.lucero@netronome.com>
> ---
> drivers/bus/pci/linux/pci.c | 15 +++++++++++----
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c
> index 74deef3..792c819 100644
> --- a/drivers/bus/pci/linux/pci.c
> +++ b/drivers/bus/pci/linux/pci.c
> @@ -43,6 +43,7 @@
> #include <rte_devargs.h>
> #include <rte_memcpy.h>
> #include <rte_vfio.h>
> +#include <rte_memory.h>
>
> #include "eal_private.h"
> #include "eal_filesystem.h"
> @@ -613,10 +614,12 @@
> fclose(fp);
>
> mgaw = ((vtd_cap_reg & VTD_CAP_MGAW_MASK) >> VTD_CAP_MGAW_SHIFT) +
> 1;
> - if (mgaw < X86_VA_WIDTH)
> +
> + if (!rte_eal_check_dma_mask(mgaw))
> + return true;
> + else
> return false;
>
> - return true;
> }
> #elif defined(RTE_ARCH_PPC_64)
> static bool
> @@ -640,13 +643,17 @@
> {
> struct rte_pci_device *dev = NULL;
> struct rte_pci_driver *drv = NULL;
> + int iommu_dma_mask_check_done = 0;
>
> FOREACH_DRIVER_ON_PCIBUS(drv) {
> FOREACH_DEVICE_ON_PCIBUS(dev) {
> if (!rte_pci_match(drv, dev))
> continue;
> - if (!pci_one_device_iommu_support_va(dev))
> - return false;
> + if (!iommu_dma_mask_check_done) {
> + if (pci_one_device_iommu_support_va(dev) < 0)
> + return false;
> + iommu_dma_mask_check_done = 1;
As I do not know enough on what IOMMU hardware can coexist, I leave this
patch for others to review.
Here is the previous question/answer:
>>> Not sure why this change? Why do we only need to check one device on
>>> all the buses?
>> Because there is just one emulated IOMMU hardware. The limitation in
>> this case is not in a specific PCI device. And I do not think it is
>> possible to have two different (emulated or not) IOMMU hardware. Yes,
>> you can have more than one controller but being same IOMMU type.
If the above is confirmed, you can consider this patch ack’ed.
> + }
> }
> }
> return true;
> --
> 1.9.1
next prev parent reply other threads:[~2018-07-11 10:18 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-10 17:25 [dpdk-stable] [PATCH v4 0/5] use IOVAs check based on DMA mask Alejandro Lucero
2018-07-10 17:25 ` [dpdk-stable] [PATCH v4 1/5] mem: add function for checking memsegs IOVAs addresses Alejandro Lucero
2018-07-11 10:12 ` Eelco Chaudron
2018-07-10 17:25 ` [dpdk-stable] [PATCH v4 2/5] bus/pci: use IOVAs check when setting IOVA mode Alejandro Lucero
2018-07-11 10:18 ` Eelco Chaudron [this message]
2018-07-11 10:41 ` Burakov, Anatoly
2018-07-10 17:25 ` [dpdk-stable] [PATCH v4 3/5] mem: use address hint for mapping hugepages Alejandro Lucero
2018-07-10 17:25 ` [dpdk-stable] [PATCH v4 4/5] net/nfp: check hugepages IOVAs based on DMA mask Alejandro Lucero
2018-07-10 17:25 ` [dpdk-stable] [PATCH v4 5/5] net/nfp: support IOVA VA mode Alejandro Lucero
[not found] ` <3971346.ugMje1iWhR@xps>
[not found] ` <CAD+H990j8iynw3g06wEOWZESwGbyS_nV8ZLYuJG3ZDpZqD3bbQ@mail.gmail.com>
[not found] ` <1558429.OuX7aYRipb@xps>
2018-07-27 8:22 ` [dpdk-stable] [dpdk-dev] [PATCH v4 0/5] use IOVAs check based on DMA mask Alejandro Lucero
2018-07-27 8:52 ` Thomas Monjalon
2018-07-27 8:59 ` Alejandro Lucero
2018-07-27 8:54 ` Burakov, Anatoly
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