From: David Christensen <drc@linux.vnet.ibm.com>
To: dev@dpdk.org
Subject: Re: [PATCH v2] eal/linux: force iova-mode va without pa available
Date: Wed, 29 Nov 2023 13:50:57 -0800 [thread overview]
Message-ID: <bf521b7f-fcf1-43e6-9172-2ed649a42934@linux.vnet.ibm.com> (raw)
In-Reply-To: <20231124100904.388453-1-christian.ehrhardt@canonical.com>
On 11/24/23 2:09 AM, christian.ehrhardt@canonical.com wrote:
> From: David Wilder <dwilder@us.ibm.com>
>
> When using --no-huge option physical address are not guaranteed
> to be persistent.
>
> This change effectively makes "--no-huge" the same as
> "--no-huge --iova-mode=va".
>
> When --no-huge is used (or any other condition making physical
> addresses unavailable) setting --iova-mode=pa will have no effect.
>
> Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
> ---
> doc/guides/prog_guide/env_abstraction_layer.rst | 9 ++++++---
> lib/eal/linux/eal.c | 16 ++++++++++------
> 2 files changed, 16 insertions(+), 9 deletions(-)
>
> diff --git a/doc/guides/prog_guide/env_abstraction_layer.rst b/doc/guides/prog_guide/env_abstraction_layer.rst
> index 6debf54efb..20c7355e0f 100644
> --- a/doc/guides/prog_guide/env_abstraction_layer.rst
> +++ b/doc/guides/prog_guide/env_abstraction_layer.rst
> @@ -559,9 +559,12 @@ IOVA Mode is selected by considering what the current usable Devices on the
> system require and/or support.
>
> On FreeBSD, RTE_IOVA_PA is always the default. On Linux, the IOVA mode is
> -detected based on a 2-step heuristic detailed below.
> +detected based on a heuristic detailed below.
>
> -For the first step, EAL asks each bus its requirement in terms of IOVA mode
> +For the first step, if no Physical Addresses are available RTE_IOVA_VA is
> +selected.
> +
> +Then EAL asks each bus its requirement in terms of IOVA mode
> and decides on a preferred IOVA mode.
>
> - if all buses report RTE_IOVA_PA, then the preferred IOVA mode is RTE_IOVA_PA,
> @@ -575,7 +578,7 @@ and decides on a preferred IOVA mode.
> If the buses have expressed no preference on which IOVA mode to pick, then a
> default is selected using the following logic:
>
> -- if physical addresses are not available, RTE_IOVA_VA mode is used
> +- if enable_iova_as_pa was not set at build RTE_IOVA_VA mode is used
> - if /sys/kernel/iommu_groups is not empty, RTE_IOVA_VA mode is used
> - otherwise, RTE_IOVA_PA mode is used
>
> diff --git a/lib/eal/linux/eal.c b/lib/eal/linux/eal.c
> index 57da058cec..2f1fce3c54 100644
> --- a/lib/eal/linux/eal.c
> +++ b/lib/eal/linux/eal.c
> @@ -1067,6 +1067,16 @@ rte_eal_init(int argc, char **argv)
>
> phys_addrs = rte_eal_using_phys_addrs() != 0;
>
> + if (!phys_addrs) {
> + /* if we have no access to physical addresses, pick IOVA as VA mode. */
> + if (internal_conf->iova_mode == RTE_IOVA_PA)
> + RTE_LOG(WARNING, EAL, "WARNING: --iova-mode=pa, but Physical addresses are unavailable, selecting IOVA as VA mode.\n");
> + else
> + RTE_LOG(DEBUG, EAL, "Physical addresses are unavailable, selecting IOVA as VA mode.\n");
> + internal_conf->iova_mode = RTE_IOVA_VA;
> + rte_eal_get_configuration()->iova_mode = internal_conf->iova_mode;
> + }
> +
> /* if no EAL option "--iova-mode=<pa|va>", use bus IOVA scheme */
> if (internal_conf->iova_mode == RTE_IOVA_DC) {
> /* autodetect the IOVA mapping mode */
> @@ -1078,12 +1088,6 @@ rte_eal_init(int argc, char **argv)
> if (!RTE_IOVA_IN_MBUF) {
> iova_mode = RTE_IOVA_VA;
> RTE_LOG(DEBUG, EAL, "IOVA as VA mode is forced by build option.\n");
> - } else if (!phys_addrs) {
> - /* if we have no access to physical addresses,
> - * pick IOVA as VA mode.
> - */
> - iova_mode = RTE_IOVA_VA;
> - RTE_LOG(DEBUG, EAL, "Physical addresses are unavailable, selecting IOVA as VA mode.\n");
> } else if (is_iommu_enabled()) {
> /* we have an IOMMU, pick IOVA as VA mode */
> iova_mode = RTE_IOVA_VA;
What tests are you running that generate an error without explicitly
selecting the iova-mode? When I run the fast-tests I see the system
correctly selecting VA without any additional command-line parameters
when running 23.11:
21:47:05 DPDK_TEST=acl_autotest MALLOC_PERTURB_=201
/home/drc/src/dpdk/build/app/dpdk-test --no-huge -m 2048
----------------------------------- output
-----------------------------------
stdout:
RTE>>acl_autotest
acl context <acl_ctx>@0x179cbd300
socket_id=-1
alg=5
first_load_sz=0
max_rules=196608
rule_size=128
num_rules=0
num_categories=0
num_tries=0
acl context <acl_ctx>@0x179cbd300
socket_id=-1
alg=5
first_load_sz=0
max_rules=196608
rule_size=128
num_rules=0
num_categories=0
num_tries=0
running test_convert_rules(acl_ipv4vlan_tuple)
running test_convert_rules(acl_ipv4vlan_tuple,
RTE_ACL_FIELD_TYPE_BITMASK type for IPv4)
running test_convert_rules(acl_ipv4vlan_tuple, RTE_ACL_FIELD_TYPE_RANGE
type for IPv4)
running test_convert_rules(acl_ipv4vlan_tuple: swap VLAN and PORTs order)
running test_convert_rules(acl_ipv4vlan_tuple: swap SRC and DST IPv4 order)
test_u32_range#1704 starting range test from 0 to 264192
Test OK
RTE>>
stderr:
EAL: Detected CPU lcores: 128
EAL: Detected NUMA nodes: 2
EAL: Detected static linkage of DPDK
EAL: Multi-process socket /var/run/dpdk/rte/mp_socket
EAL: Selected IOVA mode 'VA'
Dave
next prev parent reply other threads:[~2023-11-29 21:51 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-11-24 10:09 christian.ehrhardt
2023-11-24 10:29 ` Dmitry Kozlyuk
2023-11-28 14:39 ` Christian Ehrhardt
2023-11-29 21:50 ` David Christensen [this message]
2023-11-30 13:48 ` Christian Ehrhardt
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