On 29-Jul-19 10:31 AM, David Marchand wrote:
On Fri, Jul 26, 2019 at 5:37 PM Anatoly Burakov
<anatoly.bura...@intel.com> wrote:
When IOMMU is not available, /sys/kernel/iommu_groups will not be
populated. This is happening since at least 3.6 when VFIO support
was added. If the directory is empty, EAL should not pick IOVA as
VA as the default IOVA mode.
Signed-off-by: Anatoly Burakov <anatoly.bura...@intel.com>
Tested-by: Darek Stojaczyk <dariusz.stojac...@intel.com>
Tested-by: Jerin Jacob <jer...@marvell.com>
Reviewed-by: Jerin Jacob <jer...@marvell.com>
---
Notes:
v4:
- Fix indentation in release notes' known issues
v3:
- Add documentation changes
- Fix a typo pointed out by checkpatch
v2:
- Decouple IOMMU from VFIO
- Add a check for physical addresses availability
.../prog_guide/env_abstraction_layer.rst | 27 +++++++++++------
doc/guides/rel_notes/known_issues.rst | 26 ++++++++++++++++
doc/guides/rel_notes/release_19_08.rst | 16 ++++++++++
lib/librte_eal/linux/eal/eal.c | 21 +++++++++++--
lib/librte_eal/linux/eal/eal_vfio.c | 30 +++++++++++++++++++
lib/librte_eal/linux/eal/eal_vfio.h | 2 ++
6 files changed, 111 insertions(+), 11 deletions(-)
diff --git a/doc/guides/prog_guide/env_abstraction_layer.rst
b/doc/guides/prog_guide/env_abstraction_layer.rst
index 1487ea550..e6e70e5a8 100644
--- a/doc/guides/prog_guide/env_abstraction_layer.rst
+++ b/doc/guides/prog_guide/env_abstraction_layer.rst
@@ -425,6 +425,9 @@ IOVA Mode Detection
IOVA Mode is selected by considering what the current usable Devices on the
system require and/or support.
+On FreeBSD, RTE_IOVA_VA mode is not supported, so RTE_IOVA_PA is always used.
We still allow setting it via --iova-mode=
Is it really unsupported ? vdev like rings could work.
Oh, right, we don't *really* support IOVA as VA mode, but you can still
run in --no-huge mode (or using only virtual devices) and pretend like
it works ;)
Still, i think FreeBSD should default to PA unless it's not running as root.
+On Linux, the IOVA mode is detected based on a heuristic.
+
Below is the 2-step heuristic for this choice.
We can combine those two sentences as a single one.
Sure.
For the first step, EAL asks each bus its requirement in terms of IOVA mode
@@ -438,20 +441,26 @@ and decides on a preferred IOVA mode.
RTE_IOVA_VA), then the preferred IOVA mode is RTE_IOVA_DC (see below with
the
check on Physical Addresses availability),
+If the buses have expressed no preference on which IOVA mode to pick, then a
+default is selected using the following logic:
+
<snip>
@@ -1061,8 +1061,25 @@ rte_eal_init(int argc, char **argv)
enum rte_iova_mode iova_mode = rte_bus_get_iommu_class();
if (iova_mode == RTE_IOVA_DC) {
- iova_mode = RTE_IOVA_VA;
- RTE_LOG(DEBUG, EAL, "Buses did not request a specific IOVA
mode, select IOVA as VA mode.\n");
+ RTE_LOG(DEBUG, EAL, "Buses did not request a specific IOVA
mode.\n");
+
+ 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 (vfio_iommu_enabled()) {
How about:
s/vfio_iommu_enabled/is_iommu_available/
And the code would move from vfio specific files to eal.c.
Can do.
--
Thanks,
Anatoly
