On 31-Oct-18 5:29 PM, Alejandro Lucero wrote:
If DMA mask checks shows mapped memory out of the supported range
specified by the DMA mask, nothing can be done but return an error
an report the error. This can imply the app not being executed at
all or precluding dynamic memory allocation once the app is running.
In any case, we can advice the user to force IOVA as PA if currently
IOVA being VA and user being root.
Signed-off-by: Alejandro Lucero <alejandro.luc...@netronome.com>
---
General comment - legacy memory will also need this check, correct?
lib/librte_eal/common/malloc_heap.c | 35 +++++++++++++++++++++++++----
1 file changed, 31 insertions(+), 4 deletions(-)
diff --git a/lib/librte_eal/common/malloc_heap.c
b/lib/librte_eal/common/malloc_heap.c
index 7d423089d..711622f19 100644
--- a/lib/librte_eal/common/malloc_heap.c
+++ b/lib/librte_eal/common/malloc_heap.c
@@ -5,8 +5,10 @@
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
+#include <unistd.h>
#include <stdarg.h>
#include <errno.h>
+#include <sys/types.h>
#include <sys/queue.h>
#include <rte_memory.h>
@@ -294,7 +296,6 @@ alloc_pages_on_heap(struct malloc_heap *heap, uint64_t
pg_sz, size_t elt_size,
size_t alloc_sz;
int allocd_pages;
void *ret, *map_addr;
- uint64_t mask;
alloc_sz = (size_t)pg_sz * n_segs;
@@ -322,11 +323,37 @@ alloc_pages_on_heap(struct malloc_heap *heap, uint64_t pg_sz, size_t elt_size,
goto fail;
}
+ /* Once we have all the memseg lists configured, if there is a dma mask
+ * set, check iova addresses are not out of range. Otherwise the device
+ * setting the dma mask could have problems with the mapped memory.
+ *
+ * There are two situations when this can happen:
+ * 1) memory initialization
+ * 2) dynamic memory allocation
+ *
+ * For 1), an error when checking dma mask implies app can not be
+ * executed. For 2) implies the new memory can not be added.
+ */
if (mcfg->dma_maskbits) {
if (rte_mem_check_dma_mask(mcfg->dma_maskbits)) {
- RTE_LOG(ERR, EAL,
- "%s(): couldn't allocate memory due to DMA
mask\n",
- __func__);
+ /* Currently this can only happen if IOMMU is enabled
+ * with RTE_ARCH_X86. It is not safe to use this memory
+ * so returning an error here.
I don't think it's RTE_ARCH_X86-only. It can be any other arch with an
IOMMU that's reporting addressing limitations.
+ *
+ * If IOVA is VA, advice to try with '--iova-mode pa'
+ * which could solve some situations when IOVA VA is not
+ * really needed.
+ */
+ uid_t user = getuid();
+ if ((rte_eal_iova_mode() == RTE_IOVA_VA) && user == 0)
rte_eal_using_phys_addrs()?
(the above function name is a bit of a misnomer, it really checks if
they are available, but not necessarily used - it will return true in
RTE_IOVA_VA mode if you're running as root)
+ RTE_LOG(ERR, EAL,
+ "%s(): couldn't allocate memory due to DMA
mask.\n"
+ "Try with 'iova-mode=pa'\n",
+ __func__);
+ else
+ RTE_LOG(ERR, EAL,
+ "%s(): couldn't allocate memory due to DMA
mask\n",
+ __func__);
I don't think the error message is terribly descriptive. Looking at it
through the eyes of someone who sees it for the first time and who has
no idea what "iova-mode=pa" is, i think it would be more useful to word
it the following way:
couldn't allocate memory due to IOVA exceeding limits of current DMA mask.
[for non-using phys addrs case] Please try initializing EAL with
--iova-mode=pa parameter.
Also, generally newlines in RTE_LOG look ugly unless you indent the line :)
goto fail;
}
}
--
Thanks,
Anatoly
