[dpdk-dev] [PATCH 2/2] mem: fix freeing an IVSHMEM memzone
Sergio Gonzalez Monroy
sergio.gonzalez.monroy at intel.com
Fri Aug 7 17:27:33 CEST 2015
There is no sync between host and guest to allow removal of memzones,
and freeing them result in undefined behavior.
In the guest, we identify IVSHMEM memsegs/memzones by having
ioremap_addr != 0. In the host, nothing is done to the memzone, meaning
ioremap_addr == 0.
As a solution, mark memzones being added to IVSHMEM in the host, by
setting ioremap_addr, then return an error whenever we try to free an
IVSHMEM memzone.
Fixes: ff909fe21f0 ("mem: introduce memzone freeing")
Signed-off-by: Sergio Gonzalez Monroy <sergio.gonzalez.monroy at intel.com>
---
lib/librte_eal/common/eal_common_memzone.c | 8 ++++++++
lib/librte_eal/common/include/rte_memzone.h | 4 +++-
lib/librte_ivshmem/rte_ivshmem.c | 15 +++++++++++++++
3 files changed, 26 insertions(+), 1 deletion(-)
diff --git a/lib/librte_eal/common/eal_common_memzone.c b/lib/librte_eal/common/eal_common_memzone.c
index 7b1d77e..febc56b 100644
--- a/lib/librte_eal/common/eal_common_memzone.c
+++ b/lib/librte_eal/common/eal_common_memzone.c
@@ -322,6 +322,14 @@ rte_memzone_free(const struct rte_memzone *mz)
idx = idx / sizeof(struct rte_memzone);
addr = mcfg->memzone[idx].addr;
+#ifdef RTE_LIBRTE_IVSHMEM
+ /*
+ * If ioremap_addr is set, it's an IVSHMEM memzone and we cannot
+ * free it.
+ */
+ if (mcfg->memzone[idx].ioremap_addr != 0)
+ ret = -EINVAL;
+#endif
if (addr == NULL)
ret = -EINVAL;
else if (mcfg->memzone_cnt == 0) {
diff --git a/lib/librte_eal/common/include/rte_memzone.h b/lib/librte_eal/common/include/rte_memzone.h
index 38e5f5b..6a92222 100644
--- a/lib/librte_eal/common/include/rte_memzone.h
+++ b/lib/librte_eal/common/include/rte_memzone.h
@@ -258,10 +258,12 @@ const struct rte_memzone *rte_memzone_reserve_bounded(const char *name,
/**
* Free a memzone.
*
+ * Note: an IVSHMEM zone cannot be freed.
+ *
* @param mz
* A pointer to the memzone
* @return
- * -EINVAL - invalid parameter
+ * -EINVAL - invalid parameter, IVSHMEM memzone.
* 0 - success
*/
int rte_memzone_free(const struct rte_memzone *mz);
diff --git a/lib/librte_ivshmem/rte_ivshmem.c b/lib/librte_ivshmem/rte_ivshmem.c
index 9621906..8fc4b57 100644
--- a/lib/librte_ivshmem/rte_ivshmem.c
+++ b/lib/librte_ivshmem/rte_ivshmem.c
@@ -504,7 +504,22 @@ add_memzone_to_metadata(const struct rte_memzone * mz,
config->metadata->name);
goto fail;
}
+#ifdef RTE_LIBRTE_IVSHMEM
+ struct rte_mem_config *mcfg;
+ unsigned int idx;
+ mcfg = rte_eal_get_configuration()->mem_config;
+
+ rte_rwlock_write_lock(&mcfg->mlock);
+
+ idx = ((uintptr_t)mz - (uintptr_t)mcfg->memzone);
+ idx = idx / sizeof(struct rte_memzone);
+
+ /* mark the memzone not freeable */
+ mcfg->memzone[idx].ioremap_addr = mz->phys_addr;
+
+ rte_rwlock_write_unlock(&mcfg->mlock);
+#endif
rte_spinlock_unlock(&config->sl);
return 0;
fail:
--
1.9.3
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