pci: keep API compatibility with mmap values
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Commit Message
The function pci_map_resource() returns MAP_FAILED in case of error.
When replacing the call to mmap() by rte_mem_map(),
the error code became NULL, breaking the API.
This function is probably not used outside of DPDK,
but it is still a problem for two reasons:
- the deprecation process was not followed
- the Linux function pci_vfio_mmap_bar() is broken for i40e
The error code is reverted to the Unix value MAP_FAILED.
Windows needs to define this special value (-1 as in Unix).
After proper deprecation process, the API could be changed again
if really needed.
Because of the switch from mmap() to rte_mem_map(),
another part of the API was changed: "int additional_flags"
are defined as "additional flags for the mapping range"
without mentioning it was directly used in mmap().
Currently it is directly used in rte_mem_map(),
that's why the values rte_map_flags must be mapped (sic) on the mmap ones
in case of Unix OS.
These are side effects of a badly defined API using Unix values.
Bugzilla ID: 503
Fixes: 2fd3567e5425 ("pci: use OS generic memory mapping functions")
Cc: talshn@mellanox.com
Reported-by: David Marchand <david.marchand@redhat.com>
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
---
drivers/bus/pci/bsd/pci.c | 2 +-
drivers/bus/pci/linux/pci_uio.c | 2 +-
drivers/bus/pci/linux/pci_vfio.c | 4 ++--
drivers/bus/pci/pci_common_uio.c | 2 +-
lib/librte_eal/include/rte_eal_paging.h | 8 ++++++++
lib/librte_eal/windows/include/sys/mman.h | 9 +++++++++
lib/librte_pci/rte_pci.c | 1 +
lib/librte_pci/rte_pci.h | 2 +-
8 files changed, 24 insertions(+), 6 deletions(-)
create mode 100644 lib/librte_eal/windows/include/sys/mman.h
Comments
On Fri, Jul 10, 2020 at 1:53 PM Thomas Monjalon <thomas@monjalon.net> wrote:
>
> The function pci_map_resource() returns MAP_FAILED in case of error.
> When replacing the call to mmap() by rte_mem_map(),
> the error code became NULL, breaking the API.
> This function is probably not used outside of DPDK,
> but it is still a problem for two reasons:
> - the deprecation process was not followed
> - the Linux function pci_vfio_mmap_bar() is broken for i40e
>
> The error code is reverted to the Unix value MAP_FAILED.
> Windows needs to define this special value (-1 as in Unix).
> After proper deprecation process, the API could be changed again
> if really needed.
>
> Because of the switch from mmap() to rte_mem_map(),
> another part of the API was changed: "int additional_flags"
> are defined as "additional flags for the mapping range"
> without mentioning it was directly used in mmap().
> Currently it is directly used in rte_mem_map(),
> that's why the values rte_map_flags must be mapped (sic) on the mmap ones
> in case of Unix OS.
>
> These are side effects of a badly defined API using Unix values.
>
> Bugzilla ID: 503
> Fixes: 2fd3567e5425 ("pci: use OS generic memory mapping functions")
> Cc: talshn@mellanox.com
>
> Reported-by: David Marchand <david.marchand@redhat.com>
> Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
> ---
> drivers/bus/pci/bsd/pci.c | 2 +-
> drivers/bus/pci/linux/pci_uio.c | 2 +-
> drivers/bus/pci/linux/pci_vfio.c | 4 ++--
> drivers/bus/pci/pci_common_uio.c | 2 +-
> lib/librte_eal/include/rte_eal_paging.h | 8 ++++++++
> lib/librte_eal/windows/include/sys/mman.h | 9 +++++++++
> lib/librte_pci/rte_pci.c | 1 +
> lib/librte_pci/rte_pci.h | 2 +-
> 8 files changed, 24 insertions(+), 6 deletions(-)
> create mode 100644 lib/librte_eal/windows/include/sys/mman.h
>
> diff --git a/drivers/bus/pci/bsd/pci.c b/drivers/bus/pci/bsd/pci.c
> index 8bc473eb9a..6ec27b4b5b 100644
> --- a/drivers/bus/pci/bsd/pci.c
> +++ b/drivers/bus/pci/bsd/pci.c
> @@ -192,7 +192,7 @@ pci_uio_map_resource_by_index(struct rte_pci_device *dev, int res_idx,
> mapaddr = pci_map_resource(NULL, fd, (off_t)offset,
> (size_t)dev->mem_resource[res_idx].len, 0);
> close(fd);
> - if (mapaddr == NULL)
> + if (mapaddr == MAP_FAILED)
> goto error;
>
> maps[map_idx].phaddr = dev->mem_resource[res_idx].phys_addr;
> diff --git a/drivers/bus/pci/linux/pci_uio.c b/drivers/bus/pci/linux/pci_uio.c
> index b622001539..097dc19225 100644
> --- a/drivers/bus/pci/linux/pci_uio.c
> +++ b/drivers/bus/pci/linux/pci_uio.c
> @@ -345,7 +345,7 @@ pci_uio_map_resource_by_index(struct rte_pci_device *dev, int res_idx,
> mapaddr = pci_map_resource(pci_map_addr, fd, 0,
> (size_t)dev->mem_resource[res_idx].len, 0);
> close(fd);
> - if (mapaddr == NULL)
> + if (mapaddr == MAP_FAILED)
> goto error;
>
> pci_map_addr = RTE_PTR_ADD(mapaddr,
> diff --git a/drivers/bus/pci/linux/pci_vfio.c b/drivers/bus/pci/linux/pci_vfio.c
> index fdeb9a8caf..07e072e13f 100644
> --- a/drivers/bus/pci/linux/pci_vfio.c
> +++ b/drivers/bus/pci/linux/pci_vfio.c
> @@ -566,7 +566,7 @@ pci_vfio_mmap_bar(int vfio_dev_fd, struct mapped_pci_resource *vfio_res,
> }
>
> /* if there's a second part, try to map it */
> - if (map_addr != NULL
> + if (map_addr != MAP_FAILED
> && memreg[1].offset && memreg[1].size) {
> void *second_addr = RTE_PTR_ADD(bar_addr,
> (uintptr_t)(memreg[1].offset -
> @@ -578,7 +578,7 @@ pci_vfio_mmap_bar(int vfio_dev_fd, struct mapped_pci_resource *vfio_res,
> RTE_MAP_FORCE_ADDRESS);
> }
>
> - if (map_addr == NULL) {
> + if (map_addr == NULL || map_addr == MAP_FAILED) {
> munmap(bar_addr, bar->size);
> bar_addr = MAP_FAILED;
> RTE_LOG(ERR, EAL, "Failed to map pci BAR%d\n",
> diff --git a/drivers/bus/pci/pci_common_uio.c b/drivers/bus/pci/pci_common_uio.c
> index 793dfd0a7c..f4dca9da91 100644
> --- a/drivers/bus/pci/pci_common_uio.c
> +++ b/drivers/bus/pci/pci_common_uio.c
> @@ -58,7 +58,7 @@ pci_uio_map_secondary(struct rte_pci_device *dev)
> "Cannot mmap device resource file %s to address: %p\n",
> uio_res->maps[i].path,
> uio_res->maps[i].addr);
> - if (mapaddr != NULL) {
> + if (mapaddr != MAP_FAILED) {
> /* unmap addrs correctly mapped */
> for (j = 0; j < i; j++)
> pci_unmap_resource(
> diff --git a/lib/librte_eal/include/rte_eal_paging.h b/lib/librte_eal/include/rte_eal_paging.h
> index ed98e70e9e..680a7f2505 100644
> --- a/lib/librte_eal/include/rte_eal_paging.h
> +++ b/lib/librte_eal/include/rte_eal_paging.h
> @@ -3,6 +3,7 @@
> */
>
> #include <stdint.h>
> +#include <sys/mman.h>
>
> #include <rte_compat.h>
>
> @@ -22,6 +23,7 @@ enum rte_mem_prot {
>
> /** Additional flags for memory mapping. */
> enum rte_map_flags {
> +#ifdef RTE_EXEC_ENV_WINDOWS
> /** Changes to the mapped memory are visible to other processes. */
> RTE_MAP_SHARED = 1 << 0,
> /** Mapping is not backed by a regular file. */
> @@ -35,6 +37,12 @@ enum rte_map_flags {
> * it is not required to do so, thus mapping with this flag may fail.
> */
> RTE_MAP_FORCE_ADDRESS = 1 << 3
> +#else /* map mmap flags because they are exposed in pci_map_resource() API */
> + RTE_MAP_SHARED = MAP_SHARED,
> + RTE_MAP_ANONYMOUS = MAP_ANONYMOUS,
> + RTE_MAP_PRIVATE = MAP_PRIVATE,
> + RTE_MAP_FORCE_ADDRESS = MAP_FIXED,
> +#endif
> };
>
> /**
> diff --git a/lib/librte_eal/windows/include/sys/mman.h b/lib/librte_eal/windows/include/sys/mman.h
> new file mode 100644
> index 0000000000..0b4b10df1f
> --- /dev/null
> +++ b/lib/librte_eal/windows/include/sys/mman.h
> @@ -0,0 +1,9 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright 2020 Mellanox Technologies, Ltd
> + */
> +
> +/*
> + * The syscall mmap does not exist on Windows,
> + * but this error code is used in a badly defined DPDK API for PCI mapping.
> + */
> +#define MAP_FAILED ((void *) -1)
> diff --git a/lib/librte_pci/rte_pci.c b/lib/librte_pci/rte_pci.c
> index d8272b9076..1d1cbc75ac 100644
> --- a/lib/librte_pci/rte_pci.c
> +++ b/lib/librte_pci/rte_pci.c
> @@ -163,6 +163,7 @@ pci_map_resource(void *requested_addr, int fd, off_t offset, size_t size,
> __func__, fd, requested_addr, size,
> (unsigned long long)offset,
> rte_strerror(rte_errno), mapaddr);
> + mapaddr = MAP_FAILED; /* API uses mmap error code */
> } else
> RTE_LOG(DEBUG, EAL, " PCI memory mapped at %p\n", mapaddr);
>
> diff --git a/lib/librte_pci/rte_pci.h b/lib/librte_pci/rte_pci.h
> index 104b2bb858..a03235da1f 100644
> --- a/lib/librte_pci/rte_pci.h
> +++ b/lib/librte_pci/rte_pci.h
> @@ -160,7 +160,7 @@ int rte_pci_addr_parse(const char *str, struct rte_pci_addr *addr);
> * The additional flags for the mapping range.
> * @return
> * - On success, the function returns a pointer to the mapped area.
> - * - On error, NULL is returned.
> + * - On error, MAP_FAILED is returned.
> */
> void *pci_map_resource(void *requested_addr, int fd, off_t offset,
> size_t size, int additional_flags);
> --
> 2.27.0
>
As we discussed offlist, I am not really ecstatic about this.
But the function was exposed, so no breaking.
Reviewed-by: David Marchand <david.marchand@redhat.com>
On 10-Jul-20 12:53 PM, Thomas Monjalon wrote:
> The function pci_map_resource() returns MAP_FAILED in case of error.
> When replacing the call to mmap() by rte_mem_map(),
> the error code became NULL, breaking the API.
> This function is probably not used outside of DPDK,
> but it is still a problem for two reasons:
> - the deprecation process was not followed
> - the Linux function pci_vfio_mmap_bar() is broken for i40e
>
> The error code is reverted to the Unix value MAP_FAILED.
> Windows needs to define this special value (-1 as in Unix).
> After proper deprecation process, the API could be changed again
> if really needed.
>
> Because of the switch from mmap() to rte_mem_map(),
> another part of the API was changed: "int additional_flags"
> are defined as "additional flags for the mapping range"
> without mentioning it was directly used in mmap().
> Currently it is directly used in rte_mem_map(),
> that's why the values rte_map_flags must be mapped (sic) on the mmap ones
> in case of Unix OS.
>
> These are side effects of a badly defined API using Unix values.
>
> Bugzilla ID: 503
> Fixes: 2fd3567e5425 ("pci: use OS generic memory mapping functions")
> Cc: talshn@mellanox.com
>
> Reported-by: David Marchand <david.marchand@redhat.com>
> Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
> ---
<snip>
> /* unmap addrs correctly mapped */
> for (j = 0; j < i; j++)
> pci_unmap_resource(
> diff --git a/lib/librte_eal/include/rte_eal_paging.h b/lib/librte_eal/include/rte_eal_paging.h
> index ed98e70e9e..680a7f2505 100644
> --- a/lib/librte_eal/include/rte_eal_paging.h
> +++ b/lib/librte_eal/include/rte_eal_paging.h
> @@ -3,6 +3,7 @@
> */
>
> #include <stdint.h>
> +#include <sys/mman.h>
>
> #include <rte_compat.h>
>
> @@ -22,6 +23,7 @@ enum rte_mem_prot {
>
> /** Additional flags for memory mapping. */
> enum rte_map_flags {
> +#ifdef RTE_EXEC_ENV_WINDOWS
> /** Changes to the mapped memory are visible to other processes. */
> RTE_MAP_SHARED = 1 << 0,
> /** Mapping is not backed by a regular file. */
> @@ -35,6 +37,12 @@ enum rte_map_flags {
> * it is not required to do so, thus mapping with this flag may fail.
> */
> RTE_MAP_FORCE_ADDRESS = 1 << 3
> +#else /* map mmap flags because they are exposed in pci_map_resource() API */
> + RTE_MAP_SHARED = MAP_SHARED,
> + RTE_MAP_ANONYMOUS = MAP_ANONYMOUS,
> + RTE_MAP_PRIVATE = MAP_PRIVATE,
> + RTE_MAP_FORCE_ADDRESS = MAP_FIXED,
> +#endif
I'm probably missing something, but why is this needed? Doesn't
rte_mem_map() automatically translate these flags into proper ones?
pci_map_resource() will call rte_mem_map(), and that will translate
these flags into their Unix equivalents.
10/07/2020 17:39, Burakov, Anatoly:
> On 10-Jul-20 12:53 PM, Thomas Monjalon wrote:
> > The function pci_map_resource() returns MAP_FAILED in case of error.
> > When replacing the call to mmap() by rte_mem_map(),
> > the error code became NULL, breaking the API.
> > This function is probably not used outside of DPDK,
> > but it is still a problem for two reasons:
> > - the deprecation process was not followed
> > - the Linux function pci_vfio_mmap_bar() is broken for i40e
> >
> > The error code is reverted to the Unix value MAP_FAILED.
> > Windows needs to define this special value (-1 as in Unix).
> > After proper deprecation process, the API could be changed again
> > if really needed.
> >
> > Because of the switch from mmap() to rte_mem_map(),
> > another part of the API was changed: "int additional_flags"
> > are defined as "additional flags for the mapping range"
> > without mentioning it was directly used in mmap().
> > Currently it is directly used in rte_mem_map(),
> > that's why the values rte_map_flags must be mapped (sic) on the mmap ones
> > in case of Unix OS.
> >
> > These are side effects of a badly defined API using Unix values.
[...]
> > /** Additional flags for memory mapping. */
> > enum rte_map_flags {
> > +#ifdef RTE_EXEC_ENV_WINDOWS
> > /** Changes to the mapped memory are visible to other processes. */
> > RTE_MAP_SHARED = 1 << 0,
> > /** Mapping is not backed by a regular file. */
> > @@ -35,6 +37,12 @@ enum rte_map_flags {
> > * it is not required to do so, thus mapping with this flag may fail.
> > */
> > RTE_MAP_FORCE_ADDRESS = 1 << 3
> > +#else /* map mmap flags because they are exposed in pci_map_resource() API */
> > + RTE_MAP_SHARED = MAP_SHARED,
> > + RTE_MAP_ANONYMOUS = MAP_ANONYMOUS,
> > + RTE_MAP_PRIVATE = MAP_PRIVATE,
> > + RTE_MAP_FORCE_ADDRESS = MAP_FIXED,
> > +#endif
>
> I'm probably missing something, but why is this needed? Doesn't
Yes you missed reading the commit log :)
Or maybe it is not written clearly enough. Will try to rephrase.
> rte_mem_map() automatically translate these flags into proper ones?
> pci_map_resource() will call rte_mem_map(), and that will translate
> these flags into their Unix equivalents.
The problem is that we have an API which is taking mmap flags as input.
"int additional_flags" is a parameter of the function,
and are supposed to be mmap flags. But it is not stated clearly.
When Windows will use this function, it won't use mmap flags
but RTE_MAP_*. So we must accept both.
That's why the best is to make values the same.
In 20.11, we could change the API,
make clear that only RTE_MAP_* is accepted,
and remove this workaround.
Or even better, remove pci_map_resource from the PCI lib,
and implement it in the PCI bus driver.
pci_map_resource() function is a bad designed API
10/07/2020 13:53, Thomas Monjalon:
> The function pci_map_resource() returns MAP_FAILED in case of error.
> When replacing the call to mmap() by rte_mem_map(),
> the error code became NULL, breaking the API.
> This function is probably not used outside of DPDK,
> but it is still a problem for two reasons:
> - the deprecation process was not followed
> - the Linux function pci_vfio_mmap_bar() is broken for i40e
>
> The error code is reverted to the Unix value MAP_FAILED.
> Windows needs to define this special value (-1 as in Unix).
> After proper deprecation process, the API could be changed again
> if really needed.
>
> Because of the switch from mmap() to rte_mem_map(),
> another part of the API was changed: "int additional_flags"
> are defined as "additional flags for the mapping range"
> without mentioning it was directly used in mmap().
> Currently it is directly used in rte_mem_map(),
> that's why the values rte_map_flags must be mapped (sic) on the mmap ones
> in case of Unix OS.
>
> These are side effects of a badly defined API using Unix values.
>
> Bugzilla ID: 503
This is urgent. i40e does not probe in some cases.
If no test is done, I don't merge it and Intel will complain about
validation issue in 20.08-rc1.
And next time, I won't rush on bug fixing.
My apologies for not examining mmap() usage thoroughly enough when designing
these internal APIs. I support your suggestion to move PCI mapping functions
to bus driver after proper deprecation.
On Fri, 10 Jul 2020 13:53:24 +0200, Thomas Monjalon wrote:
[snip]
> diff --git a/lib/librte_eal/include/rte_eal_paging.h b/lib/librte_eal/include/rte_eal_paging.h
> index ed98e70e9e..680a7f2505 100644
> --- a/lib/librte_eal/include/rte_eal_paging.h
> +++ b/lib/librte_eal/include/rte_eal_paging.h
> @@ -3,6 +3,7 @@
> */
>
> #include <stdint.h>
> +#include <sys/mman.h>
>
> #include <rte_compat.h>
>
> @@ -22,6 +23,7 @@ enum rte_mem_prot {
>
> /** Additional flags for memory mapping. */
> enum rte_map_flags {
> +#ifdef RTE_EXEC_ENV_WINDOWS
> /** Changes to the mapped memory are visible to other processes. */
> RTE_MAP_SHARED = 1 << 0,
> /** Mapping is not backed by a regular file. */
> @@ -35,6 +37,12 @@ enum rte_map_flags {
> * it is not required to do so, thus mapping with this flag may fail.
> */
> RTE_MAP_FORCE_ADDRESS = 1 << 3
> +#else /* map mmap flags because they are exposed in pci_map_resource() API */
> + RTE_MAP_SHARED = MAP_SHARED,
> + RTE_MAP_ANONYMOUS = MAP_ANONYMOUS,
> + RTE_MAP_PRIVATE = MAP_PRIVATE,
> + RTE_MAP_FORCE_ADDRESS = MAP_FIXED,
> +#endif
> };
>
> /**
> diff --git a/lib/librte_eal/windows/include/sys/mman.h b/lib/librte_eal/windows/include/sys/mman.h
> new file mode 100644
> index 0000000000..0b4b10df1f
> --- /dev/null
> +++ b/lib/librte_eal/windows/include/sys/mman.h
> @@ -0,0 +1,9 @@
> +/* SPDX-License-Identifier: BSD-3-Clause
> + * Copyright 2020 Mellanox Technologies, Ltd
> + */
> +
> +/*
> + * The syscall mmap does not exist on Windows,
> + * but this error code is used in a badly defined DPDK API for PCI mapping.
> + */
> +#define MAP_FAILED ((void *) -1)
I see why we can't help exposing <sys/mman.h> in <rte_eal_paging.h>, but I'm
against adding this stub header. Why not make #include <sys/mman.h>
conditional and define MAP_FAIELD in <rte_os.h> for Windows?
(While networking headers we have define things that are common to all
platforms, just expressed in incompatible ways, memory management is
inherently OS-specific.)
10/07/2020 20:31, Dmitry Kozlyuk:
> On Fri, 10 Jul 2020 13:53:24 +0200, Thomas Monjalon wrote:
> > --- /dev/null
> > +++ b/lib/librte_eal/windows/include/sys/mman.h
> > @@ -0,0 +1,9 @@
> > +/* SPDX-License-Identifier: BSD-3-Clause
> > + * Copyright 2020 Mellanox Technologies, Ltd
> > + */
> > +
> > +/*
> > + * The syscall mmap does not exist on Windows,
> > + * but this error code is used in a badly defined DPDK API for PCI mapping.
> > + */
> > +#define MAP_FAILED ((void *) -1)
>
> I see why we can't help exposing <sys/mman.h> in <rte_eal_paging.h>, but I'm
> against adding this stub header. Why not make #include <sys/mman.h>
> conditional and define MAP_FAIELD in <rte_os.h> for Windows?
Yes this macro can be in lib/librte_eal/windows/include/rte_os.h
I'll do a v2.
tested-by:ma,Lihong<lihongx.ma@intel.com>
Regards,
Ma,lihong
-----Original Message-----
From: dev <dev-bounces@dpdk.org> On Behalf Of Thomas Monjalon
Sent: Friday, July 10, 2020 7:53 PM
To: dev@dpdk.org
Cc: david.marchand@redhat.com; Yigit, Ferruh <ferruh.yigit@intel.com>; grive@u256.net; Zhang, AlvinX <alvinx.zhang@intel.com>; Xing, Beilei <beilei.xing@intel.com>; Guo, Jia <jia.guo@intel.com>; Burakov, Anatoly <anatoly.burakov@intel.com>; Richardson, Bruce <bruce.richardson@intel.com>; dmitry.kozliuk@gmail.com; navasile@linux.microsoft.com; dmitrym@microsoft.com; Kadam, Pallavi <pallavi.kadam@intel.com>; talshn@mellanox.com
Subject: [dpdk-dev] [PATCH] pci: keep API compatibility with mmap values
The function pci_map_resource() returns MAP_FAILED in case of error.
When replacing the call to mmap() by rte_mem_map(), the error code became NULL, breaking the API.
This function is probably not used outside of DPDK, but it is still a problem for two reasons:
- the deprecation process was not followed
- the Linux function pci_vfio_mmap_bar() is broken for i40e
The error code is reverted to the Unix value MAP_FAILED.
Windows needs to define this special value (-1 as in Unix).
After proper deprecation process, the API could be changed again if really needed.
Because of the switch from mmap() to rte_mem_map(), another part of the API was changed: "int additional_flags"
are defined as "additional flags for the mapping range"
without mentioning it was directly used in mmap().
Currently it is directly used in rte_mem_map(), that's why the values rte_map_flags must be mapped (sic) on the mmap ones in case of Unix OS.
These are side effects of a badly defined API using Unix values.
Bugzilla ID: 503
Fixes: 2fd3567e5425 ("pci: use OS generic memory mapping functions")
Cc: talshn@mellanox.com
Reported-by: David Marchand <david.marchand@redhat.com>
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
---
drivers/bus/pci/bsd/pci.c | 2 +-
drivers/bus/pci/linux/pci_uio.c | 2 +-
drivers/bus/pci/linux/pci_vfio.c | 4 ++--
drivers/bus/pci/pci_common_uio.c | 2 +-
lib/librte_eal/include/rte_eal_paging.h | 8 ++++++++
lib/librte_eal/windows/include/sys/mman.h | 9 +++++++++
lib/librte_pci/rte_pci.c | 1 +
lib/librte_pci/rte_pci.h | 2 +-
8 files changed, 24 insertions(+), 6 deletions(-) create mode 100644 lib/librte_eal/windows/include/sys/mman.h
diff --git a/drivers/bus/pci/bsd/pci.c b/drivers/bus/pci/bsd/pci.c index 8bc473eb9a..6ec27b4b5b 100644
--- a/drivers/bus/pci/bsd/pci.c
+++ b/drivers/bus/pci/bsd/pci.c
@@ -192,7 +192,7 @@ pci_uio_map_resource_by_index(struct rte_pci_device *dev, int res_idx,
mapaddr = pci_map_resource(NULL, fd, (off_t)offset,
(size_t)dev->mem_resource[res_idx].len, 0);
close(fd);
- if (mapaddr == NULL)
+ if (mapaddr == MAP_FAILED)
goto error;
maps[map_idx].phaddr = dev->mem_resource[res_idx].phys_addr;
diff --git a/drivers/bus/pci/linux/pci_uio.c b/drivers/bus/pci/linux/pci_uio.c index b622001539..097dc19225 100644
--- a/drivers/bus/pci/linux/pci_uio.c
+++ b/drivers/bus/pci/linux/pci_uio.c
@@ -345,7 +345,7 @@ pci_uio_map_resource_by_index(struct rte_pci_device *dev, int res_idx,
mapaddr = pci_map_resource(pci_map_addr, fd, 0,
(size_t)dev->mem_resource[res_idx].len, 0);
close(fd);
- if (mapaddr == NULL)
+ if (mapaddr == MAP_FAILED)
goto error;
pci_map_addr = RTE_PTR_ADD(mapaddr,
diff --git a/drivers/bus/pci/linux/pci_vfio.c b/drivers/bus/pci/linux/pci_vfio.c
index fdeb9a8caf..07e072e13f 100644
--- a/drivers/bus/pci/linux/pci_vfio.c
+++ b/drivers/bus/pci/linux/pci_vfio.c
@@ -566,7 +566,7 @@ pci_vfio_mmap_bar(int vfio_dev_fd, struct mapped_pci_resource *vfio_res,
}
/* if there's a second part, try to map it */
- if (map_addr != NULL
+ if (map_addr != MAP_FAILED
&& memreg[1].offset && memreg[1].size) {
void *second_addr = RTE_PTR_ADD(bar_addr,
(uintptr_t)(memreg[1].offset -
@@ -578,7 +578,7 @@ pci_vfio_mmap_bar(int vfio_dev_fd, struct mapped_pci_resource *vfio_res,
RTE_MAP_FORCE_ADDRESS);
}
- if (map_addr == NULL) {
+ if (map_addr == NULL || map_addr == MAP_FAILED) {
munmap(bar_addr, bar->size);
bar_addr = MAP_FAILED;
RTE_LOG(ERR, EAL, "Failed to map pci BAR%d\n", diff --git a/drivers/bus/pci/pci_common_uio.c b/drivers/bus/pci/pci_common_uio.c
index 793dfd0a7c..f4dca9da91 100644
--- a/drivers/bus/pci/pci_common_uio.c
+++ b/drivers/bus/pci/pci_common_uio.c
@@ -58,7 +58,7 @@ pci_uio_map_secondary(struct rte_pci_device *dev)
"Cannot mmap device resource file %s to address: %p\n",
uio_res->maps[i].path,
uio_res->maps[i].addr);
- if (mapaddr != NULL) {
+ if (mapaddr != MAP_FAILED) {
/* unmap addrs correctly mapped */
for (j = 0; j < i; j++)
pci_unmap_resource(
diff --git a/lib/librte_eal/include/rte_eal_paging.h b/lib/librte_eal/include/rte_eal_paging.h
index ed98e70e9e..680a7f2505 100644
--- a/lib/librte_eal/include/rte_eal_paging.h
+++ b/lib/librte_eal/include/rte_eal_paging.h
@@ -3,6 +3,7 @@
*/
#include <stdint.h>
+#include <sys/mman.h>
#include <rte_compat.h>
@@ -22,6 +23,7 @@ enum rte_mem_prot {
/** Additional flags for memory mapping. */ enum rte_map_flags {
+#ifdef RTE_EXEC_ENV_WINDOWS
/** Changes to the mapped memory are visible to other processes. */
RTE_MAP_SHARED = 1 << 0,
/** Mapping is not backed by a regular file. */ @@ -35,6 +37,12 @@ enum rte_map_flags {
* it is not required to do so, thus mapping with this flag may fail.
*/
RTE_MAP_FORCE_ADDRESS = 1 << 3
+#else /* map mmap flags because they are exposed in pci_map_resource() API */
+ RTE_MAP_SHARED = MAP_SHARED,
+ RTE_MAP_ANONYMOUS = MAP_ANONYMOUS,
+ RTE_MAP_PRIVATE = MAP_PRIVATE,
+ RTE_MAP_FORCE_ADDRESS = MAP_FIXED,
+#endif
};
/**
diff --git a/lib/librte_eal/windows/include/sys/mman.h b/lib/librte_eal/windows/include/sys/mman.h
new file mode 100644
index 0000000000..0b4b10df1f
--- /dev/null
+++ b/lib/librte_eal/windows/include/sys/mman.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2020 Mellanox Technologies, Ltd */
+
+/*
+ * The syscall mmap does not exist on Windows,
+ * but this error code is used in a badly defined DPDK API for PCI mapping.
+ */
+#define MAP_FAILED ((void *) -1)
diff --git a/lib/librte_pci/rte_pci.c b/lib/librte_pci/rte_pci.c index d8272b9076..1d1cbc75ac 100644
--- a/lib/librte_pci/rte_pci.c
+++ b/lib/librte_pci/rte_pci.c
@@ -163,6 +163,7 @@ pci_map_resource(void *requested_addr, int fd, off_t offset, size_t size,
__func__, fd, requested_addr, size,
(unsigned long long)offset,
rte_strerror(rte_errno), mapaddr);
+ mapaddr = MAP_FAILED; /* API uses mmap error code */
} else
RTE_LOG(DEBUG, EAL, " PCI memory mapped at %p\n", mapaddr);
diff --git a/lib/librte_pci/rte_pci.h b/lib/librte_pci/rte_pci.h index 104b2bb858..a03235da1f 100644
--- a/lib/librte_pci/rte_pci.h
+++ b/lib/librte_pci/rte_pci.h
@@ -160,7 +160,7 @@ int rte_pci_addr_parse(const char *str, struct rte_pci_addr *addr);
* The additional flags for the mapping range.
* @return
* - On success, the function returns a pointer to the mapped area.
- * - On error, NULL is returned.
+ * - On error, MAP_FAILED is returned.
*/
void *pci_map_resource(void *requested_addr, int fd, off_t offset,
size_t size, int additional_flags);
--
2.27.0
On 10-Jul-20 5:17 PM, Thomas Monjalon wrote:
> 10/07/2020 17:39, Burakov, Anatoly:
>> On 10-Jul-20 12:53 PM, Thomas Monjalon wrote:
>>> The function pci_map_resource() returns MAP_FAILED in case of error.
>>> When replacing the call to mmap() by rte_mem_map(),
>>> the error code became NULL, breaking the API.
>>> This function is probably not used outside of DPDK,
>>> but it is still a problem for two reasons:
>>> - the deprecation process was not followed
>>> - the Linux function pci_vfio_mmap_bar() is broken for i40e
>>>
>>> The error code is reverted to the Unix value MAP_FAILED.
>>> Windows needs to define this special value (-1 as in Unix).
>>> After proper deprecation process, the API could be changed again
>>> if really needed.
>>>
>>> Because of the switch from mmap() to rte_mem_map(),
>>> another part of the API was changed: "int additional_flags"
>>> are defined as "additional flags for the mapping range"
>>> without mentioning it was directly used in mmap().
>>> Currently it is directly used in rte_mem_map(),
>>> that's why the values rte_map_flags must be mapped (sic) on the mmap ones
>>> in case of Unix OS.
>>>
>>> These are side effects of a badly defined API using Unix values.
> [...]
>>> /** Additional flags for memory mapping. */
>>> enum rte_map_flags {
>>> +#ifdef RTE_EXEC_ENV_WINDOWS
>>> /** Changes to the mapped memory are visible to other processes. */
>>> RTE_MAP_SHARED = 1 << 0,
>>> /** Mapping is not backed by a regular file. */
>>> @@ -35,6 +37,12 @@ enum rte_map_flags {
>>> * it is not required to do so, thus mapping with this flag may fail.
>>> */
>>> RTE_MAP_FORCE_ADDRESS = 1 << 3
>>> +#else /* map mmap flags because they are exposed in pci_map_resource() API */
>>> + RTE_MAP_SHARED = MAP_SHARED,
>>> + RTE_MAP_ANONYMOUS = MAP_ANONYMOUS,
>>> + RTE_MAP_PRIVATE = MAP_PRIVATE,
>>> + RTE_MAP_FORCE_ADDRESS = MAP_FIXED,
>>> +#endif
>>
>> I'm probably missing something, but why is this needed? Doesn't
>
> Yes you missed reading the commit log :)
> Or maybe it is not written clearly enough. Will try to rephrase.
>
>> rte_mem_map() automatically translate these flags into proper ones?
>> pci_map_resource() will call rte_mem_map(), and that will translate
>> these flags into their Unix equivalents.
>
> The problem is that we have an API which is taking mmap flags as input.
> "int additional_flags" is a parameter of the function,
> and are supposed to be mmap flags. But it is not stated clearly.
> When Windows will use this function, it won't use mmap flags
> but RTE_MAP_*. So we must accept both.
> That's why the best is to make values the same.
>
> In 20.11, we could change the API,
> make clear that only RTE_MAP_* is accepted,
> and remove this workaround.
> Or even better, remove pci_map_resource from the PCI lib,
> and implement it in the PCI bus driver.
>
> pci_map_resource() function is a bad designed API
>
>
Right, this makes it clearer :) Thanks!
On Fri, Jul 10, 2020 at 6:17 PM Thomas Monjalon <thomas@monjalon.net> wrote:
> The problem is that we have an API which is taking mmap flags as input.
> "int additional_flags" is a parameter of the function,
> and are supposed to be mmap flags. But it is not stated clearly.
> When Windows will use this function, it won't use mmap flags
> but RTE_MAP_*. So we must accept both.
> That's why the best is to make values the same.
>
> In 20.11, we could change the API,
> make clear that only RTE_MAP_* is accepted,
> and remove this workaround.
> Or even better, remove pci_map_resource from the PCI lib,
> and implement it in the PCI bus driver.
My preference goes to simple removal.
Maybe it can be handled/rediscussed when the windows porting touches
pci resources mappings.
Removal needs to be announced, so something to plan right now.
@@ -192,7 +192,7 @@ pci_uio_map_resource_by_index(struct rte_pci_device *dev, int res_idx,
mapaddr = pci_map_resource(NULL, fd, (off_t)offset,
(size_t)dev->mem_resource[res_idx].len, 0);
close(fd);
- if (mapaddr == NULL)
+ if (mapaddr == MAP_FAILED)
goto error;
maps[map_idx].phaddr = dev->mem_resource[res_idx].phys_addr;
@@ -345,7 +345,7 @@ pci_uio_map_resource_by_index(struct rte_pci_device *dev, int res_idx,
mapaddr = pci_map_resource(pci_map_addr, fd, 0,
(size_t)dev->mem_resource[res_idx].len, 0);
close(fd);
- if (mapaddr == NULL)
+ if (mapaddr == MAP_FAILED)
goto error;
pci_map_addr = RTE_PTR_ADD(mapaddr,
@@ -566,7 +566,7 @@ pci_vfio_mmap_bar(int vfio_dev_fd, struct mapped_pci_resource *vfio_res,
}
/* if there's a second part, try to map it */
- if (map_addr != NULL
+ if (map_addr != MAP_FAILED
&& memreg[1].offset && memreg[1].size) {
void *second_addr = RTE_PTR_ADD(bar_addr,
(uintptr_t)(memreg[1].offset -
@@ -578,7 +578,7 @@ pci_vfio_mmap_bar(int vfio_dev_fd, struct mapped_pci_resource *vfio_res,
RTE_MAP_FORCE_ADDRESS);
}
- if (map_addr == NULL) {
+ if (map_addr == NULL || map_addr == MAP_FAILED) {
munmap(bar_addr, bar->size);
bar_addr = MAP_FAILED;
RTE_LOG(ERR, EAL, "Failed to map pci BAR%d\n",
@@ -58,7 +58,7 @@ pci_uio_map_secondary(struct rte_pci_device *dev)
"Cannot mmap device resource file %s to address: %p\n",
uio_res->maps[i].path,
uio_res->maps[i].addr);
- if (mapaddr != NULL) {
+ if (mapaddr != MAP_FAILED) {
/* unmap addrs correctly mapped */
for (j = 0; j < i; j++)
pci_unmap_resource(
@@ -3,6 +3,7 @@
*/
#include <stdint.h>
+#include <sys/mman.h>
#include <rte_compat.h>
@@ -22,6 +23,7 @@ enum rte_mem_prot {
/** Additional flags for memory mapping. */
enum rte_map_flags {
+#ifdef RTE_EXEC_ENV_WINDOWS
/** Changes to the mapped memory are visible to other processes. */
RTE_MAP_SHARED = 1 << 0,
/** Mapping is not backed by a regular file. */
@@ -35,6 +37,12 @@ enum rte_map_flags {
* it is not required to do so, thus mapping with this flag may fail.
*/
RTE_MAP_FORCE_ADDRESS = 1 << 3
+#else /* map mmap flags because they are exposed in pci_map_resource() API */
+ RTE_MAP_SHARED = MAP_SHARED,
+ RTE_MAP_ANONYMOUS = MAP_ANONYMOUS,
+ RTE_MAP_PRIVATE = MAP_PRIVATE,
+ RTE_MAP_FORCE_ADDRESS = MAP_FIXED,
+#endif
};
/**
new file mode 100644
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2020 Mellanox Technologies, Ltd
+ */
+
+/*
+ * The syscall mmap does not exist on Windows,
+ * but this error code is used in a badly defined DPDK API for PCI mapping.
+ */
+#define MAP_FAILED ((void *) -1)
@@ -163,6 +163,7 @@ pci_map_resource(void *requested_addr, int fd, off_t offset, size_t size,
__func__, fd, requested_addr, size,
(unsigned long long)offset,
rte_strerror(rte_errno), mapaddr);
+ mapaddr = MAP_FAILED; /* API uses mmap error code */
} else
RTE_LOG(DEBUG, EAL, " PCI memory mapped at %p\n", mapaddr);
@@ -160,7 +160,7 @@ int rte_pci_addr_parse(const char *str, struct rte_pci_addr *addr);
* The additional flags for the mapping range.
* @return
* - On success, the function returns a pointer to the mapped area.
- * - On error, NULL is returned.
+ * - On error, MAP_FAILED is returned.
*/
void *pci_map_resource(void *requested_addr, int fd, off_t offset,
size_t size, int additional_flags);