Re: [PATCH v5 3/3] xen: add helpers to allocate unpopulated memory
On 04.09.20 10:42, Roger Pau Monné wrote:
On Fri, Sep 04, 2020 at 09:00:18AM +0200, Jürgen Groß wrote:
On 03.09.20 18:38, Roger Pau Monné wrote:
On Thu, Sep 03, 2020 at 05:30:07PM +0200, Jürgen Groß wrote:
On 01.09.20 10:33, Roger Pau Monne wrote:
To be used in order to create foreign mappings. This is based on the
ZONE_DEVICE facility which is used by persistent memory devices in
order to create struct pages and kernel virtual mappings for the IOMEM
areas of such devices. Note that on kernels without support for
ZONE_DEVICE Xen will fallback to use ballooned pages in order to
create foreign mappings.
The newly added helpers use the same parameters as the existing
{alloc/free}_xenballooned_pages functions, which allows for in-place
replacement of the callers. Once a memory region has been added to be
used as scratch mapping space it will no longer be released, and pages
returned are kept in a linked list. This allows to have a buffer of
pages and prevents resorting to frequent additions and removals of
regions.
If enabled (because ZONE_DEVICE is supported) the usage of the new
functionality untangles Xen balloon and RAM hotplug from the usage of
unpopulated physical memory ranges to map foreign pages, which is the
correct thing to do in order to avoid mappings of foreign pages depend
on memory hotplug.
Note the driver is currently not enabled on Arm platforms because it
would interfere with the identity mapping required on some platforms.
Signed-off-by: Roger Pau Monné
Sorry, I just got a build error for x86 32-bit build:
WARNING: unmet direct dependencies detected for ZONE_DEVICE
Depends on [n]: MEMORY_HOTPLUG [=n] && MEMORY_HOTREMOVE [=n] &&
SPARSEMEM_VMEMMAP [=n] && ARCH_HAS_PTE_DEVMAP [=n]
Selected by [y]:
- XEN_UNPOPULATED_ALLOC [=y] && XEN [=y] && X86 [=y]
GEN Makefile
CC kernel/bounds.s
CALL/home/gross/korg/src/scripts/atomic/check-atomics.sh
UPD include/generated/bounds.h
CC arch/x86/kernel/asm-offsets.s
In file included from /home/gross/korg/src/include/linux/mmzone.h:19:0,
from /home/gross/korg/src/include/linux/gfp.h:6,
from /home/gross/korg/src/include/linux/slab.h:15,
from /home/gross/korg/src/include/linux/crypto.h:19,
from /home/gross/korg/src/arch/x86/kernel/asm-offsets.c:9:
/home/gross/korg/src/include/linux/page-flags-layout.h:95:2: error: #error
"Not enough bits in page flags"
#error "Not enough bits in page flags"
^
make[2]: *** [/home/gross/korg/src/scripts/Makefile.build:114:
arch/x86/kernel/asm-offsets.s] Error 1
make[1]: *** [/home/gross/korg/src/Makefile:1175: prepare0] Error 2
make[1]: Leaving directory '/home/gross/korg/x8632'
make: *** [Makefile:185: __sub-make] Error 2
Sorry for this. I've tested a 32bit build but I think it was before
the last Kconfig changes. I'm a little unsure how to solve this, as
ZONE_DEVICE doesn't select the required options for it to run, but
rather depends on them to be available.
You can trigger something similar on x86-64 by doing:
$ make ARCH=x86_64 xen.config
Using .config as base
Merging ./kernel/configs/xen.config
Merging ./arch/x86/configs/xen.config
#
# merged configuration written to .config (needs make)
#
scripts/kconfig/conf --olddefconfig Kconfig
WARNING: unmet direct dependencies detected for ZONE_DEVICE
Depends on [n]: MEMORY_HOTPLUG [=y] && MEMORY_HOTREMOVE [=n] && SPARSEMEM_VMEMMAP
[=y] && ARCH_HAS_PTE_DEVMAP [=y]
Selected by [y]:
- XEN_UNPOPULATED_ALLOC [=y] && XEN [=y] && X86_64 [=y]
#
# configuration written to .config
#
I think the only solution is to have XEN_UNPOPULATED_ALLOC depend on
ZONE_DEVICE rather than select it?
Yes, I think so.
I've folded that in and now build is fine.
Thanks, I assume no further action is needed on my side.
Right.
Juergen
Re: [PATCH v5 3/3] xen: add helpers to allocate unpopulated memory
On Fri, Sep 04, 2020 at 09:00:18AM +0200, Jürgen Groß wrote:
> On 03.09.20 18:38, Roger Pau Monné wrote:
> > On Thu, Sep 03, 2020 at 05:30:07PM +0200, Jürgen Groß wrote:
> > > On 01.09.20 10:33, Roger Pau Monne wrote:
> > > > To be used in order to create foreign mappings. This is based on the
> > > > ZONE_DEVICE facility which is used by persistent memory devices in
> > > > order to create struct pages and kernel virtual mappings for the IOMEM
> > > > areas of such devices. Note that on kernels without support for
> > > > ZONE_DEVICE Xen will fallback to use ballooned pages in order to
> > > > create foreign mappings.
> > > >
> > > > The newly added helpers use the same parameters as the existing
> > > > {alloc/free}_xenballooned_pages functions, which allows for in-place
> > > > replacement of the callers. Once a memory region has been added to be
> > > > used as scratch mapping space it will no longer be released, and pages
> > > > returned are kept in a linked list. This allows to have a buffer of
> > > > pages and prevents resorting to frequent additions and removals of
> > > > regions.
> > > >
> > > > If enabled (because ZONE_DEVICE is supported) the usage of the new
> > > > functionality untangles Xen balloon and RAM hotplug from the usage of
> > > > unpopulated physical memory ranges to map foreign pages, which is the
> > > > correct thing to do in order to avoid mappings of foreign pages depend
> > > > on memory hotplug.
> > > >
> > > > Note the driver is currently not enabled on Arm platforms because it
> > > > would interfere with the identity mapping required on some platforms.
> > > >
> > > > Signed-off-by: Roger Pau Monné
> > >
> > > Sorry, I just got a build error for x86 32-bit build:
> > >
> > > WARNING: unmet direct dependencies detected for ZONE_DEVICE
> > >Depends on [n]: MEMORY_HOTPLUG [=n] && MEMORY_HOTREMOVE [=n] &&
> > > SPARSEMEM_VMEMMAP [=n] && ARCH_HAS_PTE_DEVMAP [=n]
> > >Selected by [y]:
> > >- XEN_UNPOPULATED_ALLOC [=y] && XEN [=y] && X86 [=y]
> > >GEN Makefile
> > >CC kernel/bounds.s
> > >CALL/home/gross/korg/src/scripts/atomic/check-atomics.sh
> > >UPD include/generated/bounds.h
> > >CC arch/x86/kernel/asm-offsets.s
> > > In file included from /home/gross/korg/src/include/linux/mmzone.h:19:0,
> > > from /home/gross/korg/src/include/linux/gfp.h:6,
> > > from /home/gross/korg/src/include/linux/slab.h:15,
> > > from /home/gross/korg/src/include/linux/crypto.h:19,
> > > from
> > > /home/gross/korg/src/arch/x86/kernel/asm-offsets.c:9:
> > > /home/gross/korg/src/include/linux/page-flags-layout.h:95:2: error: #error
> > > "Not enough bits in page flags"
> > > #error "Not enough bits in page flags"
> > >^
> > > make[2]: *** [/home/gross/korg/src/scripts/Makefile.build:114:
> > > arch/x86/kernel/asm-offsets.s] Error 1
> > > make[1]: *** [/home/gross/korg/src/Makefile:1175: prepare0] Error 2
> > > make[1]: Leaving directory '/home/gross/korg/x8632'
> > > make: *** [Makefile:185: __sub-make] Error 2
> >
> > Sorry for this. I've tested a 32bit build but I think it was before
> > the last Kconfig changes. I'm a little unsure how to solve this, as
> > ZONE_DEVICE doesn't select the required options for it to run, but
> > rather depends on them to be available.
> >
> > You can trigger something similar on x86-64 by doing:
> >
> > $ make ARCH=x86_64 xen.config
> > Using .config as base
> > Merging ./kernel/configs/xen.config
> > Merging ./arch/x86/configs/xen.config
> > #
> > # merged configuration written to .config (needs make)
> > #
> > scripts/kconfig/conf --olddefconfig Kconfig
> >
> > WARNING: unmet direct dependencies detected for ZONE_DEVICE
> >Depends on [n]: MEMORY_HOTPLUG [=y] && MEMORY_HOTREMOVE [=n] &&
> > SPARSEMEM_VMEMMAP [=y] && ARCH_HAS_PTE_DEVMAP [=y]
> >Selected by [y]:
> >- XEN_UNPOPULATED_ALLOC [=y] && XEN [=y] && X86_64 [=y]
> > #
> > # configuration written to .config
> > #
> >
> > I think the only solution is to have XEN_UNPOPULATED_ALLOC depend on
> > ZONE_DEVICE rather than select it?
>
> Yes, I think so.
>
> I've folded that in and now build is fine.
Thanks, I assume no further action is needed on my side.
Roger.
Re: [PATCH v5 3/3] xen: add helpers to allocate unpopulated memory
On 03.09.20 18:38, Roger Pau Monné wrote:
On Thu, Sep 03, 2020 at 05:30:07PM +0200, Jürgen Groß wrote:
On 01.09.20 10:33, Roger Pau Monne wrote:
To be used in order to create foreign mappings. This is based on the
ZONE_DEVICE facility which is used by persistent memory devices in
order to create struct pages and kernel virtual mappings for the IOMEM
areas of such devices. Note that on kernels without support for
ZONE_DEVICE Xen will fallback to use ballooned pages in order to
create foreign mappings.
The newly added helpers use the same parameters as the existing
{alloc/free}_xenballooned_pages functions, which allows for in-place
replacement of the callers. Once a memory region has been added to be
used as scratch mapping space it will no longer be released, and pages
returned are kept in a linked list. This allows to have a buffer of
pages and prevents resorting to frequent additions and removals of
regions.
If enabled (because ZONE_DEVICE is supported) the usage of the new
functionality untangles Xen balloon and RAM hotplug from the usage of
unpopulated physical memory ranges to map foreign pages, which is the
correct thing to do in order to avoid mappings of foreign pages depend
on memory hotplug.
Note the driver is currently not enabled on Arm platforms because it
would interfere with the identity mapping required on some platforms.
Signed-off-by: Roger Pau Monné
Sorry, I just got a build error for x86 32-bit build:
WARNING: unmet direct dependencies detected for ZONE_DEVICE
Depends on [n]: MEMORY_HOTPLUG [=n] && MEMORY_HOTREMOVE [=n] &&
SPARSEMEM_VMEMMAP [=n] && ARCH_HAS_PTE_DEVMAP [=n]
Selected by [y]:
- XEN_UNPOPULATED_ALLOC [=y] && XEN [=y] && X86 [=y]
GEN Makefile
CC kernel/bounds.s
CALL/home/gross/korg/src/scripts/atomic/check-atomics.sh
UPD include/generated/bounds.h
CC arch/x86/kernel/asm-offsets.s
In file included from /home/gross/korg/src/include/linux/mmzone.h:19:0,
from /home/gross/korg/src/include/linux/gfp.h:6,
from /home/gross/korg/src/include/linux/slab.h:15,
from /home/gross/korg/src/include/linux/crypto.h:19,
from /home/gross/korg/src/arch/x86/kernel/asm-offsets.c:9:
/home/gross/korg/src/include/linux/page-flags-layout.h:95:2: error: #error
"Not enough bits in page flags"
#error "Not enough bits in page flags"
^
make[2]: *** [/home/gross/korg/src/scripts/Makefile.build:114:
arch/x86/kernel/asm-offsets.s] Error 1
make[1]: *** [/home/gross/korg/src/Makefile:1175: prepare0] Error 2
make[1]: Leaving directory '/home/gross/korg/x8632'
make: *** [Makefile:185: __sub-make] Error 2
Sorry for this. I've tested a 32bit build but I think it was before
the last Kconfig changes. I'm a little unsure how to solve this, as
ZONE_DEVICE doesn't select the required options for it to run, but
rather depends on them to be available.
You can trigger something similar on x86-64 by doing:
$ make ARCH=x86_64 xen.config
Using .config as base
Merging ./kernel/configs/xen.config
Merging ./arch/x86/configs/xen.config
#
# merged configuration written to .config (needs make)
#
scripts/kconfig/conf --olddefconfig Kconfig
WARNING: unmet direct dependencies detected for ZONE_DEVICE
Depends on [n]: MEMORY_HOTPLUG [=y] && MEMORY_HOTREMOVE [=n] && SPARSEMEM_VMEMMAP
[=y] && ARCH_HAS_PTE_DEVMAP [=y]
Selected by [y]:
- XEN_UNPOPULATED_ALLOC [=y] && XEN [=y] && X86_64 [=y]
#
# configuration written to .config
#
I think the only solution is to have XEN_UNPOPULATED_ALLOC depend on
ZONE_DEVICE rather than select it?
Yes, I think so.
I've folded that in and now build is fine.
Juergen
Re: [PATCH v5 3/3] xen: add helpers to allocate unpopulated memory
On Thu, Sep 03, 2020 at 05:30:07PM +0200, Jürgen Groß wrote:
> On 01.09.20 10:33, Roger Pau Monne wrote:
> > To be used in order to create foreign mappings. This is based on the
> > ZONE_DEVICE facility which is used by persistent memory devices in
> > order to create struct pages and kernel virtual mappings for the IOMEM
> > areas of such devices. Note that on kernels without support for
> > ZONE_DEVICE Xen will fallback to use ballooned pages in order to
> > create foreign mappings.
> >
> > The newly added helpers use the same parameters as the existing
> > {alloc/free}_xenballooned_pages functions, which allows for in-place
> > replacement of the callers. Once a memory region has been added to be
> > used as scratch mapping space it will no longer be released, and pages
> > returned are kept in a linked list. This allows to have a buffer of
> > pages and prevents resorting to frequent additions and removals of
> > regions.
> >
> > If enabled (because ZONE_DEVICE is supported) the usage of the new
> > functionality untangles Xen balloon and RAM hotplug from the usage of
> > unpopulated physical memory ranges to map foreign pages, which is the
> > correct thing to do in order to avoid mappings of foreign pages depend
> > on memory hotplug.
> >
> > Note the driver is currently not enabled on Arm platforms because it
> > would interfere with the identity mapping required on some platforms.
> >
> > Signed-off-by: Roger Pau Monné
>
> Sorry, I just got a build error for x86 32-bit build:
>
> WARNING: unmet direct dependencies detected for ZONE_DEVICE
> Depends on [n]: MEMORY_HOTPLUG [=n] && MEMORY_HOTREMOVE [=n] &&
> SPARSEMEM_VMEMMAP [=n] && ARCH_HAS_PTE_DEVMAP [=n]
> Selected by [y]:
> - XEN_UNPOPULATED_ALLOC [=y] && XEN [=y] && X86 [=y]
> GEN Makefile
> CC kernel/bounds.s
> CALL/home/gross/korg/src/scripts/atomic/check-atomics.sh
> UPD include/generated/bounds.h
> CC arch/x86/kernel/asm-offsets.s
> In file included from /home/gross/korg/src/include/linux/mmzone.h:19:0,
> from /home/gross/korg/src/include/linux/gfp.h:6,
> from /home/gross/korg/src/include/linux/slab.h:15,
> from /home/gross/korg/src/include/linux/crypto.h:19,
> from /home/gross/korg/src/arch/x86/kernel/asm-offsets.c:9:
> /home/gross/korg/src/include/linux/page-flags-layout.h:95:2: error: #error
> "Not enough bits in page flags"
> #error "Not enough bits in page flags"
> ^
> make[2]: *** [/home/gross/korg/src/scripts/Makefile.build:114:
> arch/x86/kernel/asm-offsets.s] Error 1
> make[1]: *** [/home/gross/korg/src/Makefile:1175: prepare0] Error 2
> make[1]: Leaving directory '/home/gross/korg/x8632'
> make: *** [Makefile:185: __sub-make] Error 2
Sorry for this. I've tested a 32bit build but I think it was before
the last Kconfig changes. I'm a little unsure how to solve this, as
ZONE_DEVICE doesn't select the required options for it to run, but
rather depends on them to be available.
You can trigger something similar on x86-64 by doing:
$ make ARCH=x86_64 xen.config
Using .config as base
Merging ./kernel/configs/xen.config
Merging ./arch/x86/configs/xen.config
#
# merged configuration written to .config (needs make)
#
scripts/kconfig/conf --olddefconfig Kconfig
WARNING: unmet direct dependencies detected for ZONE_DEVICE
Depends on [n]: MEMORY_HOTPLUG [=y] && MEMORY_HOTREMOVE [=n] &&
SPARSEMEM_VMEMMAP [=y] && ARCH_HAS_PTE_DEVMAP [=y]
Selected by [y]:
- XEN_UNPOPULATED_ALLOC [=y] && XEN [=y] && X86_64 [=y]
#
# configuration written to .config
#
I think the only solution is to have XEN_UNPOPULATED_ALLOC depend on
ZONE_DEVICE rather than select it?
Thanks, Roger.
Re: [PATCH v5 3/3] xen: add helpers to allocate unpopulated memory
On 01.09.20 10:33, Roger Pau Monne wrote:
To be used in order to create foreign mappings. This is based on the
ZONE_DEVICE facility which is used by persistent memory devices in
order to create struct pages and kernel virtual mappings for the IOMEM
areas of such devices. Note that on kernels without support for
ZONE_DEVICE Xen will fallback to use ballooned pages in order to
create foreign mappings.
The newly added helpers use the same parameters as the existing
{alloc/free}_xenballooned_pages functions, which allows for in-place
replacement of the callers. Once a memory region has been added to be
used as scratch mapping space it will no longer be released, and pages
returned are kept in a linked list. This allows to have a buffer of
pages and prevents resorting to frequent additions and removals of
regions.
If enabled (because ZONE_DEVICE is supported) the usage of the new
functionality untangles Xen balloon and RAM hotplug from the usage of
unpopulated physical memory ranges to map foreign pages, which is the
correct thing to do in order to avoid mappings of foreign pages depend
on memory hotplug.
Note the driver is currently not enabled on Arm platforms because it
would interfere with the identity mapping required on some platforms.
Signed-off-by: Roger Pau Monné
Sorry, I just got a build error for x86 32-bit build:
WARNING: unmet direct dependencies detected for ZONE_DEVICE
Depends on [n]: MEMORY_HOTPLUG [=n] && MEMORY_HOTREMOVE [=n] &&
SPARSEMEM_VMEMMAP [=n] && ARCH_HAS_PTE_DEVMAP [=n]
Selected by [y]:
- XEN_UNPOPULATED_ALLOC [=y] && XEN [=y] && X86 [=y]
GEN Makefile
CC kernel/bounds.s
CALL/home/gross/korg/src/scripts/atomic/check-atomics.sh
UPD include/generated/bounds.h
CC arch/x86/kernel/asm-offsets.s
In file included from /home/gross/korg/src/include/linux/mmzone.h:19:0,
from /home/gross/korg/src/include/linux/gfp.h:6,
from /home/gross/korg/src/include/linux/slab.h:15,
from /home/gross/korg/src/include/linux/crypto.h:19,
from /home/gross/korg/src/arch/x86/kernel/asm-offsets.c:9:
/home/gross/korg/src/include/linux/page-flags-layout.h:95:2: error:
#error "Not enough bits in page flags"
#error "Not enough bits in page flags"
^
make[2]: *** [/home/gross/korg/src/scripts/Makefile.build:114:
arch/x86/kernel/asm-offsets.s] Error 1
make[1]: *** [/home/gross/korg/src/Makefile:1175: prepare0] Error 2
make[1]: Leaving directory '/home/gross/korg/x8632'
make: *** [Makefile:185: __sub-make] Error 2
Juergen
Re: [PATCH v5 3/3] xen: add helpers to allocate unpopulated memory
On 01.09.20 16:45, Roger Pau Monné wrote:
On Tue, Sep 01, 2020 at 10:33:26AM +0200, Roger Pau Monne wrote:
+static int fill_list(unsigned int nr_pages)
+{
+ struct dev_pagemap *pgmap;
+ void *vaddr;
+ unsigned int i, alloc_pages = round_up(nr_pages, PAGES_PER_SECTION);
+ int nid, ret;
+
+ pgmap = kzalloc(sizeof(*pgmap), GFP_KERNEL);
+ if (!pgmap)
+ return -ENOMEM;
+
+ pgmap->type = MEMORY_DEVICE_GENERIC;
+ pgmap->res.name = "Xen scratch";
+ pgmap->res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+
+ ret = allocate_resource(_resource, >res,
+ alloc_pages * PAGE_SIZE, 0, -1,
+ PAGES_PER_SECTION * PAGE_SIZE, NULL, NULL);
+ if (ret < 0) {
+ pr_err("Cannot allocate new IOMEM resource\n");
+ kfree(pgmap);
+ return ret;
+ }
+
+ nid = memory_add_physaddr_to_nid(pgmap->res.start);
I think this is not needed ...
+
+#ifdef CONFIG_XEN_HAVE_PVMMU
+/*
+ * memremap will build page tables for the new memory so
+ * the p2m must contain invalid entries so the correct
+ * non-present PTEs will be written.
+ *
+ * If a failure occurs, the original (identity) p2m entries
+ * are not restored since this region is now known not to
+ * conflict with any devices.
+ */
+ if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+ xen_pfn_t pfn = PFN_DOWN(pgmap->res.start);
+
+ for (i = 0; i < alloc_pages; i++) {
+ if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) {
+ pr_warn("set_phys_to_machine() failed, no memory
added\n");
+ release_resource(>res);
+ kfree(pgmap);
+ return -ENOMEM;
+ }
+}
+ }
+#endif
+
+ vaddr = memremap_pages(pgmap, nid);
... and NUMA_NO_NODE should be used here instead, as this memory is just
fictitious space to map foreign memory, and shouldn't be related to
any NUMA node.
The following chunk should be folded in, or I can resend.
I can fold it in.
Juergen
Re: [PATCH v5 3/3] xen: add helpers to allocate unpopulated memory
On Tue, Sep 01, 2020 at 10:33:26AM +0200, Roger Pau Monne wrote:
> +static int fill_list(unsigned int nr_pages)
> +{
> + struct dev_pagemap *pgmap;
> + void *vaddr;
> + unsigned int i, alloc_pages = round_up(nr_pages, PAGES_PER_SECTION);
> + int nid, ret;
> +
> + pgmap = kzalloc(sizeof(*pgmap), GFP_KERNEL);
> + if (!pgmap)
> + return -ENOMEM;
> +
> + pgmap->type = MEMORY_DEVICE_GENERIC;
> + pgmap->res.name = "Xen scratch";
> + pgmap->res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
> +
> + ret = allocate_resource(_resource, >res,
> + alloc_pages * PAGE_SIZE, 0, -1,
> + PAGES_PER_SECTION * PAGE_SIZE, NULL, NULL);
> + if (ret < 0) {
> + pr_err("Cannot allocate new IOMEM resource\n");
> + kfree(pgmap);
> + return ret;
> + }
> +
> + nid = memory_add_physaddr_to_nid(pgmap->res.start);
I think this is not needed ...
> +
> +#ifdef CONFIG_XEN_HAVE_PVMMU
> +/*
> + * memremap will build page tables for the new memory so
> + * the p2m must contain invalid entries so the correct
> + * non-present PTEs will be written.
> + *
> + * If a failure occurs, the original (identity) p2m entries
> + * are not restored since this region is now known not to
> + * conflict with any devices.
> + */
> + if (!xen_feature(XENFEAT_auto_translated_physmap)) {
> + xen_pfn_t pfn = PFN_DOWN(pgmap->res.start);
> +
> + for (i = 0; i < alloc_pages; i++) {
> + if (!set_phys_to_machine(pfn + i, INVALID_P2M_ENTRY)) {
> + pr_warn("set_phys_to_machine() failed, no
> memory added\n");
> + release_resource(>res);
> + kfree(pgmap);
> + return -ENOMEM;
> + }
> +}
> + }
> +#endif
> +
> + vaddr = memremap_pages(pgmap, nid);
... and NUMA_NO_NODE should be used here instead, as this memory is just
fictitious space to map foreign memory, and shouldn't be related to
any NUMA node.
The following chunk should be folded in, or I can resend.
Thanks, Roger.
---8<---
diff --git a/drivers/xen/unpopulated-alloc.c b/drivers/xen/unpopulated-alloc.c
index 1b5d157c6977..3b98dc921426 100644
--- a/drivers/xen/unpopulated-alloc.c
+++ b/drivers/xen/unpopulated-alloc.c
@@ -20,7 +20,7 @@ static int fill_list(unsigned int nr_pages)
struct dev_pagemap *pgmap;
void *vaddr;
unsigned int i, alloc_pages = round_up(nr_pages, PAGES_PER_SECTION);
- int nid, ret;
+ int ret;
pgmap = kzalloc(sizeof(*pgmap), GFP_KERNEL);
if (!pgmap)
@@ -39,8 +39,6 @@ static int fill_list(unsigned int nr_pages)
return ret;
}
- nid = memory_add_physaddr_to_nid(pgmap->res.start);
-
#ifdef CONFIG_XEN_HAVE_PVMMU
/*
* memremap will build page tables for the new memory so
@@ -65,7 +63,7 @@ static int fill_list(unsigned int nr_pages)
}
#endif
- vaddr = memremap_pages(pgmap, nid);
+ vaddr = memremap_pages(pgmap, NUMA_NO_NODE);
if (IS_ERR(vaddr)) {
pr_err("Cannot remap memory range\n");
release_resource(>res);
Re: [PATCH v5 3/3] xen: add helpers to allocate unpopulated memory
Hi Roger,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on xen-tip/linux-next]
[also build test ERROR on linux/master hnaz-linux-mm/master linus/master
v5.9-rc3]
[cannot apply to next-20200828]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]
url:
https://github.com/0day-ci/linux/commits/Roger-Pau-Monne/xen-balloon-fixes-for-memory-hotplug/20200901-163414
base: https://git.kernel.org/pub/scm/linux/kernel/git/xen/tip.git linux-next
config: x86_64-randconfig-a011-20200901 (attached as .config)
compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project
c10e63677f5d20f18010f8f68c631ddc97546f7d)
reproduce (this is a W=1 build):
wget
https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O
~/bin/make.cross
chmod +x ~/bin/make.cross
# install x86_64 cross compiling tool for clang build
# apt-get install binutils-x86-64-linux-gnu
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot
All errors (new ones prefixed by >>):
>> drivers/xen/unpopulated-alloc.c:42:8: error: implicit declaration of
>> function 'memory_add_physaddr_to_nid'
>> [-Werror,-Wimplicit-function-declaration]
nid = memory_add_physaddr_to_nid(pgmap->res.start);
^
1 error generated.
#
https://github.com/0day-ci/linux/commit/b66f7f6a65710bd99d21d22f52fa5bc46636d425
git remote add linux-review https://github.com/0day-ci/linux
git fetch --no-tags linux-review
Roger-Pau-Monne/xen-balloon-fixes-for-memory-hotplug/20200901-163414
git checkout b66f7f6a65710bd99d21d22f52fa5bc46636d425
vim +/memory_add_physaddr_to_nid +42 drivers/xen/unpopulated-alloc.c
17
18 static int fill_list(unsigned int nr_pages)
19 {
20 struct dev_pagemap *pgmap;
21 void *vaddr;
22 unsigned int i, alloc_pages = round_up(nr_pages,
PAGES_PER_SECTION);
23 int nid, ret;
24
25 pgmap = kzalloc(sizeof(*pgmap), GFP_KERNEL);
26 if (!pgmap)
27 return -ENOMEM;
28
29 pgmap->type = MEMORY_DEVICE_GENERIC;
30 pgmap->res.name = "Xen scratch";
31 pgmap->res.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
32
33 ret = allocate_resource(_resource, >res,
34 alloc_pages * PAGE_SIZE, 0, -1,
35 PAGES_PER_SECTION * PAGE_SIZE, NULL,
NULL);
36 if (ret < 0) {
37 pr_err("Cannot allocate new IOMEM resource\n");
38 kfree(pgmap);
39 return ret;
40 }
41
> 42 nid = memory_add_physaddr_to_nid(pgmap->res.start);
43
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-...@lists.01.org
.config.gz
Description: application/gzip
[PATCH v5 3/3] xen: add helpers to allocate unpopulated memory
To be used in order to create foreign mappings. This is based on the
ZONE_DEVICE facility which is used by persistent memory devices in
order to create struct pages and kernel virtual mappings for the IOMEM
areas of such devices. Note that on kernels without support for
ZONE_DEVICE Xen will fallback to use ballooned pages in order to
create foreign mappings.
The newly added helpers use the same parameters as the existing
{alloc/free}_xenballooned_pages functions, which allows for in-place
replacement of the callers. Once a memory region has been added to be
used as scratch mapping space it will no longer be released, and pages
returned are kept in a linked list. This allows to have a buffer of
pages and prevents resorting to frequent additions and removals of
regions.
If enabled (because ZONE_DEVICE is supported) the usage of the new
functionality untangles Xen balloon and RAM hotplug from the usage of
unpopulated physical memory ranges to map foreign pages, which is the
correct thing to do in order to avoid mappings of foreign pages depend
on memory hotplug.
Note the driver is currently not enabled on Arm platforms because it
would interfere with the identity mapping required on some platforms.
Signed-off-by: Roger Pau Monné
---
Cc: Oleksandr Andrushchenko
Cc: David Airlie
Cc: Daniel Vetter
Cc: Boris Ostrovsky
Cc: Juergen Gross
Cc: Stefano Stabellini
Cc: Dan Carpenter
Cc: Roger Pau Monne
Cc: Wei Liu
Cc: Yan Yankovskyi
Cc: dri-de...@lists.freedesktop.org
Cc: xen-de...@lists.xenproject.org
Cc: linux...@kvack.org
Cc: David Hildenbrand
Cc: Michal Hocko
Cc: Dan Williams
---
Changes since v4:
- Introduce a description for the option.
- Force selection of ZONE_DEVICE on X86 and select
XEN_UNPOPULATED_ALLOC if running on dom0 mode or having any
backends.
Changes since v3:
- Introduce a Kconfig option that gates the addition of the
unpopulated alloc driver. This allows to easily disable it on Arm
platforms.
- Dropped Juergen RB due to the addition of the Kconfig option.
- Switched from MEMORY_DEVICE_DEVDAX to MEMORY_DEVICE_GENERIC.
Changes since v2:
- Drop BUILD_BUG_ON regarding PVMMU page sizes.
- Use a SPDX license identifier.
- Call fill with only the minimum required number of pages.
- Include xen.h header in xen_drm_front_gem.c.
- Use less generic function names.
- Exit early from the init function if not a PV guest.
- Don't use all caps for region name.
---
drivers/gpu/drm/xen/xen_drm_front_gem.c | 9 +-
drivers/xen/Kconfig | 11 ++
drivers/xen/Makefile| 1 +
drivers/xen/balloon.c | 4 +-
drivers/xen/grant-table.c | 4 +-
drivers/xen/privcmd.c | 4 +-
drivers/xen/unpopulated-alloc.c | 185
drivers/xen/xenbus/xenbus_client.c | 6 +-
drivers/xen/xlate_mmu.c | 4 +-
include/xen/xen.h | 9 ++
10 files changed, 222 insertions(+), 15 deletions(-)
create mode 100644 drivers/xen/unpopulated-alloc.c
diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c
b/drivers/gpu/drm/xen/xen_drm_front_gem.c
index 39ff95b75357..534daf37c97e 100644
--- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
+++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
@@ -18,6 +18,7 @@
#include
#include
+#include
#include "xen_drm_front.h"
#include "xen_drm_front_gem.h"
@@ -99,8 +100,8 @@ static struct xen_gem_object *gem_create(struct drm_device
*dev, size_t size)
* allocate ballooned pages which will be used to map
* grant references provided by the backend
*/
- ret = alloc_xenballooned_pages(xen_obj->num_pages,
- xen_obj->pages);
+ ret = xen_alloc_unpopulated_pages(xen_obj->num_pages,
+ xen_obj->pages);
if (ret < 0) {
DRM_ERROR("Cannot allocate %zu ballooned pages: %d\n",
xen_obj->num_pages, ret);
@@ -152,8 +153,8 @@ void xen_drm_front_gem_free_object_unlocked(struct
drm_gem_object *gem_obj)
} else {
if (xen_obj->pages) {
if (xen_obj->be_alloc) {
- free_xenballooned_pages(xen_obj->num_pages,
- xen_obj->pages);
+ xen_free_unpopulated_pages(xen_obj->num_pages,
+ xen_obj->pages);
gem_free_pages_array(xen_obj);
} else {
drm_gem_put_pages(_obj->base,
diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig
index ea6c1e7e3e42..e38c33558d0d 100644
--- a/drivers/xen/Kconfig
+++ b/drivers/xen/Kconfig
@@ -325,4 +325,15 @@ config XEN_HAVE_VPMU
config XEN_FRONT_PGDIR_SHBUF
tristate
