2021-05-19 13:54:15

by Claire Chang

[permalink] [raw]
Subject: [PATCH v7 01/15] swiotlb: Refactor swiotlb init functions

Add a new function, swiotlb_init_io_tlb_mem, for the io_tlb_mem struct
initialization to make the code reusable.

Note that we now also call set_memory_decrypted in swiotlb_init_with_tbl.

Signed-off-by: Claire Chang <[email protected]>
---
kernel/dma/swiotlb.c | 51 ++++++++++++++++++++++----------------------
1 file changed, 25 insertions(+), 26 deletions(-)

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 8ca7d505d61c..d3232fc19385 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -168,9 +168,30 @@ void __init swiotlb_update_mem_attributes(void)
memset(vaddr, 0, bytes);
}

-int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
+static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start,
+ unsigned long nslabs, bool late_alloc)
{
+ void *vaddr = phys_to_virt(start);
unsigned long bytes = nslabs << IO_TLB_SHIFT, i;
+
+ mem->nslabs = nslabs;
+ mem->start = start;
+ mem->end = mem->start + bytes;
+ mem->index = 0;
+ mem->late_alloc = late_alloc;
+ spin_lock_init(&mem->lock);
+ for (i = 0; i < mem->nslabs; i++) {
+ mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
+ mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
+ mem->slots[i].alloc_size = 0;
+ }
+
+ set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
+ memset(vaddr, 0, bytes);
+}
+
+int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
+{
struct io_tlb_mem *mem;
size_t alloc_size;

@@ -186,16 +207,8 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
if (!mem)
panic("%s: Failed to allocate %zu bytes align=0x%lx\n",
__func__, alloc_size, PAGE_SIZE);
- mem->nslabs = nslabs;
- mem->start = __pa(tlb);
- mem->end = mem->start + bytes;
- mem->index = 0;
- spin_lock_init(&mem->lock);
- for (i = 0; i < mem->nslabs; i++) {
- mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
- mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
- mem->slots[i].alloc_size = 0;
- }
+
+ swiotlb_init_io_tlb_mem(mem, __pa(tlb), nslabs, false);

io_tlb_default_mem = mem;
if (verbose)
@@ -282,7 +295,6 @@ swiotlb_late_init_with_default_size(size_t default_size)
int
swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
{
- unsigned long bytes = nslabs << IO_TLB_SHIFT, i;
struct io_tlb_mem *mem;

if (swiotlb_force == SWIOTLB_NO_FORCE)
@@ -297,20 +309,7 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
if (!mem)
return -ENOMEM;

- mem->nslabs = nslabs;
- mem->start = virt_to_phys(tlb);
- mem->end = mem->start + bytes;
- mem->index = 0;
- mem->late_alloc = 1;
- spin_lock_init(&mem->lock);
- for (i = 0; i < mem->nslabs; i++) {
- mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
- mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
- mem->slots[i].alloc_size = 0;
- }
-
- set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT);
- memset(tlb, 0, bytes);
+ swiotlb_init_io_tlb_mem(mem, virt_to_phys(tlb), nslabs, true);

io_tlb_default_mem = mem;
swiotlb_print_info();
--
2.31.1.751.gd2f1c929bd-goog



2021-05-19 20:21:34

by Florian Fainelli

[permalink] [raw]
Subject: Re: [PATCH v7 01/15] swiotlb: Refactor swiotlb init functions



On 5/17/2021 11:42 PM, Claire Chang wrote:
> Add a new function, swiotlb_init_io_tlb_mem, for the io_tlb_mem struct
> initialization to make the code reusable.
>
> Note that we now also call set_memory_decrypted in swiotlb_init_with_tbl.
>
> Signed-off-by: Claire Chang <[email protected]>
> ---
> kernel/dma/swiotlb.c | 51 ++++++++++++++++++++++----------------------
> 1 file changed, 25 insertions(+), 26 deletions(-)
>
> diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
> index 8ca7d505d61c..d3232fc19385 100644
> --- a/kernel/dma/swiotlb.c
> +++ b/kernel/dma/swiotlb.c
> @@ -168,9 +168,30 @@ void __init swiotlb_update_mem_attributes(void)
> memset(vaddr, 0, bytes);
> }
>
> -int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
> +static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start,
> + unsigned long nslabs, bool late_alloc)
> {
> + void *vaddr = phys_to_virt(start);
> unsigned long bytes = nslabs << IO_TLB_SHIFT, i;
> +
> + mem->nslabs = nslabs;
> + mem->start = start;
> + mem->end = mem->start + bytes;
> + mem->index = 0;
> + mem->late_alloc = late_alloc;
> + spin_lock_init(&mem->lock);
> + for (i = 0; i < mem->nslabs; i++) {
> + mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
> + mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
> + mem->slots[i].alloc_size = 0;
> + }
> +
> + set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
> + memset(vaddr, 0, bytes);

You are doing an unconditional set_memory_decrypted() followed by a
memset here, and then:

> +}
> +
> +int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
> +{
> struct io_tlb_mem *mem;
> size_t alloc_size;
>
> @@ -186,16 +207,8 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
> if (!mem)
> panic("%s: Failed to allocate %zu bytes align=0x%lx\n",
> __func__, alloc_size, PAGE_SIZE);
> - mem->nslabs = nslabs;
> - mem->start = __pa(tlb);
> - mem->end = mem->start + bytes;
> - mem->index = 0;
> - spin_lock_init(&mem->lock);
> - for (i = 0; i < mem->nslabs; i++) {
> - mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
> - mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
> - mem->slots[i].alloc_size = 0;
> - }
> +
> + swiotlb_init_io_tlb_mem(mem, __pa(tlb), nslabs, false);

You convert this call site with swiotlb_init_io_tlb_mem() which did not
do the set_memory_decrypted()+memset(). Is this okay or should
swiotlb_init_io_tlb_mem() add an additional argument to do this
conditionally?
--
Florian

2021-05-20 06:47:12

by Claire Chang

[permalink] [raw]
Subject: Re: [PATCH v7 01/15] swiotlb: Refactor swiotlb init functions

On Thu, May 20, 2021 at 2:50 AM Florian Fainelli <[email protected]> wrote:
>
>
>
> On 5/17/2021 11:42 PM, Claire Chang wrote:
> > Add a new function, swiotlb_init_io_tlb_mem, for the io_tlb_mem struct
> > initialization to make the code reusable.
> >
> > Note that we now also call set_memory_decrypted in swiotlb_init_with_tbl.
> >
> > Signed-off-by: Claire Chang <[email protected]>
> > ---
> > kernel/dma/swiotlb.c | 51 ++++++++++++++++++++++----------------------
> > 1 file changed, 25 insertions(+), 26 deletions(-)
> >
> > diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
> > index 8ca7d505d61c..d3232fc19385 100644
> > --- a/kernel/dma/swiotlb.c
> > +++ b/kernel/dma/swiotlb.c
> > @@ -168,9 +168,30 @@ void __init swiotlb_update_mem_attributes(void)
> > memset(vaddr, 0, bytes);
> > }
> >
> > -int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
> > +static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start,
> > + unsigned long nslabs, bool late_alloc)
> > {
> > + void *vaddr = phys_to_virt(start);
> > unsigned long bytes = nslabs << IO_TLB_SHIFT, i;
> > +
> > + mem->nslabs = nslabs;
> > + mem->start = start;
> > + mem->end = mem->start + bytes;
> > + mem->index = 0;
> > + mem->late_alloc = late_alloc;
> > + spin_lock_init(&mem->lock);
> > + for (i = 0; i < mem->nslabs; i++) {
> > + mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
> > + mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
> > + mem->slots[i].alloc_size = 0;
> > + }
> > +
> > + set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
> > + memset(vaddr, 0, bytes);
>
> You are doing an unconditional set_memory_decrypted() followed by a
> memset here, and then:
>
> > +}
> > +
> > +int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
> > +{
> > struct io_tlb_mem *mem;
> > size_t alloc_size;
> >
> > @@ -186,16 +207,8 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
> > if (!mem)
> > panic("%s: Failed to allocate %zu bytes align=0x%lx\n",
> > __func__, alloc_size, PAGE_SIZE);
> > - mem->nslabs = nslabs;
> > - mem->start = __pa(tlb);
> > - mem->end = mem->start + bytes;
> > - mem->index = 0;
> > - spin_lock_init(&mem->lock);
> > - for (i = 0; i < mem->nslabs; i++) {
> > - mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
> > - mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
> > - mem->slots[i].alloc_size = 0;
> > - }
> > +
> > + swiotlb_init_io_tlb_mem(mem, __pa(tlb), nslabs, false);
>
> You convert this call site with swiotlb_init_io_tlb_mem() which did not
> do the set_memory_decrypted()+memset(). Is this okay or should
> swiotlb_init_io_tlb_mem() add an additional argument to do this
> conditionally?

I'm actually not sure if this it okay. If not, will add an additional
argument for it.

> --
> Florian

2021-05-24 16:02:01

by Konrad Rzeszutek Wilk

[permalink] [raw]
Subject: Re: [PATCH v7 01/15] swiotlb: Refactor swiotlb init functions

> > do the set_memory_decrypted()+memset(). Is this okay or should
> > swiotlb_init_io_tlb_mem() add an additional argument to do this
> > conditionally?
>
> I'm actually not sure if this it okay. If not, will add an additional
> argument for it.

Any observations discovered? (Want to make sure my memory-cache has the
correct semantics for set_memory_decrypted in mind).
>
> > --
> > Florian

2021-05-25 03:18:31

by Claire Chang

[permalink] [raw]
Subject: Re: [PATCH v7 01/15] swiotlb: Refactor swiotlb init functions

On Mon, May 24, 2021 at 11:53 PM Konrad Rzeszutek Wilk
<[email protected]> wrote:
>
> > > do the set_memory_decrypted()+memset(). Is this okay or should
> > > swiotlb_init_io_tlb_mem() add an additional argument to do this
> > > conditionally?
> >
> > I'm actually not sure if this it okay. If not, will add an additional
> > argument for it.
>
> Any observations discovered? (Want to make sure my memory-cache has the
> correct semantics for set_memory_decrypted in mind).

It works fine on my arm64 device.

> >
> > > --
> > > Florian

2021-05-27 13:03:28

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH v7 01/15] swiotlb: Refactor swiotlb init functions

On Wed, May 19, 2021 at 11:50:07AM -0700, Florian Fainelli wrote:
> You convert this call site with swiotlb_init_io_tlb_mem() which did not
> do the set_memory_decrypted()+memset(). Is this okay or should
> swiotlb_init_io_tlb_mem() add an additional argument to do this
> conditionally?

The zeroing is useful and was missing before. I think having a clean
state here is the right thing.

Not sure about the set_memory_decrypted, swiotlb_update_mem_attributes
kinda suggests it is too early to set the memory decrupted.

Adding Tom who should now about all this.

2021-05-27 18:54:21

by Tom Lendacky

[permalink] [raw]
Subject: Re: [PATCH v7 01/15] swiotlb: Refactor swiotlb init functions

On 5/27/21 9:41 AM, Tom Lendacky wrote:
> On 5/27/21 8:02 AM, Christoph Hellwig wrote:
>> On Wed, May 19, 2021 at 11:50:07AM -0700, Florian Fainelli wrote:
>>> You convert this call site with swiotlb_init_io_tlb_mem() which did not
>>> do the set_memory_decrypted()+memset(). Is this okay or should
>>> swiotlb_init_io_tlb_mem() add an additional argument to do this
>>> conditionally?
>>
>> The zeroing is useful and was missing before. I think having a clean
>> state here is the right thing.
>>
>> Not sure about the set_memory_decrypted, swiotlb_update_mem_attributes
>> kinda suggests it is too early to set the memory decrupted.
>>
>> Adding Tom who should now about all this.
>
> The reason for adding swiotlb_update_mem_attributes() was because having
> the call to set_memory_decrypted() in swiotlb_init_with_tbl() triggered a
> BUG_ON() related to interrupts not being enabled yet during boot. So that
> call had to be delayed until interrupts were enabled.

I pulled down and tested the patch set and booted with SME enabled. The
following was seen during the boot:

[ 0.134184] BUG: Bad page state in process swapper pfn:108002
[ 0.134196] page:(____ptrval____) refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 pfn:0x108002
[ 0.134201] flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff)
[ 0.134208] raw: 0017ffffc0000000 ffff88847f355e28 ffff88847f355e28 0000000000000000
[ 0.134210] raw: 0000000000000000 0000000000000001 00000000ffffff7f 0000000000000000
[ 0.134212] page dumped because: nonzero mapcount
[ 0.134213] Modules linked in:
[ 0.134218] CPU: 0 PID: 0 Comm: swapper Not tainted 5.13.0-rc2-sos-custom #3
[ 0.134221] Hardware name: ...
[ 0.134224] Call Trace:
[ 0.134233] dump_stack+0x76/0x94
[ 0.134244] bad_page+0xa6/0xf0
[ 0.134252] __free_pages_ok+0x331/0x360
[ 0.134256] memblock_free_all+0x158/0x1c1
[ 0.134267] mem_init+0x1f/0x14c
[ 0.134273] start_kernel+0x290/0x574
[ 0.134279] secondary_startup_64_no_verify+0xb0/0xbb

I see this about 40 times during the boot, each with a different PFN. The
system boots (which seemed odd), but I don't know if there will be side
effects to this (I didn't stress the system).

I modified the code to add a flag to not do the set_memory_decrypted(), as
suggested by Florian, when invoked from swiotlb_init_with_tbl(), and that
eliminated the bad page state BUG.

Thanks,
Tom

>
> Thanks,
> Tom
>
>>

2021-05-27 22:03:49

by Tom Lendacky

[permalink] [raw]
Subject: Re: [PATCH v7 01/15] swiotlb: Refactor swiotlb init functions

On 5/27/21 8:02 AM, Christoph Hellwig wrote:
> On Wed, May 19, 2021 at 11:50:07AM -0700, Florian Fainelli wrote:
>> You convert this call site with swiotlb_init_io_tlb_mem() which did not
>> do the set_memory_decrypted()+memset(). Is this okay or should
>> swiotlb_init_io_tlb_mem() add an additional argument to do this
>> conditionally?
>
> The zeroing is useful and was missing before. I think having a clean
> state here is the right thing.
>
> Not sure about the set_memory_decrypted, swiotlb_update_mem_attributes
> kinda suggests it is too early to set the memory decrupted.
>
> Adding Tom who should now about all this.

The reason for adding swiotlb_update_mem_attributes() was because having
the call to set_memory_decrypted() in swiotlb_init_with_tbl() triggered a
BUG_ON() related to interrupts not being enabled yet during boot. So that
call had to be delayed until interrupts were enabled.

Thanks,
Tom

>

2021-05-31 17:07:04

by Claire Chang

[permalink] [raw]
Subject: Re: [PATCH v7 01/15] swiotlb: Refactor swiotlb init functions

On Fri, May 28, 2021 at 12:32 AM Tom Lendacky <[email protected]> wrote:
>
> On 5/27/21 9:41 AM, Tom Lendacky wrote:
> > On 5/27/21 8:02 AM, Christoph Hellwig wrote:
> >> On Wed, May 19, 2021 at 11:50:07AM -0700, Florian Fainelli wrote:
> >>> You convert this call site with swiotlb_init_io_tlb_mem() which did not
> >>> do the set_memory_decrypted()+memset(). Is this okay or should
> >>> swiotlb_init_io_tlb_mem() add an additional argument to do this
> >>> conditionally?
> >>
> >> The zeroing is useful and was missing before. I think having a clean
> >> state here is the right thing.
> >>
> >> Not sure about the set_memory_decrypted, swiotlb_update_mem_attributes
> >> kinda suggests it is too early to set the memory decrupted.
> >>
> >> Adding Tom who should now about all this.
> >
> > The reason for adding swiotlb_update_mem_attributes() was because having
> > the call to set_memory_decrypted() in swiotlb_init_with_tbl() triggered a
> > BUG_ON() related to interrupts not being enabled yet during boot. So that
> > call had to be delayed until interrupts were enabled.
>
> I pulled down and tested the patch set and booted with SME enabled. The
> following was seen during the boot:
>
> [ 0.134184] BUG: Bad page state in process swapper pfn:108002
> [ 0.134196] page:(____ptrval____) refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0 pfn:0x108002
> [ 0.134201] flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff)
> [ 0.134208] raw: 0017ffffc0000000 ffff88847f355e28 ffff88847f355e28 0000000000000000
> [ 0.134210] raw: 0000000000000000 0000000000000001 00000000ffffff7f 0000000000000000
> [ 0.134212] page dumped because: nonzero mapcount
> [ 0.134213] Modules linked in:
> [ 0.134218] CPU: 0 PID: 0 Comm: swapper Not tainted 5.13.0-rc2-sos-custom #3
> [ 0.134221] Hardware name: ...
> [ 0.134224] Call Trace:
> [ 0.134233] dump_stack+0x76/0x94
> [ 0.134244] bad_page+0xa6/0xf0
> [ 0.134252] __free_pages_ok+0x331/0x360
> [ 0.134256] memblock_free_all+0x158/0x1c1
> [ 0.134267] mem_init+0x1f/0x14c
> [ 0.134273] start_kernel+0x290/0x574
> [ 0.134279] secondary_startup_64_no_verify+0xb0/0xbb
>
> I see this about 40 times during the boot, each with a different PFN. The
> system boots (which seemed odd), but I don't know if there will be side
> effects to this (I didn't stress the system).
>
> I modified the code to add a flag to not do the set_memory_decrypted(), as
> suggested by Florian, when invoked from swiotlb_init_with_tbl(), and that
> eliminated the bad page state BUG.

Thanks. Will add a flag to skip set_memory_decrypted() in v9.

>
> Thanks,
> Tom
>
> >
> > Thanks,
> > Tom
> >
> >>