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From: Tom Lendacky <thomas.lendacky@amd.com>
To: Claire Chang <tientzu@chromium.org>,
	Stefano Stabellini <sstabellini@kernel.org>
Cc: Rob Herring <robh+dt@kernel.org>,
	mpe@ellerman.id.au, Joerg Roedel <joro@8bytes.org>,
	Will Deacon <will@kernel.org>,
	Frank Rowand <frowand.list@gmail.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	boris.ostrovsky@oracle.com, jgross@suse.com,
	Christoph Hellwig <hch@lst.de>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	benh@kernel.crashing.org, paulus@samba.org,
	"list@263.net:IOMMU DRIVERS" <iommu@lists.linux-foundation.org>,
	Robin Murphy <robin.murphy@arm.com>,
	grant.likely@arm.com, xypron.glpk@gmx.de,
	Thierry Reding <treding@nvidia.com>,
	mingo@kernel.org, bauerman@linux.ibm.com, peterz@infradead.org,
	Greg KH <gregkh@linuxfoundation.org>,
	Saravana Kannan <saravanak@google.com>,
	"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
	heikki.krogerus@linux.intel.com,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Randy Dunlap <rdunlap@infradead.org>,
	Dan Williams <dan.j.williams@intel.com>,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>,
	linux-devicetree <devicetree@vger.kernel.org>,
	lkml <linux-kernel@vger.kernel.org>,
	linuxppc-dev@lists.ozlabs.org, xen-devel@lists.xenproject.org,
	Nicolas Boichat <drinkcat@chromium.org>,
	Jim Quinlan <james.quinlan@broadcom.com>,
	Tomasz Figa <tfiga@chromium.org>,
	bskeggs@redhat.com, Bjorn Helgaas <bhelgaas@google.com>,
	chris@chris-wilson.co.uk, Daniel Vetter <daniel@ffwll.ch>,
	airlied@linux.ie, dri-devel@lists.freedesktop.org,
	intel-gfx@lists.freedesktop.org, jani.nikula@linux.intel.com,
	Jianxiong Gao <jxgao@google.com>,
	joonas.lahtinen@linux.intel.com, linux-pci@vger.kernel.org,
	maarten.lankhorst@linux.intel.com, matthew.auld@intel.com,
	rodrigo.vivi@intel.com, thomas.hellstrom@linux.intel.com
Subject: Re: [PATCH v13 01/12] swiotlb: Refactor swiotlb init functions
Date: Fri, 18 Jun 2021 09:09:17 -0500	[thread overview]
Message-ID: <741a34cc-547c-984d-8af4-2f309880acfa@amd.com> (raw)
In-Reply-To: <CALiNf29SJ0jXirWVDhJw4BUNvkjUeGPyGNJK9m8c30OPX41=5Q@mail.gmail.com>

On 6/18/21 1:25 AM, Claire Chang wrote:
> On Fri, Jun 18, 2021 at 7:30 AM Stefano Stabellini
> <sstabellini@kernel.org> wrote:
>>
>> On Thu, 17 Jun 2021, Claire Chang wrote:
>>> Add a new function, swiotlb_init_io_tlb_mem, for the io_tlb_mem struct
>>> initialization to make the code reusable.
>>>
>>> Signed-off-by: Claire Chang <tientzu@chromium.org>
>>> Reviewed-by: Christoph Hellwig <hch@lst.de>
>>> Tested-by: Stefano Stabellini <sstabellini@kernel.org>
>>> Tested-by: Will Deacon <will@kernel.org>
>>> ---
>>>  kernel/dma/swiotlb.c | 50 ++++++++++++++++++++++----------------------
>>>  1 file changed, 25 insertions(+), 25 deletions(-)
>>>
>>> diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
>>> index 52e2ac526757..47bb2a766798 100644
>>> --- a/kernel/dma/swiotlb.c
>>> +++ b/kernel/dma/swiotlb.c
>>> @@ -168,9 +168,28 @@ 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;
>>> +     }
>>> +     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 +205,8 @@ 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)
>>> @@ -282,8 +293,8 @@ 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;
>>> +     unsigned long bytes = nslabs << IO_TLB_SHIFT;
>>>
>>>       if (swiotlb_force == SWIOTLB_NO_FORCE)
>>>               return 0;
>>> @@ -297,20 +308,9 @@ 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;
>>> -     }
>>> -
>>> +     memset(mem, 0, sizeof(*mem));
>>> +     swiotlb_init_io_tlb_mem(mem, virt_to_phys(tlb), nslabs, true);
>>>       set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT);
>>> -     memset(tlb, 0, bytes);
>>
>> This is good for swiotlb_late_init_with_tbl. However I have just noticed
>> that mem could also be allocated from swiotlb_init_with_tbl, in which
>> case the zeroing is missing. I think we need another memset in
>> swiotlb_init_with_tbl as well. Or maybe it could be better to have a
>> single memset at the beginning of swiotlb_init_io_tlb_mem instead. Up to
>> you.
> 
> swiotlb_init_with_tbl uses memblock_alloc to allocate the io_tlb_mem
> and memblock_alloc[1] will do memset in memblock_alloc_try_nid[2], so
> swiotlb_init_with_tbl is also good.
> I'm happy to add the memset in swiotlb_init_io_tlb_mem if you think
> it's clearer and safer.

On x86, if the memset is done before set_memory_decrypted() and memory
encryption is active, then the memory will look like ciphertext afterwards
and not be zeroes. If zeroed memory is required, then a memset must be
done after the set_memory_decrypted() calls.

Thanks,
Tom

> 
> [1] https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir.bootlin.com%2Flinux%2Fv5.13-rc6%2Fsource%2Finclude%2Flinux%2Fmemblock.h%23L407&amp;data=04%7C01%7Cthomas.lendacky%40amd.com%7C3e33e04212b84f9e4ed108d932230511%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637595948355050693%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=TGBDj18KuSHTb45EBz%2Bypfbr4Xgqb1aGTRDCTIpIgJo%3D&amp;reserved=0
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> 

WARNING: multiple messages have this Message-ID
From: Tom Lendacky <thomas.lendacky@amd.com>
To: Claire Chang <tientzu@chromium.org>,
	Stefano Stabellini <sstabellini@kernel.org>
Cc: heikki.krogerus@linux.intel.com,
	thomas.hellstrom@linux.intel.com, peterz@infradead.org,
	joonas.lahtinen@linux.intel.com, dri-devel@lists.freedesktop.org,
	chris@chris-wilson.co.uk, grant.likely@arm.com, paulus@samba.org,
	Frank Rowand <frowand.list@gmail.com>,
	mingo@kernel.org, Marek Szyprowski <m.szyprowski@samsung.com>,
	Nicolas Boichat <drinkcat@chromium.org>,
	Saravana Kannan <saravanak@google.com>,
	Joerg Roedel <joro@8bytes.org>,
	"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
	Christoph Hellwig <hch@lst.de>,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>,
	bskeggs@redhat.com, linux-pci@vger.kernel.org,
	xen-devel@lists.xenproject.org,
	Thierry Reding <treding@nvidia.com>,
	intel-gfx@lists.freedesktop.org, matthew.auld@intel.com,
	linux-devicetree <devicetree@vger.kernel.org>,
	Jianxiong Gao <jxgao@google.com>, Daniel Vetter <daniel@ffwll.ch>,
	Will Deacon <will@kernel.org>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	maarten.lankhorst@linux.intel.com, airlied@linux.ie,
	Dan Williams <dan.j.williams@intel.com>,
	linuxppc-dev@lists.ozlabs.org, jani.nikula@linux.intel.com,
	Rob Herring <robh+dt@kernel.org>,
	rodrigo.vivi@intel.com, Bjorn Helgaas <bhelgaas@google.com>,
	boris.ostrovsky@oracle.com,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	jgross@suse.com, Greg KH <gregkh@linuxfoundation.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	lkml <linux-kernel@vger.kernel.org>,
	Tomasz Figa <tfiga@chromium.org>,
	"list@263.net:IOMMU DRIVERS" <iommu@lists.linux-foundation.org>,
	Jim Quinlan <james.quinlan@broadcom.com>,
	xypron.glpk@gmx.de, Robin Murphy <robin.murphy@arm.com>,
	bauerman@linux.ibm.com
Subject: Re: [PATCH v13 01/12] swiotlb: Refactor swiotlb init functions
Date: Fri, 18 Jun 2021 09:09:17 -0500	[thread overview]
Message-ID: <741a34cc-547c-984d-8af4-2f309880acfa@amd.com> (raw)
In-Reply-To: <CALiNf29SJ0jXirWVDhJw4BUNvkjUeGPyGNJK9m8c30OPX41=5Q@mail.gmail.com>

On 6/18/21 1:25 AM, Claire Chang wrote:
> On Fri, Jun 18, 2021 at 7:30 AM Stefano Stabellini
> <sstabellini@kernel.org> wrote:
>>
>> On Thu, 17 Jun 2021, Claire Chang wrote:
>>> Add a new function, swiotlb_init_io_tlb_mem, for the io_tlb_mem struct
>>> initialization to make the code reusable.
>>>
>>> Signed-off-by: Claire Chang <tientzu@chromium.org>
>>> Reviewed-by: Christoph Hellwig <hch@lst.de>
>>> Tested-by: Stefano Stabellini <sstabellini@kernel.org>
>>> Tested-by: Will Deacon <will@kernel.org>
>>> ---
>>>  kernel/dma/swiotlb.c | 50 ++++++++++++++++++++++----------------------
>>>  1 file changed, 25 insertions(+), 25 deletions(-)
>>>
>>> diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
>>> index 52e2ac526757..47bb2a766798 100644
>>> --- a/kernel/dma/swiotlb.c
>>> +++ b/kernel/dma/swiotlb.c
>>> @@ -168,9 +168,28 @@ 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;
>>> +     }
>>> +     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 +205,8 @@ 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)
>>> @@ -282,8 +293,8 @@ 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;
>>> +     unsigned long bytes = nslabs << IO_TLB_SHIFT;
>>>
>>>       if (swiotlb_force == SWIOTLB_NO_FORCE)
>>>               return 0;
>>> @@ -297,20 +308,9 @@ 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;
>>> -     }
>>> -
>>> +     memset(mem, 0, sizeof(*mem));
>>> +     swiotlb_init_io_tlb_mem(mem, virt_to_phys(tlb), nslabs, true);
>>>       set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT);
>>> -     memset(tlb, 0, bytes);
>>
>> This is good for swiotlb_late_init_with_tbl. However I have just noticed
>> that mem could also be allocated from swiotlb_init_with_tbl, in which
>> case the zeroing is missing. I think we need another memset in
>> swiotlb_init_with_tbl as well. Or maybe it could be better to have a
>> single memset at the beginning of swiotlb_init_io_tlb_mem instead. Up to
>> you.
> 
> swiotlb_init_with_tbl uses memblock_alloc to allocate the io_tlb_mem
> and memblock_alloc[1] will do memset in memblock_alloc_try_nid[2], so
> swiotlb_init_with_tbl is also good.
> I'm happy to add the memset in swiotlb_init_io_tlb_mem if you think
> it's clearer and safer.

On x86, if the memset is done before set_memory_decrypted() and memory
encryption is active, then the memory will look like ciphertext afterwards
and not be zeroes. If zeroed memory is required, then a memset must be
done after the set_memory_decrypted() calls.

Thanks,
Tom

> 
> [1] https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir.bootlin.com%2Flinux%2Fv5.13-rc6%2Fsource%2Finclude%2Flinux%2Fmemblock.h%23L407&amp;data=04%7C01%7Cthomas.lendacky%40amd.com%7C3e33e04212b84f9e4ed108d932230511%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637595948355050693%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=TGBDj18KuSHTb45EBz%2Bypfbr4Xgqb1aGTRDCTIpIgJo%3D&amp;reserved=0
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WARNING: multiple messages have this Message-ID
From: Tom Lendacky via iommu <iommu@lists.linux-foundation.org>
To: Claire Chang <tientzu@chromium.org>,
	Stefano Stabellini <sstabellini@kernel.org>
Cc: heikki.krogerus@linux.intel.com,
	thomas.hellstrom@linux.intel.com, peterz@infradead.org,
	benh@kernel.crashing.org, joonas.lahtinen@linux.intel.com,
	dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk,
	grant.likely@arm.com, paulus@samba.org,
	Frank Rowand <frowand.list@gmail.com>,
	mingo@kernel.org, Nicolas Boichat <drinkcat@chromium.org>,
	Saravana Kannan <saravanak@google.com>,
	mpe@ellerman.id.au,
	"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
	Christoph Hellwig <hch@lst.de>,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>,
	bskeggs@redhat.com, linux-pci@vger.kernel.org,
	xen-devel@lists.xenproject.org,
	Thierry Reding <treding@nvidia.com>,
	intel-gfx@lists.freedesktop.org, matthew.auld@intel.com,
	linux-devicetree <devicetree@vger.kernel.org>,
	Jianxiong Gao <jxgao@google.com>, Daniel Vetter <daniel@ffwll.ch>,
	Will Deacon <will@kernel.org>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	maarten.lankhorst@linux.intel.com, airlied@linux.ie,
	Dan Williams <dan.j.williams@intel.com>,
	linuxppc-dev@lists.ozlabs.org, jani.nikula@linux.intel.com,
	Rob Herring <robh+dt@kernel.org>,
	rodrigo.vivi@intel.com, Bjorn Helgaas <bhelgaas@google.com>,
	boris.ostrovsky@oracle.com,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	jgross@suse.com, Greg KH <gregkh@linuxfoundation.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	lkml <linux-kernel@vger.kernel.org>,
	"list@263.net:IOMMU DRIVERS" <iommu@lists.linux-foundation.org>,
	Jim Quinlan <james.quinlan@broadcom.com>,
	xypron.glpk@gmx.de, Robin Murphy <robin.murphy@arm.com>,
	bauerman@linux.ibm.com
Subject: Re: [PATCH v13 01/12] swiotlb: Refactor swiotlb init functions
Date: Fri, 18 Jun 2021 09:09:17 -0500	[thread overview]
Message-ID: <741a34cc-547c-984d-8af4-2f309880acfa@amd.com> (raw)
In-Reply-To: <CALiNf29SJ0jXirWVDhJw4BUNvkjUeGPyGNJK9m8c30OPX41=5Q@mail.gmail.com>

On 6/18/21 1:25 AM, Claire Chang wrote:
> On Fri, Jun 18, 2021 at 7:30 AM Stefano Stabellini
> <sstabellini@kernel.org> wrote:
>>
>> On Thu, 17 Jun 2021, Claire Chang wrote:
>>> Add a new function, swiotlb_init_io_tlb_mem, for the io_tlb_mem struct
>>> initialization to make the code reusable.
>>>
>>> Signed-off-by: Claire Chang <tientzu@chromium.org>
>>> Reviewed-by: Christoph Hellwig <hch@lst.de>
>>> Tested-by: Stefano Stabellini <sstabellini@kernel.org>
>>> Tested-by: Will Deacon <will@kernel.org>
>>> ---
>>>  kernel/dma/swiotlb.c | 50 ++++++++++++++++++++++----------------------
>>>  1 file changed, 25 insertions(+), 25 deletions(-)
>>>
>>> diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
>>> index 52e2ac526757..47bb2a766798 100644
>>> --- a/kernel/dma/swiotlb.c
>>> +++ b/kernel/dma/swiotlb.c
>>> @@ -168,9 +168,28 @@ 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;
>>> +     }
>>> +     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 +205,8 @@ 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)
>>> @@ -282,8 +293,8 @@ 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;
>>> +     unsigned long bytes = nslabs << IO_TLB_SHIFT;
>>>
>>>       if (swiotlb_force == SWIOTLB_NO_FORCE)
>>>               return 0;
>>> @@ -297,20 +308,9 @@ 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;
>>> -     }
>>> -
>>> +     memset(mem, 0, sizeof(*mem));
>>> +     swiotlb_init_io_tlb_mem(mem, virt_to_phys(tlb), nslabs, true);
>>>       set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT);
>>> -     memset(tlb, 0, bytes);
>>
>> This is good for swiotlb_late_init_with_tbl. However I have just noticed
>> that mem could also be allocated from swiotlb_init_with_tbl, in which
>> case the zeroing is missing. I think we need another memset in
>> swiotlb_init_with_tbl as well. Or maybe it could be better to have a
>> single memset at the beginning of swiotlb_init_io_tlb_mem instead. Up to
>> you.
> 
> swiotlb_init_with_tbl uses memblock_alloc to allocate the io_tlb_mem
> and memblock_alloc[1] will do memset in memblock_alloc_try_nid[2], so
> swiotlb_init_with_tbl is also good.
> I'm happy to add the memset in swiotlb_init_io_tlb_mem if you think
> it's clearer and safer.

On x86, if the memset is done before set_memory_decrypted() and memory
encryption is active, then the memory will look like ciphertext afterwards
and not be zeroes. If zeroed memory is required, then a memset must be
done after the set_memory_decrypted() calls.

Thanks,
Tom

> 
> [1] https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir.bootlin.com%2Flinux%2Fv5.13-rc6%2Fsource%2Finclude%2Flinux%2Fmemblock.h%23L407&amp;data=04%7C01%7Cthomas.lendacky%40amd.com%7C3e33e04212b84f9e4ed108d932230511%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637595948355050693%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=TGBDj18KuSHTb45EBz%2Bypfbr4Xgqb1aGTRDCTIpIgJo%3D&amp;reserved=0
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WARNING: multiple messages have this Message-ID
From: Tom Lendacky <thomas.lendacky@amd.com>
To: Claire Chang <tientzu@chromium.org>,
	Stefano Stabellini <sstabellini@kernel.org>
Cc: heikki.krogerus@linux.intel.com,
	thomas.hellstrom@linux.intel.com, peterz@infradead.org,
	dri-devel@lists.freedesktop.org, chris@chris-wilson.co.uk,
	grant.likely@arm.com, paulus@samba.org,
	Frank Rowand <frowand.list@gmail.com>,
	mingo@kernel.org, Marek Szyprowski <m.szyprowski@samsung.com>,
	Nicolas Boichat <drinkcat@chromium.org>,
	Saravana Kannan <saravanak@google.com>,
	mpe@ellerman.id.au, Joerg Roedel <joro@8bytes.org>,
	"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
	Christoph Hellwig <hch@lst.de>,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>,
	bskeggs@redhat.com, linux-pci@vger.kernel.org,
	xen-devel@lists.xenproject.org,
	Thierry Reding <treding@nvidia.com>,
	intel-gfx@lists.freedesktop.org, matthew.auld@intel.com,
	linux-devicetree <devicetree@vger.kernel.org>,
	Jianxiong Gao <jxgao@google.com>, Will Deacon <will@kernel.org>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	airlied@linux.ie, Dan Williams <dan.j.williams@intel.com>,
	linuxppc-dev@lists.ozlabs.org, Rob Herring <robh+dt@kernel.org>,
	rodrigo.vivi@intel.com, Bjorn Helgaas <bhelgaas@google.com>,
	boris.ostrovsky@oracle.com,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	jgross@suse.com, Greg KH <gregkh@linuxfoundation.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	lkml <linux-kernel@vger.kernel.org>,
	Tomasz Figa <tfiga@chromium.org>,
	"list@263.net:IOMMU DRIVERS" <iommu@lists.linux-foundation.org>,
	Jim Quinlan <james.quinlan@broadcom.com>,
	xypron.glpk@gmx.de, Robin Murphy <robin.murphy@arm.com>,
	bauerman@linux.ibm.com
Subject: Re: [PATCH v13 01/12] swiotlb: Refactor swiotlb init functions
Date: Fri, 18 Jun 2021 09:09:17 -0500	[thread overview]
Message-ID: <741a34cc-547c-984d-8af4-2f309880acfa@amd.com> (raw)
In-Reply-To: <CALiNf29SJ0jXirWVDhJw4BUNvkjUeGPyGNJK9m8c30OPX41=5Q@mail.gmail.com>

On 6/18/21 1:25 AM, Claire Chang wrote:
> On Fri, Jun 18, 2021 at 7:30 AM Stefano Stabellini
> <sstabellini@kernel.org> wrote:
>>
>> On Thu, 17 Jun 2021, Claire Chang wrote:
>>> Add a new function, swiotlb_init_io_tlb_mem, for the io_tlb_mem struct
>>> initialization to make the code reusable.
>>>
>>> Signed-off-by: Claire Chang <tientzu@chromium.org>
>>> Reviewed-by: Christoph Hellwig <hch@lst.de>
>>> Tested-by: Stefano Stabellini <sstabellini@kernel.org>
>>> Tested-by: Will Deacon <will@kernel.org>
>>> ---
>>>  kernel/dma/swiotlb.c | 50 ++++++++++++++++++++++----------------------
>>>  1 file changed, 25 insertions(+), 25 deletions(-)
>>>
>>> diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
>>> index 52e2ac526757..47bb2a766798 100644
>>> --- a/kernel/dma/swiotlb.c
>>> +++ b/kernel/dma/swiotlb.c
>>> @@ -168,9 +168,28 @@ 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;
>>> +     }
>>> +     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 +205,8 @@ 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)
>>> @@ -282,8 +293,8 @@ 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;
>>> +     unsigned long bytes = nslabs << IO_TLB_SHIFT;
>>>
>>>       if (swiotlb_force == SWIOTLB_NO_FORCE)
>>>               return 0;
>>> @@ -297,20 +308,9 @@ 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;
>>> -     }
>>> -
>>> +     memset(mem, 0, sizeof(*mem));
>>> +     swiotlb_init_io_tlb_mem(mem, virt_to_phys(tlb), nslabs, true);
>>>       set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT);
>>> -     memset(tlb, 0, bytes);
>>
>> This is good for swiotlb_late_init_with_tbl. However I have just noticed
>> that mem could also be allocated from swiotlb_init_with_tbl, in which
>> case the zeroing is missing. I think we need another memset in
>> swiotlb_init_with_tbl as well. Or maybe it could be better to have a
>> single memset at the beginning of swiotlb_init_io_tlb_mem instead. Up to
>> you.
> 
> swiotlb_init_with_tbl uses memblock_alloc to allocate the io_tlb_mem
> and memblock_alloc[1] will do memset in memblock_alloc_try_nid[2], so
> swiotlb_init_with_tbl is also good.
> I'm happy to add the memset in swiotlb_init_io_tlb_mem if you think
> it's clearer and safer.

On x86, if the memset is done before set_memory_decrypted() and memory
encryption is active, then the memory will look like ciphertext afterwards
and not be zeroes. If zeroed memory is required, then a memset must be
done after the set_memory_decrypted() calls.

Thanks,
Tom

> 
> [1] https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir.bootlin.com%2Flinux%2Fv5.13-rc6%2Fsource%2Finclude%2Flinux%2Fmemblock.h%23L407&amp;data=04%7C01%7Cthomas.lendacky%40amd.com%7C3e33e04212b84f9e4ed108d932230511%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637595948355050693%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=TGBDj18KuSHTb45EBz%2Bypfbr4Xgqb1aGTRDCTIpIgJo%3D&amp;reserved=0
> [2] https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir.bootlin.com%2Flinux%2Fv5.13-rc6%2Fsource%2Fmm%2Fmemblock.c%23L1555&amp;data=04%7C01%7Cthomas.lendacky%40amd.com%7C3e33e04212b84f9e4ed108d932230511%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637595948355060689%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=K%2FWbN6iKN9JNtwDSkIaKH2BVLdDTWhn8tPfNdCOVkSA%3D&amp;reserved=0
> 

WARNING: multiple messages have this Message-ID
From: Tom Lendacky <thomas.lendacky@amd.com>
To: Claire Chang <tientzu@chromium.org>,
	Stefano Stabellini <sstabellini@kernel.org>
Cc: heikki.krogerus@linux.intel.com,
	thomas.hellstrom@linux.intel.com, peterz@infradead.org,
	benh@kernel.crashing.org, dri-devel@lists.freedesktop.org,
	chris@chris-wilson.co.uk, grant.likely@arm.com, paulus@samba.org,
	Frank Rowand <frowand.list@gmail.com>,
	mingo@kernel.org, Marek Szyprowski <m.szyprowski@samsung.com>,
	Nicolas Boichat <drinkcat@chromium.org>,
	Saravana Kannan <saravanak@google.com>,
	mpe@ellerman.id.au, Joerg Roedel <joro@8bytes.org>,
	"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
	Christoph Hellwig <hch@lst.de>,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>,
	bskeggs@redhat.com, linux-pci@vger.kernel.org,
	xen-devel@lists.xenproject.org,
	Thierry Reding <treding@nvidia.com>,
	intel-gfx@lists.freedesktop.org, matthew.auld@intel.com,
	linux-devicetree <devicetree@vger.kernel.org>,
	Jianxiong Gao <jxgao@google.com>, Will Deacon <will@kernel.org>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	airlied@linux.ie, Dan Williams <dan.j.williams@intel.com>,
	linuxppc-dev@lists.ozlabs.org, Rob Herring <robh+dt@kernel.org>,
	Bjorn Helgaas <bhelgaas@google.com>,
	boris.ostrovsky@oracle.com,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	jgross@suse.com, Greg KH <gregkh@linuxfoundation.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	lkml <linux-kernel@vger.kernel.org>,
	Tomasz Figa <tfiga@chromium.org>,
	"list@263.net:IOMMU DRIVERS" <iommu@lists.linux-foundation.org>,
	Jim Quinlan <james.quinlan@broadcom.com>,
	xypron.glpk@gmx.de, Robin Murphy <robin.murphy@arm.com>,
	bauerman@linux.ibm.com
Subject: Re: [Intel-gfx] [PATCH v13 01/12] swiotlb: Refactor swiotlb init functions
Date: Fri, 18 Jun 2021 09:09:17 -0500	[thread overview]
Message-ID: <741a34cc-547c-984d-8af4-2f309880acfa@amd.com> (raw)
In-Reply-To: <CALiNf29SJ0jXirWVDhJw4BUNvkjUeGPyGNJK9m8c30OPX41=5Q@mail.gmail.com>

On 6/18/21 1:25 AM, Claire Chang wrote:
> On Fri, Jun 18, 2021 at 7:30 AM Stefano Stabellini
> <sstabellini@kernel.org> wrote:
>>
>> On Thu, 17 Jun 2021, Claire Chang wrote:
>>> Add a new function, swiotlb_init_io_tlb_mem, for the io_tlb_mem struct
>>> initialization to make the code reusable.
>>>
>>> Signed-off-by: Claire Chang <tientzu@chromium.org>
>>> Reviewed-by: Christoph Hellwig <hch@lst.de>
>>> Tested-by: Stefano Stabellini <sstabellini@kernel.org>
>>> Tested-by: Will Deacon <will@kernel.org>
>>> ---
>>>  kernel/dma/swiotlb.c | 50 ++++++++++++++++++++++----------------------
>>>  1 file changed, 25 insertions(+), 25 deletions(-)
>>>
>>> diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
>>> index 52e2ac526757..47bb2a766798 100644
>>> --- a/kernel/dma/swiotlb.c
>>> +++ b/kernel/dma/swiotlb.c
>>> @@ -168,9 +168,28 @@ 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;
>>> +     }
>>> +     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 +205,8 @@ 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)
>>> @@ -282,8 +293,8 @@ 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;
>>> +     unsigned long bytes = nslabs << IO_TLB_SHIFT;
>>>
>>>       if (swiotlb_force == SWIOTLB_NO_FORCE)
>>>               return 0;
>>> @@ -297,20 +308,9 @@ 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;
>>> -     }
>>> -
>>> +     memset(mem, 0, sizeof(*mem));
>>> +     swiotlb_init_io_tlb_mem(mem, virt_to_phys(tlb), nslabs, true);
>>>       set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT);
>>> -     memset(tlb, 0, bytes);
>>
>> This is good for swiotlb_late_init_with_tbl. However I have just noticed
>> that mem could also be allocated from swiotlb_init_with_tbl, in which
>> case the zeroing is missing. I think we need another memset in
>> swiotlb_init_with_tbl as well. Or maybe it could be better to have a
>> single memset at the beginning of swiotlb_init_io_tlb_mem instead. Up to
>> you.
> 
> swiotlb_init_with_tbl uses memblock_alloc to allocate the io_tlb_mem
> and memblock_alloc[1] will do memset in memblock_alloc_try_nid[2], so
> swiotlb_init_with_tbl is also good.
> I'm happy to add the memset in swiotlb_init_io_tlb_mem if you think
> it's clearer and safer.

On x86, if the memset is done before set_memory_decrypted() and memory
encryption is active, then the memory will look like ciphertext afterwards
and not be zeroes. If zeroed memory is required, then a memset must be
done after the set_memory_decrypted() calls.

Thanks,
Tom

> 
> [1] https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir.bootlin.com%2Flinux%2Fv5.13-rc6%2Fsource%2Finclude%2Flinux%2Fmemblock.h%23L407&amp;data=04%7C01%7Cthomas.lendacky%40amd.com%7C3e33e04212b84f9e4ed108d932230511%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637595948355050693%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=TGBDj18KuSHTb45EBz%2Bypfbr4Xgqb1aGTRDCTIpIgJo%3D&amp;reserved=0
> [2] https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Felixir.bootlin.com%2Flinux%2Fv5.13-rc6%2Fsource%2Fmm%2Fmemblock.c%23L1555&amp;data=04%7C01%7Cthomas.lendacky%40amd.com%7C3e33e04212b84f9e4ed108d932230511%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637595948355060689%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=K%2FWbN6iKN9JNtwDSkIaKH2BVLdDTWhn8tPfNdCOVkSA%3D&amp;reserved=0
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  reply	other threads:[~2021-06-18 14:09 UTC|newest]

Thread overview: 139+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-17  6:26 [PATCH v13 00/12] Restricted DMA Claire Chang
2021-06-17  6:26 ` [Intel-gfx] " Claire Chang
2021-06-17  6:26 ` Claire Chang
2021-06-17  6:26 ` Claire Chang
2021-06-17  6:26 ` Claire Chang
2021-06-17  6:26 ` [PATCH v13 01/12] swiotlb: Refactor swiotlb init functions Claire Chang
2021-06-17  6:26   ` [Intel-gfx] " Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17 23:30   ` Stefano Stabellini
2021-06-17 23:30     ` Stefano Stabellini
2021-06-17 23:30     ` [Intel-gfx] " Stefano Stabellini
2021-06-17 23:30     ` Stefano Stabellini
2021-06-17 23:30     ` Stefano Stabellini
2021-06-17 23:30     ` Stefano Stabellini
2021-06-18  6:25     ` Claire Chang
2021-06-18  6:25       ` Claire Chang
2021-06-18  6:25       ` [Intel-gfx] " Claire Chang
2021-06-18  6:25       ` Claire Chang
2021-06-18  6:25       ` Claire Chang
2021-06-18  6:25       ` Claire Chang
2021-06-18 14:09       ` Tom Lendacky [this message]
2021-06-18 14:09         ` [Intel-gfx] " Tom Lendacky
2021-06-18 14:09         ` Tom Lendacky
2021-06-18 14:09         ` Tom Lendacky via iommu
2021-06-18 14:09         ` Tom Lendacky
2021-06-18 14:32         ` Christoph Hellwig
2021-06-18 14:32           ` [Intel-gfx] " Christoph Hellwig
2021-06-18 14:32           ` Christoph Hellwig
2021-06-18 14:32           ` Christoph Hellwig
2021-06-21 17:59           ` Stefano Stabellini
2021-06-21 17:59             ` Stefano Stabellini
2021-06-21 17:59             ` [Intel-gfx] " Stefano Stabellini
2021-06-21 17:59             ` Stefano Stabellini
2021-06-21 17:59             ` Stefano Stabellini
2021-06-21 17:59             ` Stefano Stabellini
2021-06-21 20:19             ` Christoph Hellwig
2021-06-21 20:19               ` [Intel-gfx] " Christoph Hellwig
2021-06-21 20:19               ` Christoph Hellwig
2021-06-21 20:19               ` Christoph Hellwig
2021-06-17  6:26 ` [PATCH v13 02/12] swiotlb: Refactor swiotlb_create_debugfs Claire Chang
2021-06-17  6:26   ` [Intel-gfx] " Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26 ` [PATCH v13 03/12] swiotlb: Set dev->dma_io_tlb_mem to the swiotlb pool used Claire Chang
2021-06-17  6:26   ` [Intel-gfx] " Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17 23:30   ` Stefano Stabellini
2021-06-17 23:30     ` Stefano Stabellini
2021-06-17 23:30     ` [Intel-gfx] " Stefano Stabellini
2021-06-17 23:30     ` Stefano Stabellini
2021-06-17 23:30     ` Stefano Stabellini
2021-06-17 23:30     ` Stefano Stabellini
2021-06-17  6:26 ` [PATCH v13 04/12] swiotlb: Update is_swiotlb_buffer to add a struct device argument Claire Chang
2021-06-17  6:26   ` [Intel-gfx] " Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17 23:30   ` Stefano Stabellini
2021-06-17 23:30     ` Stefano Stabellini
2021-06-17 23:30     ` [Intel-gfx] " Stefano Stabellini
2021-06-17 23:30     ` Stefano Stabellini
2021-06-17 23:30     ` Stefano Stabellini
2021-06-17 23:30     ` Stefano Stabellini
2021-06-17  6:26 ` [PATCH v13 05/12] swiotlb: Update is_swiotlb_active " Claire Chang
2021-06-17  6:26   ` [Intel-gfx] " Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17 23:30   ` Stefano Stabellini
2021-06-17 23:30     ` Stefano Stabellini
2021-06-17 23:30     ` [Intel-gfx] " Stefano Stabellini
2021-06-17 23:30     ` Stefano Stabellini
2021-06-17 23:30     ` Stefano Stabellini
2021-06-17 23:30     ` Stefano Stabellini
2021-06-17  6:26 ` [PATCH v13 06/12] swiotlb: Use is_swiotlb_force_bounce for swiotlb data bouncing Claire Chang
2021-06-17  6:26   ` [Intel-gfx] " Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17 23:31   ` Stefano Stabellini
2021-06-17 23:31     ` Stefano Stabellini
2021-06-17 23:31     ` [Intel-gfx] " Stefano Stabellini
2021-06-17 23:31     ` Stefano Stabellini
2021-06-17 23:31     ` Stefano Stabellini
2021-06-17 23:31     ` Stefano Stabellini
2021-06-17  6:26 ` [PATCH v13 07/12] swiotlb: Move alloc_size to swiotlb_find_slots Claire Chang
2021-06-17  6:26   ` [Intel-gfx] " Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26 ` [PATCH v13 08/12] swiotlb: Refactor swiotlb_tbl_unmap_single Claire Chang
2021-06-17  6:26   ` [Intel-gfx] " Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26 ` [PATCH v13 09/12] swiotlb: Add restricted DMA alloc/free support Claire Chang
2021-06-17  6:26   ` [Intel-gfx] " Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17 23:31   ` Stefano Stabellini
2021-06-17 23:31     ` Stefano Stabellini
2021-06-17 23:31     ` [Intel-gfx] " Stefano Stabellini
2021-06-17 23:31     ` Stefano Stabellini
2021-06-17 23:31     ` Stefano Stabellini
2021-06-17 23:31     ` Stefano Stabellini
2021-06-17  6:26 ` [PATCH v13 10/12] swiotlb: Add restricted DMA pool initialization Claire Chang
2021-06-17  6:26   ` [Intel-gfx] " Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26 ` [PATCH v13 11/12] dt-bindings: of: Add restricted DMA pool Claire Chang
2021-06-17  6:26   ` [Intel-gfx] " Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26 ` [PATCH v13 12/12] of: Add plumbing for " Claire Chang
2021-06-17  6:26   ` [Intel-gfx] " Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:26   ` Claire Chang
2021-06-17  6:32 ` [PATCH v13 00/12] Restricted DMA Claire Chang
2021-06-17  6:32   ` Claire Chang
2021-06-17  6:32   ` [Intel-gfx] " Claire Chang
2021-06-17  6:32   ` Claire Chang
2021-06-17  6:32   ` Claire Chang
2021-06-17  6:32   ` Claire Chang
2021-06-19  3:43   ` Claire Chang
2021-06-19  3:43     ` Claire Chang
2021-06-19  3:43     ` [Intel-gfx] " Claire Chang
2021-06-19  3:43     ` Claire Chang
2021-06-19  3:43     ` Claire Chang
2021-06-19  3:43     ` Claire Chang
2021-06-17  6:33 ` [Intel-gfx] ✗ Fi.CI.BUILD: failure for " Patchwork

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