Re: [Qemu-devel] [PATCH for-4.2 v10 08/15] virtio-iommu: Implement map/unmap
On Wed, Sep 04, 2019 at 09:54:12AM +0200, Auger Eric wrote:
> Hi,
>
> On 9/4/19 7:46 AM, Tian, Kevin wrote:
> >> From: Peter Xu [mailto:pet...@redhat.com]
> >> Sent: Wednesday, September 4, 2019 1:37 PM
> >>
> >> On Wed, Sep 04, 2019 at 04:23:50AM +, Tian, Kevin wrote:
> From: Peter Xu [mailto:pet...@redhat.com]
> Sent: Wednesday, September 4, 2019 9:44 AM
>
> On Tue, Sep 03, 2019 at 01:37:11PM +0200, Auger Eric wrote:
> > Hi Peter,
> >
> > On 8/19/19 10:11 AM, Peter Xu wrote:
> >> On Tue, Jul 30, 2019 at 07:21:30PM +0200, Eric Auger wrote:
> >>
> >> [...]
> >>
> >>> +mapping = g_tree_lookup(domain->mappings,
> >> (gpointer)());
> >>> +
> >>> +while (mapping) {
> >>> +viommu_interval current;
> >>> +uint64_t low = mapping->virt_addr;
> >>> +uint64_t high = mapping->virt_addr + mapping->size - 1;
> >>> +
> >>> +current.low = low;
> >>> +current.high = high;
> >>> +
> >>> +if (low == interval.low && size >= mapping->size) {
> >>> +g_tree_remove(domain->mappings, (gpointer)());
> >>> +interval.low = high + 1;
> >>> +trace_virtio_iommu_unmap_left_interval(current.low,
> current.high,
> >>> +interval.low, interval.high);
> >>> +} else if (high == interval.high && size >= mapping->size) {
> >>> +trace_virtio_iommu_unmap_right_interval(current.low,
> current.high,
> >>> +interval.low, interval.high);
> >>> +g_tree_remove(domain->mappings, (gpointer)());
> >>> +interval.high = low - 1;
> >>> +} else if (low > interval.low && high < interval.high) {
> >>> +trace_virtio_iommu_unmap_inc_interval(current.low,
> current.high);
> >>> +g_tree_remove(domain->mappings, (gpointer)());
> >>> +} else {
> >>> +break;
> >>> +}
> >>> +if (interval.low >= interval.high) {
> >>> +return VIRTIO_IOMMU_S_OK;
> >>> +} else {
> >>> +mapping = g_tree_lookup(domain->mappings,
> (gpointer)());
> >>> +}
> >>> +}
> >>> +
> >>> +if (mapping) {
> >>> +qemu_log_mask(LOG_GUEST_ERROR,
> >>> + "** %s: Unmap 0x%"PRIx64" size=0x%"PRIx64
> >>> + " from 0x%"PRIx64" size=0x%"PRIx64" is not
> >>> supported\n",
> >>> + __func__, interval.low, size,
> >>> + mapping->virt_addr, mapping->size);
> >>> +} else {
> >>> +return VIRTIO_IOMMU_S_OK;
> >>> +}
> >>> +
> >>> +return VIRTIO_IOMMU_S_INVAL;
> >>
> >> Could the above chunk be simplified as something like below?
> >>
> >> while ((mapping = g_tree_lookup(domain->mappings, ))) {
> >> g_tree_remove(domain->mappings, mapping);
> >> }
> > Indeed the code could be simplified. I only need to make sure I don't
> > split an existing mapping.
>
> Hmm... Do we need to still split an existing mapping if necessary?
> For example when with this mapping:
>
> iova=0x1000, size=0x2000, phys=ADDR1, flags=FLAGS1
>
> And if we want to unmap the range (iova=0, size=0x2000), then we
> should split the existing mappping and leave this one:
>
> iova=0x2000, size=0x1000, phys=(ADDR1+0x1000), flags=FLAGS1
>
> Right?
>
> >>>
> >>> virtio-iommu spec explicitly disallows partial unmap.
> >>>
> >>> 5.11.6.6.1 Driver Requirements: UNMAP request
> >>>
> >>> The first address of a range MUST either be the first address of a
> >>> mapping or be outside any mapping. The last address of a range
> >>> MUST either be the last address of a mapping or be outside any
> >>> mapping.
> >>>
> >>> 5.11.6.6.2 Device Requirements: UNMAP request
> >>>
> >>> If a mapping affected by the range is not covered in its entirety
> >>> by the range (the UNMAP request would split the mapping),
> >>> then the device SHOULD set the request status to VIRTIO_IOMMU
> >>> _S_RANGE, and SHOULD NOT remove any mapping.
> >>
> >> I see, thanks Kevin.
> >>
> >> Though why so strict? (Sorry if I missed some discussions
> >> ... pointers welcomed...)
> >>
> >> What I'm thinking is when we want to allocate a bunch of buffers
> >> (e.g., 1M) while we will also need to be able to free them with
> >> smaller chunks (e.g., 4K), then it would be even better that we allow
> >> to allocate a whole 1M buffer within the guest and map it as a whole,
> >> then we can selectively unmap the pages after used. If with the
> >> strict rule, we'll need to map one by one, that can be a total of
> >> 1M/4K roundtrips.
> >>
> >
> > Sorry I forgot the original discussion. Need Jean to respond. :-)
> >
> > A possible reason is that no such
Re: [Qemu-devel] [PATCH for-4.2 v10 08/15] virtio-iommu: Implement map/unmap
Hi,
On 9/4/19 7:46 AM, Tian, Kevin wrote:
>> From: Peter Xu [mailto:pet...@redhat.com]
>> Sent: Wednesday, September 4, 2019 1:37 PM
>>
>> On Wed, Sep 04, 2019 at 04:23:50AM +, Tian, Kevin wrote:
From: Peter Xu [mailto:pet...@redhat.com]
Sent: Wednesday, September 4, 2019 9:44 AM
On Tue, Sep 03, 2019 at 01:37:11PM +0200, Auger Eric wrote:
> Hi Peter,
>
> On 8/19/19 10:11 AM, Peter Xu wrote:
>> On Tue, Jul 30, 2019 at 07:21:30PM +0200, Eric Auger wrote:
>>
>> [...]
>>
>>> +mapping = g_tree_lookup(domain->mappings,
>> (gpointer)());
>>> +
>>> +while (mapping) {
>>> +viommu_interval current;
>>> +uint64_t low = mapping->virt_addr;
>>> +uint64_t high = mapping->virt_addr + mapping->size - 1;
>>> +
>>> +current.low = low;
>>> +current.high = high;
>>> +
>>> +if (low == interval.low && size >= mapping->size) {
>>> +g_tree_remove(domain->mappings, (gpointer)());
>>> +interval.low = high + 1;
>>> +trace_virtio_iommu_unmap_left_interval(current.low,
current.high,
>>> +interval.low, interval.high);
>>> +} else if (high == interval.high && size >= mapping->size) {
>>> +trace_virtio_iommu_unmap_right_interval(current.low,
current.high,
>>> +interval.low, interval.high);
>>> +g_tree_remove(domain->mappings, (gpointer)());
>>> +interval.high = low - 1;
>>> +} else if (low > interval.low && high < interval.high) {
>>> +trace_virtio_iommu_unmap_inc_interval(current.low,
current.high);
>>> +g_tree_remove(domain->mappings, (gpointer)());
>>> +} else {
>>> +break;
>>> +}
>>> +if (interval.low >= interval.high) {
>>> +return VIRTIO_IOMMU_S_OK;
>>> +} else {
>>> +mapping = g_tree_lookup(domain->mappings,
(gpointer)());
>>> +}
>>> +}
>>> +
>>> +if (mapping) {
>>> +qemu_log_mask(LOG_GUEST_ERROR,
>>> + "** %s: Unmap 0x%"PRIx64" size=0x%"PRIx64
>>> + " from 0x%"PRIx64" size=0x%"PRIx64" is not
>>> supported\n",
>>> + __func__, interval.low, size,
>>> + mapping->virt_addr, mapping->size);
>>> +} else {
>>> +return VIRTIO_IOMMU_S_OK;
>>> +}
>>> +
>>> +return VIRTIO_IOMMU_S_INVAL;
>>
>> Could the above chunk be simplified as something like below?
>>
>> while ((mapping = g_tree_lookup(domain->mappings, ))) {
>> g_tree_remove(domain->mappings, mapping);
>> }
> Indeed the code could be simplified. I only need to make sure I don't
> split an existing mapping.
Hmm... Do we need to still split an existing mapping if necessary?
For example when with this mapping:
iova=0x1000, size=0x2000, phys=ADDR1, flags=FLAGS1
And if we want to unmap the range (iova=0, size=0x2000), then we
should split the existing mappping and leave this one:
iova=0x2000, size=0x1000, phys=(ADDR1+0x1000), flags=FLAGS1
Right?
>>>
>>> virtio-iommu spec explicitly disallows partial unmap.
>>>
>>> 5.11.6.6.1 Driver Requirements: UNMAP request
>>>
>>> The first address of a range MUST either be the first address of a
>>> mapping or be outside any mapping. The last address of a range
>>> MUST either be the last address of a mapping or be outside any
>>> mapping.
>>>
>>> 5.11.6.6.2 Device Requirements: UNMAP request
>>>
>>> If a mapping affected by the range is not covered in its entirety
>>> by the range (the UNMAP request would split the mapping),
>>> then the device SHOULD set the request status to VIRTIO_IOMMU
>>> _S_RANGE, and SHOULD NOT remove any mapping.
>>
>> I see, thanks Kevin.
>>
>> Though why so strict? (Sorry if I missed some discussions
>> ... pointers welcomed...)
>>
>> What I'm thinking is when we want to allocate a bunch of buffers
>> (e.g., 1M) while we will also need to be able to free them with
>> smaller chunks (e.g., 4K), then it would be even better that we allow
>> to allocate a whole 1M buffer within the guest and map it as a whole,
>> then we can selectively unmap the pages after used. If with the
>> strict rule, we'll need to map one by one, that can be a total of
>> 1M/4K roundtrips.
>>
>
> Sorry I forgot the original discussion. Need Jean to respond. :-)
>
> A possible reason is that no such usage exists today, thus simplification
> was made?
In
https://virtualization.linux-foundation.narkive.com/q6XOkO76/rfc-0-3-virtio-iommu-a-paravirtualized-iommu
I found
"
(Note: the semantics of unmap are chosen to be compatible with VFIO's
type1 v2 IOMMU API. This way a device serving as intermediary
Re: [Qemu-devel] [PATCH for-4.2 v10 08/15] virtio-iommu: Implement map/unmap
> From: Peter Xu [mailto:pet...@redhat.com]
> Sent: Wednesday, September 4, 2019 1:37 PM
>
> On Wed, Sep 04, 2019 at 04:23:50AM +, Tian, Kevin wrote:
> > > From: Peter Xu [mailto:pet...@redhat.com]
> > > Sent: Wednesday, September 4, 2019 9:44 AM
> > >
> > > On Tue, Sep 03, 2019 at 01:37:11PM +0200, Auger Eric wrote:
> > > > Hi Peter,
> > > >
> > > > On 8/19/19 10:11 AM, Peter Xu wrote:
> > > > > On Tue, Jul 30, 2019 at 07:21:30PM +0200, Eric Auger wrote:
> > > > >
> > > > > [...]
> > > > >
> > > > >> +mapping = g_tree_lookup(domain->mappings,
> (gpointer)());
> > > > >> +
> > > > >> +while (mapping) {
> > > > >> +viommu_interval current;
> > > > >> +uint64_t low = mapping->virt_addr;
> > > > >> +uint64_t high = mapping->virt_addr + mapping->size - 1;
> > > > >> +
> > > > >> +current.low = low;
> > > > >> +current.high = high;
> > > > >> +
> > > > >> +if (low == interval.low && size >= mapping->size) {
> > > > >> +g_tree_remove(domain->mappings, (gpointer)());
> > > > >> +interval.low = high + 1;
> > > > >> +trace_virtio_iommu_unmap_left_interval(current.low,
> > > current.high,
> > > > >> +interval.low, interval.high);
> > > > >> +} else if (high == interval.high && size >= mapping->size) {
> > > > >> +trace_virtio_iommu_unmap_right_interval(current.low,
> > > current.high,
> > > > >> +interval.low, interval.high);
> > > > >> +g_tree_remove(domain->mappings, (gpointer)());
> > > > >> +interval.high = low - 1;
> > > > >> +} else if (low > interval.low && high < interval.high) {
> > > > >> +trace_virtio_iommu_unmap_inc_interval(current.low,
> > > current.high);
> > > > >> +g_tree_remove(domain->mappings, (gpointer)());
> > > > >> +} else {
> > > > >> +break;
> > > > >> +}
> > > > >> +if (interval.low >= interval.high) {
> > > > >> +return VIRTIO_IOMMU_S_OK;
> > > > >> +} else {
> > > > >> +mapping = g_tree_lookup(domain->mappings,
> > > (gpointer)());
> > > > >> +}
> > > > >> +}
> > > > >> +
> > > > >> +if (mapping) {
> > > > >> +qemu_log_mask(LOG_GUEST_ERROR,
> > > > >> + "** %s: Unmap 0x%"PRIx64" size=0x%"PRIx64
> > > > >> + " from 0x%"PRIx64" size=0x%"PRIx64" is not
> > > > >> supported\n",
> > > > >> + __func__, interval.low, size,
> > > > >> + mapping->virt_addr, mapping->size);
> > > > >> +} else {
> > > > >> +return VIRTIO_IOMMU_S_OK;
> > > > >> +}
> > > > >> +
> > > > >> +return VIRTIO_IOMMU_S_INVAL;
> > > > >
> > > > > Could the above chunk be simplified as something like below?
> > > > >
> > > > > while ((mapping = g_tree_lookup(domain->mappings, ))) {
> > > > > g_tree_remove(domain->mappings, mapping);
> > > > > }
> > > > Indeed the code could be simplified. I only need to make sure I don't
> > > > split an existing mapping.
> > >
> > > Hmm... Do we need to still split an existing mapping if necessary?
> > > For example when with this mapping:
> > >
> > > iova=0x1000, size=0x2000, phys=ADDR1, flags=FLAGS1
> > >
> > > And if we want to unmap the range (iova=0, size=0x2000), then we
> > > should split the existing mappping and leave this one:
> > >
> > > iova=0x2000, size=0x1000, phys=(ADDR1+0x1000), flags=FLAGS1
> > >
> > > Right?
> > >
> >
> > virtio-iommu spec explicitly disallows partial unmap.
> >
> > 5.11.6.6.1 Driver Requirements: UNMAP request
> >
> > The first address of a range MUST either be the first address of a
> > mapping or be outside any mapping. The last address of a range
> > MUST either be the last address of a mapping or be outside any
> > mapping.
> >
> > 5.11.6.6.2 Device Requirements: UNMAP request
> >
> > If a mapping affected by the range is not covered in its entirety
> > by the range (the UNMAP request would split the mapping),
> > then the device SHOULD set the request status to VIRTIO_IOMMU
> > _S_RANGE, and SHOULD NOT remove any mapping.
>
> I see, thanks Kevin.
>
> Though why so strict? (Sorry if I missed some discussions
> ... pointers welcomed...)
>
> What I'm thinking is when we want to allocate a bunch of buffers
> (e.g., 1M) while we will also need to be able to free them with
> smaller chunks (e.g., 4K), then it would be even better that we allow
> to allocate a whole 1M buffer within the guest and map it as a whole,
> then we can selectively unmap the pages after used. If with the
> strict rule, we'll need to map one by one, that can be a total of
> 1M/4K roundtrips.
>
Sorry I forgot the original discussion. Need Jean to respond. :-)
A possible reason is that no such usage exists today, thus simplification
was made?
Thanks
Kevin
Re: [Qemu-devel] [PATCH for-4.2 v10 08/15] virtio-iommu: Implement map/unmap
On Wed, Sep 04, 2019 at 04:23:50AM +, Tian, Kevin wrote:
> > From: Peter Xu [mailto:pet...@redhat.com]
> > Sent: Wednesday, September 4, 2019 9:44 AM
> >
> > On Tue, Sep 03, 2019 at 01:37:11PM +0200, Auger Eric wrote:
> > > Hi Peter,
> > >
> > > On 8/19/19 10:11 AM, Peter Xu wrote:
> > > > On Tue, Jul 30, 2019 at 07:21:30PM +0200, Eric Auger wrote:
> > > >
> > > > [...]
> > > >
> > > >> +mapping = g_tree_lookup(domain->mappings, (gpointer)());
> > > >> +
> > > >> +while (mapping) {
> > > >> +viommu_interval current;
> > > >> +uint64_t low = mapping->virt_addr;
> > > >> +uint64_t high = mapping->virt_addr + mapping->size - 1;
> > > >> +
> > > >> +current.low = low;
> > > >> +current.high = high;
> > > >> +
> > > >> +if (low == interval.low && size >= mapping->size) {
> > > >> +g_tree_remove(domain->mappings, (gpointer)());
> > > >> +interval.low = high + 1;
> > > >> +trace_virtio_iommu_unmap_left_interval(current.low,
> > current.high,
> > > >> +interval.low, interval.high);
> > > >> +} else if (high == interval.high && size >= mapping->size) {
> > > >> +trace_virtio_iommu_unmap_right_interval(current.low,
> > current.high,
> > > >> +interval.low, interval.high);
> > > >> +g_tree_remove(domain->mappings, (gpointer)());
> > > >> +interval.high = low - 1;
> > > >> +} else if (low > interval.low && high < interval.high) {
> > > >> +trace_virtio_iommu_unmap_inc_interval(current.low,
> > current.high);
> > > >> +g_tree_remove(domain->mappings, (gpointer)());
> > > >> +} else {
> > > >> +break;
> > > >> +}
> > > >> +if (interval.low >= interval.high) {
> > > >> +return VIRTIO_IOMMU_S_OK;
> > > >> +} else {
> > > >> +mapping = g_tree_lookup(domain->mappings,
> > (gpointer)());
> > > >> +}
> > > >> +}
> > > >> +
> > > >> +if (mapping) {
> > > >> +qemu_log_mask(LOG_GUEST_ERROR,
> > > >> + "** %s: Unmap 0x%"PRIx64" size=0x%"PRIx64
> > > >> + " from 0x%"PRIx64" size=0x%"PRIx64" is not
> > > >> supported\n",
> > > >> + __func__, interval.low, size,
> > > >> + mapping->virt_addr, mapping->size);
> > > >> +} else {
> > > >> +return VIRTIO_IOMMU_S_OK;
> > > >> +}
> > > >> +
> > > >> +return VIRTIO_IOMMU_S_INVAL;
> > > >
> > > > Could the above chunk be simplified as something like below?
> > > >
> > > > while ((mapping = g_tree_lookup(domain->mappings, ))) {
> > > > g_tree_remove(domain->mappings, mapping);
> > > > }
> > > Indeed the code could be simplified. I only need to make sure I don't
> > > split an existing mapping.
> >
> > Hmm... Do we need to still split an existing mapping if necessary?
> > For example when with this mapping:
> >
> > iova=0x1000, size=0x2000, phys=ADDR1, flags=FLAGS1
> >
> > And if we want to unmap the range (iova=0, size=0x2000), then we
> > should split the existing mappping and leave this one:
> >
> > iova=0x2000, size=0x1000, phys=(ADDR1+0x1000), flags=FLAGS1
> >
> > Right?
> >
>
> virtio-iommu spec explicitly disallows partial unmap.
>
> 5.11.6.6.1 Driver Requirements: UNMAP request
>
> The first address of a range MUST either be the first address of a
> mapping or be outside any mapping. The last address of a range
> MUST either be the last address of a mapping or be outside any
> mapping.
>
> 5.11.6.6.2 Device Requirements: UNMAP request
>
> If a mapping affected by the range is not covered in its entirety
> by the range (the UNMAP request would split the mapping),
> then the device SHOULD set the request status to VIRTIO_IOMMU
> _S_RANGE, and SHOULD NOT remove any mapping.
I see, thanks Kevin.
Though why so strict? (Sorry if I missed some discussions
... pointers welcomed...)
What I'm thinking is when we want to allocate a bunch of buffers
(e.g., 1M) while we will also need to be able to free them with
smaller chunks (e.g., 4K), then it would be even better that we allow
to allocate a whole 1M buffer within the guest and map it as a whole,
then we can selectively unmap the pages after used. If with the
strict rule, we'll need to map one by one, that can be a total of
1M/4K roundtrips.
Regards,
--
Peter Xu
Re: [Qemu-devel] [PATCH for-4.2 v10 08/15] virtio-iommu: Implement map/unmap
> From: Peter Xu [mailto:pet...@redhat.com]
> Sent: Wednesday, September 4, 2019 9:44 AM
>
> On Tue, Sep 03, 2019 at 01:37:11PM +0200, Auger Eric wrote:
> > Hi Peter,
> >
> > On 8/19/19 10:11 AM, Peter Xu wrote:
> > > On Tue, Jul 30, 2019 at 07:21:30PM +0200, Eric Auger wrote:
> > >
> > > [...]
> > >
> > >> +mapping = g_tree_lookup(domain->mappings, (gpointer)());
> > >> +
> > >> +while (mapping) {
> > >> +viommu_interval current;
> > >> +uint64_t low = mapping->virt_addr;
> > >> +uint64_t high = mapping->virt_addr + mapping->size - 1;
> > >> +
> > >> +current.low = low;
> > >> +current.high = high;
> > >> +
> > >> +if (low == interval.low && size >= mapping->size) {
> > >> +g_tree_remove(domain->mappings, (gpointer)());
> > >> +interval.low = high + 1;
> > >> +trace_virtio_iommu_unmap_left_interval(current.low,
> current.high,
> > >> +interval.low, interval.high);
> > >> +} else if (high == interval.high && size >= mapping->size) {
> > >> +trace_virtio_iommu_unmap_right_interval(current.low,
> current.high,
> > >> +interval.low, interval.high);
> > >> +g_tree_remove(domain->mappings, (gpointer)());
> > >> +interval.high = low - 1;
> > >> +} else if (low > interval.low && high < interval.high) {
> > >> +trace_virtio_iommu_unmap_inc_interval(current.low,
> current.high);
> > >> +g_tree_remove(domain->mappings, (gpointer)());
> > >> +} else {
> > >> +break;
> > >> +}
> > >> +if (interval.low >= interval.high) {
> > >> +return VIRTIO_IOMMU_S_OK;
> > >> +} else {
> > >> +mapping = g_tree_lookup(domain->mappings,
> (gpointer)());
> > >> +}
> > >> +}
> > >> +
> > >> +if (mapping) {
> > >> +qemu_log_mask(LOG_GUEST_ERROR,
> > >> + "** %s: Unmap 0x%"PRIx64" size=0x%"PRIx64
> > >> + " from 0x%"PRIx64" size=0x%"PRIx64" is not
> > >> supported\n",
> > >> + __func__, interval.low, size,
> > >> + mapping->virt_addr, mapping->size);
> > >> +} else {
> > >> +return VIRTIO_IOMMU_S_OK;
> > >> +}
> > >> +
> > >> +return VIRTIO_IOMMU_S_INVAL;
> > >
> > > Could the above chunk be simplified as something like below?
> > >
> > > while ((mapping = g_tree_lookup(domain->mappings, ))) {
> > > g_tree_remove(domain->mappings, mapping);
> > > }
> > Indeed the code could be simplified. I only need to make sure I don't
> > split an existing mapping.
>
> Hmm... Do we need to still split an existing mapping if necessary?
> For example when with this mapping:
>
> iova=0x1000, size=0x2000, phys=ADDR1, flags=FLAGS1
>
> And if we want to unmap the range (iova=0, size=0x2000), then we
> should split the existing mappping and leave this one:
>
> iova=0x2000, size=0x1000, phys=(ADDR1+0x1000), flags=FLAGS1
>
> Right?
>
virtio-iommu spec explicitly disallows partial unmap.
5.11.6.6.1 Driver Requirements: UNMAP request
The first address of a range MUST either be the first address of a
mapping or be outside any mapping. The last address of a range
MUST either be the last address of a mapping or be outside any
mapping.
5.11.6.6.2 Device Requirements: UNMAP request
If a mapping affected by the range is not covered in its entirety
by the range (the UNMAP request would split the mapping),
then the device SHOULD set the request status to VIRTIO_IOMMU
_S_RANGE, and SHOULD NOT remove any mapping.
Thanks
Kevin
Re: [Qemu-devel] [PATCH for-4.2 v10 08/15] virtio-iommu: Implement map/unmap
On Tue, Sep 03, 2019 at 01:37:11PM +0200, Auger Eric wrote:
> Hi Peter,
>
> On 8/19/19 10:11 AM, Peter Xu wrote:
> > On Tue, Jul 30, 2019 at 07:21:30PM +0200, Eric Auger wrote:
> >
> > [...]
> >
> >> +mapping = g_tree_lookup(domain->mappings, (gpointer)());
> >> +
> >> +while (mapping) {
> >> +viommu_interval current;
> >> +uint64_t low = mapping->virt_addr;
> >> +uint64_t high = mapping->virt_addr + mapping->size - 1;
> >> +
> >> +current.low = low;
> >> +current.high = high;
> >> +
> >> +if (low == interval.low && size >= mapping->size) {
> >> +g_tree_remove(domain->mappings, (gpointer)());
> >> +interval.low = high + 1;
> >> +trace_virtio_iommu_unmap_left_interval(current.low,
> >> current.high,
> >> +interval.low, interval.high);
> >> +} else if (high == interval.high && size >= mapping->size) {
> >> +trace_virtio_iommu_unmap_right_interval(current.low,
> >> current.high,
> >> +interval.low, interval.high);
> >> +g_tree_remove(domain->mappings, (gpointer)());
> >> +interval.high = low - 1;
> >> +} else if (low > interval.low && high < interval.high) {
> >> +trace_virtio_iommu_unmap_inc_interval(current.low,
> >> current.high);
> >> +g_tree_remove(domain->mappings, (gpointer)());
> >> +} else {
> >> +break;
> >> +}
> >> +if (interval.low >= interval.high) {
> >> +return VIRTIO_IOMMU_S_OK;
> >> +} else {
> >> +mapping = g_tree_lookup(domain->mappings,
> >> (gpointer)());
> >> +}
> >> +}
> >> +
> >> +if (mapping) {
> >> +qemu_log_mask(LOG_GUEST_ERROR,
> >> + "** %s: Unmap 0x%"PRIx64" size=0x%"PRIx64
> >> + " from 0x%"PRIx64" size=0x%"PRIx64" is not
> >> supported\n",
> >> + __func__, interval.low, size,
> >> + mapping->virt_addr, mapping->size);
> >> +} else {
> >> +return VIRTIO_IOMMU_S_OK;
> >> +}
> >> +
> >> +return VIRTIO_IOMMU_S_INVAL;
> >
> > Could the above chunk be simplified as something like below?
> >
> > while ((mapping = g_tree_lookup(domain->mappings, ))) {
> > g_tree_remove(domain->mappings, mapping);
> > }
> Indeed the code could be simplified. I only need to make sure I don't
> split an existing mapping.
Hmm... Do we need to still split an existing mapping if necessary?
For example when with this mapping:
iova=0x1000, size=0x2000, phys=ADDR1, flags=FLAGS1
And if we want to unmap the range (iova=0, size=0x2000), then we
should split the existing mappping and leave this one:
iova=0x2000, size=0x1000, phys=(ADDR1+0x1000), flags=FLAGS1
Right?
>
> Also I needed to use g_tree_lookup_extended to retrieve the actual key
> to remove. The usage of g_tree_lookup_extended() allows me to remove the
> virt_addr and size fields from the mapping value value struct as those
> info can be retrieved from the key.
True. Thanks,
--
Peter Xu
Re: [Qemu-devel] [PATCH for-4.2 v10 08/15] virtio-iommu: Implement map/unmap
Hi Peter,
On 8/19/19 10:11 AM, Peter Xu wrote:
> On Tue, Jul 30, 2019 at 07:21:30PM +0200, Eric Auger wrote:
>
> [...]
>
>> +mapping = g_tree_lookup(domain->mappings, (gpointer)());
>> +
>> +while (mapping) {
>> +viommu_interval current;
>> +uint64_t low = mapping->virt_addr;
>> +uint64_t high = mapping->virt_addr + mapping->size - 1;
>> +
>> +current.low = low;
>> +current.high = high;
>> +
>> +if (low == interval.low && size >= mapping->size) {
>> +g_tree_remove(domain->mappings, (gpointer)());
>> +interval.low = high + 1;
>> +trace_virtio_iommu_unmap_left_interval(current.low,
>> current.high,
>> +interval.low, interval.high);
>> +} else if (high == interval.high && size >= mapping->size) {
>> +trace_virtio_iommu_unmap_right_interval(current.low,
>> current.high,
>> +interval.low, interval.high);
>> +g_tree_remove(domain->mappings, (gpointer)());
>> +interval.high = low - 1;
>> +} else if (low > interval.low && high < interval.high) {
>> +trace_virtio_iommu_unmap_inc_interval(current.low,
>> current.high);
>> +g_tree_remove(domain->mappings, (gpointer)());
>> +} else {
>> +break;
>> +}
>> +if (interval.low >= interval.high) {
>> +return VIRTIO_IOMMU_S_OK;
>> +} else {
>> +mapping = g_tree_lookup(domain->mappings,
>> (gpointer)());
>> +}
>> +}
>> +
>> +if (mapping) {
>> +qemu_log_mask(LOG_GUEST_ERROR,
>> + "** %s: Unmap 0x%"PRIx64" size=0x%"PRIx64
>> + " from 0x%"PRIx64" size=0x%"PRIx64" is not
>> supported\n",
>> + __func__, interval.low, size,
>> + mapping->virt_addr, mapping->size);
>> +} else {
>> +return VIRTIO_IOMMU_S_OK;
>> +}
>> +
>> +return VIRTIO_IOMMU_S_INVAL;
>
> Could the above chunk be simplified as something like below?
>
> while ((mapping = g_tree_lookup(domain->mappings, ))) {
> g_tree_remove(domain->mappings, mapping);
> }
Indeed the code could be simplified. I only need to make sure I don't
split an existing mapping.
Also I needed to use g_tree_lookup_extended to retrieve the actual key
to remove. The usage of g_tree_lookup_extended() allows me to remove the
virt_addr and size fields from the mapping value value struct as those
info can be retrieved from the key.
Thanks!
Eric
>
> Thanks,
>
Re: [Qemu-devel] [PATCH for-4.2 v10 08/15] virtio-iommu: Implement map/unmap
On Tue, Jul 30, 2019 at 07:21:30PM +0200, Eric Auger wrote:
[...]
> +mapping = g_tree_lookup(domain->mappings, (gpointer)());
> +
> +while (mapping) {
> +viommu_interval current;
> +uint64_t low = mapping->virt_addr;
> +uint64_t high = mapping->virt_addr + mapping->size - 1;
> +
> +current.low = low;
> +current.high = high;
> +
> +if (low == interval.low && size >= mapping->size) {
> +g_tree_remove(domain->mappings, (gpointer)());
> +interval.low = high + 1;
> +trace_virtio_iommu_unmap_left_interval(current.low, current.high,
> +interval.low, interval.high);
> +} else if (high == interval.high && size >= mapping->size) {
> +trace_virtio_iommu_unmap_right_interval(current.low,
> current.high,
> +interval.low, interval.high);
> +g_tree_remove(domain->mappings, (gpointer)());
> +interval.high = low - 1;
> +} else if (low > interval.low && high < interval.high) {
> +trace_virtio_iommu_unmap_inc_interval(current.low, current.high);
> +g_tree_remove(domain->mappings, (gpointer)());
> +} else {
> +break;
> +}
> +if (interval.low >= interval.high) {
> +return VIRTIO_IOMMU_S_OK;
> +} else {
> +mapping = g_tree_lookup(domain->mappings, (gpointer)());
> +}
> +}
> +
> +if (mapping) {
> +qemu_log_mask(LOG_GUEST_ERROR,
> + "** %s: Unmap 0x%"PRIx64" size=0x%"PRIx64
> + " from 0x%"PRIx64" size=0x%"PRIx64" is not supported\n",
> + __func__, interval.low, size,
> + mapping->virt_addr, mapping->size);
> +} else {
> +return VIRTIO_IOMMU_S_OK;
> +}
> +
> +return VIRTIO_IOMMU_S_INVAL;
Could the above chunk be simplified as something like below?
while ((mapping = g_tree_lookup(domain->mappings, ))) {
g_tree_remove(domain->mappings, mapping);
}
Thanks,
--
Peter Xu
