similar to: [PATCH] xen/gntdev: do not set VM_PFNMAP

The only time when granted pages need to be treated specially is when using Xen''s PTE modification for grant mappings owned by another domain. Otherwise, the area does not require VM_DONTCOPY and VM_PFNMAP, since it can be accessed just like any other page of RAM. Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov> --- drivers/xen/gntalloc.c | 14 ++++++++++++--

Since we are using the m2p_override we do have struct pages corresponding to the user vma mmap''ed by gntdev. Removing the VM_PFNMAP flag makes get_user_pages work on that vma. An example test case would be using a Xen userspace block backend (QDISK) on a file on NFS using O_DIRECT. The patch should be backported back to 2.6.38. Signed-off-by: Stefano Stabellini

This flag controls the meaning of gnttab_map_grant_ref.host_addr and specifies that the field contains a refernce to the pte entry to be used to perform the mapping. Therefore move the use of this flag to the point at which we actually use a reference to the pte instead of something else, splitting up the usage of the flag in this way is confusing and potentially error prone. The other flags are

From: Jason Gunthorpe <jgg at mellanox.com> gntdev simply wants to monitor a specific VMA for any notifier events, this can be done straightforwardly using mmu_range_notifier_insert() over the VMA's VA range. The notifier should be attached until the original VMA is destroyed. It is unclear if any of this is even sane, but at least a lot of duplicate code is removed. Cc: Oleksandr

On 10/28/19 4:10 PM, Jason Gunthorpe wrote: > From: Jason Gunthorpe <jgg at mellanox.com> > > gntdev simply wants to monitor a specific VMA for any notifier events, > this can be done straightforwardly using mmu_range_notifier_insert() over > the VMA's VA range. > > The notifier should be attached until the original VMA is destroyed. > > It is unclear if any of

We should unlock here and also decrement the number of &map->users. Signed-off-by: Dan Carpenter <error27 at gmail.com> --- I'm not very familiar with this code. Please review carefully. diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 017ce60..b0f9e8f 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -662,7 +662,7 @@ static int gntdev_mmap(struct

We should unlock here and also decrement the number of &map->users. Signed-off-by: Dan Carpenter <error27 at gmail.com> --- I'm not very familiar with this code. Please review carefully. diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 017ce60..b0f9e8f 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -662,7 +662,7 @@ static int gntdev_mmap(struct

We should unlock here and also decrement the number of &map->users. Signed-off-by: Dan Carpenter <error27 at gmail.com> --- I'm not very familiar with this code. Please review carefully. diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 017ce60..b0f9e8f 100644 --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -662,7 +662,7 @@ static int gntdev_mmap(struct

On Wed, Oct 30, 2019 at 12:55:37PM -0400, Boris Ostrovsky wrote: > On 10/28/19 4:10 PM, Jason Gunthorpe wrote: > > From: Jason Gunthorpe <jgg at mellanox.com> > > > > gntdev simply wants to monitor a specific VMA for any notifier events, > > this can be done straightforwardly using mmu_range_notifier_insert() over > > the VMA's VA range. > > >

This patch is a significant performance improvement for the m2p_override: about 6% using the gntdev device. Each m2p_add/remove_override call issues a MULTI_grant_table_op and a __flush_tlb_single if kmap_op != NULL. Batching all the calls together is a great performance benefit because it means issuing one hypercall total rather than two hypercall per page. If paravirt_lazy_mode is set

(This is a continuation of "[PATCH v9] xen/grant-table: Avoid m2p_override during mapping") The grant mapping API does m2p_override unnecessarily: only gntdev needs it, for blkback and future netback patches it just cause a lock contention, as those pages never go to userspace. Therefore this series does the following: - the bulk of the original function (everything after the mapping

(This is a continuation of "[PATCH v9] xen/grant-table: Avoid m2p_override during mapping") The grant mapping API does m2p_override unnecessarily: only gntdev needs it, for blkback and future netback patches it just cause a lock contention, as those pages never go to userspace. Therefore this series does the following: - the bulk of the original function (everything after the mapping

copy_to_user() returns the amount of data remaining to be copied. We want to return a negative error code here. The upper layers just call WARN_ON() if we return non-zero so this doesn't change the behavior. But returning -EFAULT is still cleaner. Signed-off-by: Dan Carpenter <error27 at gmail.com> diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 017ce60..b0f9e8f

copy_to_user() returns the amount of data remaining to be copied. We want to return a negative error code here. The upper layers just call WARN_ON() if we return non-zero so this doesn't change the behavior. But returning -EFAULT is still cleaner. Signed-off-by: Dan Carpenter <error27 at gmail.com> diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 017ce60..b0f9e8f

copy_to_user() returns the amount of data remaining to be copied. We want to return a negative error code here. The upper layers just call WARN_ON() if we return non-zero so this doesn't change the behavior. But returning -EFAULT is still cleaner. Signed-off-by: Dan Carpenter <error27 at gmail.com> diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c index 017ce60..b0f9e8f

On Mon, Oct 28, 2019 at 05:10:25PM -0300, Jason Gunthorpe wrote: > From: Jason Gunthorpe <jgg at mellanox.com> > > DMA_SHARED_BUFFER can not be enabled by the user (it represents a library > set in the kernel). The kconfig convention is to use select for such > symbols so they are turned on implicitly when the user enables a kconfig > that needs them. > > Otherwise

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> diff -r cfb49fe940fd -r 81f75ed45ec2 tools/hotplug/Linux/init.d/xencommons --- a/tools/hotplug/Linux/init.d/xencommons Tue Aug 16 16:56:16 2011 -0700 +++ b/tools/hotplug/Linux/init.d/xencommons Tue Aug 16 17:05:18 2011 -0700 @@ -29,12 +29,18 @@ XENCONSOLED_PIDFILE=/var/run/xenconsoled.pid shopt -s extglob -if [

On Tue, Nov 05, 2019 at 10:16:46AM -0500, Boris Ostrovsky wrote: > > So, I suppose it can be relaxed to a null test and a WARN_ON that it > > hasn't changed? > > You mean > > if (use_ptemod) { > ??????? WARN_ON(map->vma != vma); > ??????? ... > > > Yes, that sounds good. I amended my copy of the patch with the above, has this rework shown signs

On 10/28/19 4:10 PM, Jason Gunthorpe wrote: > @@ -445,17 +438,9 @@ static void gntdev_vma_close(struct vm_area_struct *vma) > struct gntdev_priv *priv = file->private_data; > > pr_debug("gntdev_vma_close %p\n", vma); > - if (use_ptemod) { > - /* It is possible that an mmu notifier could be running > - * concurrently, so take priv->lock to ensure that

On Mon, Nov 04, 2019 at 05:03:31PM -0500, Boris Ostrovsky wrote: > On 10/28/19 4:10 PM, Jason Gunthorpe wrote: > > @@ -445,17 +438,9 @@ static void gntdev_vma_close(struct vm_area_struct *vma) > > struct gntdev_priv *priv = file->private_data; > > > > pr_debug("gntdev_vma_close %p\n", vma); > > - if (use_ptemod) { > > - /* It is possible