The PV xenbus control/shutdown node is written by the toolstack as a
request to the guest to perform a particular action (shutdown, reboot,
suspend etc). The guest is expected to acknowledge that it will
complete a request by clearing the control node.
Previously it would acknowledge any request, even if it did not know
what to do with it. Specifically in the case where CONFIG_PM_SLEEP is
not enabled the kernel would acknowledge a suspend request even though
it was not actually going to do anything.
Instead make the kernel only acknowledge requests if it is actually
going to do something with it. This will improve the toolstack's
ability to diagnose and deal with failures.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Now that xenstore_ready is used correctly for PV on HVM guests too, we
don't need to delay the initialization of xen_setup_shutdown_event
anymore.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
The handle with numeric value 0 is a valid map handle, so it cannot
be used to indicate that a page has not been mapped. Use -1 instead.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Otherwise we fail to properly suspend/resume all of the emulated devices.
Something between 2.6.38-rc2 and rc3 appears to have exposed this
issue, but it's always been wrong not to do this.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
When CONFIG_XEN is enabled the gntdev and gntalloc driver will be
compiled as a module by default.
[v2: Added the fix for the gntalloc driver as well]
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
If an already-mapped area of the device was mapped into userspace a
second time, a hypercall was incorrectly made to remap the memory
again. Avoid the hypercall on later mmap calls, and fail the mmap call
if a writable mapping is attempted on a read-only range.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
In paravirtualized domains, mn_invl_page or mn_invl_range_start can
unmap a segment of a mapped region without unmapping all pages. When
the region is later released, the pages will be unmapped twice, leading
to an incorrect -EINVAL return.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The is_mapped flag used to be set at the completion of the map operation,
but was not checked in all error paths. Use map->vma instead, which will
now be cleared if the initial grant mapping fails.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
In paravirtualized guests, the struct page* for mappings is only a
placeholder, and cannot be used to access the granted memory. Use the
userspace mapping that we have set up in order to implement
UNMAP_NOTIFY_CLEAR_BYTE.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The error path did not decrement the reference count of the grant structure.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This ioctl allows the users of a shared page to be notified when
the other end exits abnormally.
[v2: updated description in structs]
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This allows a userspace application to allocate a shared page for
implementing inter-domain communication or device drivers. These
shared pages can be mapped using the gntdev device or by the kernel
in another domain.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
HVM does not allow direct PTE modification, so instead we request
that Xen change its internal p2m mappings on the allocated pages and
map the memory into userspace normally.
Note:
The HVM path for map and unmap is slightly different: HVM keeps the pages
mapped until the area is deleted, while the PV case (use_ptemod being true)
must unmap them when userspace unmaps the range. In the normal use case,
this makes no difference to users since unmap time is deletion time.
[v2: Expanded commit descr.]
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This allows userspace to perform mmap() on the gntdev device and then
immediately close the filehandle or remove the mapping using the
remove ioctl, with the mapped area remaining valid until unmapped.
This also fixes an infinite loop when a gntdev device is closed
without first unmapping all areas.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This should be faster if many mappings exist, and also removes
the only user of map->vma not related to PTE modification.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Because there is no limitation on how many times a user can open a
given device file, an per-file-description limit on the number of
pages granted offers little to no benefit. Change to a global limit
and remove the ioctl() as the parameter can now be changed via sysfs.
Xen tools changeset 22768:f8d801e5573e is needed to eliminate the
error this change produces in xc_gnttab_set_max_grants.
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Ian Campbell
Stefano Stabellini
Daniel De Graaf