Currently map_vm_area() takes (struct page *** pages) as third argument,
and after mapping, it moves (*pages) to point to (*pages +
nr_mappped_pages).
It looks like this kind of increment is useless to its caller these
days. The callers don't care about the increments and actually they're
trying to avoid this by passing another copy to map_vm_area().
The caller can always guarantee all the pages can be mapped into vm_area
as specified in first argument and the caller only cares about whether
map_vm_area() fails or not.
This patch cleans up the pointer movement in map_vm_area() and updates
its callers accordingly.
Signed-off-by: WANG Chao <chaowang@redhat.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <ngupta@vflare.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tell the compiler that the inline assembler statement
references lguest_entry.
This fixes compile problems with LTO where the variable
and the assembler code may end up in different files.
Cc: x86@kernel.org
Cc: rusty@rustcorp.com.au
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Currently a host kick error is silently ignored and not reflected in
the virtqueue of a particular virtio device.
Changing the notify API for guest->host notification seems to be one
prerequisite in order to be able to handle such errors in the context
where the kick is triggered.
This patch changes the notify API. The notify function must return a
bool return value. It returns false if the host notification failed.
Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The symptoms are that running gdb on a binary causes the guest to
overflow the kernels stack (after some period of time), resulting in
it finally being killed with a "Bad address" message.
Reported-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If we discover the entry is invalid, we kill the guest, but we must
avoid calling gpte_addr() on the invalid pmd, otherwise:
kernel BUG at drivers/lguest/page_tables.c:157!
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Pull trivial tree updates from Jiri Kosina:
"The usual stuff from trivial tree"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits)
treewide: relase -> release
Documentation/cgroups/memory.txt: fix stat file documentation
sysctl/net.txt: delete reference to obsolete 2.4.x kernel
spinlock_api_smp.h: fix preprocessor comments
treewide: Fix typo in printk
doc: device tree: clarify stuff in usage-model.txt.
open firmware: "/aliasas" -> "/aliases"
md: bcache: Fixed a typo with the word 'arithmetic'
irq/generic-chip: fix a few kernel-doc entries
frv: Convert use of typedef ctl_table to struct ctl_table
sgi: xpc: Convert use of typedef ctl_table to struct ctl_table
doc: clk: Fix incorrect wording
Documentation/arm/IXP4xx fix a typo
Documentation/networking/ieee802154 fix a typo
Documentation/DocBook/media/v4l fix a typo
Documentation/video4linux/si476x.txt fix a typo
Documentation/virtual/kvm/api.txt fix a typo
Documentation/early-userspace/README fix a typo
Documentation/video4linux/soc-camera.txt fix a typo
lguest: fix CONFIG_PAE -> CONFIG_x86_PAE in comment
...
commit v3.9-rc1-53-g6d0cda9 "lguest: cache last cpu we ran on." missed
one case, which causes a triple fault. The guest calls guest_set_pgd()
on the top page, and we carefully remap the Switcher text page. But
we didn't reset last_host_cpu, so map_switcher_in_guest() thinks
the guest's regs and IDT/GDT etc are already mapped.
Reported-by: Paul Bolle <pebolle@tiscali.nl>
Tested-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Pull virtio & lguest updates from Rusty Russell:
"Lots of virtio work which wasn't quite ready for last merge window.
Plus I dived into lguest again, reworking the pagetable code so we can
move the switcher page: our fixmaps sometimes take more than 2MB now..."
Ugh. Annoying conflicts with the tcm_vhost -> vhost_scsi rename.
Hopefully correctly resolved.
* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (57 commits)
caif_virtio: Remove bouncing email addresses
lguest: improve code readability in lg_cpu_start.
virtio-net: fill only rx queues which are being used
lguest: map Switcher below fixmap.
lguest: cache last cpu we ran on.
lguest: map Switcher text whenever we allocate a new pagetable.
lguest: don't share Switcher PTE pages between guests.
lguest: expost switcher_pages array (as lg_switcher_pages).
lguest: extract shadow PTE walking / allocating.
lguest: make check_gpte et. al return bool.
lguest: assume Switcher text is a single page.
lguest: rename switcher_page to switcher_pages.
lguest: remove RESERVE_MEM constant.
lguest: check vaddr not pgd for Switcher protection.
lguest: prepare to make SWITCHER_ADDR a variable.
virtio: console: replace EMFILE with EBUSY for already-open port
virtio-scsi: reset virtqueue affinity when doing cpu hotplug
virtio-scsi: introduce multiqueue support
virtio-scsi: push vq lock/unlock into virtscsi_vq_done
virtio-scsi: pass struct virtio_scsi to virtqueue completion function
...
Now we've adjusted all the code, we can simply set switcher_addr to
wherever it needs to go below the fixmaps, rather than asserting that
it should be so.
With large NR_CPUS and PAE, people were hitting the "mapping switcher
would thwack fixmap" message.
Reported-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
It's always to same, so no need to put in the PTE every time we're
about to run. Keep a flag to track whether the pagetable has the
Switcher entries allocated, and when allocating always initialize the
Switcher text PTE.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We currently use the whole top PGD entry for the switcher, so we
simply share a fixed page of PTEs between all guests (actually, it's
one per Host CPU, to ensure isolation between guests).
Changes to a scheme where every guest has its own mappings.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We want a separate find_pte() function so we can call it for populating the
switcher PTE entries.
We can also use it in page_writable().
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is a bit neater: we can immediately return if a PTE/PGD/PMD entry
is invalid (which also kills the guest). It means we don't risk using
invalid entries as we reshuffle the code.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
ie. SHARED_SWITCHER_PAGES == 1. It is well under a page, and it's a
minor simplification: it's nice to have *one* simplification in a
patch series!
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We currently assume that the Switcher the top pgd; we want to remove
this assumption, so check that vaddr is OK, rather then checking pgd
index.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We currently use the whole top PGD entry for the switcher, but that's
hitting the fixmap in some configurations (mainly, large NR_CPUS).
Introduce a variable, currently set to the constant.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
