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path: root/drivers/lguest/page_tables.c
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2009-09-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linusLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: lguest: don't force VIRTIO_F_NOTIFY_ON_EMPTY lguest: cleanup for map_switcher() lguest: use PGDIR_SHIFT for PAE code to allow different PAGE_OFFSET lguest: use set_pte/set_pmd uniformly for real page table entries lguest: move panic notifier registration to its expected place. virtio_blk: add support for cache flush virtio: add virtio IDs file virtio: get rid of redundant VIRTIO_ID_9P definition virtio: make add_buf return capacity remaining virtio_pci: minor MSI-X cleanups
2009-09-23lguest: use PGDIR_SHIFT for PAE code to allow different PAGE_OFFSETRusty Russell
We still assume the Guest and Host have the same PAGE_OFFSET settings, but now we don't assume 0xC0000000. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Matias Zabaljauregui <zabaljauregui@gmail.com>
2009-09-23lguest: use set_pte/set_pmd uniformly for real page table entriesRusty Russell
If we're building a pte, we can use simple assigment; only use set_pte etc. when we're actually going to use that destination as a PTE. I don't know that we'll ever run under Xen, but it's neater. And use set_pte/set_pmd rather than assuming native_ versions, even though that's probably true for most people. (Includes compile fix by Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>) Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Matias Zabaljauregui <zabaljauregui@gmail.com> Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
2009-09-21trivial: fix typo "to to" in multiple filesAnand Gadiyar
Signed-off-by: Anand Gadiyar <gadiyar@ti.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-07-30lguest: update commentryRusty Russell
Every so often, after code shuffles, I need to go through and unbitrot the Lguest Journey (see drivers/lguest/README). Since we now use RCU in a simple form in one place I took the opportunity to expand that explanation. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
2009-07-30lguest: fix comment styleRusty Russell
I don't really notice it (except to begrudge the extra vertical space), but Ingo does. And he pointed out that one excuse of lguest is as a teaching tool, it should set a good example. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Ingo Molnar <mingo@redhat.com>
2009-06-12lguest: PAE fixesRusty Russell
1) j wasn't initialized in setup_pagetables, so they weren't set up for me causing immediate guest crashes. 2) gpte_addr should not re-read the pmd from the Guest. Especially not BUG_ON() based on the value. If we ever supported SMP guests, they could trigger that. And the Launcher could also trigger it (tho currently root-only). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12lguest: PAE supportMatias Zabaljauregui
This version requires that host and guest have the same PAE status. NX cap is not offered to the guest, yet. Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12lguest: replace hypercall name LHCALL_SET_PMD with LHCALL_SET_PGDMatias Zabaljauregui
replace LHCALL_SET_PMD with LHCALL_SET_PGD hypercall name (That's really what it is, and the confusion gets worse with PAE support) Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Reported-by: Jeremy Fitzhardinge <jeremy@goop.org>
2009-06-12lguest: use native_set_* macros, which properly handle 64-bit entries when ↵Matias Zabaljauregui
PAE is activated Some cleanups and replace direct assignment with native_set_* macros which properly handle 64-bit entries when PAE is activated Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12lguest: map switcher with executable page table entriesMatias Zabaljauregui
Map switcher with executable page table entries. (This bug didn't matter before PAE and hence NX support -- RR) Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-03-30lguest: use bool instead of intMatias Zabaljauregui
Impact: clean up Rusty told me, some time ago, that he had become a fan of "bool". So, here are some replacements. Signed-off-by: Matias Zabaljauregui <zabaljauregui at gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-03-30lguest: fix spurious BUG_ON() on invalid guest stack.Rusty Russell
Impact: fix crash on misbehaving guest gpte_addr() contains a BUG_ON(), insisting that the present flag is set. We need to return before we call it if that isn't the case. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
2008-12-30lguest: move the initial guest page table creation code to the hostMatias Zabaljauregui
This patch moves the initial guest page table creation code to the host, so the launcher keeps working with PAE enabled configs. Signed-off-by: Matias Zabaljauregui <zabaljauregui@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-08-12lguest: use get_user_pages_fast() instead of get_user_pages()Rusty Russell
Using a simple page table thrashing program I measure a slight improvement. The program creates five processes. Each touches 1000 pages then schedules the next process. We repeat this 1000 times. As lguest only caches 4 cr3 values, this rebuilds a lot of shadow page tables requiring virt->phys mappings. Before: 5.93 seconds After: 5.40 seconds (Counts of slow vs fastpath in this usage are 6092 and 2852462 respectively.) And more importantly for lguest, the code is simpler. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-03-28lguest: comment documentation update.Rusty Russell
Took some cycles to re-read the Lguest Journey end-to-end, fix some rot and tighten some phrases. Only comments change. No new jokes, but a couple of recycled old jokes. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-03-11lguest: Revert 1ce70c4fac3c3954bd48c035f448793867592bc0, fix real problem.Rusty Russell
Ahmed managed to crash the Host in release_pgd(), which cannot be a Guest bug, and indeed it wasn't. The bug was that handing a 0 as the address of the toplevel page table being manipulated can cause the lookup code in find_pgdir() to return an uninitialized cache entry (we shadow up to 4 top level page tables for each Guest). Commit 37cc8d7f963ba2deec29c9b68716944516a3244f introduced this behaviour in the Guest, uncovering the bug. The patch which he submitted (which removed the /4 from the index calculation) simply ensured that these high-indexed entries hit the early exit path of guest_set_pmd(). But you get lots of segfaults in guest userspace as the PMDs aren't being updated. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-02-09lguest: accept guest _PAGE_PWT page table entriesAhmed S. Darwish
Beginning from commit 4138cc3418f5, ioremap_nocache() sets the _PAGE_PWT flag. Lguest doesn't accept a guest pte with a _PWT flag and reports a "bad page table entry" in that case. Accept guest _PAGE_PWT page table entries. Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30lguest: use __PAGE_KERNEL instead of _PAGE_KERNELGlauber de Oliveira Costa
x86_64 don't expose the intermediate representation with one underline, _PAGE_KERNEL, just the double-underlined one. Use it, to get a common ground between 32 and 64-bit Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30lguest: get rid of lg variable assignmentsGlauber de Oliveira Costa
We can save some lines of code by getting rid of *lg = cpu... lines of code spread everywhere by now. Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30lguest: change gpte_addr headerGlauber de Oliveira Costa
gpte_addr() does not depend on any guest information. So we wipe out the lg parameter from it completely. Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30lguest: change spte_addr headerGlauber de Oliveira Costa
spte_addr does not depend on any guest information, so we wipe out the lg parameter completely. Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30lguest: per-vcpu lguest pgdir managementGlauber de Oliveira Costa
this patch makes the pgdir management per-vcpu. The pgdirs pool is still guest-wide (although it'll probably need to grow when we are really executing more vcpus), but the pgdidx index is gone, since it makes no sense anymore. Instead, we use a per-vcpu index. Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30lguest: makes special fields be per-vcpuGlauber de Oliveira Costa
lguest struct have room for some fields, namely, cr2, ts, esp1 and ss1, that are not really guest-wide, but rather, vcpu-wide. This patch puts it in the vcpu struct Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30lguest: make registers per-vcpuGlauber de Oliveira Costa
This is the most obvious per-vcpu field: registers. So this patch moves it from struct lguest to struct vcpu, and patch the places in which they are used, accordingly Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30lguest: map_switcher_in_guest() per-vcpuGlauber de Oliveira Costa
The switcher needs to be mapped per-vcpu, because different vcpus will potentially have different page tables (they don't have to, because threads will share the same). So our first step is the make the function receive a vcpu struct Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-25lguest: documentation updateRusty Russell
Went through the documentation doing typo and content fixes. This patch contains only comment and whitespace changes. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-23generalize lgread_u32/lgwrite_u32.Rusty Russell
Jes complains that page table code still uses lgread_u32 even though it now uses general kernel pte types. The best thing to do is to generalize lgread_u32 and lgwrite_u32. This means we lose the efficiency of getuser(). We could potentially regain it if we used __copy_from_user instead of copy_from_user, but I'm not certain that our range check is equivalent to access_ok() on all platforms. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Jes Sorensen <jes@sgi.com>
2007-10-23Boot with virtual == physical to get closer to native Linux.Rusty Russell
1) This allows us to get alot closer to booting bzImages. 2) It means we don't have to know page_offset. 3) The Guest needs to modify the boot pagetables to create the PAGE_OFFSET mapping before jumping to C code. 4) guest_pa() walks the page tables rather than using page_offset. 5) We don't use page_offset to figure out whether to emulate: it was always kinda quesationable, and won't work for instructions done before remapping (bzImage unpacking in particular). 6) We still want the kernel address for tlb flushing: have the initial hypercall give us that, too. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-23Rename "cr3" to "gpgdir" to avoid x86-specific naming.Rusty Russell
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-23Pagetables to use normal kernel typesMatias Zabaljauregui
This is my first step in the migration of page_tables.c to the kernel types and functions/macros (2.6.23-rc3). Seems to be working OK. Signed-off-by: Matias Zabaljauregui <matias.zabaljauregui@cern.ch> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-23Introduce guest mem offset, static link example launcherRusty Russell
In order to avoid problematic special linking of the Launcher, we give the Host an offset: this means we can use any memory region in the Launcher as Guest memory rather than insisting on mmap() at 0. The result is quite pleasing: a number of casts are replaced with simple additions. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-07-26lguest: documentation VII: FIXMEsRusty Russell
Documentation: The FIXMEs Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-26lguest: documentation V: HostRusty Russell
Documentation: The Host Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-26lguest: documentation I: PreparationRusty Russell
The netfilter code had very good documentation: the Netfilter Hacking HOWTO. Noone ever read it. So this time I'm trying something different, using a bit of Knuthiness. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-19lguest: the host codeRusty Russell
This is the code for the "lg.ko" module, which allows lguest guests to be launched. [akpm@linux-foundation.org: update for futex-new-private-futexes] [akpm@linux-foundation.org: build fix] [jmorris@namei.org: lguest: use hrtimers] [akpm@linux-foundation.org: x86_64 build fix] Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Andi Kleen <ak@suse.de> Cc: Eric Dumazet <dada1@cosmosbay.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>