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2008-07-22x86: add PTE_FLAGS_MASKJeremy Fitzhardinge
PTE_PFN_MASK was getting lonely, so I made it a friend. Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-22x86: rename PTE_MASK to PTE_PFN_MASKJeremy Fitzhardinge
Rusty, in his peevish way, complained that macros defining constants should have a name which somewhat accurately reflects the actual purpose of the constant. Aside from the fact that PTE_MASK gives no clue as to what's actually being masked, and is misleadingly similar to the functionally entirely different PMD_MASK, PUD_MASK and PGD_MASK, I don't really see what the problem is. But if this patch silences the incessent noise, then it will have achieved its goal (TODO: write test-case). Signed-off-by: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16xen64: allocate and manage user pagetablesJeremy Fitzhardinge
Because the x86_64 architecture does not enforce segment limits, Xen cannot protect itself with them as it does in 32-bit mode. Therefore, to protect itself, it runs the guest kernel in ring 3. Since it also runs the guest userspace in ring3, the guest kernel must maintain a second pagetable for its userspace, which does not map kernel space. Naturally, the guest kernel pagetables map both kernel and userspace. The userspace pagetable is attached to the corresponding kernel pagetable via the pgd's page->private field. It is allocated and freed at the same time as the kernel pgd via the paravirt_pgd_alloc/free hooks. Fortunately, the user pagetable is almost entirely shared with the kernel pagetable; the only difference is the pgd page itself. set_pgd will populate all entries in the kernel pagetable, and also set the corresponding user pgd entry if the address is less than STACK_TOP_MAX. The user pagetable must be pinned and unpinned with the kernel one, but because the pagetables are aliased, pgd_walk() only needs to be called on the kernel pagetable. The user pgd page is then pinned/unpinned along with the kernel pgd page. xen_write_cr3 must write both the kernel and user cr3s. The init_mm.pgd pagetable never has a user pagetable allocated for it, because it can never be used while running usermode. One awkward area is that early in boot the page structures are not available. No user pagetable can exist at that point, but it complicates the logic to avoid looking at the page structure. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16xen: rework pgd_walk to deal with 32/64 bitJeremy Fitzhardinge
Rewrite pgd_walk to deal with 64-bit address spaces. There are two notible features of 64-bit workspaces: 1. The physical address is only 48 bits wide, with the upper 16 bits being sign extension; kernel addresses are negative, and userspace is positive. 2. The Xen hypervisor mapping is at the negative-most address, just above the sign-extension hole. 1. means that we can't easily use addresses when traversing the space, since we must deal with sign extension. This rewrite expresses everything in terms of pgd/pud/pmd indices, which means we don't need to worry about the exact configuration of the virtual memory space. This approach works equally well in 32-bit. To deal with 2, assume the hole is between the uppermost userspace address and PAGE_OFFSET. For 64-bit this skips the Xen mapping hole. For 32-bit, the hole is zero-sized. In all cases, the uppermost kernel address is FIXADDR_TOP. A side-effect of this patch is that the upper boundary is actually handled properly, exposing a long-standing bug in 32-bit, which failed to pin kernel pmd page. The kernel pmd is not shared, and so must be explicitly pinned, even though the kernel ptes are shared and don't need pinning. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16xen: use set_pte_vaddrJeremy Fitzhardinge
Make Xen's set_pte_mfn() use set_pte_vaddr rather than copying it. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Juan Quintela <quintela@redhat.com> Signed-off-by: Mark McLoughlin <markmc@redhat.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16xen64: use arbitrary_virt_to_machine for xen_set_pmdJeremy Fitzhardinge
When building initial pagetables in 64-bit kernel the pud/pmd pointer may be in ioremap/fixmap space, so we need to walk the pagetable to look up the physical address. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16xen: fix truncation of machine addressJeremy Fitzhardinge
arbitrary_virt_to_machine can truncate a machine address if its above 4G. Cast the problem away. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16xen64: get active_mm from the pdaJeremy Fitzhardinge
x86_64 stores the active_mm in the pda, so fetch it from there. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16xen64: add extra pv_mmu_opsJeremy Fitzhardinge
We need extra pv_mmu_ops for 64-bit, to deal with the extra level of pagetable. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16x86: use __page_aligned_data/bssJeremy Fitzhardinge
Update arch/x86's use of page-aligned variables. The change to arch/x86/xen/mmu.c fixes an actual bug, but the rest are cleanups and to set a precedent. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Eduardo Habkost <ehabkost@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-16pvops-64: call paravirt_post_allocator_init() on setup_arch()Eduardo Habkost
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stephen Tweedie <sct@redhat.com> Cc: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-15Merge branch 'generic-ipi' into generic-ipi-for-linusIngo Molnar
Conflicts: arch/powerpc/Kconfig arch/s390/kernel/time.c arch/x86/kernel/apic_32.c arch/x86/kernel/cpu/perfctr-watchdog.c arch/x86/kernel/i8259_64.c arch/x86/kernel/ldt.c arch/x86/kernel/nmi_64.c arch/x86/kernel/smpboot.c arch/x86/xen/smp.c include/asm-x86/hw_irq_32.h include/asm-x86/hw_irq_64.h include/asm-x86/mach-default/irq_vectors.h include/asm-x86/mach-voyager/irq_vectors.h include/asm-x86/smp.h kernel/Makefile Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-08Merge branches 'x86/numa-fixes', 'x86/apic', 'x86/apm', 'x86/bitops', ↵Ingo Molnar
'x86/build', 'x86/cleanups', 'x86/cpa', 'x86/cpu', 'x86/defconfig', 'x86/gart', 'x86/i8259', 'x86/intel', 'x86/irqstats', 'x86/kconfig', 'x86/ldt', 'x86/mce', 'x86/memtest', 'x86/pat', 'x86/ptemask', 'x86/resumetrace', 'x86/threadinfo', 'x86/timers', 'x86/vdso' and 'x86/xen' into x86/devel
2008-07-04xen: fix address truncation in pte mfn<->pfn conversionJeremy Fitzhardinge
When converting the page number in a pte/pmd/pud/pgd between machine and pseudo-physical addresses, the converted result was being truncated at 32-bits. This caused failures on machines with more than 4G of physical memory. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: "Christopher S. Aker" <caker@theshore.net> Cc: Ian Campbell <Ian.Campbell@eu.citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-26x86: convert to generic helpers for IPI function callsJens Axboe
This converts x86, x86-64, and xen to use the new helpers for smp_call_function() and friends, and adds support for smp_call_function_single(). Acked-by: Ingo Molnar <mingo@elte.hu> Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-06-25xen: add mechanism to extend existing multicallsJeremy Fitzhardinge
Some Xen hypercalls accept an array of operations to work on. In general this is because its more efficient for the hypercall to the work all at once rather than as separate hypercalls (even batched as a multicall). This patch adds a mechanism (xen_mc_extend_args()) to allocate more argument space to the last-issued multicall, in order to extend its argument list. The user of this mechanism is xen/mmu.c, which uses it to extend the args array of mmu_update. This is particularly valuable when doing the update for a large mprotect, which goes via ptep_modify_prot_commit(), but it also manages to batch updates to pgd/pmds as well. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-25xen: implement ptep_modify_prot_start/commitJeremy Fitzhardinge
Xen has a pte update function which will update a pte while preserving its accessed and dirty bits. This means that ptep_modify_prot_start() can be implemented as a simple read of the pte value. The hardware may update the pte in the meantime, but ptep_modify_prot_commit() updates it while preserving any changes that may have happened in the meantime. The updates in ptep_modify_prot_commit() are batched if we're currently in lazy mmu mode. The mmu_update hypercall can take a batch of updates to perform, but this code doesn't make particular use of that feature, in favour of using generic multicall batching to get them all into the hypervisor. The net effect of this is that each mprotect pte update turns from two expensive trap-and-emulate faults into they hypervisor into a single hypercall whose cost is amortized in a batched multicall. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-24xen: remove support for non-PAE 32-bitJeremy Fitzhardinge
Non-PAE operation has been deprecated in Xen for a while, and is rarely tested or used. xen-unstable has now officially dropped non-PAE support. Since Xen/pvops' non-PAE support has also been broken for a while, we may as well completely drop it altogether. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20xen: don't drop NX bitJeremy Fitzhardinge
Because NX is now enforced properly, we must put the hypercall page into the .text segment so that it is executable. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stable Kernel <stable@kernel.org> Cc: the arch/x86 maintainers <x86@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20xen: mask unwanted pte bits in __supported_pte_maskJeremy Fitzhardinge
[ Stable: this isn't a bugfix in itself, but it's a pre-requiste for "xen: don't drop NX bit" ] Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stable Kernel <stable@kernel.org> Cc: the arch/x86 maintainers <x86@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20xen: don't drop NX bitJeremy Fitzhardinge
Because NX is now enforced properly, we must put the hypercall page into the .text segment so that it is executable. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stable Kernel <stable@kernel.org> Cc: the arch/x86 maintainers <x86@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-20xen: mask unwanted pte bits in __supported_pte_maskJeremy Fitzhardinge
[ Stable: this isn't a bugfix in itself, but it's a pre-requiste for "xen: don't drop NX bit" ] Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Stable Kernel <stable@kernel.org> Cc: the arch/x86 maintainers <x86@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-16Merge branch 'linus' into x86/xenIngo Molnar
2008-06-02xen: avoid hypercalls when updating unpinned pud/pmdJeremy Fitzhardinge
When operating on an unpinned pagetable (ie, one under construction or destruction), it isn't necessary to use a hypercall to update a pud/pmd entry. Jan Beulich observed that a similar optimisation avoided many thousands of hypercalls while doing a kernel build. One tricky part is that early in the kernel boot there's no page structure, so we can't check to see if the page is pinned. In that case, we just always use the hypercall. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-02xen: export get_phys_to_machineIngo Molnar
-tip testing found the following xen-console symbols trouble: ERROR: "get_phys_to_machine" [drivers/video/xen-fbfront.ko] undefined! ERROR: "get_phys_to_machine" [drivers/net/xen-netfront.ko] undefined! ERROR: "get_phys_to_machine" [drivers/input/xen-kbdfront.ko] undefined! with: http://redhat.com/~mingo/misc/config-Mon_Jun__2_12_25_13_CEST_2008.bad
2008-05-28xen: fix early bootup crash on native hardwareIngo Molnar
-tip tree auto-testing found the following early bootup hang: --------------> get_memcfg_from_srat: assigning address to rsdp RSD PTR v0 [Nvidia] BUG: Int 14: CR2 ffd00040 EDI 8092fbfe ESI ffd00040 EBP 80b0aee8 ESP 80b0aed0 EBX 000f76f0 EDX 0000000e ECX 00000003 EAX ffd00040 err 00000000 EIP 802c055a CS 00000060 flg 00010006 Stack: ffd00040 80bc78d0 80b0af6c 80b1dbfe 8093d8ba 00000008 80b42810 80b4ddb4 80b42842 00000000 80b0af1c 801079c8 808e724e 00000000 80b42871 802c0531 00000100 00000000 0003fff0 80b0af40 80129999 00040100 00040100 00000000 Pid: 0, comm: swapper Not tainted 2.6.26-rc4-sched-devel.git #570 [<802c055a>] ? strncmp+0x11/0x25 [<80b1dbfe>] ? get_memcfg_from_srat+0xb4/0x568 [<801079c8>] ? mcount_call+0x5/0x9 [<802c0531>] ? strcmp+0xa/0x22 [<80129999>] ? printk+0x38/0x3a [<80129999>] ? printk+0x38/0x3a [<8011b122>] ? memory_present+0x66/0x6f [<80b216b4>] ? setup_memory+0x13/0x40c [<80b16b47>] ? propagate_e820_map+0x80/0x97 [<80b1622a>] ? setup_arch+0x248/0x477 [<80129999>] ? printk+0x38/0x3a [<80b11759>] ? start_kernel+0x6e/0x2eb [<80b110fc>] ? i386_start_kernel+0xeb/0xf2 ======================= <------ with this config: http://redhat.com/~mingo/misc/config-Wed_May_28_01_33_33_CEST_2008.bad The thing is, the crash makes little sense at first sight. We crash on a benign-looking printk. The code around it got changed in -tip but checking those topic branches individually did not reproduce the bug. Bisection led to this commit: | d5edbc1f75420935b1ec7e65df10c8f81cea82de is first bad commit | commit d5edbc1f75420935b1ec7e65df10c8f81cea82de | Author: Jeremy Fitzhardinge <jeremy@goop.org> | Date: Mon May 26 23:31:22 2008 +0100 | | xen: add p2m mfn_list_list Which is somewhat surprising, as on native hardware Xen client side should have little to no side-effects. After some head scratching, it turns out the following happened: randconfig enabled the following Xen options: CONFIG_XEN=y CONFIG_XEN_MAX_DOMAIN_MEMORY=8 # CONFIG_XEN_BLKDEV_FRONTEND is not set # CONFIG_XEN_NETDEV_FRONTEND is not set CONFIG_HVC_XEN=y # CONFIG_XEN_BALLOON is not set which activated this piece of code in arch/x86/xen/mmu.c: > @@ -69,6 +69,13 @@ > __attribute__((section(".data.page_aligned"))) = > { [ 0 ... TOP_ENTRIES - 1] = &p2m_missing[0] }; > > +/* Arrays of p2m arrays expressed in mfns used for save/restore */ > +static unsigned long p2m_top_mfn[TOP_ENTRIES] > + __attribute__((section(".bss.page_aligned"))); > + > +static unsigned long p2m_top_mfn_list[TOP_ENTRIES / P2M_ENTRIES_PER_PAGE] > + __attribute__((section(".bss.page_aligned"))); The problem is, you must only put variables into .bss.page_aligned that have a _size_ that is _exactly_ page aligned. In this case the size of p2m_top_mfn_list is not page aligned: 80b8d000 b p2m_top_mfn 80b8f000 b p2m_top_mfn_list 80b8f008 b softirq_stack 80b97008 b hardirq_stack 80b9f008 b bm_pte So all subsequent variables get unaligned which, depending on luck, breaks the kernel in various funny ways. In this case what killed the kernel first was the misaligned bootmap pte page, resulting in that creative crash above. Anyway, this was a fun bug to track down :-) I think the moral is that .bss.page_aligned is a dangerous construct in its current form, and the symptoms of breakage are very non-trivial, so i think we need build-time checks to make sure all symbols in .bss.page_aligned are truly page aligned. The Xen fix below gets the kernel booting again. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-05-27xen: implement save/restoreJeremy Fitzhardinge
This patch implements Xen save/restore and migration. Saving is triggered via xenbus, which is polled in drivers/xen/manage.c. When a suspend request comes in, the kernel prepares itself for saving by: 1 - Freeze all processes. This is primarily to prevent any partially-completed pagetable updates from confusing the suspend process. If CONFIG_PREEMPT isn't defined, then this isn't necessary. 2 - Suspend xenbus and other devices 3 - Stop_machine, to make sure all the other vcpus are quiescent. The Xen tools require the domain to run its save off vcpu0. 4 - Within the stop_machine state, it pins any unpinned pgds (under construction or destruction), performs canonicalizes various other pieces of state (mostly converting mfns to pfns), and finally 5 - Suspend the domain Restore reverses the steps used to save the domain, ending when all the frozen processes are thawed. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-27xen: add p2m mfn_list_listJeremy Fitzhardinge
When saving a domain, the Xen tools need to remap all our mfns to portable pfns. In order to remap our p2m table, it needs to know where all its pages are, so maintain the references to the p2m table for it to use. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-27xen: efficiently support a holey p2m tableJeremy Fitzhardinge
When using sparsemem and memory hotplug, the kernel's pseudo-physical address space can be discontigious. Previously this was dealt with by having the upper parts of the radix tree stubbed off. Unfortunately, this is incompatible with save/restore, which requires a complete p2m table. The solution is to have a special distinguished all-invalid p2m leaf page, which we can point all the hole areas at. This allows the tools to see a complete p2m table, but it only costs a page for all memory holes. It also simplifies the code since it removes a few special cases. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-27xen: add configurable max domain sizeJeremy Fitzhardinge
Add a config option to set the max size of a Xen domain. This is used to scale the size of the physical-to-machine array; it ends up using around 1 page/GByte, so there's no reason to be very restrictive. For a 32-bit guest, the default value of 8GB is probably sufficient; there's not much point in giving a 32-bit machine much more memory than that. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-27xen: make phys_to_machine structure dynamicJeremy Fitzhardinge
We now support the use of memory hotplug, so the physical to machine page mapping structure must be dynamic. This is implemented as a two-level radix tree structure, which allows us to efficiently incrementally allocate memory for the p2m table as new pages are added. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23x86/xen: fix arbitrary_virt_to_machine()Jan Beulich
While I realize that the function isn't currently being used, I still think an obvious mistake like this should be corrected. Signed-off-by: Jan Beulich <jbeulich@novell.com> Acked-by: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-22xen: remove support for non-PAE 32-bitJeremy Fitzhardinge
Non-PAE operation has been deprecated in Xen for a while, and is rarely tested or used. xen-unstable has now officially dropped non-PAE support. Since Xen/pvops' non-PAE support has also been broken for a while, we may as well completely drop it altogether. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-28pageflags: use proper page flag functions in XenChristoph Lameter
Xen uses bitops to manipulate page flags. Make it use proper page flag functions. Signed-off-by: Christoph Lameter <clameter@sgi.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-24xen: allow set_pte_at on init_mm to be locklessJeremy Fitzhardinge
The usual pagetable locking protocol doesn't seem to apply to updates to init_mm, so don't rely on preemption being disabled in xen_set_pte_at on init_mm. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24xen: unify pte operationsJeremy Fitzhardinge
We can fold the essentially common pte functions together now. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24xen: make use of pte_t unionJeremy Fitzhardinge
pte_t always contains a "pte" field for the whole pte value, so make use of it. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24xen: use appropriate pte typesJeremy Fitzhardinge
Convert Xen pagetable handling to use appropriate *val_t types. Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-04xen: refactor xen_{alloc,release}_{pt,pd}()Mark McLoughlin
Signed-off-by: Mark McLoughlin <markmc@redhat.com> Cc: xen-devel@lists.xensource.com Cc: Mark McLoughlin <markmc@redhat.com> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-02-09x86: sparse warnings in pageattr.cHarvey Harrison
Adjust the definition of lookup_address to take an unsigned long level argument. Adjust callers in xen/mmu.c that pass in a dummy variable. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: return the page table level in lookup_address()Ingo Molnar
based on this patch from Andi Kleen: | Subject: CPA: Return the page table level in lookup_address() | From: Andi Kleen <ak@suse.de> | | Needed for the next change. | | And change all the callers. and ported it to x86.git. Signed-off-by: Andi Kleen <ak@suse.de> Acked-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30xen: fix mismerge in masking pte flagsJeremy Fitzhardinge
Looks like a mismerge/misapply dropped one of the cases of pte flag masking for Xen. Also, only mask the flags for present ptes. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30xen: mask out PWT tooJeremy Fitzhardinge
The hypervisor doesn't allow PCD or PWT to be set on guest ptes, so make sure they're masked out. Also, fix up some previous mispatching. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-01-30x86: page.h: make pte_t a union to always includeJeremy Fitzhardinge
Make sure pte_t, whatever its definition, has a pte element with type pteval_t. This allows common code to access it without needing to be specifically parameterised on what pagetable mode we're compiling for. For 32-bit, this means that pte_t becomes a union with "pte" and "{ pte_low, pte_high }" (PAE) or just "pte_low" (non-PAE). Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2007-11-29xen: mask _PAGE_PCD from ptesJeremy Fitzhardinge
_PAGE_PCD maps a page with caching disabled, which is typically used for mapping harware registers. Xen never allows it to be set on a mapping, and unprivileged guests never need it since they can't see the real underlying hardware. However, some uncached mappings are made early when probing the (non-existent) APIC, and its OK to mask off the PCD flag in these cases. This became necessary because Xen started checking for this bit, rather than silently masking it off. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16xen: lock pte pages while pinning/unpinningJeremy Fitzhardinge
When a pagetable is created, it is made globally visible in the rmap prio tree before it is pinned via arch_dup_mmap(), and remains in the rmap tree while it is unpinned with arch_exit_mmap(). This means that other CPUs may race with the pinning/unpinning process, and see a pte between when it gets marked RO and actually pinned, causing any pte updates to fail with write-protect faults. As a result, all pte pages must be properly locked, and only unlocked once the pinning/unpinning process has finished. In order to avoid taking spinlocks for the whole pagetable - which may overflow the PREEMPT_BITS portion of preempt counter - it locks and pins each pte page individually, and then finally pins the whole pagetable. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickens <hugh@veritas.com> Cc: David Rientjes <rientjes@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andi Kleen <ak@suse.de> Cc: Keir Fraser <keir@xensource.com> Cc: Jan Beulich <jbeulich@novell.com>
2007-10-16xen: deal with stale cr3 values when unpinning pagetablesJeremy Fitzhardinge
When a pagetable is no longer in use, it must be unpinned so that its pages can be freed. However, this is only possible if there are no stray uses of the pagetable. The code currently deals with all the usual cases, but there's a rare case where a vcpu is changing cr3, but is doing so lazily, and the change hasn't actually happened by the time the pagetable is unpinned, even though it appears to have been completed. This change adds a second per-cpu cr3 variable - xen_current_cr3 - which tracks the actual state of the vcpu cr3. It is only updated once the actual hypercall to set cr3 has been completed. Other processors wishing to unpin a pagetable can check other vcpu's xen_current_cr3 values to see if any cross-cpu IPIs are needed to clean things up. [ Stable folks: 2.6.23 bugfix ] Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Stable Kernel <stable@kernel.org>
2007-10-16Clean up duplicate includes in arch/i386/xen/Jesper Juhl
This patch cleans up duplicate includes in arch/i386/xen/ Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
2007-10-16paravirt: clean up lazy mode handlingJeremy Fitzhardinge
Currently, the set_lazy_mode pv_op is overloaded with 5 functions: 1. enter lazy cpu mode 2. leave lazy cpu mode 3. enter lazy mmu mode 4. leave lazy mmu mode 5. flush pending batched operations This complicates each paravirt backend, since it needs to deal with all the possible state transitions, handling flushing, etc. In particular, flushing is quite distinct from the other 4 functions, and seems to just cause complication. This patch removes the set_lazy_mode operation, and adds "enter" and "leave" lazy mode operations on mmu_ops and cpu_ops. All the logic associated with enter and leaving lazy states is now in common code (basically BUG_ONs to make sure that no mode is current when entering a lazy mode, and make sure that the mode is current when leaving). Also, flush is handled in a common way, by simply leaving and re-entering the lazy mode. The result is that the Xen, lguest and VMI lazy mode implementations are much simpler. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Andi Kleen <ak@suse.de> Cc: Zach Amsden <zach@vmware.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Avi Kivity <avi@qumranet.com> Cc: Anthony Liguory <aliguori@us.ibm.com> Cc: "Glauber de Oliveira Costa" <glommer@gmail.com> Cc: Jun Nakajima <jun.nakajima@intel.com>
2007-10-11i386: move xenThomas Gleixner
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>