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path: root/drivers/lguest/core.c
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2009-09-23lguest: cleanup for map_switcher()Xiao Guangrong
We can use alloc_page() instead of get_zeroed_page() and virt_to_page() Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
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: remove obsolete LHREQ_BREAK callRusty Russell
We no longer need an efficient mechanism to force the Guest back into host userspace, as each device is serviced without bothering the main Guest process (aka. the Launcher). Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12lguest: use eventfds for device notificationRusty Russell
Currently, when a Guest wants to perform I/O it calls LHCALL_NOTIFY with an address: the main Launcher process returns with this address, and figures out what device to run. A far nicer model is to let processes bind an eventfd to an address: if we find one, we simply signal the eventfd. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Davide Libenzi <davidel@xmailserver.org>
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>
2009-06-12lguest: improve interrupt handling, speed up stream networkingRusty Russell
lguest never checked for pending interrupts when enabling interrupts, and things still worked. However, it makes a significant difference to TCP performance, so it's time we fixed it by introducing a pending_irq flag and checking it on irq_restore and irq_enable. These two routines are now too big to patch into the 8/10 bytes patch space, so we drop that code. Note: The high latency on interrupt delivery had a very curious effect: once everything else was optimized, networking without GSO was faster than networking with GSO, since more interrupts were sent and hence a greater chance of one getting through to the Guest! Note2: (Almost) Closing the same loophole for iret doesn't have any measurable effect, so I'm leaving that patch for the moment. Before: 1GB tcpblast Guest->Host: 30.7 seconds 1GB tcpblast Guest->Host (no GSO): 76.0 seconds After: 1GB tcpblast Guest->Host: 6.8 seconds 1GB tcpblast Guest->Host (no GSO): 27.8 seconds Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12lguest: fix race in halt codeRusty Russell
When the Guest does the LHCALL_HALT hypercall, we go to sleep, expecting that a timer or the Waker will wake_up_process() us. But we do it in a stupid way, leaving a classic missing wakeup race. So split maybe_do_interrupt() into interrupt_pending() and try_deliver_interrupt(), and check maybe_do_interrupt() and the "break_out" flag before calling schedule. 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>
2009-01-30lguest: typos fixAtsushi SAKAI
3 points lguest_asm.S => i386_head.S LHCALL_BREAK => LHREQ_BREAK perferred => preferred Signed-off-by: Atsushi SAKAI <sakaia@jp.fujitsu.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-29lguest: fix switcher_page leak on unloadJohannes Weiner
map_switcher allocates the array, unmap_switcher has to free it accordingly. Signed-off-by: Johannes Weiner <hannes@saeurebad.de> 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: fix __get_vm_area usage.Rusty Russell
Robert Bragg's 5dc331852848a38ca00a2817e5b98a1d0561b116 tightened (ie. fixed) the checking in __get_vm_area, and it broke lguest. lguest should pass the exact "end" it wants, not some random constant (it was possible previously that it would actually get an address different from SWITCHER_ADDR). Also, Fabio Checconi pointed out that we should make sure we're not hitting the fixmap area. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Robert Bragg <robert@sixbynine.org>
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: make pending notifications per-vcpuGlauber de Oliveira Costa
this patch makes the pending_notify field, used to control pending notifications, per-vcpu, instead of per-guest 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 task managementGlauber de Oliveira Costa
lguest uses tasks to control its running behaviour (like sending breaks, controlling halted state, etc). In a per-vcpu environment, each vcpu will have its own underlying task. So this patch makes the infrastructure for that possible Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30lguest: per-vcpu interrupt processing.Glauber de Oliveira Costa
This patch adapts interrupt processing for using 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 hypercalls use the vcpu structGlauber de Oliveira Costa
this patch changes do_hcall() and do_async_hcall() interfaces (and obviously their callers) to get a vcpu struct. Again, a vcpu services the hypercall, not the whole guest Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30lguest: per-cpu run guestGlauber de Oliveira Costa
This patch makes the run_guest() routine use the lg_cpu struct. This is required since in a smp guest environment, there's no more the notion of "running the guest", but rather, it is "running the vcpu" Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30lguest: Reboot supportBalaji Rao
Reboot Implemented (Prevent fd leak, fix style and fix documentation --RR) Signed-off-by: Balaji Rao <balajirrao@gmail.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-01-30lguest: remove pv_info dependencyGlauber de Oliveira Costa
Currently, lguest module can't be compiled without the PARAVIRT flag being on. This is a fake dependency, since the module itself shouldn't need any paravirt override. Reason for that is the reference to pv_info structure in initial loading tests. This patch removes it in favour of a more generic error message. 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>
2007-10-23Remove old lguest I/O infrrasructure.Rusty Russell
This patch gets rid of the old lguest host I/O infrastructure and replaces it with a single hypercall "LHCALL_NOTIFY" which takes an address. The main change is the removal of io.c: that mainly did inter-guest I/O, which virtio doesn't yet support. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-23Allow guest to specify syscall vector to use.Rusty Russell
(Based on Ron Minnich's LGUEST_PLAN9_SYSCALL patch). This patch allows Guests to specify what system call vector they want, and we try to reserve it. We only allow one non-Linux system call vector, to try to avoid DoS on the Host. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-23Introduce "hcall" pointer to indicate pending hypercall.Rusty Russell
Currently we look at the "trapnum" to see if the Guest wants a hypercall. But once the hypercall is done we have to reset trapnum to a bogus value, otherwise if we exit to userspace and return, we'd run the same hypercall twice (that was a nasty bug to find!). This has two main effects: 1) When Jes's patch changes the hypercall args to be a generic "struct hcall_args" we simply change the type of "lg->hcall". It's set by arch code, so if it has to copy args or something it can do so, and point "hcall" into lg->arch somewhere. 2) Async hypercalls only get run when an actual hypercall is pending. This simplfies the code a little and is a more logical semantic. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-23Move i386 part of core.c to x86/core.c.Jes Sorensen
Separate i386 architecture specific from core.c and move it to x86/core.c and add x86/lguest.h header file to match. Signed-off-by: Jes Sorensen <jes@sgi.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2007-10-23Remove fixed limit on number of guests, and lguests array.Rusty Russell
Back when we had all the Guest state in the switcher, we had a fixed array of them. This is no longer necessary. If we switch the network code to using random_ether_addr (46 bits is enough to avoid clashes), we can get rid of the concept of "guest id" altogether. 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>
2007-10-16paravirt: refactor struct paravirt_ops into smaller pv_*_opsJeremy Fitzhardinge
This patch refactors the paravirt_ops structure into groups of functionally related ops: pv_info - random info, rather than function entrypoints pv_init_ops - functions used at boot time (some for module_init too) pv_misc_ops - lazy mode, which didn't fit well anywhere else pv_time_ops - time-related functions pv_cpu_ops - various privileged instruction ops pv_irq_ops - operations for managing interrupt state pv_apic_ops - APIC operations pv_mmu_ops - operations for managing pagetables There are several motivations for this: 1. Some of these ops will be general to all x86, and some will be i386/x86-64 specific. This makes it easier to share common stuff while allowing separate implementations where needed. 2. At the moment we must export all of paravirt_ops, but modules only need selected parts of it. This allows us to export on a case by case basis (and also choose which export license we want to apply). 3. Functional groupings make things a bit more readable. Struct paravirt_ops is now only used as a template to generate patch-site identifiers, and to extract function pointers for inserting into jmp/calls when patching. It is only instantiated when needed. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Andi Kleen <ak@suse.de> Cc: Zach Amsden <zach@vmware.com> 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>
2007-08-09lguest: Fix Malicious Guest GDT Host CrashRusty Russell
If a Guest makes hypercall which sets a GDT entry to not present, we currently set any segment registers using that GDT entry to 0. Unfortunately, this is not sufficient: there are other ways of altering GDT entries which will cause a fault. The correct solution to do what Linux does: let them set any GDT value they want and handle the #GP when popping causes a fault. This has the added benefit of making our Switcher slightly more robust in the case of any other bugs which cause it to fault. We kill the Guest if it causes a fault in the Switcher: it's the Guest's responsibility to make sure it's not using segments when it changes them. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-26lguest: documentation VI: SwitcherRusty Russell
Documentation: The Switcher 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 IV: LauncherRusty Russell
Documentation: The Launcher 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>