06 Dec, 2011
1 commit
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The x86_64 kernel pushes the fake kernel stack in
arch/x86/kernel/entry_64.S:FAKE_STACK_FRAME, and
rflags register in it does not conform to the specification.Although Intel's manual[1] says bit 1 of it shall be set to 1,
this bit is cleared to 0 on pushing the fake stack.[1] Intel(R) 64 and IA-32 Architectures Software Developer's Manual
Vol.1 3-21 Figure 3-8. EFLAGS RegisterIf it is not on purpose, it is better to be fixed, because
it can lead some tools misunderstanding the stack frame. For example,
"crash" utility[2] actually detects it and warns you like
below:RIP: ffffffff8005dfa2 RSP: ffff8104ce0c7f58 RFLAGS: 00000200
[...]bt: WARNING: possibly bogus exception frame
Signed-off-by: Seiichi Ikarashi
Tested-by: Masayoshi MIZUMA
Cc: Jan Beulich
Cc: Frederic Weisbecker
Cc: Linus Torvalds
Signed-off-by: Ingo Molnar
22 Jul, 2011
3 commits
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We were blatting too much of the register. Linux didn't care, but in
theory it might.Reported-by: Jonas Maebe
Signed-off-by: Rusty Russell -
Also removes a long-unused #define and an extraneous semicolon.
Signed-off-by: Rusty Russell
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Now we no longer use vmcall, we don't need to rewrite it in the Guest.
Signed-off-by: Rusty Russell
20 Jan, 2011
2 commits
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arch/x86/lguest/boot.c: In function ‘lguest_init_IRQ’:
arch/x86/lguest/boot.c:824: error: macro "__this_cpu_write" requires 2 arguments, but only 1 given
arch/x86/lguest/boot.c:824: error: ‘__this_cpu_write’ undeclared (first use in this function)
arch/x86/lguest/boot.c:824: error: (Each undeclared identifier is reported only once
arch/x86/lguest/boot.c:824: error: for each function it appears in.)drivers/lguest/x86/core.c: In function ‘copy_in_guest_info’:
drivers/lguest/x86/core.c:94: error: lvalue required as left operand of assignmentSigned-off-by: Rusty Russell
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Use this_cpu_ops in a couple of places in lguest.
Signed-off-by: Christoph Lameter
Signed-off-by: Rusty Russell
14 Apr, 2010
1 commit
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It's only used by cmpxchg8b_emu (see db677ffa5f5a for the gory
details), and fixing that to be paravirt aware would be more work than
simply ignoring it (and AFAICT only help lguest). This makes lguest
work on machines which have cmpxchg8b, for kernels compiled for older
processors.(We can't emulate it properly: the popf which expects to restore interrupts
does not trap).Signed-off-by: Rusty Russell
Cc: Jeremy Fitzhardinge
Cc: virtualization@lists.osdl.org
29 Oct, 2009
1 commit
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This patch updates misc percpu related symbols such that percpu
symbols are unique and don't clash with local symbols. This serves
two purposes of decreasing the possibility of global percpu symbol
collision and allowing dropping per_cpu__ prefix from percpu symbols.* drivers/crypto/padlock-aes.c: s/last_cword/paes_last_cword/
* drivers/lguest/x86/core.c: s/last_cpu/lg_last_cpu/
* drivers/s390/net/netiucv.c: rename the variable used in a macro to
avoid clashing with percpu symbol* arch/mn10300/kernel/kprobes.c: replace current_ prefix with cur_ for
static variables. Please note that percpu symbol current_kprobe
can't be changed as it's used by generic code.Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.Signed-off-by: Tejun Heo
Reviewed-by: Christoph Lameter
Cc: Rusty Russell
Cc: Herbert Xu
Cc: Chuck Ebbert
Cc: David Howells
Cc: Koichi Yasutake
Cc: Ananth N Mavinakayanahalli
Cc: Anil S Keshavamurthy
Cc: David S. Miller
Cc: Masami Hiramatsu
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Cc: linux390@de.ibm.com
30 Jul, 2009
2 commits
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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
Cc: Ingo Molnar
Cc: Paul McKenney -
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
Cc: Ingo Molnar
27 May, 2009
1 commit
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When KVM is loaded, and hence VT set up, the vmcall instruction in an
lguest guest causes a #GP, not #UD.Signed-off-by: Rusty Russell
Signed-off-by: Linus Torvalds
19 Apr, 2009
2 commits
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Fixes guest crash 'lguest: bad read address 0x4800000 len 256'
The new per-cpu allocator ends up handing a non-linear address to
write_gdt_entry. We do __pa() on it, and hand it to the host, which
kills us.I've long wanted to make the hypercall "LOAD_GDT_ENTRY" to match the IDT
code, but had no pressing reason until now.Signed-off-by: Rusty Russell
Cc: lguest@ozlabs.org -
Typical message: 'lguest: unhandled trap 6 at 0x418726 (0x0)'
vmlinux guests were broken by 4cd8b5e2a159f18a1507f1187b44a1acbfa6341b
'lguest: use KVM hypercalls', which rewrites guest text from kvm hypercalls
to trap 31.The Launcher mmaps the kernel image. The Guest executes and
immediately faults in the first text page (read-only). Then it hits a
hypercall, and we rewrite that hypercall, causing a copy-on-write.
But the Guest pagetables still refer to the old page: we fault again,
but as Host we see the hypercall already rewritten, and pass the fault
back to the Guest. The Guest hasn't set up an IDT yet, so we kill it.This doesn't happen with bzImages: they unpack themselves and so the
text pages are already read-write.Signed-off-by: Rusty Russell
Tested-by: Patrick McHardy
30 Mar, 2009
1 commit
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Impact: cleanup
This patch allow us to use KVM hypercalls
Signed-off-by: Matias Zabaljauregui
Signed-off-by: Rusty Russell
29 Jul, 2008
1 commit
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To support my little make-x86-bitops-use-proper-typechecking projectlet.
Cc: Thomas Gleixner
Cc: Andrea Arcangeli
Signed-off-by: Andrew Morton
Acked-by: Ingo Molnar
Signed-off-by: Rusty Russell
26 Jun, 2008
1 commit
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It's not even passed on to smp_call_function() anymore, since that
was removed. So kill it.Acked-by: Jeremy Fitzhardinge
Reviewed-by: Paul E. McKenney
Signed-off-by: Jens Axboe
20 Jun, 2008
1 commit
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I am able to reproduce the oops reported by Simon in __switch_to() with
lguest.My debug showed that there is at least one lguest specific
issue (which should be present in 2.6.25 and before aswell) and it got
exposed with a kernel oops with the recent fpu dynamic allocation patches.In addition to the previous possible scenario (with fpu_counter), in the
presence of lguest, it is possible that the cpu's TS bit it still set and the
lguest launcher task's thread_info has TS_USEDFPU still set.This is because of the way the lguest launcher handling the guest's TS bit.
(look at lguest_set_ts() in lguest_arch_run_guest()). This can result
in a DNA fault while doing unlazy_fpu() in __switch_to(). This will
end up causing a DNA fault in the context of new process thats
getting context switched in (as opossed to handling DNA fault in the context
of lguest launcher/helper process).This is wrong in both pre and post 2.6.25 kernels. In the recent
2.6.26-rc series, this is showing up as NULL pointer dereferences or
sleeping function called from atomic context(__switch_to()), as
we free and dynamically allocate the FPU context for the newly
created threads. Older kernels might show some FPU corruption for processes
running inside of lguest.With the appended patch, my test system is running for more than 50 mins
now. So atleast some of your oops (hopefully all!) should get fixed.
Please give it a try. I will spend more time with this fix tomorrow.Reported-by: Simon Holm Thøgersen
Reported-by: Patrick McHardy
Signed-off-by: Suresh Siddha
Signed-off-by: Ingo Molnar
28 Mar, 2008
1 commit
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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
31 Jan, 2008
2 commits
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drivers/lguest/x86/core.c: In function ‘copy_in_guest_info’:
drivers/lguest/x86/core.c:97: error: ‘struct x86_hw_tss’ has no member named ‘esp1’Signed-off-by: Rusty Russell
Signed-off-by: Linus Torvalds -
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: (27 commits)
lguest: use __PAGE_KERNEL instead of _PAGE_KERNEL
lguest: Use explicit includes rateher than indirect
lguest: get rid of lg variable assignments
lguest: change gpte_addr header
lguest: move changed bitmap to lg_cpu
lguest: move last_pages to lg_cpu
lguest: change last_guest to last_cpu
lguest: change spte_addr header
lguest: per-vcpu lguest pgdir management
lguest: make pending notifications per-vcpu
lguest: makes special fields be per-vcpu
lguest: per-vcpu lguest task management
lguest: replace lguest_arch with lg_cpu_arch.
lguest: make registers per-vcpu
lguest: make emulate_insn receive a vcpu struct.
lguest: map_switcher_in_guest() per-vcpu
lguest: per-vcpu interrupt processing.
lguest: per-vcpu lguest timers
lguest: make hypercalls use the vcpu struct
lguest: make write() operation smp aware
...Manual conflict resolved (maybe even correctly, who knows) in
drivers/lguest/x86/core.c
30 Jan, 2008
14 commits
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This changes size-specific register names (eip/rip, esp/rsp, etc.) to
generic names in the thread and tss structures.Signed-off-by: H. Peter Anvin
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner -
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
Signed-off-by: Rusty Russell -
events represented in the 'changed' bitmap are per-cpu, not per-guest.
move it to the lg_cpu structureSigned-off-by: Glauber de Oliveira Costa
Signed-off-by: Rusty Russell -
in our new model, pages are assigned to a virtual cpu, not to a guest.
We move it to the lg_cpu structure.Signed-off-by: Glauber de Oliveira Costa
Signed-off-by: Rusty Russell -
in our model, a guest does not run in a cpu anymore: a virtual cpu
does. So we change last_guest to last_cpuSigned-off-by: Glauber de Oliveira Costa
Signed-off-by: Rusty Russell -
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
Signed-off-by: Rusty Russell -
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
Signed-off-by: Rusty Russell -
The fields found in lguest_arch are not really per-guest,
but per-cpu (gdt, idt, etc). So this patch turns lguest_arch
into lg_cpu_arch.It makes sense to have a per-guest per-arch struct, but this
can be addressed later, when the need arrives.Signed-off-by: Glauber de Oliveira Costa
Signed-off-by: Rusty Russell -
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, accordinglySigned-off-by: Glauber de Oliveira Costa
Signed-off-by: Rusty Russell -
emulate_insn() needs to know about current eip, which will be,
in the future, a per-vcpu thing. So in this patch, the function
prototype is modified to receive a vcpu structSigned-off-by: Glauber de Oliveira Costa
Signed-off-by: Rusty Russell -
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
Signed-off-by: Rusty Russell -
This patch adapts interrupt processing for using the vcpu struct.
Signed-off-by: Glauber de Oliveira Costa
Signed-off-by: Rusty Russell -
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
guestSigned-off-by: Glauber de Oliveira Costa
Signed-off-by: Rusty Russell -
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
Signed-off-by: Rusty Russell
26 Jan, 2008
1 commit
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Replace all lock_cpu_hotplug/unlock_cpu_hotplug from the kernel and use
get_online_cpus and put_online_cpus instead as it highlights the
refcount semantics in these operations.The new API guarantees protection against the cpu-hotplug operation, but
it doesn't guarantee serialized access to any of the local data
structures. Hence the changes needs to be reviewed.In case of pseries_add_processor/pseries_remove_processor, use
cpu_maps_update_begin()/cpu_maps_update_done() as we're modifying the
cpu_present_map there.Signed-off-by: Gautham R Shenoy
Signed-off-by: Ingo Molnar
25 Oct, 2007
2 commits
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Went through the documentation doing typo and content fixes. This
patch contains only comment and whitespace changes.Signed-off-by: Rusty Russell
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Signed-off-by: Rusty Russell
23 Oct, 2007
3 commits
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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
Acked-by: Jes Sorensen -
This gets rid of the lguest bus, drivers and DMA mechanism, to make
way for a generic virtio mechanism.Signed-off-by: Rusty Russell
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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