Linus Torvalds [Sat, 13 Oct 2007 17:02:11 +0000 (10:02 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm: (106 commits)
KVM: Replace enum by #define
KVM: Skip pio instruction when it is emulated, not executed
KVM: x86 emulator: popf
KVM: x86 emulator: fix src, dst value initialization
KVM: x86 emulator: jmp abs
KVM: x86 emulator: lea
KVM: X86 emulator: jump conditional short
KVM: x86 emulator: imlpement jump conditional relative
KVM: x86 emulator: sort opcodes into ascending order
KVM: Improve emulation failure reporting
KVM: x86 emulator: pushf
KVM: x86 emulator: call near
KVM: x86 emulator: push imm8
KVM: VMX: Fix exit qualification width on i386
KVM: Move main vcpu loop into subarch independent code
KVM: VMX: Move vm entry failure handling to the exit handler
KVM: MMU: Don't do GFP_NOWAIT allocations
KVM: Rename kvm_arch_ops to kvm_x86_ops
KVM: Simplify memory allocation
KVM: Hoist SVM's get_cs_db_l_bits into core code.
...
Dave Jones [Sat, 13 Oct 2007 01:10:53 +0000 (21:10 -0400)]
Delete filenames in comments.
Since the x86 merge, lots of files that referenced their own filenames
are no longer correct. Rather than keep them up to date, just delete
them, as they add no real value.
Additionally:
- fix up comment formatting in scx200_32.c
- Remove a credit from myself in setup_64.c from a time when we had no SCM
- remove longwinded history from tsc_32.c which can be figured out from
git.
Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Al Viro [Sat, 13 Oct 2007 07:40:24 +0000 (08:40 +0100)]
fix sparc32 breakage (result of vmlinux.lds.S bug)
In commit 4665079cbb2a3e17de82f2ab2940b9f97f37d65e ("[NETNS]: Move some
code into __init section when CONFIG_NET_NS=n") we got a new section -
.exit.text.refok (more of 'let's tell modpost that some bogus calls are
not bogus', a-la text.init.refok).
Unfortunately, the commit in question forgot to add it to TEXT_TEXT,
with rather amusing results.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Al Viro [Sat, 13 Oct 2007 07:16:04 +0000 (08:16 +0100)]
minimal build fixes for uml (fallout from x86 merge)
a) include/asm-um/arch can't just point to include/asm-$(SUBARCH) now
b) arch/{i386,x86_64}/crypto are merged now
c) subarch-obj needed changes
d) cpufeature_64.h should pull "cpufeature_32.h", not <asm/cpufeature_32.h>
since it can be included from asm-um/cpufeature.h
e) in case of uml-i386 we need CONFIG_X86_32 for make and gcc, but not
for Kconfig
f) sysctl.c shouldn't do vdso_enabled for uml-i386 (actually, that one
should be registered from corresponding arch/*/kernel/*, with ifdef
going away; that's a separate patch, though).
With that and with Stephen's patch ("[PATCH net-2.6] uml: hard_header fix")
we have uml allmodconfig building both on i386 and amd64.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Randy Dunlap [Sat, 13 Oct 2007 04:17:49 +0000 (21:17 -0700)]
net core: fix kernel-doc for new function parameters
Fix networking code kernel-doc for newly added parameters.
Warning(linux-2.6.23-git2//net/core/sock.c:879): No description found for parameter 'net'
Warning(linux-2.6.23-git2//net/core/dev.c:570): No description found for parameter 'net'
Warning(linux-2.6.23-git2//net/core/dev.c:594): No description found for parameter 'net'
Warning(linux-2.6.23-git2//net/core/dev.c:617): No description found for parameter 'net'
Warning(linux-2.6.23-git2//net/core/dev.c:641): No description found for parameter 'net'
Warning(linux-2.6.23-git2//net/core/dev.c:667): No description found for parameter 'net'
Warning(linux-2.6.23-git2//net/core/dev.c:722): No description found for parameter 'net'
Warning(linux-2.6.23-git2//net/core/dev.c:959): No description found for parameter 'net'
Warning(linux-2.6.23-git2//net/core/dev.c:1195): No description found for parameter 'dev'
Warning(linux-2.6.23-git2//net/core/dev.c:2105): No description found for parameter 'n'
Warning(linux-2.6.23-git2//net/core/dev.c:3272): No description found for parameter 'net'
Warning(linux-2.6.23-git2//net/core/dev.c:3445): No description found for parameter 'net'
Warning(linux-2.6.23-git2//include/linux/netdevice.h:1301): No description found for parameter 'cpu'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh64-2.6:
sh64: mach-cayman: Build fixes.
sh64: Symbol export fixups.
sh64: linker script tidying and alignment fixups.
sh64: Set KBUILD_IMAGE to make the rpm target happy.
sh64: Kill off obsolete linux/blk.h reference.
sh64: cleanup struct irqaction initializers.
sh64: Kill off dead gdb stub symbol.
sh64: alphanumeric display only on Cayman.
sh64: Add defconfigs for mach-sim and mach-harp.
sh64: update cayman defconfig.
sh64: Tidy up Kconfig dependencies.
sh64: Move consistent DMA routines to arch/sh64/mm/.
sh64: Some symbol exports and build fixes.
sh64: mach-sim: Build fixes.
sh64: mach-harp: Build fixes.
sh64: Kill off duplicate frame pointer option.
sh64: Kill off dead ROM-RAM and generic boards.
sh64: Tidy up includes for Cayman board.
sh64: Move *_p() I/O routine variants to io.h.
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (124 commits)
sh: allow building for both r2d boards in same binary.
sh: fix r2d board detection
sh: Discard .exit.text/.exit.data at runtime.
sh: Fix up some section alignments in linker script.
sh: Fix SH-4 DMAC CHCR masking.
sh: Rip out left-over nommu cond syscall cruft.
sh: Make kgdb i-cache flushing less inept.
sh: kgdb section mismatches and tidying.
sh: cleanup struct irqaction initializers.
sh: early_printk tidying.
video: pvr2fb: Add TV (RGB) support to Dreamcast PVR driver.
sh: Conditionalize gUSA support.
sh: Follow gUSA preempt changes in __switch_to().
sh: Tidy up gUSA preempt handling.
sh: __copy_user() optimizations for small copies.
sh: clkfwk: Support multi-level clock propagation.
sh: Fix URAM start address on SH7785.
sh: Use boot_cpu_data for CPU probe.
sh: Support extended mode TLB on SH-X3.
sh: Bump MAX_ACTIVE_REGIONS for SH7785.
...
linux/drivers/ssb/main.c: In function 'ssb_ssb_read16':
linux/drivers/ssb/main.c:518: error: implicit declaration of function 'readw'
linux/drivers/ssb/main.c: In function 'ssb_ssb_read32':
linux/drivers/ssb/main.c:526: error: implicit declaration of function 'readl'
linux/drivers/ssb/main.c: In function 'ssb_ssb_write16':
linux/drivers/ssb/main.c:534: error: implicit declaration of function 'writew'
linux/drivers/ssb/main.c: In function 'ssb_ssb_write32':
linux/drivers/ssb/main.c:542: error: implicit declaration of function 'writel'
linux/drivers/net/wireless/b43/pio.h: In function 'b43_pio_write':
linux/drivers/net/wireless/b43/pio.h:89: error: implicit declaration of function 'mmiowb'
linux/drivers/net/wireless/b43/phy.c: In function 'b43_phy_write':
linux/drivers/net/wireless/b43/phy.c:301: error: implicit declaration of function 'mmiowb'
linuxdrivers/net/wireless/b43/sysfs.c: In function 'b43_attr_interfmode_store':
linuxdrivers/net/wireless/b43/sysfs.c:147: error: implicit declaration of function 'mmiowb'
emc_endio returns void:
linux/drivers/md/dm-emc.c: In function 'emc_endio':
linux/drivers/md/dm-emc.c:58: warning: 'return' with a value, in function returning void
m68k: Atari input drivers cleanup:
- memleak on failed init/register of input devices fixed
- correct keycodes table (Atari keycodes are almost, but not entirely, equal
to Linux keycodes).
init_dma_ali15x3() guarantees that hwif->dma_base will never be set for
m5229_revision < 0x20 so remove redundant m5229_revision >= 0x20 check from
init_hwif_common_ali15x3().
Set hwif->atapi_dma/{ultra,mwdma}_mask and drive->autodma after checking that
->dma_base exists. If ->dma_base is not set (== PCI BAR4 cannot be reserved)
then DMA hooks shouldn't be initialized or bad things will happen.
OTOH hwif->set_{pio,dma}_mode hooks should be set even if hwif->dma_base == 0.
Set hwif->ide_dma_{check,on} and hwif->autodma to 1 after checking that
->dma_base exists. If ->dma_base is not set (== PCI BAR4 cannot be reserved)
then DMA hooks shouldn't be initialized or bad things will happen.
Devices which don't set word 93 validation bit should be now handled by
ide-iops.c::ivb_list[] and for debugging purposes cable detection can be
completely overriden with "idex=ata66" parameter.
ide: move ide_config_drive_speed() calls to upper layers (take 2)
* Convert {ide_hwif_t,ide_pci_device_t}->host_flag to be u16.
* Add IDE_HFLAG_POST_SET_MODE host flag to indicate the need to program
the host for the transfer mode after programming the device. Set it
in au1xxx-ide, amd74xx, cs5530, cs5535, pdc202xx_new, sc1200, pmac
and via82cxxx host drivers.
* Add IDE_HFLAG_NO_SET_MODE host flag to indicate the need to completely
skip programming of host/device for the transfer mode ("smart" hosts).
Set it in it821x host driver and check it in ide_tune_dma().
* Add ide_set_pio_mode()/ide_set_dma_mode() helpers and convert all
direct ->set_pio_mode/->speedproc users to use these helpers.
* Move ide_config_drive_speed() calls from ->set_pio_mode/->speedproc
methods to callers.
* Rename ->speedproc method to ->set_dma_mode, make it void and update
all implementations accordingly.
* Update ide_set_xfer_rate() comments.
* Unexport ide_config_drive_speed().
v2:
* Fix issues noticed by Sergei:
- export ide_set_dma_mode() instead of moving ->set_pio_mode abuse wrt
to setting DMA modes from sc1200_set_pio_mode() to do_special()
- check IDE_HFLAG_NO_SET_MODE in ide_tune_dma()
- check for (hwif->set_pio_mode) == NULL in ide_set_pio_mode()
- check for (hwif->set_dma_mode) == NULL in ide_set_dma_mode()
- return -1 from ide_set_{pio,dma}_mode() if ->set_{pio,dma}_mode == NULL
- don't set ->set_{pio,dma}_mode on it821x in "smart" mode
- fix build problem in pmac.c
- minor fixes in au1xxx-ide.c/cs5530.c/siimage.c
- improve patch description
Changes in behavior caused by this patch:
- HDIO_SET_PIO_MODE ioctl would now return -ENOSYS for attempts to change
PIO mode if it821x controller is in "smart" mode
- removal of two debugging printk-s (from cs5530.c and sc1200.c)
- transfer modes 0x00-0x07 passed from user space may be programmed twice on
the device (not really an issue since 0x00 is not supported correctly by
any host driver ATM, 0x01 is not supported at all and 0x02-0x07 are invalid)
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
amd74xx/via82cxxx: check ide_config_drive_speed() return value
* Check ide_config_drive_speed() return value.
* While at also call ide_config_drive_speed() if the transfer mode is
XFER_PIO_SLOW (this case happens iff the transfer mode has already been
set on the device by ide-proc.c::set_xfer_rate()) and remove redundant
setting of ->{init,current}_speed.
* Bump driver version.
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Add "good DMA drives" hack for icside to ide-dma.c::ide_find_dma_mode()
(in the long-term it should be either removed or generalized for all hosts).
* Use ide_tune_dma() in icside.c::icside_dma_check().
This results in the following changes in behavior:
- pre-EIDE SWDMA modes are now also respected
- drive->autodma is checked instead of hwif->autodma
(doesn't really matter as icside sets both to "1")
* Make ide-dma.c::__ide_dma_good_drive() static and drop "__" prefix.
Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Add missing initialization of hwif->autodma and drive->autodma to
pmac_ide_setup_dma().
* Use ide_tune_dma() in pmac_ide_dma_check().
While at it:
* Fix pmac_ide_dma_check() return value if DMA mode is not programmed
(should be "-1" otherwise ide_set_dma() will try to enable DMA).
* Remove unnecessary drive->using_dma fiddling (->dma_off_quietly is always
called before ide_set_dma() call and ide_set_dma() calls ->ide_dma_on if
->ide_dma_check returns "0").
v2:
* No reason to blacklist all ide_floppy devices and the old code was always
enabling DMA anyway (without even programming controller/device if the
device was ide_floppy).
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Use ide_config_drive_speed() instead of pmac_ide_do_setfeature() and remove
the latter, also ide-iops.c::__ide_wait_stat() could be static again.
Since for IDE PMAC host driver IDE_CONTROL_REG is always true, device's
->quirk_list is always zero and ->ide_dma_host_{on,off} are nops than
the only changes in behavior are:
* if PIO mode is set then ->dma_off_queitly is called to disable DMA
* if setting transfer mode fails ide_dump_status() is called to dump status
v2:
* IDE PMAC controllers allow separate PIO and DMA timings and PPC userland
depends on this fact, and calls "hdparm -p" without calling "hdparm -d".
Therefore to compensate for DMA being disabled by ide_config_drive_speed()
for PIO modes:
- add IDE_HFLAG_SET_PIO_MODE_KEEP_DMA flag and set it in PMAC host driver
- add handling of the new flag to ide-io.c::do_special()
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Split off checking of the status register from ide_wait_stat() to
__ide_wait_stat() helper.
* Use the new helper in ide_config_drive_speed(). The only change in the
functionality is that the function now fails if after 20 sec (WAIT_CMD)
device is still busy (BUSY_STAT bit is set) while previously instead of
failing the function continued with checking for the correct device status
(which would give the device additional 10 usec to clear BUSY_STAT bit).
* Remove stale comment for ide_config_drive_speed().
* Remove duplicate comment for ide_wait_stat() from <linux/ide.h>.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
ide-pmac: remove control register messing from pmac_ide_dma_check()
pmac_ide_do_setfeature() contains matching nIEN setting/clearing so this
Device Control register messing in pmac_ide_dma_check() is totally unnecessary.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
* Don't check check for pmif == NULL (it should never be NULL if we got here).
* Make a local copy of the timings and set the pmif->timings[] only after
setting the transfer mode on the device (otherwise SELECT_DRIVE() call in
pmac_ide_do_setfeature() will program new timings before the transfer mode
is set on the device - this was pointed out by Sergei). This change makes
pmac_ide_tune_chipset() behavior match this of pmac_ide_{m,u}dma_enable().
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Adrian Bunk [Sat, 13 Oct 2007 15:47:48 +0000 (17:47 +0200)]
ide: unexport ide_acpi_set_state
This patch removes the unused EXPORT_SYMBOL_GPL(ide_acpi_set_state)
Signed-off-by: Adrian Bunk <bunk@kernel.org> Cc: Shaohua Li <shaohua.li@intel.com> Cc: Len Brown <lenb@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
This is the driver for latest Blackfin on-chip nand flash controller
- use nand_chip and mtd_info common nand driver interface
- provide both PIO and dma operation
- compiled with ezkit bf548 configuration
- use hardware 1-bit ECC
- tested with YAFFS2 and can mount YAFFS2 filesystem as rootfs
ChangeLog from try#1
- use hweight32() instead of count_bits()
- replace bf54x with bf5xx and BF54X with BF5XX
- compare against plat->page_size in 2 cases when enable hardware ECC
ChangeLog from try#2
- passed nand_test suites
- use cpu_relax() instead of busy wait loop
- some coding style issue pointed out by Andrew
Signed-off-by: Bryan Wu <bryan.wu@analog.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Kevin Hao [Tue, 2 Oct 2007 20:56:04 +0000 (13:56 -0700)]
[MTD] [NOR] fix ctrl-alt-del can't reboot for intel flash bug
When we press ctrl-alt-del,kernel_restart_prepare will invoke
cfi_intelext_reboot which will set flash to read array mode, but later
when device_shutdown is invoked which may put current work queue to
sleep and other process may be scheduled to running and programming
flash in not FL_READY mode again. So we can't boot up if this flash is
used for bootloader.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
David Woodhouse [Sat, 13 Oct 2007 10:31:23 +0000 (11:31 +0100)]
[JFFS2] Check whether garbage-collection actually obsoleted its victim.
In OLPC trac #4184 we found a case where a corrupted node didn't
actually get obsoleted when we tried to garbage-collect it. So we wrote
out many million copies of it, in repeated attempts to obsolete it,
until the flash became full. Don't Do That.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
David Woodhouse [Sat, 13 Oct 2007 10:29:07 +0000 (11:29 +0100)]
[JFFS2] Relax threshold for triggering GC due to dirty blocks.
Instead of matching resv_blocks_gcmerge, which is only about 3, instead
match resv_blocks_gctrigger, which includes a proportion of the total
device size.
These ought to become tunable from userspace, at some point.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Avi Kivity [Sat, 15 Sep 2007 14:34:36 +0000 (17:34 +0300)]
KVM: Skip pio instruction when it is emulated, not executed
If we defer updating rip until pio instructions are executed, we have a
problem with reset: a pio reset updates rip, and when the instruction
completes we skip the emulated instruction, pointing rip somewhere completely
unrelated.
Fix by updating rip when we see decode the instruction, not after emulation.
According to Intel Software Developer's Manual, Vol. 3B, Appendix H.4.2,
exit qualification should be of natural width. However, current code
uses u64 as the data type for this register, which occasionally
introduces invalid value to VMExit handling logics. This patch fixes
this bug.
I have tested Windows and Linux guest on i386 host, and they can boot
successfully with this patch.
Signed-off-by: Qing He <qing.he@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
Avi Kivity [Mon, 10 Sep 2007 08:28:17 +0000 (11:28 +0300)]
KVM: MMU: Don't do GFP_NOWAIT allocations
Before preempt notifiers, kvm needed to allocate memory with GFP_NOWAIT so
as not to have to enable preemption and take a heavyweight exit. On oom, we'd
fall back to a GFP_KERNEL allocation.
With preemption notifiers, we can do a GFP_KERNEL allocation, and perform
the heavyweight exit only if the kernel decides to put us to sleep.
Laurent Vivier [Thu, 30 Aug 2007 12:56:21 +0000 (14:56 +0200)]
KVM: Simplify memory allocation
The mutex->splinlock convertion alllows us to make some code simplifications.
As we can keep the lock longer, we don't have to release it and then
have to check if the environment has not been modified before re-taking it. We
can remove kvm->busy and kvm->memory_config_version.
Signed-off-by: Laurent Vivier <Laurent.Vivier@bull.net> Signed-off-by: Avi Kivity <avi@qumranet.com>
Rusty Russell [Sun, 9 Sep 2007 11:12:54 +0000 (14:12 +0300)]
KVM: Clean up unloved invlpg emulation
invlpg shouldn't fetch the "src" address, since it may not be valid,
however SVM's "solution" which neuters emulation of all group 7
instruction is horrible and breaks kvm-lite. The simplest fix is to
put a special check in for invlpg.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Avi Kivity <avi@qumranet.com>
Qing He [Mon, 17 Sep 2007 06:47:13 +0000 (14:47 +0800)]
KVM: deliver PIC interrupt only to vcpu0
This patch changes the PIC interrupts delivery. Now it is only delivered
to vcpu0 when either condition is met (on vcpu0):
1. local APIC is hardware disabled
2. LVT0 is unmasked and configured to delivery mode ExtInt
It fixes the 2x faster wall clock on x86_64 and SMP i386 Linux guests
Signed-off-by: Eddie (Yaozu) Dong <eddie.dong@intel.com> Signed-off-by: Qing He <qing.he@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
Eddie Dong [Mon, 3 Sep 2007 13:56:58 +0000 (16:56 +0300)]
KVM: Keep track of missed timer irq injections
APIC timer IRQ is set every time when a certain period
expires at host time, but the guest may be descheduled
at that time and thus the irq be overwritten by later fire.
This patch keep track of firing irq numbers and decrease
only when the IRQ is injected to guest or buffered in
APIC.
Signed-off-by: Yaozu (Eddie) Dong <Eddie.Dong@intel.com> Signed-off-by: Qing He <qing.he@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
This patch enables TPR shadow of VMX on CR8 access. 64bit Windows using
CR8 access TPR frequently. The TPR shadow can improve the performance of
access TPR by not causing vmexit.
Signed-off-by: Sheng Yang <sheng.yang@intel.com> Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com> Signed-off-by: Qing He <qing.he@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
Eddie Dong [Thu, 6 Sep 2007 09:22:56 +0000 (12:22 +0300)]
KVM: in-kernel LAPIC save and restore support
This patch adds a new vcpu-based IOCTL to save and restore the local
apic registers for a single vcpu. The kernel only copies the apic page as
a whole, extraction of registers is left to userspace side. On restore, the
APIC timer is restarted from the initial count, this introduces a little
delay, but works fine.
Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com> Signed-off-by: Qing He <qing.he@intel.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
He, Qing [Thu, 2 Aug 2007 11:03:07 +0000 (14:03 +0300)]
KVM: Bypass irq_pending get/set when using in kernel irqchip
vcpu->irq_pending is saved in get/set_sreg IOCTL, but when in-kernel
local APIC is used, doing this may occasionally overwrite vcpu->apic to
an invalid value, as in the vm restore path.