linux/arch
Jan Kiszka 4d25a066b6 KVM: Don't automatically expose the TSC deadline timer in cpuid
Unlike all of the other cpuid bits, the TSC deadline timer bit is set
unconditionally, regardless of what userspace wants.

This is broken in several ways:
 - if userspace doesn't use KVM_CREATE_IRQCHIP, and doesn't emulate the TSC
   deadline timer feature, a guest that uses the feature will break
 - live migration to older host kernels that don't support the TSC deadline
   timer will cause the feature to be pulled from under the guest's feet;
   breaking it
 - guests that are broken wrt the feature will fail.

Fix by not enabling the feature automatically; instead report it to userspace.
Because the feature depends on KVM_CREATE_IRQCHIP, which we cannot guarantee
will be called, we expose it via a KVM_CAP_TSC_DEADLINE_TIMER and not
KVM_GET_SUPPORTED_CPUID.

Fixes the Illumos guest kernel, which uses the TSC deadline timer feature.

[avi: add the KVM_CAP + documentation]

Reported-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
Tested-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-26 13:27:44 +02:00
..
alpha Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
arm Merge branch 'rmobile-fixes-for-linus' of git://github.com/pmundt/linux-sh 2011-12-20 11:32:18 -08:00
avr32 Merge git://git.infradead.org/mtd-2.6 2011-11-07 09:11:16 -08:00
blackfin blackfin: Fixup export.h includes 2011-11-14 17:15:23 +08:00
cris net: Fix references to deleted NET_ETHERNET Kconfig setting. 2011-11-09 19:26:53 -05:00
frv kgdb: follow rename pack_hex_byte() to hex_byte_pack() 2011-10-31 17:30:56 -07:00
h8300 Merge branch 'gpio/next' of git://git.secretlab.ca/git/linux-2.6 2011-10-29 07:27:45 -07:00
hexagon Hexagon: Add basic stacktrace functionality for Hexagon architecture. 2011-11-01 07:34:21 -07:00
ia64 Merge branch 'upstream/xen-settime' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen 2011-11-06 20:15:05 -08:00
m32r Merge branch 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2011-11-06 18:54:53 -08:00
m68k m68k: Wire up process_vm_{read,write}v 2011-12-06 20:37:58 +01:00
microblaze microblaze: bury asm/namei.h 2011-11-21 16:48:28 -05:00
mips Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2011-12-05 16:54:00 -08:00
mn10300 kgdb: follow rename pack_hex_byte() to hex_byte_pack() 2011-10-31 17:30:56 -07:00
openrisc Merge branch 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild 2011-11-06 18:54:53 -08:00
parisc parisc: Add export.h to files needing EXPORT_SYMBOL/THIS_MODULE 2011-10-31 19:31:00 -04:00
powerpc powerpc/44x: Add mtd ndfc to the ppx44x defconfig 2011-11-25 10:06:00 +11:00
s390 oprofile: Fix uninitialized memory access when writing to writing to oprofilefs 2011-12-19 17:18:43 +01:00
score score: drop unused Kconfig symbols 2011-10-31 23:39:51 +01:00
sh sh: fix build warning in board-sh7757lcr 2011-11-18 16:45:50 +09:00
sparc sparc64: Fix MSIQ HV call ordering in pci_sun4v_msiq_build_irq(). 2011-12-22 13:46:53 -08:00
tile arch/tile: use new generic {enable,disable}_percpu_irq() routines 2011-12-03 15:31:49 -05:00
um Merge branch 'for-linus' of git://github.com/richardweinberger/linux 2011-11-02 09:45:39 -07:00
unicore32 unicore32, exec: remove redundant set_fs(USER_DS) 2011-11-16 10:50:09 +08:00
x86 KVM: Don't automatically expose the TSC deadline timer in cpuid 2011-12-26 13:27:44 +02:00
xtensa Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2011-10-26 17:15:03 +02:00
.gitignore
Kconfig