linux/arch
Sean Christopherson 39497d7660 KVM: lapic: Track lapic timer advance per vCPU
Automatically adjusting the globally-shared timer advancement could
corrupt the timer, e.g. if multiple vCPUs are concurrently adjusting
the advancement value.  That could be partially fixed by using a local
variable for the arithmetic, but it would still be susceptible to a
race when setting timer_advance_adjust_done.

And because virtual_tsc_khz and tsc_scaling_ratio are per-vCPU, the
correct calibration for a given vCPU may not apply to all vCPUs.

Furthermore, lapic_timer_advance_ns is marked __read_mostly, which is
effectively violated when finding a stable advancement takes an extended
amount of timer.

Opportunistically change the definition of lapic_timer_advance_ns to
a u32 so that it matches the style of struct kvm_timer.  Explicitly
pass the param to kvm_create_lapic() so that it doesn't have to be
exposed to lapic.c, thus reducing the probability of unintentionally
using the global value instead of the per-vCPU value.

Cc: Liran Alon <liran.alon@oracle.com>
Cc: Wanpeng Li <wanpengli@tencent.com>
Reviewed-by: Liran Alon <liran.alon@oracle.com>
Cc: stable@vger.kernel.org
Fixes: 3b8a5df6c4 ("KVM: LAPIC: Tune lapic_timer_advance_ns automatically")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-04-18 18:55:41 +02:00
..
alpha KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
arc syscalls: Remove start and number from syscall_get_arguments() args 2019-04-05 09:26:43 -04:00
arm ARM: SoC fixes 2019-04-07 13:46:17 -10:00
arm64 ARM: SoC fixes 2019-04-07 13:46:17 -10:00
c6x syscalls: Remove start and number from syscall_set_arguments() args 2019-04-05 09:27:23 -04:00
csky syscalls: Remove start and number from syscall_set_arguments() args 2019-04-05 09:27:23 -04:00
h8300 syscalls: Remove start and number from syscall_get_arguments() args 2019-04-05 09:26:43 -04:00
hexagon syscalls: Remove start and number from syscall_get_arguments() args 2019-04-05 09:26:43 -04:00
ia64 syscalls: Remove start and number from syscall_set_arguments() args 2019-04-05 09:27:23 -04:00
m68k KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
microblaze syscalls: Remove start and number from syscall_set_arguments() args 2019-04-05 09:27:23 -04:00
mips A few minor MIPS fixes: 2019-04-09 16:27:18 -10:00
nds32 syscalls: Remove start and number from syscall_set_arguments() args 2019-04-05 09:27:23 -04:00
nios2 syscalls: Remove start and number from syscall_set_arguments() args 2019-04-05 09:27:23 -04:00
openrisc syscalls: Remove start and number from syscall_set_arguments() args 2019-04-05 09:27:23 -04:00
parisc parisc: Detect QEMU earlier in boot process 2019-04-06 19:07:55 +02:00
powerpc KVM/PPC fixes for 5.1 2019-04-18 18:53:12 +02:00
riscv Andy Lutomirski approached me to tell me that the syscall_get_arguments() 2019-04-05 13:15:57 -10:00
s390 syscalls: Remove start and number from syscall_set_arguments() args 2019-04-05 09:27:23 -04:00
sh Merge branch 'akpm' (patches from Andrew) 2019-04-05 17:08:55 -10:00
sparc syscalls: Remove start and number from syscall_set_arguments() args 2019-04-05 09:27:23 -04:00
um syscalls: Remove start and number from syscall_set_arguments() args 2019-04-05 09:27:23 -04:00
unicore32 KVM: export <linux/kvm_para.h> and <asm/kvm_para.h> iif KVM is supported 2019-03-28 17:27:42 +01:00
x86 KVM: lapic: Track lapic timer advance per vCPU 2019-04-18 18:55:41 +02:00
xtensa xtensa fixes for v5.1-rc5 2019-04-08 17:04:42 -10:00
.gitignore
Kconfig Char/Misc driver patches for 5.1-rc1 2019-03-06 14:18:59 -08:00