linux_dsm_epyc7002/arch
Wanpeng Li 6550c4df7e KVM: nVMX: Fix interrupt window request with "Acknowledge interrupt on exit"
------------[ cut here ]------------
 WARNING: CPU: 5 PID: 2288 at arch/x86/kvm/vmx.c:11124 nested_vmx_vmexit+0xd64/0xd70 [kvm_intel]
 CPU: 5 PID: 2288 Comm: qemu-system-x86 Not tainted 4.13.0-rc2+ #7
 RIP: 0010:nested_vmx_vmexit+0xd64/0xd70 [kvm_intel]
Call Trace:
  vmx_check_nested_events+0x131/0x1f0 [kvm_intel]
  ? vmx_check_nested_events+0x131/0x1f0 [kvm_intel]
  kvm_arch_vcpu_ioctl_run+0x5dd/0x1be0 [kvm]
  ? vmx_vcpu_load+0x1be/0x220 [kvm_intel]
  ? kvm_arch_vcpu_load+0x62/0x230 [kvm]
  kvm_vcpu_ioctl+0x340/0x700 [kvm]
  ? kvm_vcpu_ioctl+0x340/0x700 [kvm]
  ? __fget+0xfc/0x210
  do_vfs_ioctl+0xa4/0x6a0
  ? __fget+0x11d/0x210
  SyS_ioctl+0x79/0x90
  do_syscall_64+0x8f/0x750
  ? trace_hardirqs_on_thunk+0x1a/0x1c
  entry_SYSCALL64_slow_path+0x25/0x25

This can be reproduced by booting L1 guest w/ 'noapic' grub parameter, which
means that tells the kernel to not make use of any IOAPICs that may be present
in the system.

Actually external_intr variable in nested_vmx_vmexit() is the req_int_win
variable passed from vcpu_enter_guest() which means that the L0's userspace
requests an irq window. I observed the scenario (!kvm_cpu_has_interrupt(vcpu) &&
L0's userspace reqeusts an irq window) is true, so there is no interrupt which
L1 requires to inject to L2, we should not attempt to emualte "Acknowledge
interrupt on exit" for the irq window requirement in this scenario.

This patch fixes it by not attempt to emulate "Acknowledge interrupt on exit"
if there is no L1 requirement to inject an interrupt to L2.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
[Added code comment to make it obvious that the behavior is not correct.
 We should do a userspace exit with open interrupt window instead of the
 nested VM exit.  This patch still improves the behavior, so it was
 accepted as a (temporary) workaround.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-08-03 15:38:11 +02:00
..
alpha tty: Fix TIOCGPTPEER ioctl definition 2017-07-17 17:04:41 +02:00
arc dma-coherent: introduce interface for default DMA pool 2017-07-20 16:09:10 +02:00
arm arm64 fixes: 2017-07-28 13:29:36 -07:00
arm64 arm64 fixes: 2017-07-28 13:29:36 -07:00
blackfin Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-21 10:41:19 -07:00
c6x Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
cris Kbuild updates for v4.13 (2nd) 2017-07-13 13:37:57 -07:00
frv FRV: tlbflush: move asmlinkage before return type 2017-07-12 16:26:04 -07:00
h8300 h8300: Add missing closing parenthesis in flat_get_addr_from_rp() 2017-07-16 09:24:06 -07:00
hexagon hexagon: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-10 03:43:26 +09:00
ia64 Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
m32r Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
m68k blackfin, m68k: Fix flat_set_persistent() for unsigned long to u32 changes 2017-07-16 09:24:06 -07:00
metag metag: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-10 03:43:30 +09:00
microblaze Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
mips dma mapping fixes for 4.13-rc2: 2017-07-25 17:17:18 -07:00
mn10300 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-07-21 10:41:19 -07:00
nios2 nios2: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-11 21:33:43 +09:00
openrisc openrisc: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-11 21:33:50 +09:00
parisc parisc: Extend disabled preemption in copy_user_page 2017-07-25 23:36:54 +02:00
powerpc s390: SRCU fix. 2017-07-28 13:36:56 -07:00
s390 s390: SRCU fix. 2017-07-28 13:36:56 -07:00
score Merge branch 'uaccess.strlen' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-06 22:07:44 -07:00
sh TTY/Serial fixes for 4.13-rc2 2017-07-22 09:00:24 -07:00
sparc TTY/Serial fixes for 4.13-rc2 2017-07-22 09:00:24 -07:00
tile Merge branch 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 11:17:52 -07:00
um Merge branch 'for-linus-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2017-07-15 10:49:33 -07:00
unicore32 unicore32: move generic-y of exported headers to uapi/asm/Kbuild 2017-07-11 21:33:52 +09:00
x86 KVM: nVMX: Fix interrupt window request with "Acknowledge interrupt on exit" 2017-08-03 15:38:11 +02:00
xtensa tty: Fix TIOCGPTPEER ioctl definition 2017-07-17 17:04:41 +02:00
.gitignore
Kconfig include/linux/string.h: add the option of fortified string.h functions 2017-07-12 16:26:03 -07:00