Haitao Shan b1f3291804 KVM: x86: Fix lapic timer interrupt lost after loading a snapshot. ... commit 9cfec6d097 upstream. When running android emulator (which is based on QEMU 2.12) on certain Intel hosts with kernel version 6.3-rc1 or above, guest will freeze after loading a snapshot. This is almost 100% reproducible. By default, the android emulator will use snapshot to speed up the next launching of the same android guest. So this breaks the android emulator badly. I tested QEMU 8.0.4 from Debian 12 with an Ubuntu 22.04 guest by running command "loadvm" after "savevm". The same issue is observed. At the same time, none of our AMD platforms is impacted. More experiments show that loading the KVM module with "enable_apicv=false" can workaround it. The issue started to show up after commit 8e6ed96cdd ("KVM: x86: fire timer when it is migrated and expired, and in oneshot mode"). However, as is pointed out by Sean Christopherson, it is introduced by commit 967235d320 ("KVM: vmx: clear pending interrupts on KVM_SET_LAPIC"). commit 8e6ed96cdd ("KVM: x86: fire timer when it is migrated and expired, and in oneshot mode") just makes it easier to hit the issue. Having both commits, the oneshot lapic timer gets fired immediately inside the KVM_SET_LAPIC call when loading the snapshot. On Intel platforms with APIC virtualization and posted interrupt processing, this eventually leads to setting the corresponding PIR bit. However, the whole PIR bits get cleared later in the same KVM_SET_LAPIC call by apicv_post_state_restore. This leads to timer interrupt lost. The fix is to move vmx_apicv_post_state_restore to the beginning of the KVM_SET_LAPIC call and rename to vmx_apicv_pre_state_restore. What vmx_apicv_post_state_restore does is actually clearing any former apicv state and this behavior is more suitable to carry out in the beginning. Fixes: 967235d320 ("KVM: vmx: clear pending interrupts on KVM_SET_LAPIC") Cc: stable@vger.kernel.org Suggested-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Haitao Shan <hshan@google.com> Link: https://lore.kernel.org/r/20230913000215.478387-1-hshan@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2023-11-28 17:15:00 +00:00
..
boot	x86/sev: Check for user-space IOIO pointing to kernel space	2023-10-25 12:16:10 +02:00
coco	x86/tdx: Zero out the missing RSI in TDX_HYPERCALL macro	2023-11-20 11:56:59 +01:00
configs	arch/*/configs/*defconfig: Replace AUTOFS4_FS by AUTOFS_FS	2023-07-29 14:08:22 -07:00
crypto	crypto: x86/sha - load modules based on CPU features	2023-11-28 17:14:59 +00:00
entry	x86/mm: Fix VDSO and VVAR placement on 5-level paging machines	2023-08-09 13:38:48 -07:00
events	perf/x86/lbr: Filter vsyscall addresses	2023-10-19 23:11:05 +02:00
hyperv	hyperv-fixes for 6.5-rc5	2023-08-04 17:16:14 -07:00
ia32
include	KVM: x86: Fix lapic timer interrupt lost after loading a snapshot.	2023-11-28 17:15:00 +00:00
kernel	x86/cpu/hygon: Fix the CPU topology evaluation for real	2023-11-28 17:14:59 +00:00
kvm	KVM: x86: Fix lapic timer interrupt lost after loading a snapshot.	2023-11-28 17:15:00 +00:00
lib	iov_iter, x86: Be consistent about the __user tag on copy_mc_to_user()	2023-11-20 11:56:42 +01:00
math-emu
mm	x86/mm: Drop the 4 MB restriction on minimal NUMA node memory size	2023-11-28 17:14:41 +00:00
net	bpf, x86: initialize the variable "first_off" in save_args()	2023-11-20 11:57:26 +01:00
pci	x86/PCI: Avoid PME from D3hot/D3cold for AMD Rembrandt and Phoenix USB4	2023-11-28 17:14:59 +00:00
platform	A single regression fix for x86:	2023-07-01 11:40:01 -07:00
power
purgatory	x86/purgatory: Remove LTO flags	2023-09-23 11:14:33 +02:00
ras
realmode
tools
um
video	drm changes for 6.5-rc1:	2023-06-29 11:00:17 -07:00
virt/vmx/tdx
xen	xen: branch for v6.5-rc2	2023-07-13 13:39:36 -07:00
.gitignore
Kbuild
Kconfig	efi/x86: Ensure that EFI_RUNTIME_MAP is enabled for kexec	2023-10-06 13:16:10 +02:00
Kconfig.assembler
Kconfig.cpu
Kconfig.debug
Makefile
Makefile.postlink
Makefile.um
Makefile_32.cpu