Re: [PATCH v3 00/26] KVM: x86: Halt and APICv overhaul

Maxim Levitsky
2021-12-08T23:16:41Z

On Thu, 2021-12-09 at 01:00 +0200, Maxim Levitsky wrote:
> On Wed, 2021-12-08 at 01:52 +0000, Sean Christopherson wrote:
> > Overhaul and cleanup APIC virtualization (Posted Interrupts on Intel VMX,
> > AVIC on AMD SVM) to streamline things as much as possible, remove a bunch
> > of cruft, and document the lurking gotchas along the way.
> >
> > Patch 01 is a fix from Paolo that's already been merged but hasn't made
> > its way to kvm/queue. It's included here to avoid a number of conflicts.
> >
> > Based on kvm/queue, commit 1cf84614b04a ("KVM: x86: Exit to ...")
> >
> > v3:
> > - Rebase to kvm/queue (and drop non-x86 patches as they've been queued).
> > - Redo AVIC patches, sadly the vcpu_(un)blocking() hooks need to stay.
> > - Add a patch to fix a missing (docuentation-only) barrier in nested
> > posted interrupt delivery. [Paolo]
> > - Collect reviews.
> >
> > v2:
> > - https://lore.kernel.org/all/20211009021236.4122790-1-seanjc@google.com/
> > - Collect reviews. [Christian, David]
> > - Add patch to move arm64 WFI functionality out of hooks. [Marc]
> > - Add RISC-V to the fun.
> > - Add all the APICv fun.
> >
> > v1: https://lkml.kernel.org/r/20210925005528.1145584-1-seanjc@google.com
> >
> > Paolo Bonzini (1):
> > KVM: fix avic_set_running for preemptable kernels
> >
> > Sean Christopherson (25):
> > KVM: nVMX: Ensure vCPU honors event request if posting nested IRQ
> > fails
> > KVM: VMX: Clean up PI pre/post-block WARNs
> > KVM: VMX: Handle PI wakeup shenanigans during vcpu_put/load
> > KVM: Drop unused kvm_vcpu.pre_pcpu field
> > KVM: Move x86 VMX's posted interrupt list_head to vcpu_vmx
> > KVM: VMX: Move preemption timer <=> hrtimer dance to common x86
> > KVM: x86: Unexport LAPIC's switch_to_{hv,sw}_timer() helpers
> > KVM: x86: Remove defunct pre_block/post_block kvm_x86_ops hooks
> > KVM: SVM: Signal AVIC doorbell iff vCPU is in guest mode
> > KVM: SVM: Don't bother checking for "running" AVIC when kicking for
> > IPIs
> > KVM: SVM: Remove unnecessary APICv/AVIC update in vCPU unblocking path
> > KVM: SVM: Use kvm_vcpu_is_blocking() in AVIC load to handle preemption
> > KVM: SVM: Skip AVIC and IRTE updates when loading blocking vCPU
> > iommu/amd: KVM: SVM: Use pCPU to infer IsRun state for IRTE
> > KVM: VMX: Don't do full kick when triggering posted interrupt "fails"
> > KVM: VMX: Wake vCPU when delivering posted IRQ even if vCPU == this
> > vCPU
> > KVM: VMX: Pass desired vector instead of bool for triggering posted
> > IRQ
> > KVM: VMX: Fold fallback path into triggering posted IRQ helper
> > KVM: VMX: Don't do full kick when handling posted interrupt wakeup
> > KVM: SVM: Drop AVIC's intermediate avic_set_running() helper
> > KVM: SVM: Move svm_hardware_setup() and its helpers below svm_x86_ops
> > KVM: SVM: Nullify vcpu_(un)blocking() hooks if AVIC is disabled
> > KVM: x86: Skip APICv update if APICv is disable at the module level
> > KVM: x86: Drop NULL check on kvm_x86_ops.check_apicv_inhibit_reasons
> > KVM: x86: Unexport __kvm_request_apicv_update()
> >
> > arch/x86/include/asm/kvm-x86-ops.h | 2 -
> > arch/x86/include/asm/kvm_host.h | 12 -
> > arch/x86/kvm/hyperv.c | 3 +
> > arch/x86/kvm/lapic.c | 2 -
> > arch/x86/kvm/svm/avic.c | 116 ++++---
> > arch/x86/kvm/svm/svm.c | 479 ++++++++++++++---------------
> > arch/x86/kvm/svm/svm.h | 16 +-
> > arch/x86/kvm/vmx/posted_intr.c | 234 +++++++-------
> > arch/x86/kvm/vmx/posted_intr.h | 8 +-
> > arch/x86/kvm/vmx/vmx.c | 66 ++--
> > arch/x86/kvm/vmx/vmx.h | 3 +
> > arch/x86/kvm/x86.c | 41 ++-
> > drivers/iommu/amd/iommu.c | 6 +-
> > include/linux/amd-iommu.h | 6 +-
> > include/linux/kvm_host.h | 3 -
> > virt/kvm/kvm_main.c | 3 -
> > 16 files changed, 510 insertions(+), 490 deletions(-)
> >
>
> Probably just luck (can't reproduce this anymore) but
> while running some kvm unit tests with this patch series (and few my patches
> for AVIC co-existance which shouldn't affect this) I got this
>
> (warning about is_running already set)
>
> Dec 08 22:53:26 amdlaptop kernel: ------------[ cut here ]------------
> Dec 08 22:53:26 amdlaptop kernel: WARNING: CPU: 3 PID: 72804 at arch/x86/kvm/svm/avic.c:1045 avic_vcpu_load+0xe3/0x100 [kvm_amd]
> Dec 08 22:53:26 amdlaptop kernel: Modules linked in: kvm_amd(O) ccp rng_core kvm(O) irqbypass xt_conntrack ip6table_filter ip6_tables snd_soc_dmic snd_acp3x_>
> Dec 08 22:53:26 amdlaptop kernel: r8169 realtek 8250_pci usbmon nbd fuse autofs4 [last unloaded: rng_core]
> Dec 08 22:53:26 amdlaptop kernel: CPU: 3 PID: 72804 Comm: qemu-system-i38 Tainted: G O 5.16.0-rc4.unstable #6
> Dec 08 22:53:26 amdlaptop kernel: Hardware name: LENOVO 20UF001CUS/20UF001CUS, BIOS R1CET65W(1.34 ) 06/17/2021
> Dec 08 22:53:26 amdlaptop kernel: RIP: 0010:avic_vcpu_load+0xe3/0x100 [kvm_amd]
> Dec 08 22:53:26 amdlaptop kernel: Code: 0d 9f e0 85 c0 74 e8 4c 89 f6 4c 89 ff e8 a5 99 f4 e0 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 0b 5b 41 5c 41 5d 41 5e 41 >
> Dec 08 22:53:26 amdlaptop kernel: RSP: 0018:ffffc9000b17bba8 EFLAGS: 00010247
> Dec 08 22:53:26 amdlaptop kernel: RAX: 6f63203a756d6571 RBX: ffff888106194740 RCX: ffff88812e7ac000
> Dec 08 22:53:26 amdlaptop kernel: RDX: ffff8883ff6c0000 RSI: 0000000000000003 RDI: 0000000000000003
> Dec 08 22:53:26 amdlaptop kernel: RBP: ffffc9000b17bbd0 R08: ffff888106194740 R09: 0000000000000000
> Dec 08 22:53:26 amdlaptop kernel: R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000003
> Dec 08 22:53:26 amdlaptop kernel: R13: 0000000000000003 R14: ffff88810023b060 R15: dead000000000100
> Dec 08 22:53:26 amdlaptop kernel: FS: 0000000000000000(0000) GS:ffff8883ff6c0000(0000) knlGS:0000000000000000
> Dec 08 22:53:26 amdlaptop kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> Dec 08 22:53:26 amdlaptop kernel: CR2: 00005587e812f958 CR3: 0000000105f31000 CR4: 0000000000350ee0
> Dec 08 22:53:26 amdlaptop kernel: DR0: 00000000004008da DR1: 0000000000000000 DR2: 0000000000000000
> Dec 08 22:53:26 amdlaptop kernel: DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
> Dec 08 22:53:26 amdlaptop kernel: Call Trace:
> Dec 08 22:53:26 amdlaptop kernel: <TASK>
> Dec 08 22:53:26 amdlaptop kernel: svm_vcpu_load+0x56/0x60 [kvm_amd]
> Dec 08 22:53:26 amdlaptop kernel: kvm_arch_vcpu_load+0x32/0x210 [kvm]
> Dec 08 22:53:26 amdlaptop kernel: vcpu_load+0x34/0x40 [kvm]
> Dec 08 22:53:26 amdlaptop kernel: kvm_arch_destroy_vm+0xd4/0x1c0 [kvm]
> Dec 08 22:53:26 amdlaptop kernel: kvm_destroy_vm+0x163/0x250 [kvm]
> Dec 08 22:53:26 amdlaptop kernel: kvm_put_kvm+0x26/0x40 [kvm]
> Dec 08 22:53:26 amdlaptop kernel: kvm_vm_release+0x22/0x30 [kvm]
> Dec 08 22:53:26 amdlaptop kernel: __fput+0x94/0x250
> Dec 08 22:53:26 amdlaptop kernel: ____fput+0xe/0x10
> Dec 08 22:53:26 amdlaptop kernel: task_work_run+0x63/0xa0
> Dec 08 22:53:26 amdlaptop kernel: do_exit+0x358/0xa30
> Dec 08 22:53:26 amdlaptop kernel: do_group_exit+0x3b/0xa0
> Dec 08 22:53:26 amdlaptop kernel: get_signal+0x15b/0x880
> Dec 08 22:53:26 amdlaptop kernel: ? _copy_to_user+0x20/0x30
> Dec 08 22:53:26 amdlaptop kernel: ? put_timespec64+0x3d/0x60
> Dec 08 22:53:26 amdlaptop kernel: arch_do_signal_or_restart+0x106/0x740
> Dec 08 22:53:26 amdlaptop kernel: ? hrtimer_nanosleep+0x9f/0x120
> Dec 08 22:53:26 amdlaptop kernel: ? __hrtimer_init+0xd0/0xd0
> Dec 08 22:53:26 amdlaptop kernel: exit_to_user_mode_prepare+0x112/0x1f0
> Dec 08 22:53:26 amdlaptop kernel: syscall_exit_to_user_mode+0x17/0x40
> Dec 08 22:53:26 amdlaptop kernel: do_syscall_64+0x42/0x80
> Dec 08 22:53:26 amdlaptop kernel: entry_SYSCALL_64_after_hwframe+0x44/0xae
> Dec 08 22:53:26 amdlaptop kernel: RIP: 0033:0x7f537abb13b5
> Dec 08 22:53:26 amdlaptop kernel: Code: Unable to access opcode bytes at RIP 0x7f537abb138b.
> Dec 08 22:53:26 amdlaptop kernel: RSP: 002b:00007f5376a39680 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
> Dec 08 22:53:26 amdlaptop kernel: RAX: fffffffffffffdfc RBX: 00007f5376a396d0 RCX: 00007f537abb13b5
> Dec 08 22:53:26 amdlaptop kernel: RDX: 00007f5376a396d0 RSI: 0000000000000000 RDI: 0000000000000000
> Dec 08 22:53:26 amdlaptop kernel: RBP: 00007f5376a396c0 R08: 0000000000000000 R09: 0000000000000000
> Dec 08 22:53:26 amdlaptop kernel: R10: 00007f5376a396c0 R11: 0000000000000293 R12: 00007f5376a3b640
> Dec 08 22:53:26 amdlaptop kernel: R13: 0000000000000002 R14: 00007f537ab66880 R15: 0000000000000000
> Dec 08 22:53:26 amdlaptop kernel: </TASK>
> Dec 08 22:53:26 amdlaptop kernel: ---[ end trace 676058aaf29d0267 ]---

Also got this while trying a VM with passed through device:

[mlevitsk@amdlaptop ~]$[ 34.926140] usb 5-3: reset full-speed USB device number 3 using xhci_hcd
[ 42.583661] FAT-fs (mmcblk0p1): Volume was not properly unmounted. Some data may be corrupt. Please run fsck.
[ 363.562173] VFIO - User Level meta-driver version: 0.3
[ 365.160357] vfio-pci 0000:03:00.0: vfio_ecap_init: hiding ecap 0x1e@0x154
[ 384.138110] BUG: kernel NULL pointer dereference, address: 0000000000000021
[ 384.154039] #PF: supervisor read access in kernel mode
[ 384.165645] #PF: error_code(0x0000) - not-present page
[ 384.177254] PGD 16da9d067 P4D 16da9d067 PUD 13ad1a067 PMD 0
[ 384.190036] Oops: 0000 [#1] SMP
[ 384.197117] CPU: 3 PID: 14403 Comm: CPU 3/KVM Tainted: G O 5.16.0-rc4.unstable #6
[ 384.216978] Hardware name: LENOVO 20UF001CUS/20UF001CUS, BIOS R1CET65W(1.34 ) 06/17/2021
[ 384.235258] RIP: 0010:amd_iommu_update_ga+0x32/0x160
[ 384.246469] Code: e5 41 57 41 56 41 55 41 54 53 48 83 ec 28 65 48 8b 04 25 28 00 00 00 48 89 45 d0 31 c0 83 3d 04 75 2a 01 02 0f 85 bd 00 00 00 <4c> 8b 62 20 48 8b 4a 18 4d 85 e4 0f 84 ca 00 00 00
48 85 c9 0f 84
[ 384.288932] RSP: 0018:ffffc9000036fca0 EFLAGS: 00010046
[ 384.300727] RAX: 0000000000000000 RBX: ffff88810b68ab60 RCX: ffff8881667a6018
[ 384.316850] RDX: 0000000000000001 RSI: ffff888107476b00 RDI: 0000000000000003
[ 384.332973] RBP: ffffc9000036fcf0 R08: 0000000000000010 R09: 0000000000000010
[ 384.349096] R10: 0000000000000bb8 R11: ffffffff82a0fe80 R12: 0000000000000003
[ 384.365219] R13: ffff88836b98ea68 R14: 0000000000000202 R15: ffff88836b98ea78
[ 384.381338] FS: 00007f18d9ffb640(0000) GS:ffff8883ff6c0000(0000) knlGS:0000000000000000
[ 384.399622] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 384.412597] CR2: 0000000000000021 CR3: 00000001617c3000 CR4: 0000000000350ee0
[ 384.428717] Call Trace:
[ 384.434224] <TASK>
[ 384.438951] ? svm_set_msr+0x349/0x740 [kvm_amd]
[ 384.449374] avic_vcpu_load+0xbc/0x100 [kvm_amd]
[ 384.459795] svm_vcpu_unblocking+0x2d/0x40 [kvm_amd]
[ 384.471011] kvm_vcpu_block+0x71/0x90 [kvm]
[ 384.480479] kvm_vcpu_halt+0x3b/0x390 [kvm]
[ 384.489950] kvm_arch_vcpu_ioctl_run+0xa81/0x17f0 [kvm]
[ 384.501781] kvm_vcpu_ioctl+0x284/0x6c0 [kvm]
[ 384.511640] ? vfio_pci_rw+0x6b/0xa0 [vfio_pci_core]
[ 384.522856] ? vfio_pci_core_write+0x1c/0x20 [vfio_pci_core]
[ 384.535642] ? vfio_device_fops_write+0x1f/0x30 [vfio]
[ 384.547243] __x64_sys_ioctl+0x8e/0xc0
[ 384.555701] do_syscall_64+0x35/0x80
[ 384.563765] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 384.575170] RIP: 0033:0x7f18f4c4b39b
[ 384.583241] Code: ff ff ff 85 c0 79 9b 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 5d 2a 0f 00 f7
d8 64 89 01 48
[ 384.625709] RSP: 002b:00007f18d9ff95c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[ 384.639715] [drm] Fence fallback timer expired on ring gfx
[ 384.642816] RAX: ffffffffffffffda RBX: 00000000017aef60 RCX: 00007f18f4c4b39b
[ 384.642817] RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000026
[ 384.687520] RBP: 00007f18d9ff96c0 R08: 0000000000daf570 R09: 000000000000ffff
[ 384.703646] R10: 0000070000000082 R11: 0000000000000246 R12: 00007f18d9ffb640
[ 384.719765] R13: 0000000000000000 R14: 00007f18f4bd1880 R15: 0000000000000000
[ 384.735896] </TASK>
[ 384.740812] Modules linked in: vfio_pci vfio_pci_core vfio_virqfd vfio_iommu_type1 vfio xt_conntrack ip6table_filter ip6_tables snd_ctl_led snd_hda_codec_realtek snd_hda_codec_generic
snd_hda_codec_hdmi snd_hda_intel snd_intel_dspcfg snd_usb_audio snd_acp3x_pdm_dma snd_soc_dmic snd_acp3x_rn tps6598x snd_hda_codec snd_usbmidi_lib kvm_amd(O) btusb iwlmvm regmap_i2c snd_hda_core btrtl
snd_soc_core wmi_bmof snd_hwdep tpm_crb kvm(O) btbcm irqbypass snd_rawmidi ftdi_sio btintel pcspkr psmouse snd_rn_pci_acp3x bfq k10temp i2c_piix4 thinkpad_acpi snd_pcm i2c_multi_instantiate iwlwifi
tpm_tis tpm_tis_core wmi platform_profile rtc_cmos i2c_designware_platform i2c_designware_core vendor_reset(O) dm_crypt hid_generic usbhid mmc_block amdgpu drm_ttm_helper ttm gpu_sched i2c_algo_bit
drm_kms_helper cfbfillrect syscopyarea cfbimgblt sysfillrect sysimgblt fb_sys_fops cfbcopyarea xhci_pci nvme rtsx_pci_sdmmc ucsi_acpi typec_ucsi mmc_core atkbd ccp rtsx_pci libps2 drm nvme_core
mfd_core sp5100_tco
[ 384.740851] rng_core xhci_hcd drm_panel_orientation_quirks t10_pi typec i8042 pinctrl_amd r8169 realtek 8250_pci usbmon nbd fuse autofs4
[ 384.965149] CR2: 0000000000000021
[ 384.972622] ---[ end trace 23949f0862c2ac65 ]---
[ 384.983042] RIP: 0010:amd_iommu_update_ga+0x32/0x160
[ 384.994255] Code: e5 41 57 41 56 41 55 41 54 53 48 83 ec 28 65 48 8b 04 25 28 00 00 00 48 89 45 d0 31 c0 83 3d 04 75 2a 01 02 0f 85 bd 00 00 00 <4c> 8b 62 20 48 8b 4a 18 4d 85 e4 0f 84 ca 00 00 00
48 85 c9 0f 84
[ 385.036720] RSP: 0018:ffffc9000036fca0 EFLAGS: 00010046
[ 385.048518] RAX: 0000000000000000 RBX: ffff88810b68ab60 RCX: ffff8881667a6018
[ 385.064646] RDX: 0000000000000001 RSI: ffff888107476b00 RDI: 0000000000000003
[ 385.080765] RBP: ffffc9000036fcf0 R08: 0000000000000010 R09: 0000000000000010
[ 385.096886] R10: 0000000000000bb8 R11: ffffffff82a0fe80 R12: 0000000000000003
[ 385.113004] R13: ffff88836b98ea68 R14: 0000000000000202 R15: ffff88836b98ea78
[ 385.129128] FS: 00007f18d9ffb640(0000) GS:ffff8883ff6c0000(0000) knlGS:0000000000000000
[ 385.147407] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 385.160385] CR2: 0000000000000021 CR3: 00000001617c3000 CR4: 0000000000350ee0
[ 385.172739] [drm] Fence fallback timer expired on ring sdma0
>

Oh, well tomorrow I'll see what I can do with these.

Best regards,
Maxim Levitsky
>
> I'll post my patches tomorrow, after some more testing.
>
> Best regards,
> Maxim Levitsky