Re: [PATCH v4 0/4] x86/crash: Fix double NMI shootdown bug

Sean Christopherson
2023-01-28T00:06:15Z

On Wed, 30 Nov 2022 23:36:46 +0000, Sean Christopherson wrote:
> Fix a double NMI shootdown bug found and debugged by Guilherme, who did all
> the hard work. NMI shootdown is a one-time thing; the handler leaves NMIs
> blocked and enters halt. At best, a second (or third...) shootdown is an
> expensive nop, at worst it can hang the kernel and prevent kexec'ing into
> a new kernel, e.g. prior to the hardening of register_nmi_handler(), a
> double shootdown resulted in a double list_add(), which is fatal when running
> with CONFIG_BUG_ON_DATA_CORRUPTION=y.
>
> [...]

Applied to kvm-x86 misc, thanks!

[1/4] x86/crash: Disable virt in core NMI crash handler to avoid double shootdown
https://github.com/kvm-x86/linux/commit/26044aff37a5
[2/4] x86/virt: Force GIF=1 prior to disabling SVM (for reboot flows)
https://github.com/kvm-x86/linux/commit/6a3236580b0b
[3/4] x86/reboot: Disable virtualization in an emergency if SVM is supported
https://github.com/kvm-x86/linux/commit/d81f952aa657
[4/4] x86/reboot: Disable SVM, not just VMX, when stopping CPUs
https://github.com/kvm-x86/linux/commit/a2b07fa7b933

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