On 10/29/2024 5:21 PM, Kirill A. Shutemov wrote: > On Tue, Oct 29, 2024 at 03:54:24PM +0530, Neeraj Upadhyay wrote: >> diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c >> index aeda74bf15e6..08156ac4ec6c 100644 >> --- a/arch/x86/kernel/apic/apic.c >> +++ b/arch/x86/kernel/apic/apic.c >> @@ -1163,6 +1163,9 @@ void disable_local_APIC(void) >> if (!apic_accessible()) >> return; >> >> + if (apic->teardown) >> + apic->teardown(); >> + >> apic_soft_disable(); >> >> #ifdef CONFIG_X86_32 > > Hm. I think it will call apic->teardown() for all but the one CPU that > does kexec. I believe we need to disable SAVIC for all CPUs. > I see it being called for all CPUs. For the CPU doing kexec, I see below backtrace, which lands into disable_local_APIC() disable_local_APIC native_stop_other_cpus native_machine_shutdown machine_shutdown kernel_kexec For the other CPUs, it is below: disable_local_APIC stop_this_cpu __sysvec_reboot sysvec_reboot > Have you tested the case when the target kernel doesn't support SAVIC and > tries to use a new interrupt vector on the boot CPU? I think it will > break. > For a VM launched with VMSA feature containing Secure AVIC, the target kernel also is required to support Secure AVIC. Otherwise, guest bootup would fail. I will capture this information in the documentation. So, as far as I understand, SAVIC kernel kexecing into a non-SAVIC kernel is not a valid use case. - Neeraj
