Re: [PATCH v2] KVM: x86: Fix single-step debugging

From: Alexander Popov
Date: Thu Jan 24 2019 - 03:41:31 EST


On 21.01.2019 15:48, Alexander Popov wrote:
> The single-step debugging of KVM guests on x86 is broken: if we run
> gdb 'stepi' command at the breakpoint when the guest interrupts are
> enabled, RIP always jumps to native_apic_mem_write(). Then other
> nasty effects follow.
>
> Long investigation showed that on Jun 7, 2017 the
> commit c8401dda2f0a00cd25c0 ("KVM: x86: fix singlestepping over syscall")
> introduced the kvm_run.debug corruption: kvm_vcpu_do_singlestep() can
> be called without X86_EFLAGS_TF set.
>
> Let's fix it. Please consider that for -stable.

Hello everyone!

Just a friendly ping about this fix.
Looking forward to the feedback.

Best regards,
Alexander