Re: [PATCH for-stable] KVM: VMX: clear vmx_x86_ops.sync_pir_to_irr if APICv is disabled

[Greg KH]

On Mon, Dec 20, 2021 at 10:49:50AM +0100, Paolo Bonzini wrote:
> commit e90e51d5f01d2baae5dcce280866bbb96816e978 upstream.
> 
> There is nothing to synchronize if APICv is disabled, since neither
> other vCPUs nor assigned devices can set PIR.ON.
> 
> After the patch was committed to Linus's tree, it was observed that
> this fixes an issue with commit 7e1901f6c86c ("KVM: VMX: prepare
> sync_pir_to_irr for running with APICv disabled", backported to stable
> as e.g. commit 70a37e04c08a for the 5.15 tree).  Without this patch,
> vmx_sync_pir_to_irr can be reached with enable_apicv == false, triggering
> 
>  	if (KVM_BUG_ON(!enable_apicv, vcpu->kvm))
> 
> Fixes: 7e1901f6c86c ("KVM: VMX: prepare sync_pir_to_irr for running with APICv disabled")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> ---
>  arch/x86/kvm/vmx/vmx.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Looks like it is already queued up, thanks.

greg k-h