Re: [PATCH v2] x86/entry/64/paravirt: Use paravirt-safe macro to access eflags

[Juergen Gross]

On 28/11/17 16:28, Boris Ostrovsky wrote:
> Commit 1d3e53e8624a ("x86/entry/64: Refactor IRQ stacks and make
> them NMI-safe") added DEBUG_ENTRY_ASSERT_IRQS_OFF macro that acceses
> eflags using 'pushfq' instruction when testing for IF bit. On PV Xen
> guests looking at IF flag directly will always see it set, resulting
> in 'ud2'.
> 
> Introduce SAVE_FLAGS() macro that will use appropriate save_fl pv op
> when running paravirt.
> 
> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>

Reviewed-by: Juergen Gross <jgross@xxxxxxxx>


Juergen