Re: [PATCH 2/2] amd_iommu: Fully initialize XT interrupt message state

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Jun 23, 2026 at 09:44:10AM +0100, Peter Maydell wrote:
> On Tue, 23 Jun 2026 at 01:58, Alejandro Jimenez
> <alejandro.j.jimenez@oracle.com> wrote:
> >
> > When IOMMU x2APIC interrupts generation (IntCapXTEn) is enabled,
> > amdvi_build_xt_msi_msg() builds an MSI message using the relevant values in
> > the XT IOMMU General Interrupt Control Register.
> >
> > Initialize the local X86IOMMUIrq structure with zero for all fields. This
> > ensures that X86IOMMUIrq fields not set in the XT register (e.g.
> > msi_addr_last_bits) are initialized before x86_iommu_irq_to_msi_message()
> > consumes them.
> >
> > Remove the redundant 'struct' keyword in X86IOMMUIrq irq declaration.
> >
> > CID: 1660056
> > Fixes: cf0210df65aa ("amd_iommu: Generate XT interrupts when xt support is enabled")
> > Reported-by: Peter Maydell <peter.maydell@linaro.org>
> > Suggested-by: Peter Maydell <peter.maydell@linaro.org>
> > Signed-off-by: Alejandro Jimenez <alejandro.j.jimenez@oracle.com>
> > ---
> >  hw/i386/amd_iommu.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
> > index 0d273fd33d..9005dc7aab 100644
> > --- a/hw/i386/amd_iommu.c
> > +++ b/hw/i386/amd_iommu.c
> > @@ -195,7 +195,7 @@ static void amdvi_assign_andq(AMDVIState *s, hwaddr addr, uint64_t val)
> >  static void amdvi_build_xt_msi_msg(AMDVIState *s, MSIMessage *msg)
> >  {
> >      union mmio_xt_intr xt_reg;
> > -    struct X86IOMMUIrq irq;
> > +    X86IOMMUIrq irq = { 0 };

Why don't we just initialize everything at the declaration site?

union mmio_xt_intr xt_reg = { .val = ... };
X86IOMMUIrq irq = { .... };

> This is fine for the Coverity problem, but you do also need to
> get rid of the bitfield-union as a separate issue.

Ideal task for AI actually.

> Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
> 
> thanks
> -- PMM