On Thu, Dec 2, 2021 at 4:58 AM David Woodhouse <dw...@infradead.org> wrote:
>
> From: David Woodhouse <d...@amazon.co.uk>
>
> We should probably check if we were meant to be exposing IR, before
> letting the guest turn the IRE bit on.
This looks correct, but it's a change of guest noticeable behaviour.
It's probably fine since we don't expect a guest that enable IR
without checking ecap.
So
Acked-by: Jason Wang <jasow...@redhat.com>
>
> Signed-off-by: David Woodhouse <d...@amazon.co.uk>
> ---
> hw/i386/intel_iommu.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index ffc852d110..297e1972f8 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -2197,6 +2197,7 @@ static void vtd_handle_gcmd_ire(IntelIOMMUState *s,
> bool en)
> /* Handle write to Global Command Register */
> static void vtd_handle_gcmd_write(IntelIOMMUState *s)
> {
> + X86IOMMUState *x86_iommu = X86_IOMMU_DEVICE(s);
> uint32_t status = vtd_get_long_raw(s, DMAR_GSTS_REG);
> uint32_t val = vtd_get_long_raw(s, DMAR_GCMD_REG);
> uint32_t changed = status ^ val;
> @@ -2218,7 +2219,8 @@ static void vtd_handle_gcmd_write(IntelIOMMUState *s)
> /* Set/update the interrupt remapping root-table pointer */
> vtd_handle_gcmd_sirtp(s);
> }
> - if (changed & VTD_GCMD_IRE) {
> + if ((changed & VTD_GCMD_IRE) &&
> + x86_iommu_ir_supported(x86_iommu)) {
> /* Interrupt remap enable/disable */
> vtd_handle_gcmd_ire(s, val & VTD_GCMD_IRE);
> }
> --
> 2.31.1
>
>
