On Fri, Jul 11, 2025 at 10:47:47AM +0100, David Woodhouse wrote:
> From: David Woodhouse <d...@amazon.co.uk>
>
> FreeBSD does both, and this appears to be perfectly valid. The VT-d
> spec even talks about the ordering (the status write should be done
> first, unsurprisingly).
>
> We certainly shouldn't assert() and abort QEMU if the guest asks for
> both.
>
> Fixes: ed7b8fbcfb88 ("intel-iommu: add supports for queued invalidation
> interface")
> Closes: https://gitlab.com/qemu-project/qemu/-/issues/3028
> Signed-off-by: David Woodhouse <d...@amazon.co.uk>
> ---
> Still can't get FreeBSD to boot and use CPUs with APIC ID > 255 using
> *either* Intel or AMD IOMMU with interrupt remapping, or the native
> 15-bit APIC ID enlightenment.
> cf. https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=288122
>
> hw/i386/intel_iommu.c | 16 +++++++++++-----
> 1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index 69d72ad35c..3bfaf9bd07 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -2822,6 +2822,7 @@ static bool vtd_process_wait_desc(IntelIOMMUState *s,
> VTDInvDesc *inv_desc)
> {
> uint64_t mask[4] = {VTD_INV_DESC_WAIT_RSVD_LO, VTD_INV_DESC_WAIT_RSVD_HI,
> VTD_INV_DESC_ALL_ONE, VTD_INV_DESC_ALL_ONE};
> + bool ret = true;
>
> if (!vtd_inv_desc_reserved_check(s, inv_desc, mask, false,
> __func__, "wait")) {
> @@ -2833,7 +2834,8 @@ static bool vtd_process_wait_desc(IntelIOMMUState *s,
> VTDInvDesc *inv_desc)
> uint32_t status_data = (uint32_t)(inv_desc->lo >>
> VTD_INV_DESC_WAIT_DATA_SHIFT);
>
> - assert(!(inv_desc->lo & VTD_INV_DESC_WAIT_IF));
> + if (inv_desc->lo & VTD_INV_DESC_WAIT_IF)
> + vtd_generate_completion_event(s);
>
> /* FIXME: need to be masked with HAW? */
> dma_addr_t status_addr = inv_desc->hi;
Follow QEMU coding style, please.
> @@ -2843,18 +2845,22 @@ static bool vtd_process_wait_desc(IntelIOMMUState *s,
> VTDInvDesc *inv_desc)
> &status_data, sizeof(status_data),
> MEMTXATTRS_UNSPECIFIED)) {
> trace_vtd_inv_desc_wait_write_fail(inv_desc->hi, inv_desc->lo);
> - return false;
> + ret = false;
> }
> - } else if (inv_desc->lo & VTD_INV_DESC_WAIT_IF) {
> + }
> +
> + if (inv_desc->lo & VTD_INV_DESC_WAIT_IF) {
> /* Interrupt flag */
> vtd_generate_completion_event(s);
> - } else {
> + }
> +
> + if (!(inv_desc->lo & (VTD_INV_DESC_WAIT_IF|VTD_INV_DESC_WAIT_SW))) {
> error_report_once("%s: invalid wait desc: hi=%"PRIx64", lo=%"PRIx64
> " (unknown type)", __func__, inv_desc->hi,
> inv_desc->lo);
> return false;
> }
> - return true;
> + return ret;
> }
>
> static bool vtd_process_context_cache_desc(IntelIOMMUState *s,
> --
> 2.43.0
>
>
