From: Jan Kiszka <jan.kis...@siemens.com> Xen is doing this [1] and currently triggers an abort.
[1] http://xenbits.xenproject.org/gitweb/?p=xen.git;a=blob;f=xen/drivers/passthrough/vtd/iommu.c;h=daaed0abbdd06b6ba3d948ea103aadf02651e83c;hb=refs/heads/master#l1108 Reported-by: Luis Lloret <luis_llo...@mentor.com> Signed-off-by: Jan Kiszka <jan.kis...@siemens.com> --- hw/i386/intel_iommu.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index 2e841cde27..b61d0da270 100644 --- a/hw/i386/intel_iommu.c +++ b/hw/i386/intel_iommu.c @@ -2129,7 +2129,12 @@ static void vtd_mem_write(void *opaque, hwaddr addr, /* Fault Event Address Register, 32-bit */ case DMAR_FEADDR_REG: - assert(size == 4); + /* + * While the register is 32-bit only, some guests (Xen...) write to it + * with 64-bit. Ignore the upper part, that's likely what the hardware + * does as well (plus the upper part is not used by our model anyway). + */ + assert(size >= 4); vtd_set_long(s, addr, val); break; -- 2.13.6
