On Tue, Oct 30, 2012 at 11:47 AM, Avi Kivity <a...@redhat.com> wrote:
> Accesses which do not translate will hit the fault region, which
> can then log the access.
Maybe special casing the fault region should be avoided, the IOMMU
could set up suitable fault regions by itself.
>
> Signed-off-by: Avi Kivity <a...@redhat.com>
> ---
> memory.c | 9 ++++++---
> memory.h | 4 ++++
> 2 files changed, 10 insertions(+), 3 deletions(-)
>
> diff --git a/memory.c b/memory.c
> index ba2d4a0..d6b46fd 100644
> --- a/memory.c
> +++ b/memory.c
> @@ -778,7 +778,9 @@ static void
> memory_region_destructor_rom_device(MemoryRegion *mr)
> static void memory_region_destructor_iommu(MemoryRegion *mr)
> {
> address_space_destroy(mr->iommu_target_as);
> + address_space_destroy(mr->iommu_fault_as);
> g_free(mr->iommu_target_as);
> + g_free(mr->iommu_fault_as);
> }
>
> static bool memory_region_wrong_endianness(MemoryRegion *mr)
> @@ -1001,9 +1003,7 @@ static void memory_region_iommu_rw(MemoryRegion *iommu,
> hwaddr addr,
> xlat = (tlb.translated_addr & ~tlb.addr_mask) | (addr &
> tlb.addr_mask);
> address_space_rw(iommu->iommu_target_as, xlat, buf, clen,
> is_write);
> } else {
> - if (!is_write) {
> - memset(buf, 0xff, clen);
> - }
> + address_space_rw(iommu->iommu_fault_as, addr, buf, clen,
> is_write);
> }
> buf += clen;
> addr += clen;
> @@ -1068,6 +1068,7 @@ static void memory_region_iommu_write(void *opaque,
> hwaddr addr,
> void memory_region_init_iommu(MemoryRegion *mr,
> MemoryRegionIOMMUOps *ops,
> MemoryRegion *target,
> + MemoryRegion *fault,
> const char *name,
> uint64_t size)
> {
> @@ -1079,6 +1080,8 @@ void memory_region_init_iommu(MemoryRegion *mr,
> mr->destructor = memory_region_destructor_iommu;
> mr->iommu_target_as = g_new(AddressSpace, 1);
> address_space_init(mr->iommu_target_as, target);
> + mr->iommu_fault_as = g_new(AddressSpace, 1);
> + address_space_init(mr->iommu_fault_as, fault);
> }
>
> static uint64_t invalid_read(void *opaque, hwaddr addr,
> diff --git a/memory.h b/memory.h
> index 47362c9..6312197 100644
> --- a/memory.h
> +++ b/memory.h
> @@ -162,6 +162,7 @@ struct MemoryRegion {
> unsigned ioeventfd_nb;
> MemoryRegionIoeventfd *ioeventfds;
> struct AddressSpace *iommu_target_as;
> + struct AddressSpace *iommu_fault_as;
> };
>
> struct MemoryRegionPortio {
> @@ -361,12 +362,15 @@ void memory_region_init_reservation(MemoryRegion *mr,
> * @ops: a function that translates addresses into the @target region
> * @target: a #MemoryRegion that will be used to satisfy accesses to
> translated
> * addresses
> + * @fault: a #MemoryRegion for servicing failed translations; accessed with
> + * untranslated addresses
> * @name: used for debugging; not visible to the user or ABI
> * @size: size of the region.
> */
> void memory_region_init_iommu(MemoryRegion *mr,
> MemoryRegionIOMMUOps *ops,
> MemoryRegion *target,
> + MemoryRegion *fault,
> const char *name,
> uint64_t size);
>
> --
> 1.7.12
>
