On Wed, Nov 23, 2022 at 8:20 AM Marc-André Lureau <[email protected]> wrote: > > Hi > > On Wed, Nov 23, 2022 at 12:32 AM Michael S. Tsirkin <[email protected]> wrote: >> >> On Tue, Nov 22, 2022 at 06:53:49PM +0400, [email protected] wrote: >> > From: Marc-André Lureau <[email protected]> >> > >> > 851d6d1a0f ("vfio/common: remove spurious tpm-crb-cmd misalignment >> > warning") removed the warning on vfio_listener_region_add() path. >> > >> > An error is reported for vhost-vdpa case: >> > qemu-kvm: vhost_vdpa_listener_region_add received unaligned region >> > >> > Skip the CRB device. >> > >> > Fixes: >> > https://bugzilla.redhat.com/show_bug.cgi?id=2141965 >> > >> > Signed-off-by: Marc-André Lureau <[email protected]> >> > --- >> > hw/virtio/vhost-vdpa.c | 6 ++++++ >> > 1 file changed, 6 insertions(+) >> > >> > diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c >> > index 7468e44b87..9d7206e4b8 100644 >> > --- a/hw/virtio/vhost-vdpa.c >> > +++ b/hw/virtio/vhost-vdpa.c >> > @@ -19,6 +19,7 @@ >> > #include "hw/virtio/virtio-net.h" >> > #include "hw/virtio/vhost-shadow-virtqueue.h" >> > #include "hw/virtio/vhost-vdpa.h" >> > +#include "sysemu/tpm.h" >> > #include "exec/address-spaces.h" >> > #include "migration/blocker.h" >> > #include "qemu/cutils.h" >> > @@ -46,6 +47,11 @@ static bool >> > vhost_vdpa_listener_skipped_section(MemoryRegionSection *section, >> > { >> > Int128 llend; >> > >> > + if (TPM_IS_CRB(section->mr->owner)) { >> > + /* The CRB command buffer has its base address unaligned. */ >> > + return true; >> > + } >> > + >> >> Quite a hack. We can't really keep adding dependency on random devices > > > Agree it's not great. but it's not strictly a dependency. At least you can > still build with !CONFIG_TPM. > >> to vhost. And would you add hacks like this to listeners? >> Pls figure out what's special about this buffer. >> Also if this section is unaligned then doesn't it break up >> other aligned sections? > > > See the original discussion: > https://patchew.org/QEMU/[email protected]/[email protected]/ >
Based on that, I'd tune the comment to something like: QEMU represents the CRB cmd/response buffer as a standard RAM region to the listeners, but real HW would not be able to access them. Besides, these regions may not be properly page aligned. Is that more accurate? Thanks! > It is not clear whether aligning the tpm-crb-cmd region would work > (overlapping tpm-crb-mmio). > > Peter Maydell said: "There's nothing that guarantees alignment for memory > regions at all, whether they're RAM, IO or anything else.". > > Maybe vfio/vhost should simply skip those odd regions silently. > > >> >> >> > if ((!memory_region_is_ram(section->mr) && >> > !memory_region_is_iommu(section->mr)) || >> > memory_region_is_protected(section->mr) || >> > -- >> > 2.38.1 >>
