On 7/1/26 12:26, Peter Maydell wrote:
On Wed, 1 Jul 2026 at 09:09, Cédric Le Goater <[email protected]> wrote:On aarch64 hosts with 64K pages, the platform bus MMIO allocator can allocate the 1KB "tpm-ppi" region at offsets not aligned to the host page size, triggering a noisy VFIO IOMMU warning at VM startup: vfio_listener_valid_section received unaligned region tpm-ppi iova=0xc005000 offset_within_region=0x0 qemu_real_host_page_size=0x10000 Commit 851d6d1a0ff2 ("vfio/common: remove spurious tpm-crb-cmd misalignment warning") suppressed this for TPM CRB devices via a TPM_IS_CRB(owner) check. However, this misses "tpm-ppi" regions owned by other TPM types like SysBus/ISA tpm-tis devices. Avoid enumerating every TPM device type by matching the "tpm-ppi" memory region name directly in vfio_known_safe_misalignment(). Signed-off-by: Cedric Le Goater <[email protected]> --- hw/vfio/listener.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/hw/vfio/listener.c b/hw/vfio/listener.c index c19600e980a8d02217b5d9df4aca8f879ab2c5d5..c76ba285ddb7ef4f93bb081e67de47b3aecbe212 100644 --- a/hw/vfio/listener.c +++ b/hw/vfio/listener.c @@ -355,8 +355,10 @@ static void vfio_ram_discard_unregister_listener(VFIOContainer *bcontainer, static bool vfio_known_safe_misalignment(MemoryRegionSection *section) { MemoryRegion *mr = section->mr; + const char *name = memory_region_name(mr); - if (!TPM_IS_CRB(mr->owner)) { + if (!TPM_IS_CRB(mr->owner) && + !(name && strcmp(name, "tpm-ppi") == 0)) { return false; }I think this is the wrong approach, see my comments on the other email thread. vfio should not be building up some kind of whitelist of "this specific not-page-aligned RAM is OK", because a not-page-aligned RAM backed MMIO region is in general a normal thing to have.
We should warn for only VFIO-owned regions. I agree. Forget this patch. It's minor anyway. I will see how the listener can be improved to remove vfio_known_safe_misalignment() Thanks, C.
