From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54080) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aiEed-0003Ao-R9 for qemu-devel@nongnu.org; Tue, 22 Mar 2016 01:14:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aiEea-0007dU-K2 for qemu-devel@nongnu.org; Tue, 22 Mar 2016 01:14:55 -0400 Date: Tue, 22 Mar 2016 16:14:49 +1100 From: David Gibson Message-ID: <20160322051449.GG23586@voom.redhat.com> References: <1458546426-26222-1-git-send-email-aik@ozlabs.ru> <1458546426-26222-18-git-send-email-aik@ozlabs.ru> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="0NUq3YI6/rBc6tSL" Content-Disposition: inline In-Reply-To: <1458546426-26222-18-git-send-email-aik@ozlabs.ru> Subject: Re: [Qemu-devel] [PATCH qemu v14 17/18] vfio/spapr: Use VFIO_SPAPR_TCE_v2_IOMMU List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy Cc: Alex Williamson , qemu-ppc@nongnu.org, qemu-devel@nongnu.org --0NUq3YI6/rBc6tSL Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Mar 21, 2016 at 06:47:05PM +1100, Alexey Kardashevskiy wrote: > New VFIO_SPAPR_TCE_v2_IOMMU type supports dynamic DMA window management. > This adds ability to VFIO common code to dynamically allocate/remove > DMA windows in the host kernel when new VFIO container is added/removed. >=20 > This adds VFIO_IOMMU_SPAPR_TCE_CREATE ioctl to vfio_listener_region_add > and adds just created IOMMU into the host IOMMU list; the opposite > action is taken in vfio_listener_region_del. >=20 > When creating a new window, this uses euristic to decide on the TCE table > levels number. >=20 > This should cause no guest visible change in behavior. >=20 > Signed-off-by: Alexey Kardashevskiy > --- > Changes: > v14: > * new to the series >=20 > --- > TODO: > * export levels to PHB > --- > hw/vfio/common.c | 108 +++++++++++++++++++++++++++++++++++++++++++++++++= +++--- > trace-events | 2 ++ > 2 files changed, 105 insertions(+), 5 deletions(-) >=20 > diff --git a/hw/vfio/common.c b/hw/vfio/common.c > index 4e873b7..421d6eb 100644 > --- a/hw/vfio/common.c > +++ b/hw/vfio/common.c > @@ -279,6 +279,14 @@ static int vfio_host_iommu_add(VFIOContainer *contai= ner, > return 0; > } > =20 > +static void vfio_host_iommu_del(VFIOContainer *container, hwaddr min_iov= a) > +{ > + VFIOHostIOMMU *hiommu =3D vfio_host_iommu_lookup(container, min_iova= , 0x1000); The hard-coded 0x1000 looks dubious.. > + g_assert(hiommu); > + QLIST_REMOVE(hiommu, hiommu_next); > +} > + > static bool vfio_listener_skipped_section(MemoryRegionSection *section) > { > return (!memory_region_is_ram(section->mr) && > @@ -392,6 +400,61 @@ static void vfio_listener_region_add(MemoryListener = *listener, > } > end =3D int128_get64(llend); > =20 > + if (container->iommu_type =3D=3D VFIO_SPAPR_TCE_v2_IOMMU) { I think this would be clearer split out into a helper function, vfio_create_host_window() or something. > + unsigned entries, pages; > + struct vfio_iommu_spapr_tce_create create =3D { .argsz =3D sizeo= f(create) }; > + > + g_assert(section->mr->iommu_ops); > + g_assert(memory_region_is_iommu(section->mr)); I don't think you need these asserts. AFAICT the same logic should work if a RAM MR was added directly to PCI address space - this would create the new host window, then the existing code for adding a RAM MR would map that block of RAM statically into the new window. > + trace_vfio_listener_region_add_iommu(iova, end - 1); > + /* > + * FIXME: For VFIO iommu types which have KVM acceleration to > + * avoid bouncing all map/unmaps through qemu this way, this > + * would be the right place to wire that up (tell the KVM > + * device emulation the VFIO iommu handles to use). > + */ > + create.window_size =3D memory_region_size(section->mr); > + create.page_shift =3D > + ctz64(section->mr->iommu_ops->get_page_sizes(section->mr= )); Ah.. except that I guess you'd need to fall back to host page size here to handle a RAM MR. > + /* > + * SPAPR host supports multilevel TCE tables, there is some > + * euristic to decide how many levels we want for our table: > + * 0..64 =3D 1; 65..4096 =3D 2; 4097..262144 =3D 3; 262145.. =3D= 4 > + */ > + entries =3D create.window_size >> create.page_shift; > + pages =3D (entries * sizeof(uint64_t)) / getpagesize(); > + create.levels =3D ctz64(pow2ceil(pages) - 1) / 6 + 1; > + > + ret =3D ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_CREATE, &creat= e); > + if (ret) { > + error_report("Failed to create a window, ret =3D %d (%m)", r= et); > + goto fail; > + } > + > + if (create.start_addr !=3D section->offset_within_address_space = || > + vfio_host_iommu_lookup(container, create.start_addr, > + create.start_addr + create.window_siz= e - 1)) { Under what circumstances can this trigger? Is the kernel ioctl allowed to return a different window start address than the one requested? The second check looks very strange - if it returns true doesn't that mean you *do* have host window which can accomodate this guest region, which is what you want? > + struct vfio_iommu_spapr_tce_remove remove =3D { > + .argsz =3D sizeof(remove), > + .start_addr =3D create.start_addr > + }; > + error_report("Host doesn't support DMA window at %"HWADDR_PR= Ix", must be %"PRIx64, > + section->offset_within_address_space, > + create.start_addr); > + ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_REMOVE, &remove); > + ret =3D -EINVAL; > + goto fail; > + } > + trace_vfio_spapr_create_window(create.page_shift, > + create.window_size, > + create.start_addr); > + > + vfio_host_iommu_add(container, create.start_addr, > + create.start_addr + create.window_size - 1, > + 1ULL << create.page_shift); > + } > + > if (!vfio_host_iommu_lookup(container, iova, end - 1)) { > error_report("vfio: IOMMU container %p can't map guest IOVA regi= on" > " 0x%"HWADDR_PRIx"..0x%"HWADDR_PRIx, > @@ -525,6 +588,22 @@ static void vfio_listener_region_del(MemoryListener = *listener, > container, iova, end - iova, ret); > } > =20 > + if (container->iommu_type =3D=3D VFIO_SPAPR_TCE_v2_IOMMU) { > + struct vfio_iommu_spapr_tce_remove remove =3D { > + .argsz =3D sizeof(remove), > + .start_addr =3D section->offset_within_address_space, > + }; > + ret =3D ioctl(container->fd, VFIO_IOMMU_SPAPR_TCE_REMOVE, &remov= e); > + if (ret) { > + error_report("Failed to remove window at %"PRIx64, > + remove.start_addr); > + } > + > + vfio_host_iommu_del(container, section->offset_within_address_sp= ace); > + > + trace_vfio_spapr_remove_window(remove.start_addr); > + } > + > if (iommu && iommu->iommu_ops && iommu->iommu_ops->vfio_stop) { > iommu->iommu_ops->vfio_stop(section->mr); > } > @@ -928,11 +1007,30 @@ static int vfio_connect_container(VFIOGroup *group= , AddressSpace *as) > goto listener_release_exit; > } > =20 > - /* The default table uses 4K pages */ > - vfio_host_iommu_add(container, info.dma32_window_start, > - info.dma32_window_start + > - info.dma32_window_size - 1, > - 0x1000); > + if (v2) { > + /* > + * There is a default window in just created container. > + * To make region_add/del simpler, we better remove this > + * window now and let those iommu_listener callbacks > + * create/remove them when needed. > + */ > + struct vfio_iommu_spapr_tce_remove remove =3D { > + .argsz =3D sizeof(remove), > + .start_addr =3D info.dma32_window_start, > + }; > + ret =3D ioctl(fd, VFIO_IOMMU_SPAPR_TCE_REMOVE, &remove); > + if (ret) { > + error_report("vfio: VFIO_IOMMU_SPAPR_TCE_REMOVE failed: = %m"); > + ret =3D -errno; > + goto free_container_exit; > + } > + } else { > + /* The default table uses 4K pages */ > + vfio_host_iommu_add(container, info.dma32_window_start, > + info.dma32_window_start + > + info.dma32_window_size - 1, > + 0x1000); > + } > } else { > error_report("vfio: No available IOMMU models"); > ret =3D -EINVAL; > diff --git a/trace-events b/trace-events > index cc619e1..f2b75a3 100644 > --- a/trace-events > +++ b/trace-events > @@ -1736,6 +1736,8 @@ vfio_region_finalize(const char *name, int index) "= Device %s, region %d" > vfio_region_mmaps_set_enabled(const char *name, bool enabled) "Region %s= mmaps enabled: %d" > vfio_ram_register(uint64_t va, uint64_t size, int ret) "va=3D%"PRIx64" s= ize=3D%"PRIx64" ret=3D%d" > vfio_ram_unregister(uint64_t va, uint64_t size, int ret) "va=3D%"PRIx64"= size=3D%"PRIx64" ret=3D%d" > +vfio_spapr_create_window(int ps, uint64_t ws, uint64_t off) "pageshift= =3D0x%x winsize=3D0x%"PRIx64" offset=3D0x%"PRIx64 > +vfio_spapr_remove_window(uint64_t off) "offset=3D%"PRIx64 > =20 > # hw/vfio/platform.c > vfio_platform_base_device_init(char *name, int groupid) "%s belongs to g= roup #%d" --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --0NUq3YI6/rBc6tSL Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJW8NTJAAoJEGw4ysog2bOSvPYQALvbwwWwaG/XFwHWuafLNhqb fFxNm4jX8InUApCSHTRfFs3d2RwJIdw96iNl6T9NRO0Axua1KxcZe4OorkngUTP4 0m/FkWIk2l2qNjARK/A3nAICMBo8++wx9nSso+Ee7vbT5BLHwOYrueSUI25R12C0 oBS7tpgxuBqe2mr67riybbtJ06dWmCo4V/MJvSum6/niIjQPYGiqrfz6KANb5e8G 3nKxmR+gm4u14eegPFNuXd8rp72+PEJhQxJJ6XcZzyYpgCwKK+M/cHoThpi6rXye TLhqd1F/ySMAXl1j4qE7NUyT49X0Q4K+dQQXpBSHl/m3ug6A4yxIMnwjj9w4fQaN QQPeGP28Q77hu57u946I15/5onTYO2R+fAhGXpDlnPgr2ose4uNr3v+tXRyB4ggt D7j9pdeu+W9GkGpL6oem5iJVRQWUaBYYG2qzkviaGpijNq8+94wsk4hFSX2S+4Vb 0bhA9/hdmKyg3EsPTk88c90yNNOJ5TRLJ5WODmSIocjhAV3hp8tGvqNep0A0Agh8 DZFt3Qvjp3RQBUpsjycAq1wBzihM9ydVwk0+2mlG8Ta7HTWqH4xItR1esX65x9t1 V/V7si9e2s5ZN0QxII/sA6uKuotFLST3UCu9GtunkJA22f0pSrhQH5rCJo41kMbR 3JLgBSLCyffra7Dh2SJk =eVEA -----END PGP SIGNATURE----- --0NUq3YI6/rBc6tSL--