[SLOF] [PATCH slof v3 4/4] virtio: Enable IOMMU
Alexey Kardashevskiy
aik at ozlabs.ru
Tue Dec 3 14:11:07 AEDT 2019
On 03/12/2019 13:49, Michael Roth wrote:
> Quoting Alexey Kardashevskiy (2019-11-27 18:15:03)
>>
>>
>> On 23/11/2019 01:42, Michael Roth wrote:
>>> Quoting Alexey Kardashevskiy (2019-11-21 21:14:10)
>>>>
>>>>
>>>> On 22/11/2019 12:49, Alexey Kardashevskiy wrote:
>>>>>
>>>>>
>>>>> On 22/11/2019 11:09, Michael Roth wrote:
>>>>>> Quoting Alexey Kardashevskiy (2019-11-20 17:58:01)
>>>>>>> When QEMU is started with iommu_platform=on, the guest driver must accept
>>>>>>> it or the device will fail.
>>>>>>>
>>>>>>> This enables IOMMU support for virtio-net, -scsi, -block, -serial, -9p
>>>>>>> devices. -serial and -9p are only compile tested though.
>>>>>>>
>>>>>>> For virtio-net we map all RX buffers once and TX when xmit() is called
>>>>>>> and unmap older pages when we are about to reuse the VQ descriptor.
>>>>>>> As all other devices are synchronous, we unmap IOMMU pages right after
>>>>>>> completion of a transaction.
>>>>>>>
>>>>>>> This depends on QEMU's:
>>>>>>> https://patchwork.ozlabs.org/patch/1194067/
>>>>>>>
>>>>>>> Copied-bits-and-pieces-from: Michael Roth <mdroth at linux.vnet.ibm.com>
>>>>>>> Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
>>>>>>> ---
>>>>>>> Changes:
>>>>>>> v2:
>>>>>>> * added Mike's fs/dma-instance-function.fs
>>>>>>> * total rework
>>>>>>> ---
>>>>>>> board-qemu/slof/Makefile | 1 +
>>>>>>> lib/libvirtio/virtio.h | 5 ++
>>>>>>> lib/libvirtio/virtio-9p.c | 4 ++
>>>>>>> lib/libvirtio/virtio-blk.c | 4 ++
>>>>>>> lib/libvirtio/virtio-net.c | 5 +-
>>>>>>> lib/libvirtio/virtio-scsi.c | 5 ++
>>>>>>> lib/libvirtio/virtio-serial.c | 12 +++--
>>>>>>> lib/libvirtio/virtio.c | 82 +++++++++++++++++++++++++++++++-
>>>>>>> board-qemu/slof/OF.fs | 3 ++
>>>>>>> slof/fs/dma-instance-function.fs | 28 +++++++++++
>>>>>>> 10 files changed, 143 insertions(+), 6 deletions(-)
>>>>>>> create mode 100644 slof/fs/dma-instance-function.fs
>>>>>>>
>>>>>>> diff --git a/board-qemu/slof/Makefile b/board-qemu/slof/Makefile
>>>>>>> index 2263e751bde9..d7ed2d7a6f18 100644
>>>>>>> --- a/board-qemu/slof/Makefile
>>>>>>> +++ b/board-qemu/slof/Makefile
>>>>>>> @@ -99,6 +99,7 @@ OF_FFS_FILES = \
>>>>>>> $(SLOFCMNDIR)/fs/graphics.fs \
>>>>>>> $(SLOFCMNDIR)/fs/generic-disk.fs \
>>>>>>> $(SLOFCMNDIR)/fs/dma-function.fs \
>>>>>>> + $(SLOFCMNDIR)/fs/dma-instance-function.fs \
>>>>>>> $(SLOFCMNDIR)/fs/pci-device.fs \
>>>>>>> $(SLOFCMNDIR)/fs/pci-bridge.fs \
>>>>>>> $(SLOFCMNDIR)/fs/pci-properties.fs \
>>>>>>> diff --git a/lib/libvirtio/virtio.h b/lib/libvirtio/virtio.h
>>>>>>> index 4927a97f9f5f..250120b3112b 100644
>>>>>>> --- a/lib/libvirtio/virtio.h
>>>>>>> +++ b/lib/libvirtio/virtio.h
>>>>>>> @@ -29,6 +29,7 @@
>>>>>>> #define VIRTIO_F_RING_INDIRECT_DESC BIT(28)
>>>>>>> #define VIRTIO_F_RING_EVENT_IDX BIT(29)
>>>>>>> #define VIRTIO_F_VERSION_1 BIT(32)
>>>>>>> +#define VIRTIO_F_IOMMU_PLATFORM BIT(33)
>>>>>>>
>>>>>>> #define VIRTIO_TIMEOUT 5000 /* 5 sec timeout */
>>>>>>>
>>>>>>> @@ -84,6 +85,8 @@ struct vqs {
>>>>>>> struct vring_desc *desc;
>>>>>>> struct vring_avail *avail;
>>>>>>> struct vring_used *used;
>>>>>>> + void **desc_gpas; /* to get gpa from desc->addr (which is ioba) */
>>>>>>> + uint64_t bus_desc;
>>>>>>> };
>>>>>>>
>>>>>>> struct virtio_device {
>>>>>>> @@ -109,6 +112,8 @@ extern struct vring_used *virtio_get_vring_used(struct virtio_device *dev, int q
>>>>>>> extern void virtio_fill_desc(struct vqs *vq, int id, uint64_t features,
>>>>>>> uint64_t addr, uint32_t len,
>>>>>>> uint16_t flags, uint16_t next);
>>>>>>> +extern void virtio_free_desc(struct vqs *vq, int id, uint64_t features);
>>>>>>> +void *virtio_desc_addr(struct virtio_device *vdev, int queue, int id);
>>>>>>> extern struct vqs *virtio_queue_init_vq(struct virtio_device *dev, unsigned int id);
>>>>>>> extern void virtio_queue_term_vq(struct virtio_device *dev, struct vqs *vq, unsigned int id);
>>>>>>>
>>>>>>> diff --git a/lib/libvirtio/virtio-9p.c b/lib/libvirtio/virtio-9p.c
>>>>>>> index 426069fe9509..76078612b06e 100644
>>>>>>> --- a/lib/libvirtio/virtio-9p.c
>>>>>>> +++ b/lib/libvirtio/virtio-9p.c
>>>>>>> @@ -129,6 +129,10 @@ static int virtio_9p_transact(void *opaque, uint8_t *tx, int tx_size, uint8_t *r
>>>>>>> // do something better
>>>>>>> mb();
>>>>>>> }
>>>>>>> +
>>>>>>> + virtio_free_desc(vq, id, dev->features);
>>>>>>> + virtio_free_desc(vq, id + 1, dev->features);
>>>>>>> +
>>>>>>> if (i == 0) {
>>>>>>> return -1;
>>>>>>> }
>>>>>>> diff --git a/lib/libvirtio/virtio-blk.c b/lib/libvirtio/virtio-blk.c
>>>>>>> index a0dadbb0d6a8..0363038e559d 100644
>>>>>>> --- a/lib/libvirtio/virtio-blk.c
>>>>>>> +++ b/lib/libvirtio/virtio-blk.c
>>>>>>> @@ -195,6 +195,10 @@ virtioblk_transfer(struct virtio_device *dev, char *buf, uint64_t blocknum,
>>>>>>> break;
>>>>>>> }
>>>>>>>
>>>>>>> + virtio_free_desc(vq, id, dev->features);
>>>>>>> + virtio_free_desc(vq, id + 1, dev->features);
>>>>>>> + virtio_free_desc(vq, id + 2, dev->features);
>>>>>>> +
>>>>>>> if (status == 0)
>>>>>>> return cnt;
>>>>>>>
>>>>>>> diff --git a/lib/libvirtio/virtio-net.c b/lib/libvirtio/virtio-net.c
>>>>>>> index ae67883020ef..5a0d19088527 100644
>>>>>>> --- a/lib/libvirtio/virtio-net.c
>>>>>>> +++ b/lib/libvirtio/virtio-net.c
>>>>>>> @@ -255,6 +255,9 @@ static int virtionet_xmit(struct virtio_net *vnet, char *buf, int len)
>>>>>>> idx = virtio_modern16_to_cpu(vdev, vq_tx->avail->idx);
>>>>>>> id = (idx * 2) % vq_tx->size;
>>>>>>>
>>>>>>> + virtio_free_desc(vq_tx, id, vdev->features);
>>>>>>> + virtio_free_desc(vq_tx, id + 1, vdev->features);
>>>>>>> +
>>>>>>> /* Set up virtqueue descriptor for header */
>>>>>>> virtio_fill_desc(vq_tx, id, vdev->features, (uint64_t)nethdr,
>>>>>>> net_hdr_size, VRING_DESC_F_NEXT, id + 1);
>>>>>>> @@ -317,7 +320,7 @@ static int virtionet_receive(struct virtio_net *vnet, char *buf, int maxlen)
>>>>>>> #endif
>>>>>>>
>>>>>>> /* Copy data to destination buffer */
>>>>>>> - memcpy(buf, (void *)virtio_modern64_to_cpu(vdev, vq_rx->desc[id].addr), len);
>>>>>>> + memcpy(buf, virtio_desc_addr(vdev, VQ_RX, id), len);
>>>>>>>
>>>>>>> /* Move indices to next entries */
>>>>>>> last_rx_idx = last_rx_idx + 1;
>>>>>>> diff --git a/lib/libvirtio/virtio-scsi.c b/lib/libvirtio/virtio-scsi.c
>>>>>>> index 251661e8d466..44573d10e24c 100644
>>>>>>> --- a/lib/libvirtio/virtio-scsi.c
>>>>>>> +++ b/lib/libvirtio/virtio-scsi.c
>>>>>>> @@ -81,6 +81,11 @@ int virtioscsi_send(struct virtio_device *dev,
>>>>>>> break;
>>>>>>> }
>>>>>>>
>>>>>>> + virtio_free_desc(vq, id, dev->features);
>>>>>>> + virtio_free_desc(vq, id + 1, dev->features);
>>>>>>> + if (!(buf == NULL || buf_len == 0))
>>>>>>> + virtio_free_desc(vq, id + 2, dev->features);
>>>>>>> +
>>>>>>> return 0;
>>>>>>> }
>>>>>>>
>>>>>>> diff --git a/lib/libvirtio/virtio-serial.c b/lib/libvirtio/virtio-serial.c
>>>>>>> index 78ab0e25d7db..66fbfe8b6cc6 100644
>>>>>>> --- a/lib/libvirtio/virtio-serial.c
>>>>>>> +++ b/lib/libvirtio/virtio-serial.c
>>>>>>> @@ -108,7 +108,7 @@ void virtio_serial_shutdown(struct virtio_device *dev)
>>>>>>>
>>>>>>> int virtio_serial_putchar(struct virtio_device *dev, char c)
>>>>>>> {
>>>>>>> - int id;
>>>>>>> + int id, ret;
>>>>>>> uint32_t vq_size, time;
>>>>>>> volatile uint16_t *current_used_idx;
>>>>>>> uint16_t last_used_idx, avail_idx;
>>>>>>> @@ -135,17 +135,21 @@ int virtio_serial_putchar(struct virtio_device *dev, char c)
>>>>>>> virtio_queue_notify(dev, TX_Q);
>>>>>>>
>>>>>>> /* Wait for host to consume the descriptor */
>>>>>>> + ret = 1;
>>>>>>> time = SLOF_GetTimer() + VIRTIO_TIMEOUT;
>>>>>>> while (*current_used_idx == last_used_idx) {
>>>>>>> // do something better
>>>>>>> mb();
>>>>>>> if (time < SLOF_GetTimer()) {
>>>>>>> printf("virtio_serial_putchar failed! \n");
>>>>>>> - return 0;
>>>>>>> + ret = 0;
>>>>>>> + break;
>>>>>>> }
>>>>>>> }
>>>>>>>
>>>>>>> - return 1;
>>>>>>> + virtio_free_desc(vq, id, dev->features);
>>>>>>> +
>>>>>>> + return ret;
>>>>>>> }
>>>>>>>
>>>>>>> char virtio_serial_getchar(struct virtio_device *dev)
>>>>>>> @@ -165,7 +169,7 @@ char virtio_serial_getchar(struct virtio_device *dev)
>>>>>>> % vq_rx->size;
>>>>>>>
>>>>>>> /* Copy data to destination buffer */
>>>>>>> - memcpy(buf, (void *)virtio_modern64_to_cpu(dev, vq_rx->desc[id - 1].addr), RX_ELEM_SIZE);
>>>>>>> + memcpy(buf, virtio_desc_addr(dev, RX_Q, id - 1), RX_ELEM_SIZE);
>>>>>>>
>>>>>>> /* Move indices to next entries */
>>>>>>> last_rx_idx = last_rx_idx + 1;
>>>>>>> diff --git a/lib/libvirtio/virtio.c b/lib/libvirtio/virtio.c
>>>>>>> index fff0c7e54c19..d4db5f656888 100644
>>>>>>> --- a/lib/libvirtio/virtio.c
>>>>>>> +++ b/lib/libvirtio/virtio.c
>>>>>>> @@ -273,6 +273,17 @@ void virtio_fill_desc(struct vqs *vq, int id, uint64_t features,
>>>>>>> next %= vq->size;
>>>>>>>
>>>>>>> if (features & VIRTIO_F_VERSION_1) {
>>>>>>> + if (features & VIRTIO_F_IOMMU_PLATFORM) {
>>>>>>> + void *gpa = (void *) addr;
>>>>>>> +
>>>>>>> + if (!vq->desc_gpas) {
>>>>>>> + fprintf(stderr, "IOMMU setup has not been done!\n");
>>>>>>> + return;
>>>>>>> + }
>>>>>>> +
>>>>>>> + addr = SLOF_dma_map_in(gpa, len, 0);
>>>>>>> + vq->desc_gpas[id] = gpa;
>>>>>>> + }
>>>>>>> desc->addr = cpu_to_le64(addr);
>>>>>>> desc->len = cpu_to_le32(len);
>>>>>>> desc->flags = cpu_to_le16(flags);
>>>>>>> @@ -285,6 +296,32 @@ void virtio_fill_desc(struct vqs *vq, int id, uint64_t features,
>>>>>>> }
>>>>>>> }
>>>>>>>
>>>>>>> +void virtio_free_desc(struct vqs *vq, int id, uint64_t features)
>>>>>>> +{
>>>>>>> + struct vring_desc *desc;
>>>>>>> +
>>>>>>> + id %= vq->size;
>>>>>>> + desc = &vq->desc[id];
>>>>>>> +
>>>>>>> + if (features & VIRTIO_F_VERSION_1) {
>>>>>>> + if (features & VIRTIO_F_IOMMU_PLATFORM) {
>>>>>>> + SLOF_dma_map_out(le64_to_cpu(desc->addr),
>>>>>>> + 0, le32_to_cpu(desc->len));
>>>>>>> + vq->desc_gpas[id] = NULL;
>>>>>>> + }
>>>>>>> + }
>>>>>>> +}
>>>>>>
>>>>>> On a 4.18 RHEL8 kernel I was unable to boot from virtio-blk, it complains the
>>>>>> disk isn't bootable and the H_PUT_TCE traces show:
>>>>>>
>>>>>> qemu-system-ppc-19019 [045] .... 786844.067356: kvm_hcall_enter: VCPU 0: hcall=H_PUT_TCE GPR4-7=0x80000000,0x1000,0xe46b003,0xdc73350
>>>>>> qemu-system-ppc-19019 [045] .... 786844.067358: kvm_hcall_exit: VCPU 0: ret=RESUME_GUEST hcall_rc=H_SUCCESS
>>>>>> qemu-system-ppc-19019 [045] .... 786844.067361: kvm_hcall_enter: VCPU 0: hcall=H_PUT_TCE GPR4-7=0x80000000,0x2000,0xe46c003,0xdc73350
>>>>>> qemu-system-ppc-19019 [045] .... 786844.067362: kvm_hcall_exit: VCPU 0: ret=RESUME_GUEST hcall_rc=H_SUCCESS
>>>>>> qemu-system-ppc-19019 [041] .... 786844.070532: kvm_hcall_enter: VCPU 0: hcall=H_PUT_TCE GPR4-7=0x80000000,0x3000,0xe67b003,0xdc73490
>>>>>> qemu-system-ppc-19019 [041] .... 786844.070533: kvm_hcall_exit: VCPU 0: ret=RESUME_GUEST hcall_rc=H_SUCCESS
>>>>>> qemu-system-ppc-19019 [041] .... 786844.070817: kvm_hcall_enter: VCPU 0: hcall=H_PUT_TCE GPR4-7=0x80000000,0x4000,0xe469003,0xdc73490
>>>>>> qemu-system-ppc-19019 [041] .... 786844.070818: kvm_hcall_exit: VCPU 0: ret=RESUME_GUEST hcall_rc=H_SUCCESS
>>>>>> qemu-system-ppc-19019 [041] .... 786844.071102: kvm_hcall_enter: VCPU 0: hcall=H_PUT_TCE GPR4-7=0x80000000,0x5000,0xe67a003,0xdc73490
>>>>>> qemu-system-ppc-19019 [041] .... 786844.071103: kvm_hcall_exit: VCPU 0: ret=RESUME_GUEST hcall_rc=H_SUCCESS
>>>>>> qemu-system-ppc-19019 [041] .... 786844.071123: kvm_hcall_exit: VCPU 0: ret=RESUME_GUEST hcall_rc=H_SUCCESS
>>>>>> qemu-system-ppc-19019 [041] .... 786844.073532: kvm_hcall_enter: VCPU 0: hcall=H_PUT_TCE GPR4-7=0x80000000,0x3228,0x0,0xdc73488
>>>>>> qemu-system-ppc-19019 [041] .... 786844.073534: kvm_hcall_exit: VCPU 0: ret=RESUME_GUEST hcall_rc=H_PARAMETER
>>>>>>
>>>>>> If I disable in-kernel TCE acceleration, or use TCG, it seems to work
>>>>>> fine. If I add the following hack it seems to fix things:
>>>>>>
>>>>>> @@ -305,7 +307,8 @@ void virtio_free_desc(struct vqs *vq, int id, uint64_t features)
>>>>>>
>>>>>> if (features & VIRTIO_F_VERSION_1) {
>>>>>> if (features & VIRTIO_F_IOMMU_PLATFORM) {
>>>>>> - SLOF_dma_map_out(le64_to_cpu(desc->addr),
>>>>>> + fprintf(stderr, "mapping out desc->addr: %llx\n", le64_to_cpu(desc->addr));
>>>>>> + SLOF_dma_map_out(le64_to_cpu(desc->addr) & ~(0xfff),
>>>>>> 0, le32_to_cpu(desc->len));
>>>>>> vq->desc_gpas[id] = NULL;
>>>>>> }
>>>>>>
>>>>>> I guess the kernel is a bit stricter about unmapping unaligned TCE entries? If
>>>>>> so, maybe we should align automatically in dma-map-out?
>>>>>
>>>>>
>>>>> I thought I did that as well in 1/4, I'll double check. Hmmm.
>>>>
>>>>
>>>> v2 of these patches did not align (or, trunc, really) in dma-map-out but
>>>> v3 do, it is "swap dma-trunc swap" in dma-map-out of 1/4. SO I am really
>>>> confused now.
>>>
>>> Yah sorry I think the issue was on my end. I thought:
>>>
>>> https://github.com/aik/SLOF/commits/virtio-iommu
>>
>>
>> My bad, I should have pushed it out since I started pushing them out.
>>
>> The question now is if we are good to go and I can push these out and
>> send SLOF blob update so people can actually start testing it? Thanks,
>
> System came back after clearing GARD record, re-tested disk boot for
> virtio-blk/virtio-scsi, and netboot via virtio-net, with iommu on/off and
> everything seems to be working.
>
> Still need to verify in an actual uv-capable system, but in terms of base
> IOMMU enablement the series looks good:
>
> Tested-by: Michael Roth <mdroth at linux.vnet.ibm.com>
Oh great, thanks!
Are going to give it some more review or I just push it out and send
slof blob update to qemu?
David, how much do you want to see many rb's for these?
Thanks,
>
>>
>>
>>>
>>> reflected this series, but it does contain an older version of the
>>> dma-map* patch:
>>>
>>> index f136324..be529c9 100644
>>> --- a/board-qemu/slof/pci-phb.fs
>>> +++ b/board-qemu/slof/pci-phb.fs
>>> @@ -146,6 +146,7 @@ setup-puid
>>> \ grub does not align allocated addresses to the size so when mapping,
>>> \ we might ask bm-alloc for an extra IOMMU page
>>> : dma-align ( size virt -- aligned-size ) tce-mask and + tce-ps #aligned ;
>>> +: dma-trunc ( addr -- addr&~fff) tce-mask not and ;
>>>
>>> : dma-map-in ( virt size cachable? -- devaddr )
>>> phb-debug? IF cr ." dma-map-in called: " .s cr THEN
>>> @@ -163,7 +164,7 @@ setup-puid
>>> swap ( size dev-addr virt )
>>> 2dup tce-mask and or >r \ add page offset to the return value
>>>
>>> - tce-mask not and 3 OR \ Trunk virt and add read and write perm
>>> + dma-trunc 3 OR \ Truncate and add read and write perm
>>> rot ( virt dev-addr size r: dev-addr )
>>> 0
>>> ?DO
>>> @@ -179,10 +180,10 @@ setup-puid
>>> : dma-map-out ( virt devaddr size -- )
>>> phb-debug? IF cr ." dma-map-out called: " .s cr THEN
>>> (init-dma-window-vars)
>>> - rot drop ( devaddr size )
>>> + rot drop ( devaddr size )
>>> over dma-align
>>> - 2dup swap tce-mask not and swap bm-handle -rot
>>> - bm-free
>>> + swap dma-trunc swap ( devaddr-trunc size-extended )
>>> + 2dup bm-handle -rot bm-free
>>> 0
>>> ?DO
>>> dup 0 dma-window-liobn -rot
>>>
>>>
>>> I haven't been able to re-test yet since something seems to have gone
>>> awry with the test system last night, but I assume that's what the issue
>>> was. Sorry for the confusion.
>>>
>>>>
>>>> It is true that checking differs between qemu's and kvm's h_put_tce
>>>> handlers, I added this (see below) to my qemu and it still works, can
>>>> you please try in your tree and capture the spapr_iommu_pci_put traces?
>>>> Thanks,
>>>>
>>>>
>>>> diff --git a/hw/ppc/spapr_iommu.c b/hw/ppc/spapr_iommu.c
>>>> index 3d3bcc86496a..feae27bf11fa 100644
>>>> --- a/hw/ppc/spapr_iommu.c
>>>> +++ b/hw/ppc/spapr_iommu.c
>>>> @@ -564,6 +564,9 @@ static target_ulong h_put_tce(PowerPCCPU *cpu,
>>>> SpaprMachineState *spapr,
>>>> if (tcet) {
>>>> hwaddr page_mask = IOMMU_PAGE_MASK(tcet->page_shift);
>>>>
>>>> + if (ioba & ~page_mask)
>>>> + abort();
>>>> +
>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Alexey
>>
>> --
>> Alexey
--
Alexey
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