Re: [PATCH] virtio-pci: compat page aligned ATS

[Jason Wang <jasowang@redhat.com>]

在 2021/4/2 下午5:31, Michael S. Tsirkin 写道:
> On Fri, Apr 02, 2021 at 03:55:20PM +0800, Jason Wang wrote:
>> Commit 4c70875372b8 ("pci: advertise a page aligned ATS") advertises
>> the page aligned via ATS capability (RO) to unbrek recent Linux IOMMU
>> drivers since 5.2. But it forgot the compat the capability which
>> breaks the migration from old machine type:
>>
>> (qemu) qemu-kvm: get_pci_config_device: Bad config data: i=0x104 read:
>> 0 device: 20 cmask: ff wmask: 0 w1cmask:0
>>
>> This patch introduces a new parameter "ats_page_aligned" for
>> virtio-pci device and turn it on for machine type which is newer than
>> 5.1.
>>
>> Cc: Michael S. Tsirkin <mst@redhat.com>
>> Cc: Peter Xu <peterx@redhat.com>
>> Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
>> Cc: qemu-stable@nongnu.org
>> Fixes: 4c70875372b8 ("pci: advertise a page aligned ATS")
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
> I think x-ats-page-aligned would be a better name.


Right, will post V2.

Thanks


>
>
>> ---
>>   hw/core/machine.c      |  1 +
>>   hw/pci/pcie.c          | 10 ++++++----
>>   hw/virtio/virtio-pci.c |  5 ++++-
>>   hw/virtio/virtio-pci.h |  5 +++++
>>   include/hw/pci/pcie.h  |  2 +-
>>   5 files changed, 17 insertions(+), 6 deletions(-)
>>
>> diff --git a/hw/core/machine.c b/hw/core/machine.c
>> index 9935c6ddd5..ad4459b0f2 100644
>> --- a/hw/core/machine.c
>> +++ b/hw/core/machine.c
>> @@ -53,6 +53,7 @@ GlobalProperty hw_compat_5_1[] = {
>>       { "nvme", "use-intel-id", "on"},
>>       { "pvpanic", "events", "1"}, /* PVPANIC_PANICKED */
>>       { "pl011", "migrate-clk", "off" },
>> +    { "virtio-pci", "ats_page_aligned", "off"},
>>   };
>>   const size_t hw_compat_5_1_len = G_N_ELEMENTS(hw_compat_5_1);
>>   
>> diff --git a/hw/pci/pcie.c b/hw/pci/pcie.c
>> index a733e2fb87..fd0fa157e8 100644
>> --- a/hw/pci/pcie.c
>> +++ b/hw/pci/pcie.c
>> @@ -963,16 +963,18 @@ void pcie_dev_ser_num_init(PCIDevice *dev, uint16_t offset, uint64_t ser_num)
>>       pci_set_quad(dev->config + offset + pci_dsn_cap, ser_num);
>>   }
>>   
>> -void pcie_ats_init(PCIDevice *dev, uint16_t offset)
>> +void pcie_ats_init(PCIDevice *dev, uint16_t offset, bool aligned)
>>   {
>>       pcie_add_capability(dev, PCI_EXT_CAP_ID_ATS, 0x1,
>>                           offset, PCI_EXT_CAP_ATS_SIZEOF);
>>   
>>       dev->exp.ats_cap = offset;
>>   
>> -    /* Invalidate Queue Depth 0, Page Aligned Request 1 */
>> -    pci_set_word(dev->config + offset + PCI_ATS_CAP,
>> -                 PCI_ATS_CAP_PAGE_ALIGNED);
>> +    /* Invalidate Queue Depth 0 */
>> +    if (aligned) {
>> +        pci_set_word(dev->config + offset + PCI_ATS_CAP,
>> +                     PCI_ATS_CAP_PAGE_ALIGNED);
>> +    }
>>       /* STU 0, Disabled by default */
>>       pci_set_word(dev->config + offset + PCI_ATS_CTRL, 0);
>>   
>> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
>> index 883045a223..ebe9716acf 100644
>> --- a/hw/virtio/virtio-pci.c
>> +++ b/hw/virtio/virtio-pci.c
>> @@ -1848,7 +1848,8 @@ static void virtio_pci_realize(PCIDevice *pci_dev, Error **errp)
>>           }
>>   
>>           if (proxy->flags & VIRTIO_PCI_FLAG_ATS) {
>> -            pcie_ats_init(pci_dev, last_pcie_cap_offset);
>> +            pcie_ats_init(pci_dev, last_pcie_cap_offset,
>> +                          proxy->flags & VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED);
>>               last_pcie_cap_offset += PCI_EXT_CAP_ATS_SIZEOF;
>>           }
>>   
>> @@ -1925,6 +1926,8 @@ static Property virtio_pci_properties[] = {
>>                        ignore_backend_features, false),
>>       DEFINE_PROP_BIT("ats", VirtIOPCIProxy, flags,
>>                       VIRTIO_PCI_FLAG_ATS_BIT, false),
>> +    DEFINE_PROP_BIT("ats_page_aligned", VirtIOPCIProxy, flags,
>> +                    VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED_BIT, true),
>>       DEFINE_PROP_BIT("x-pcie-deverr-init", VirtIOPCIProxy, flags,
>>                       VIRTIO_PCI_FLAG_INIT_DEVERR_BIT, true),
>>       DEFINE_PROP_BIT("x-pcie-lnkctl-init", VirtIOPCIProxy, flags,
>> diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
>> index d7d5d403a9..2446dcd9ae 100644
>> --- a/hw/virtio/virtio-pci.h
>> +++ b/hw/virtio/virtio-pci.h
>> @@ -42,6 +42,7 @@ enum {
>>       VIRTIO_PCI_FLAG_INIT_PM_BIT,
>>       VIRTIO_PCI_FLAG_INIT_FLR_BIT,
>>       VIRTIO_PCI_FLAG_AER_BIT,
>> +    VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED_BIT,
>>   };
>>   
>>   /* Need to activate work-arounds for buggy guests at vmstate load. */
>> @@ -84,6 +85,10 @@ enum {
>>   /* Advanced Error Reporting capability */
>>   #define VIRTIO_PCI_FLAG_AER (1 << VIRTIO_PCI_FLAG_AER_BIT)
>>   
>> +/* Page Aligned Address space Translation Service */
>> +#define VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED \
>> +  (1 << VIRTIO_PCI_FLAG_ATS_PAGE_ALIGNED_BIT)
>> +
>>   typedef struct {
>>       MSIMessage msg;
>>       int virq;
>> diff --git a/include/hw/pci/pcie.h b/include/hw/pci/pcie.h
>> index 14c58ebdb6..6063bee0ec 100644
>> --- a/include/hw/pci/pcie.h
>> +++ b/include/hw/pci/pcie.h
>> @@ -137,7 +137,7 @@ void pcie_acs_reset(PCIDevice *dev);
>>   
>>   void pcie_ari_init(PCIDevice *dev, uint16_t offset, uint16_t nextfn);
>>   void pcie_dev_ser_num_init(PCIDevice *dev, uint16_t offset, uint64_t ser_num);
>> -void pcie_ats_init(PCIDevice *dev, uint16_t offset);
>> +void pcie_ats_init(PCIDevice *dev, uint16_t offset, bool aligned);
>>   
>>   void pcie_cap_slot_pre_plug_cb(HotplugHandler *hotplug_dev, DeviceState *dev,
>>                                  Error **errp);
>> -- 
>> 2.24.3 (Apple Git-128)