Re: [PATCH 2/3] qemu-kvm: device assignment: Some clean up about MSI-X code

[Sheng Yang <sheng@linux.intel.com>]

On Thursday 04 November 2010 17:47:16 Michael S. Tsirkin wrote:
> On Thu, Nov 04, 2010 at 02:18:20PM +0800, Sheng Yang wrote:
> > Signed-off-by: Sheng Yang <sheng@linux.intel.com>
> 
> If you have the energy for cleanups, how about
> removing most of msi/msix code in device-assignment and using msi.c and
> msix.c instead?

Ah, this one is only used to reduce the review difficulty. I won't mind if you want 
to merge it with the last one...

Use msi.c/msix.c totally another big clean up work to do. Let put it later...

--
regards
Yang, Sheng

> 
> > ---
> > 
> >  hw/device-assignment.c |   77
> >  ++++++++++++++++++++++++++++++++--------------- 1 files changed, 52
> >  insertions(+), 25 deletions(-)
> > 
> > diff --git a/hw/device-assignment.c b/hw/device-assignment.c
> > index 2605bd1..8a98876 100644
> > --- a/hw/device-assignment.c
> > +++ b/hw/device-assignment.c
> > @@ -1106,15 +1106,10 @@ static void assigned_dev_update_msi(PCIDevice
> > *pci_dev, unsigned int ctrl_pos)
> > 
> >  #endif
> >  
> >  #ifdef KVM_CAP_DEVICE_MSIX
> > 
> > -static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
> > +static int get_msix_entries_max_nr(AssignedDevice *adev)
> > 
> >  {
> > 
> > -    AssignedDevice *adev = container_of(pci_dev, AssignedDevice, dev);
> > -    uint16_t entries_nr = 0, entries_max_nr;
> > -    int pos = 0, i, r = 0;
> > -    uint32_t msg_addr, msg_upper_addr, msg_data, msg_ctrl;
> > -    struct kvm_assigned_msix_nr msix_nr;
> > -    struct kvm_assigned_msix_entry msix_entry;
> > -    void *va = adev->msix_table_page;
> > +    int pos, entries_max_nr;
> > +    PCIDevice *pci_dev = &adev->dev;
> > 
> >      if (adev->cap.available & ASSIGNED_DEVICE_CAP_MSI)
> >      
> >          pos = pci_dev->cap.start + PCI_CAPABILITY_CONFIG_MSI_LENGTH;
> > 
> > @@ -1125,6 +1120,17 @@ static int assigned_dev_update_msix_mmio(PCIDevice
> > *pci_dev)
> > 
> >      entries_max_nr &= PCI_MSIX_TABSIZE;
> >      entries_max_nr += 1;
> > 
> > +    return entries_max_nr;
> > +}
> > +
> > +static int get_msix_valid_entries_nr(AssignedDevice *adev,
> > +				     uint16_t entries_max_nr)
> > +{
> > +    void *va = adev->msix_table_page;
> > +    uint32_t msg_data, msg_ctrl;
> > +    uint16_t entries_nr = 0;
> > +    int i;
> > +
> > 
> >      /* Get the usable entry number for allocating */
> >      for (i = 0; i < entries_max_nr; i++) {
> >      
> >          memcpy(&msg_ctrl, va + i * 16 + 12, 4);
> > 
> > @@ -1134,11 +1140,20 @@ static int
> > assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
> > 
> >              continue;
> >          
> >          entries_nr ++;
> >      
> >      }
> > 
> > +    return entries_nr;
> > +}
> > +
> > +static int assigned_dev_update_msix_mmio(PCIDevice *pci_dev,
> > +                                         uint16_t entries_nr,
> > +                                         uint16_t entries_max_nr)
> > +{
> > +    AssignedDevice *adev = container_of(pci_dev, AssignedDevice, dev);
> > +    int i, r = 0;
> > +    uint32_t msg_addr, msg_upper_addr, msg_data, msg_ctrl;
> > +    struct kvm_assigned_msix_nr msix_nr;
> > +    struct kvm_assigned_msix_entry msix_entry;
> > +    void *va = adev->msix_table_page;
> > 
> > -    if (entries_nr == 0) {
> > -        fprintf(stderr, "MSI-X entry number is zero!\n");
> > -        return -EINVAL;
> > -    }
> > 
> >      msix_nr.assigned_dev_id = calc_assigned_dev_id(adev->h_segnr,
> >      adev->h_busnr,
> >      
> >                                            (uint8_t)adev->h_devfn);
> >      
> >      msix_nr.entry_nr = entries_nr;
> > 
> > @@ -1180,8 +1195,8 @@ static int assigned_dev_update_msix_mmio(PCIDevice
> > *pci_dev)
> > 
> >          adev->entry[entries_nr].u.msi.address_lo = msg_addr;
> >          adev->entry[entries_nr].u.msi.address_hi = msg_upper_addr;
> >          adev->entry[entries_nr].u.msi.data = msg_data;
> > 
> > -        DEBUG("MSI-X data 0x%x, MSI-X addr_lo 0x%x\n!", msg_data,
> > msg_addr); -	kvm_add_routing_entry(&adev->entry[entries_nr]);
> > +        DEBUG("MSI-X data 0x%x, MSI-X addr_lo 0x%x!\n", msg_data,
> > msg_addr); +        kvm_add_routing_entry(&adev->entry[entries_nr]);
> > 
> >          msix_entry.gsi = adev->entry[entries_nr].gsi;
> >          msix_entry.entry = i;
> > 
> > @@ -1190,7 +1205,7 @@ static int assigned_dev_update_msix_mmio(PCIDevice
> > *pci_dev)
> > 
> >              fprintf(stderr, "fail to set MSI-X entry! %s\n",
> >              strerror(-r)); break;
> >          
> >          }
> > 
> > -        DEBUG("MSI-X entry gsi 0x%x, entry %d\n!",
> > +        DEBUG("MSI-X entry gsi 0x%x, entry %d!\n",
> > 
> >                  msix_entry.gsi, msix_entry.entry);
> >          
> >          entries_nr ++;
> >      
> >      }
> > 
> > @@ -1203,12 +1218,12 @@ static int
> > assigned_dev_update_msix_mmio(PCIDevice *pci_dev)
> > 
> >      return r;
> >  
> >  }
> > 
> > -static void assigned_dev_update_msix(PCIDevice *pci_dev, unsigned int
> > ctrl_pos) +static void assigned_dev_update_msix(PCIDevice *pci_dev, int
> > enable_msix)
> > 
> >  {
> >  
> >      struct kvm_assigned_irq assigned_irq_data;
> >      AssignedDevice *assigned_dev = container_of(pci_dev, AssignedDevice,
> >      dev);
> > 
> > -    uint16_t *ctrl_word = (uint16_t *)(pci_dev->config + ctrl_pos);
> > 
> >      int r;
> > 
> > +    uint16_t entries_nr, entries_max_nr;
> > 
> >      memset(&assigned_irq_data, 0, sizeof assigned_irq_data);
> >      assigned_irq_data.assigned_dev_id  =
> > 
> > @@ -1219,8 +1234,7 @@ static void assigned_dev_update_msix(PCIDevice
> > *pci_dev, unsigned int ctrl_pos)
> > 
> >       * try to catch this by only deassigning irqs if the guest is using
> >       * MSIX or intends to start. */
> >      
> >      if ((assigned_dev->irq_requested_type & KVM_DEV_IRQ_GUEST_MSIX) ||
> > 
> > -        (*ctrl_word & PCI_MSIX_ENABLE)) {
> > -
> > +            enable_msix) {
> > 
> >          assigned_irq_data.flags = assigned_dev->irq_requested_type;
> >          free_dev_irq_entries(assigned_dev);
> >          r = kvm_deassign_irq(kvm_context, &assigned_irq_data);
> > 
> > @@ -1231,14 +1245,25 @@ static void assigned_dev_update_msix(PCIDevice
> > *pci_dev, unsigned int ctrl_pos)
> > 
> >          assigned_dev->irq_requested_type = 0;
> >      
> >      }
> > 
> > -    if (*ctrl_word & PCI_MSIX_ENABLE) {
> > -        assigned_irq_data.flags = KVM_DEV_IRQ_HOST_MSIX |
> > -                                  KVM_DEV_IRQ_GUEST_MSIX;
> > -
> > -        if (assigned_dev_update_msix_mmio(pci_dev) < 0) {
> > +    entries_max_nr = get_msix_entries_max_nr(assigned_dev);
> > +    if (entries_max_nr == 0) {
> > +        fprintf(stderr, "assigned_dev_update_msix: MSI-X entries_max_nr
> > == 0"); +        return;
> > +    }
> > +    entries_nr = get_msix_valid_entries_nr(assigned_dev,
> > entries_max_nr); +    if (entries_nr == 0) {
> > +        if (enable_msix)
> > +            fprintf(stderr, "MSI-X entry number is zero!\n");
> > +        return;
> > +    }
> > +    if (enable_msix) {
> > +        if (assigned_dev_update_msix_mmio(pci_dev,
> > +                    entries_nr, entries_max_nr) < 0) {
> > 
> >              perror("assigned_dev_update_msix_mmio");
> >              return;
> >          
> >          }
> > 
> > +        assigned_irq_data.flags = KVM_DEV_IRQ_HOST_MSIX |
> > +                                  KVM_DEV_IRQ_GUEST_MSIX;
> > 
> >          if (kvm_assign_irq(kvm_context, &assigned_irq_data) < 0) {
> >          
> >              perror("assigned_dev_enable_msix: assign irq");
> >              return;
> > 
> > @@ -1254,6 +1279,7 @@ static void
> > assigned_device_pci_cap_write_config(PCIDevice *pci_dev, uint32_t ad
> > 
> >  {
> >  
> >      AssignedDevice *assigned_dev = container_of(pci_dev, AssignedDevice,
> >      dev); unsigned int pos = pci_dev->cap.start, ctrl_pos;
> > 
> > +    uint16_t *ctrl_word;
> > 
> >      pci_default_cap_write_config(pci_dev, address, val, len);
> >  
> >  #ifdef KVM_CAP_IRQ_ROUTING
> > 
> > @@ -1270,7 +1296,8 @@ static void
> > assigned_device_pci_cap_write_config(PCIDevice *pci_dev, uint32_t ad
> > 
> >          ctrl_pos = pos + 3;
> >          if (address <= ctrl_pos && address + len > ctrl_pos) {
> >          
> >              ctrl_pos--; /* control is word long */
> > 
> > -            assigned_dev_update_msix(pci_dev, ctrl_pos);
> > +            ctrl_word = (uint16_t *)(pci_dev->config + ctrl_pos);
> > +            assigned_dev_update_msix(pci_dev, (*ctrl_word &
> > PCI_MSIX_ENABLE));
> > 
> >  	}
> >  	
> >          pos += PCI_CAPABILITY_CONFIG_MSIX_LENGTH;
> >      
> >      }