Re: [Qemu-devel] [PATCH] RFC: vfio-powerpc: added VFIO support (v3)

[Alexey Kardashevskiy]

On 14/07/12 01:07, Alex Williamson wrote:
> On Fri, 2012-07-13 at 17:26 +1000, Alexey Kardashevskiy wrote:
>> It literally does the following:
>>
>> 1. POWERPC IOMMU support (the kernel counterpart is required)
>>
>> 2. The patch assumes that IOAPIC calls are going to be replaced
>> with something generic.
>>
>> 3. vfio_group_iommu_ioctl() has been added to let sPAPR IOMMU
>> handler to call VFIO IOMMU driver.
>>
>> 4. Change sPAPR PHB to scan the PCI bus which is used for
>> the IOMMU-VFIO group. Now it is enough to add the following to
>> the QEMU command line to get VFIO up with all the devices from
>> IOMMU group with id=3:
>> -device spapr-pci-host-bridge,busname=E1000E,buid=0x3,iommu=3,\
>> mem_win_addr=0x230000000000,io_win_addr=0x240000000000,msi_win_addr=0x250000000000
>>
>> Signed-off-by: Alexey Kardashevskiy <address@hidden>
>> ---
>>  hw/ppc/Makefile.objs  |    3 ++
>>  hw/spapr.h            |    4 ++
>>  hw/spapr_iommu.c      |   69 ++++++++++++++++++++++++++++++-
>>  hw/spapr_iommu_vfio.h |   49 ++++++++++++++++++++++
>>  hw/spapr_pci.c        |  108 
>> ++++++++++++++++++++++++++++++++++++++++++++++---
>>  hw/spapr_pci.h        |    4 ++
>>  hw/vfio_pci.c         |   30 ++++++++++++++
>>  hw/vfio_pci.h         |    2 +
>>  trace-events          |    1 +
>>  9 files changed, 264 insertions(+), 6 deletions(-)
>>  create mode 100644 hw/spapr_iommu_vfio.h
>>
>> diff --git a/hw/ppc/Makefile.objs b/hw/ppc/Makefile.objs
>> index f573a95..c46a049 100644
>> --- a/hw/ppc/Makefile.objs
>> +++ b/hw/ppc/Makefile.objs
>> @@ -25,4 +25,7 @@ obj-$(CONFIG_FDT) += ../device_tree.o
>>  # Xilinx PPC peripherals
>>  obj-y += xilinx_ethlite.o
>>  
>> +# VFIO PCI device assignment
>> +obj-$(CONFIG_VFIO_PCI) += vfio_pci.o
>> +
>>  obj-y := $(addprefix ../,$(obj-y))
>> diff --git a/hw/spapr.h b/hw/spapr.h
>> index b37f337..26e26f6 100644
>> --- a/hw/spapr.h
>> +++ b/hw/spapr.h
>> @@ -340,4 +340,8 @@ int spapr_dma_dt(void *fdt, int node_off, const char 
>> *propname,
>>  int spapr_tcet_dma_dt(void *fdt, int node_off, const char *propname,
>>                        DMAContext *dma);
>>  
>> +void spapr_vfio_init_dma(int group_id, uint32_t liobn,
>> +                         uint64_t *dma32_window_start,
>> +                         uint64_t *dma32_window_size);
>> +
>>  #endif /* !defined (__HW_SPAPR_H__) */
>> diff --git a/hw/spapr_iommu.c b/hw/spapr_iommu.c
>> index 50c288d..e48ced1 100644
>> --- a/hw/spapr_iommu.c
>> +++ b/hw/spapr_iommu.c
>> @@ -23,6 +23,8 @@
>>  #include "dma.h"
>>  
>>  #include "hw/spapr.h"
>> +#include "hw/spapr_iommu_vfio.h"
>> +#include "hw/vfio_pci.h"
>>  
>>  #include <libfdt.h>
>>  
>> @@ -183,6 +185,67 @@ static int put_tce_emu(target_ulong liobn, target_ulong 
>> ioba, target_ulong tce)
>>      return 0;
>>  }
>>  
>> +typedef struct sPAPRVFIOTable {
>> +    int group_id;
>> +    uint32_t liobn;
>> +    QLIST_ENTRY(sPAPRVFIOTable) list;
>> +} sPAPRVFIOTable;
>> +
>> +QLIST_HEAD(vfio_tce_tables, sPAPRVFIOTable) vfio_tce_tables;
>> +
>> +void spapr_vfio_init_dma(int group_id, uint32_t liobn,
>> +                         uint64_t *dma32_window_start,
>> +                         uint64_t *dma32_window_size)
>> +{
>> +    sPAPRVFIOTable *t;
>> +    struct tce_iommu_info info = { .argsz = sizeof(info) };
>> +
>> +    if (vfio_group_iommu_ioctl(group_id, SPAPR_TCE_IOMMU_GET_INFO, &info)) {
>> +        perror("SPAPR_TCE_IOMMU_GET_INFO failed");
>> +        return;
>> +    }
>> +    *dma32_window_start = info.dma32_window_start;
>> +    *dma32_window_size = info.dma32_window_size;
>> +
>> +    t = g_malloc0(sizeof(*t));
>> +    t->group_id = group_id;
>> +    t->liobn = liobn;
>> +
>> +    QLIST_INSERT_HEAD(&vfio_tce_tables, t, list);
>> +}
>> +
>> +static int put_tce_vfio(uint32_t liobn, target_ulong ioba, target_ulong tce)
>> +{
>> +    sPAPRVFIOTable *t;
>> +    struct tce_iommu_dma_map map = {
>> +        .argsz = sizeof(map),
>> +        .va = 0,
>> +        .dmaaddr = ioba,
>> +    };
>> +
>> +    QLIST_FOREACH(t, &vfio_tce_tables, list) {
>> +        if (t->liobn != liobn) {
>> +            continue;
>> +        }
>> +        if (tce) {
>> +            map.va = (uintptr_t)qemu_get_ram_ptr(tce & 
>> ~SPAPR_TCE_PAGE_MASK);
>> +            if (vfio_group_iommu_ioctl(t->group_id, SPAPR_TCE_IOMMU_MAP_DMA,
>> +                                       &map)) {
>> +                perror("TCE_MAP_DMA");
>> +                return H_PARAMETER;
>> +            }
>> +        } else {
>> +            if (vfio_group_iommu_ioctl(t->group_id, 
>> SPAPR_TCE_IOMMU_UNMAP_DMA,
>> +                                       &map)) {
>> +                perror("TCE_UNMAP_DMA");
>> +                return H_PARAMETER;
>> +            }
>> +        }
>> +        return H_SUCCESS;
>> +    }
>> +    return H_CONTINUE; /* positive non-zero value */
>> +}
>> +
>>  static target_ulong h_put_tce(CPUPPCState *env, sPAPREnvironment *spapr,
>>                                target_ulong opcode, target_ulong *args)
>>  {
>> @@ -200,7 +263,11 @@ static target_ulong h_put_tce(CPUPPCState *env, 
>> sPAPREnvironment *spapr,
>>      ioba &= ~(SPAPR_TCE_PAGE_SIZE - 1);
>>  
>>      ret = put_tce_emu(liobn, ioba, tce);
>> -    if (0 >= ret) {
>> +    if (ret <= 0) {
>> +        return ret ? H_PARAMETER : H_SUCCESS;
>> +    }
>> +    ret = put_tce_vfio(liobn, ioba, tce);
>> +    if (ret <= 0) {
>>          return ret ? H_PARAMETER : H_SUCCESS;
>>      }
>>  #ifdef DEBUG_TCE
>> diff --git a/hw/spapr_iommu_vfio.h b/hw/spapr_iommu_vfio.h
>> new file mode 100644
>> index 0000000..711e3e4
>> --- /dev/null
>> +++ b/hw/spapr_iommu_vfio.h
>> @@ -0,0 +1,49 @@
>> +/*
>> + * Definitions for VFIO IOMMU driver implementing SPAPR TCE.
>> + * This is the copy of the kernel header.
>> + *
>> + * Copyright (c) 2012 Alexey Kardashevskiy <address@hidden>
>> + *
>> + * This library is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU Lesser General Public
>> + * License as published by the Free Software Foundation; either
>> + * version 2 of the License, or (at your option) any later version.
>> + *
>> + * This library is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>> + * Lesser General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU Lesser General Public
>> + * License along with this library; if not, see 
>> <http://www.gnu.org/licenses/>.
>> + */
>> +
>> +#if !defined(__HW_SPAPR_IOMMU_VFIO_H__)
>> +#define __HW_SPAPR_IOMMU_VFIO_H__
>> +
>> +#include "hw/linux-vfio.h"
>> +
>> +#define SPAPR_TCE_IOMMU         2
>> +
>> +struct tce_iommu_info {
>> +    __u32 argsz;
>> +    __u32 flags;
>> +    __u32 dma32_window_start;
>> +    __u32 dma32_window_size;
>> +    __u64 dma64_window_start;
>> +    __u64 dma64_window_size;
>> +};
>> +
>> +#define SPAPR_TCE_IOMMU_GET_INFO        _IO(VFIO_TYPE, VFIO_BASE + 12)
>> +
>> +struct tce_iommu_dma_map {
>> +    __u32 argsz;
>> +    __u32 flags;
>> +    __u64 va;
>> +    __u64 dmaaddr;
>> +};
>> +
>> +#define SPAPR_TCE_IOMMU_MAP_DMA         _IO(VFIO_TYPE, VFIO_BASE + 13)
>> +#define SPAPR_TCE_IOMMU_UNMAP_DMA       _IO(VFIO_TYPE, VFIO_BASE + 14)
>> +
>> +#endif
>> diff --git a/hw/spapr_pci.c b/hw/spapr_pci.c
>> index 014297b..836ec4f 100644
>> --- a/hw/spapr_pci.c
>> +++ b/hw/spapr_pci.c
>> @@ -22,6 +22,9 @@
>>   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
>>   * THE SOFTWARE.
>>   */
>> +#include <sys/types.h>
>> +#include <dirent.h>
>> +
>>  #include "hw.h"
>>  #include "pci.h"
>>  #include "msi.h"
>> @@ -32,7 +35,6 @@
>>  #include "exec-memory.h"
>>  #include <libfdt.h>
>>  #include "trace.h"
>> -
>>  #include "hw/pci_internals.h"
>>  
>>  /* Copied from the kernel arch/powerpc/platforms/pseries/msi.c */
>> @@ -440,6 +442,12 @@ static void pci_spapr_set_irq(void *opaque, int 
>> irq_num, int level)
>>                   level);
>>  }
>>  
>> +static int pci_spapr_get_irq(void *opaque, int irq_num)
>> +{
>> +    sPAPRPHBState *phb = opaque;
>> +    return phb->lsi_table[irq_num].dt_irq;
>> +}
>> +
>>  static uint64_t spapr_io_read(void *opaque, target_phys_addr_t addr,
>>                                unsigned size)
>>  {
>> @@ -515,6 +523,79 @@ static DMAContext *spapr_pci_dma_context_fn(PCIBus 
>> *bus, void *opaque,
>>      return phb->dma;
>>  }
>>  
>> +static int spapr_pci_scan_vfio(sPAPRPHBState *phb)
>> +{
>> +    char iommupath[256];
>> +    DIR *dirp;
>> +    struct dirent *entry;
>> +
>> +    if (!phb->scan) {
>> +        trace_spapr_pci("Autoscan disabled for ", phb->dtbusname);
>> +        return 0;
>> +    }
>> +
>> +    snprintf(iommupath, sizeof(iommupath),
>> +             "/sys/kernel/iommu_groups/%d/devices/", phb->iommugroupid);
>> +    dirp = opendir(iommupath);
>> +
>> +    while ((entry = readdir(dirp)) != NULL) {
>> +        char *tmp;
>> +        FILE *deviceclassfile;
>> +        unsigned deviceclass = 0, domainid, busid, devid, fnid;
>> +        char addr[32];
>> +        DeviceState *dev;
>> +
>> +        if (sscanf(entry->d_name, "%X:%X:%X.%x",
>> +                   &domainid, &busid, &devid, &fnid) != 4) {
>> +            continue;
>> +        }
>> +
>> +        tmp = g_strdup_printf("%s%s/class", iommupath, entry->d_name);
>> +        trace_spapr_pci("Reading device class from ", tmp);
>> +
>> +        deviceclassfile = fopen(tmp, "r");
>> +        if (deviceclassfile) {
>> +            fscanf(deviceclassfile, "%x", &deviceclass);
>> +            fclose(deviceclassfile);
>> +        }
>> +        g_free(tmp);
>> +
>> +        if (!deviceclass) {
>> +            continue;
>> +        }
>> +        if ((phb->scan < 2) &&
>> +            ((deviceclass >> 16) == (PCI_CLASS_BRIDGE_OTHER >> 8))) {
>> +            /* Skip _any_ bridge */
>> +            continue;
>> +        }
>> +        if ((deviceclass == 0xc0310) || (deviceclass == 0xc0320)) {
>> +            /* Tweak USB */
>> +            phb->force_addr = 1;
>> +            phb->enable_multifunction = 1;
>> +        }
>> +
>> +        trace_spapr_pci("Creating devicei from ", entry->d_name);
>> +
>> +        dev = qdev_create(&phb->host_state.bus->qbus, "vfio-pci");
>> +        if (!dev) {
>> +            fprintf(stderr, "failed to create vfio-pci\n");
>> +            continue;
>> +        }
>> +        qdev_prop_parse(dev, "host", entry->d_name);
>> +        if (phb->force_addr) {
>> +            snprintf(addr, sizeof(addr), "%x.%x", devid, fnid);
>> +            qdev_prop_parse(dev, "addr", addr);
>> +        }
>> +        if (phb->enable_multifunction) {
>> +            qdev_prop_set_bit(dev, "multifunction", 1);
>> +        }
>> +        qdev_init_nofail(dev);
>> +    }
>> +    closedir(dirp);
>> +
>> +    return 0;
>> +}
>> +
>>  static int spapr_phb_init(SysBusDevice *s)
>>  {
>>      sPAPRPHBState *phb = DO_UPCAST(sPAPRPHBState, host_state.busdev, s);
>> @@ -567,15 +648,13 @@ static int spapr_phb_init(SysBusDevice *s)
>>  
>>      bus = pci_register_bus(&phb->host_state.busdev.qdev,
>>                             phb->busname ? phb->busname : phb->dtbusname,
>> -                           pci_spapr_set_irq, NULL, pci_spapr_map_irq, phb,
>> +                           pci_spapr_set_irq, pci_spapr_get_irq,
>> +                           pci_spapr_map_irq, phb,
>>                             &phb->memspace, &phb->iospace,
>>                             PCI_DEVFN(0, 0), PCI_NUM_PINS);
>>      phb->host_state.bus = bus;
>>  
>>      phb->dma_liobn = SPAPR_PCI_BASE_LIOBN | (pci_find_domain(bus) << 16);
>> -    phb->dma_window_start = 0;
>> -    phb->dma_window_size = 0x40000000;
>> -    phb->dma = spapr_tce_new_dma_context(phb->dma_liobn, 
>> phb->dma_window_size);
>>      pci_setup_iommu(bus, spapr_pci_dma_context_fn, phb);
>>  
>>      QLIST_INSERT_HEAD(&spapr->phbs, phb, list);
>> @@ -588,6 +667,21 @@ static int spapr_phb_init(SysBusDevice *s)
>>          }
>>      }
>>  
>> +    if (phb->iommugroupid >= 0) {
>> +        if (spapr_pci_scan_vfio(phb) < 0) {
>> +            return -1;
>> +        }
>> +        spapr_vfio_init_dma(phb->iommugroupid, phb->dma_liobn,
>> +                            &phb->dma_window_start,
>> +                            &phb->dma_window_size);
>> +        return 0;
>> +    }
>> +
>> +    phb->dma_window_start = 0;
>> +    phb->dma_window_size = 0x40000000;
>> +    phb->dma = spapr_tce_new_dma_context(phb->dma_liobn,
>> +                                         phb->dma_window_size);
>> +
>>      return 0;
>>  }
>>  
>> @@ -599,6 +693,10 @@ static Property spapr_phb_properties[] = {
>>      DEFINE_PROP_HEX64("io_win_addr", sPAPRPHBState, io_win_addr, 0),
>>      DEFINE_PROP_HEX64("io_win_size", sPAPRPHBState, io_win_size, 0x10000),
>>      DEFINE_PROP_HEX64("msi_win_addr", sPAPRPHBState, msi_win_addr, 0),
>> +    DEFINE_PROP_INT32("iommu", sPAPRPHBState, iommugroupid, -1),
>> +    DEFINE_PROP_UINT8("scan", sPAPRPHBState, scan, 1),
>> +    DEFINE_PROP_UINT8("mf", sPAPRPHBState, enable_multifunction, 0),
>> +    DEFINE_PROP_UINT8("forceaddr", sPAPRPHBState, force_addr, 0),
>>      DEFINE_PROP_END_OF_LIST(),
>>  };
>>  
>> diff --git a/hw/spapr_pci.h b/hw/spapr_pci.h
>> index 145071c..f514823 100644
>> --- a/hw/spapr_pci.h
>> +++ b/hw/spapr_pci.h
>> @@ -57,6 +57,10 @@ typedef struct sPAPRPHBState {
>>          int nvec;
>>      } msi_table[SPAPR_MSIX_MAX_DEVS];
>>  
>> +    int32_t iommugroupid;
>> +    uint8_t scan; /* 0 don't scan 1 scan only devices 2 scan everything */
>> +    uint8_t enable_multifunction, force_addr;
>> +
>>      QLIST_ENTRY(sPAPRPHBState) list;
>>  } sPAPRPHBState;
>>  
>> diff --git a/hw/vfio_pci.c b/hw/vfio_pci.c
>> index 1ac287f..fc84fb4 100644
>> --- a/hw/vfio_pci.c
>> +++ b/hw/vfio_pci.c
>> @@ -1581,6 +1581,24 @@ static int vfio_connect_container(VFIOGroup *group)
>>  
>>          memory_listener_register(&container->listener, get_system_memory());
>>  
>> +    } else if (ioctl(fd, VFIO_CHECK_EXTENSION, SPAPR_TCE_IOMMU)) {
>> +        ret = ioctl(group->fd, VFIO_GROUP_SET_CONTAINER, &fd);
>> +        if (ret) {
>> +            error_report("vfio: failed to set group container: %s\n",
>> +                         strerror(errno));
>> +            g_free(container);
>> +            close(fd);
>> +            return -1;
>> +        }
>> +
>> +        ret = ioctl(fd, VFIO_SET_IOMMU, SPAPR_TCE_IOMMU);
>> +        if (ret) {
>> +            error_report("vfio: failed to set iommu for container: %s\n",
>> +                         strerror(errno));
>> +            g_free(container);
>> +            close(fd);
>> +            return -1;
>> +        }
> 
> I think we can still do better.  The x86 code sets up a MemoryListener
> here with data for that embedded into the VFIOContainer.  You don't
> have, need, or want a MemoryListener, but that doesn't mean we can't
> follow the model of registering that this group exists here and setting
> up map/unmap callbacks.
> 
> For instance:
> 
> in vfio_pci.h:
> struct sPAPRVFIOData {
>     uint64_t dma32_window_start;
>     uint64_t dma64_window_size;
>     ....
>     int (*map)(struct tce_iommu_dma_map *);
>     int (*unmap)(struct tce_iommu_dma_map *);
> };
> 
> appended to the above spapr tce iommu setup above:
> 
> struct tce_iommu_info info;
> 
> /* the MemoryListener embedded in container becomes a union to hold
>  * iommu specific data. */
> container->u.spapr.data->map = vfio_spapr_tce_map;
> container->u.spapr.data->unmap = vfio_spapr_tce_unmap;

I could actually reuse x86 callbacks, just wanted to keep POWER ioctls 
together. The problem here is
getting the DMA window parameters and avoiding MemoryListener.

> ioctl(fd, SPAPR_TCE_IOMMU_GET_INFO, &info))did 
> 
> container->u.spapr.data->dma32_window_start = info.dma32_window_start;
> container->u.spapr.data->dma32_window_size = info.dma32_window_size;
> 
> spapr_register_vfio_container(&container->u.spapr.data)

I assume it is called within vfio_pci.c as we do not want to access 
VFIOContainer members from
anywhere but vfio_pci.c.
Or we are changing the approach? I am a bit confused.


> Then vfio_disconnect_container() could call
> spapr_unregister_vfio_container().  Maybe the container contains a
> function pointer to an uninit function so we don't have to ifdef between
> x86 and power.  Does that make sense?  Thanks,

We also need to pass the numbers from the info struct to spapr_pci.c in order 
to tell the guest
where the DMA window besides. Another callback? This exactly what I avoided in 
the kernel when we
decided not to extend IOMMU API with POWER stuff, I would like to have the same 
here.

In general, what is good in pulling to VFIO as much platform specific stuff as 
possible?

I am trying to keep sPAPR IOMMU stuff away and make it easy to add new 
platforms to VFIO.

For example, I would rather think of moving the piece of code which checks for 
SPAPR_TCE_IOMMU out
of VFIO, make it a QEMUMachine callback (together with add-eoi-notifier) as the 
way IOMMU works is
definitely the specific machine type feature.

For example, int QEMUMachine::init_iommu(VFIOContainter *container) which would 
not even try
VFIO_TYPE1_IOMMU on POWER or SPAPR_TCE_IOMMU on x86 as it knows the machine and 
IOMMU types already.


And do something like:
typedef struct VFIOContainer {
    int fd;
    void *platform_iommu_data;
} VFIOContainer;

Create additional file called vfio_iommu_x86.c with:
struct VFIO_Type1_IOMMU {
    MemoryListener listener;
    QLIST_HEAD(, VFIOGroup) group_list;
    QLIST_ENTRY(VFIOContainer) next;
};
and put all MemoryListener stuff there.

For POWER we already have spapr_iommu.c.

Wrong direction? :)


> Alex
> 
>>      } else {
>>          error_report("vfio: No available IOMMU models\n");
>>          g_free(container);
>> @@ -2005,3 +2023,15 @@ static void register_vfio_pci_dev_type(void)
>>  }
>>  
>>  type_init(register_vfio_pci_dev_type)
>> +
>> +int vfio_group_iommu_ioctl(int iommu_group, int request, void *data)
>> +{
>> +    VFIOGroup *group;
>> +
>> +    group = vfio_get_group(iommu_group);
>> +    if (!group->container) {
>> +        return -EINVAL;
>> +    }
>> +
>> +    return ioctl(group->container->fd, request, data);
>> +}
>> diff --git a/hw/vfio_pci.h b/hw/vfio_pci.h
>> index 226607c..f44ff07 100644
>> --- a/hw/vfio_pci.h
>> +++ b/hw/vfio_pci.h
>> @@ -105,4 +105,6 @@ typedef struct VFIOGroup {
>>  #define VFIO_FLAG_IOMMU_SHARED_BIT 0
>>  #define VFIO_FLAG_IOMMU_SHARED (1U << VFIO_FLAG_UIOMMU_SHARED_BIT)
>>  
>> +int vfio_group_iommu_ioctl(int iommu_group, int request, void *data);
>> +
>>  #endif /* __VFIO_H__ */
>> diff --git a/trace-events b/trace-events
>> index e548f86..9100591 100644
>> --- a/trace-events
>> +++ b/trace-events
>> @@ -848,6 +848,7 @@ qxl_render_guest_primary_resized(int32_t width, int32_t 
>> height, int32_t stride,
>>  qxl_render_update_area_done(void *cookie) "%p"
>>  
>>  # hw/spapr_pci.c
>> +spapr_pci(const char *msg1, const char *msg2) "%s%s"
>>  spapr_pci_msi(const char *msg, uint32_t n, uint32_t ca) "%s (device#%d, 
>> cfg=%x)"
>>  spapr_pci_msi_setup(const char *name, unsigned vector, uint64_t addr) 
>> "dev\"%s\" vector %u, addr=%"PRIx64
>>  spapr_pci_rtas_ibm_change_msi(unsigned func, unsigned req) "func %u, 
>> requested %u"
> 
> 
> 


-- 
Alexey