Re: [v3][PATCH 01/16] xen: introduce XENMEM_reserved_device_memory_map

["Tian, Kevin" <kevin.tian@intel.com>]

> From: Chen, Tiejun
> Sent: Thursday, June 11, 2015 9:15 AM
> 
> From: Jan Beulich <jbeulich@suse.com>
> 
> This is a prerequisite for punching holes into HVM and PVH guests' P2M
> to allow passing through devices that are associated with (on VT-d)
> RMRRs.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>

Acked-by: Kevin Tian <kevin.tian@intel.com>

> ---
>  xen/common/compat/memory.c           | 66
> ++++++++++++++++++++++++++++++++++++
>  xen/common/memory.c                  | 64
> ++++++++++++++++++++++++++++++++++
>  xen/drivers/passthrough/iommu.c      | 10 ++++++
>  xen/drivers/passthrough/vtd/dmar.c   | 32 +++++++++++++++++
>  xen/drivers/passthrough/vtd/extern.h |  1 +
>  xen/drivers/passthrough/vtd/iommu.c  |  1 +
>  xen/include/public/memory.h          | 32 ++++++++++++++++-
>  xen/include/xen/iommu.h              | 10 ++++++
>  xen/include/xen/pci.h                |  2 ++
>  xen/include/xlat.lst                 |  3 +-
>  10 files changed, 219 insertions(+), 2 deletions(-)
> 
> diff --git a/xen/common/compat/memory.c b/xen/common/compat/memory.c
> index b258138..b608496 100644
> --- a/xen/common/compat/memory.c
> +++ b/xen/common/compat/memory.c
> @@ -17,6 +17,45 @@ CHECK_TYPE(domid);
>  CHECK_mem_access_op;
>  CHECK_vmemrange;
> 
> +#ifdef HAS_PASSTHROUGH
> +struct get_reserved_device_memory {
> +    struct compat_reserved_device_memory_map map;
> +    unsigned int used_entries;
> +};
> +
> +static int get_reserved_device_memory(xen_pfn_t start, xen_ulong_t nr,
> +                                      u32 id, void *ctxt)
> +{
> +    struct get_reserved_device_memory *grdm = ctxt;
> +    u32 sbdf;
> +    struct compat_reserved_device_memory rdm = {
> +        .start_pfn = start, .nr_pages = nr
> +    };
> +
> +    sbdf = PCI_SBDF2(grdm->map.seg, grdm->map.bus, grdm->map.devfn);
> +    if ( (grdm->map.flag & PCI_DEV_RDM_ALL) || (sbdf == id) )
> +    {
> +        if ( grdm->used_entries < grdm->map.nr_entries )
> +        {
> +            if ( rdm.start_pfn != start || rdm.nr_pages != nr )
> +                return -ERANGE;
> +
> +            if ( __copy_to_compat_offset(grdm->map.buffer,
> +                                         grdm->used_entries,
> +                                         &rdm,
> +                                         1) )
> +            {
> +                return -EFAULT;
> +            }
> +        }
> +        ++grdm->used_entries;
> +        return 1;
> +    }
> +
> +    return 0;
> +}
> +#endif
> +
>  int compat_memory_op(unsigned int cmd, XEN_GUEST_HANDLE_PARAM(void) compat)
>  {
>      int split, op = cmd & MEMOP_CMD_MASK;
> @@ -303,6 +342,33 @@ int compat_memory_op(unsigned int cmd,
> XEN_GUEST_HANDLE_PARAM(void) compat)
>              break;
>          }
> 
> +#ifdef HAS_PASSTHROUGH
> +        case XENMEM_reserved_device_memory_map:
> +        {
> +            struct get_reserved_device_memory grdm;
> +
> +            if ( copy_from_guest(&grdm.map, compat, 1) ||
> +                 !compat_handle_okay(grdm.map.buffer, grdm.map.nr_entries) )
> +                return -EFAULT;
> +
> +            grdm.used_entries = 0;
> +            rc = iommu_get_reserved_device_memory(get_reserved_device_memory,
> +                                                  &grdm);
> +
> +            if ( !rc && grdm.map.nr_entries < grdm.used_entries )
> +                rc = -ENOBUFS;
> +
> +            grdm.map.nr_entries = grdm.used_entries;
> +            if ( grdm.map.nr_entries )
> +            {
> +                if ( __copy_to_guest(compat, &grdm.map, 1) )
> +                    rc = -EFAULT;
> +            }
> +
> +            return rc;
> +        }
> +#endif
> +
>          default:
>              return compat_arch_memory_op(cmd, compat);
>          }
> diff --git a/xen/common/memory.c b/xen/common/memory.c
> index 063a1c5..c789f72 100644
> --- a/xen/common/memory.c
> +++ b/xen/common/memory.c
> @@ -748,6 +748,43 @@ static int construct_memop_from_reservation(
>      return 0;
>  }
> 
> +#ifdef HAS_PASSTHROUGH
> +struct get_reserved_device_memory {
> +    struct xen_reserved_device_memory_map map;
> +    unsigned int used_entries;
> +};
> +
> +static int get_reserved_device_memory(xen_pfn_t start, xen_ulong_t nr,
> +                                      u32 id, void *ctxt)
> +{
> +    struct get_reserved_device_memory *grdm = ctxt;
> +    u32 sbdf;
> +
> +    sbdf = PCI_SBDF2(grdm->map.seg, grdm->map.bus, grdm->map.devfn);
> +    if ( (grdm->map.flag & PCI_DEV_RDM_ALL) || (sbdf == id) )
> +    {
> +        if ( grdm->used_entries < grdm->map.nr_entries )
> +        {
> +            struct xen_reserved_device_memory rdm = {
> +                .start_pfn = start, .nr_pages = nr
> +            };
> +
> +            if ( __copy_to_guest_offset(grdm->map.buffer,
> +                                        grdm->used_entries,
> +                                        &rdm,
> +                                        1) )
> +            {
> +                return -EFAULT;
> +            }
> +        }
> +        ++grdm->used_entries;
> +        return 1;
> +    }
> +
> +    return 0;
> +}
> +#endif
> +
>  long do_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
>  {
>      struct domain *d;
> @@ -1162,6 +1199,33 @@ long do_memory_op(unsigned long cmd,
> XEN_GUEST_HANDLE_PARAM(void) arg)
>          break;
>      }
> 
> +#ifdef HAS_PASSTHROUGH
> +    case XENMEM_reserved_device_memory_map:
> +    {
> +        struct get_reserved_device_memory grdm;
> +
> +        if ( copy_from_guest(&grdm.map, arg, 1) ||
> +             !guest_handle_okay(grdm.map.buffer, grdm.map.nr_entries) )
> +            return -EFAULT;
> +
> +        grdm.used_entries = 0;
> +        rc = iommu_get_reserved_device_memory(get_reserved_device_memory,
> +                                              &grdm);
> +
> +        if ( !rc && grdm.map.nr_entries < grdm.used_entries )
> +            rc = -ENOBUFS;
> +
> +        grdm.map.nr_entries = grdm.used_entries;
> +        if ( grdm.map.nr_entries )
> +        {
> +            if ( __copy_to_guest(arg, &grdm.map, 1) )
> +                rc = -EFAULT;
> +        }
> +
> +        break;
> +    }
> +#endif
> +
>      default:
>          rc = arch_memory_op(cmd, arg);
>          break;
> diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
> index 06cb38f..0b2ef52 100644
> --- a/xen/drivers/passthrough/iommu.c
> +++ b/xen/drivers/passthrough/iommu.c
> @@ -375,6 +375,16 @@ void iommu_crash_shutdown(void)
>      iommu_enabled = iommu_intremap = 0;
>  }
> 
> +int iommu_get_reserved_device_memory(iommu_grdm_t *func, void *ctxt)
> +{
> +    const struct iommu_ops *ops = iommu_get_ops();
> +
> +    if ( !iommu_enabled || !ops->get_reserved_device_memory )
> +        return 0;
> +
> +    return ops->get_reserved_device_memory(func, ctxt);
> +}
> +
>  bool_t iommu_has_feature(struct domain *d, enum iommu_feature feature)
>  {
>      const struct hvm_iommu *hd = domain_hvm_iommu(d);
> diff --git a/xen/drivers/passthrough/vtd/dmar.c b/xen/drivers/passthrough/vtd/dmar.c
> index 2b07be9..a730de5 100644
> --- a/xen/drivers/passthrough/vtd/dmar.c
> +++ b/xen/drivers/passthrough/vtd/dmar.c
> @@ -893,3 +893,35 @@ int platform_supports_x2apic(void)
>      unsigned int mask = ACPI_DMAR_INTR_REMAP | ACPI_DMAR_X2APIC_OPT_OUT;
>      return cpu_has_x2apic && ((dmar_flags & mask) == ACPI_DMAR_INTR_REMAP);
>  }
> +
> +int intel_iommu_get_reserved_device_memory(iommu_grdm_t *func, void *ctxt)
> +{
> +    struct acpi_rmrr_unit *rmrr, *rmrr_cur = NULL;
> +    int rc = 0;
> +    unsigned int i;
> +    u16 bdf;
> +
> +    for_each_rmrr_device ( rmrr, bdf, i )
> +    {
> +        if ( rmrr != rmrr_cur )
> +        {
> +            rc = func(PFN_DOWN(rmrr->base_address),
> +                      PFN_UP(rmrr->end_address) -
> +                        PFN_DOWN(rmrr->base_address),
> +                      PCI_SBDF(rmrr->segment, bdf),
> +                      ctxt);
> +
> +            if ( unlikely(rc < 0) )
> +                return rc;
> +
> +            if ( !rc )
> +                continue;
> +
> +            /* Just go next. */
> +            if ( rc == 1 )
> +                rmrr_cur = rmrr;
> +        }
> +    }
> +
> +    return 0;
> +}
> diff --git a/xen/drivers/passthrough/vtd/extern.h
> b/xen/drivers/passthrough/vtd/extern.h
> index 5524dba..f9ee9b0 100644
> --- a/xen/drivers/passthrough/vtd/extern.h
> +++ b/xen/drivers/passthrough/vtd/extern.h
> @@ -75,6 +75,7 @@ int domain_context_mapping_one(struct domain *domain, struct
> iommu *iommu,
>                                 u8 bus, u8 devfn, const struct pci_dev *);
>  int domain_context_unmap_one(struct domain *domain, struct iommu *iommu,
>                               u8 bus, u8 devfn);
> +int intel_iommu_get_reserved_device_memory(iommu_grdm_t *func, void *ctxt);
> 
>  unsigned int io_apic_read_remap_rte(unsigned int apic, unsigned int reg);
>  void io_apic_write_remap_rte(unsigned int apic,
> diff --git a/xen/drivers/passthrough/vtd/iommu.c
> b/xen/drivers/passthrough/vtd/iommu.c
> index 9053a1f..6a37624 100644
> --- a/xen/drivers/passthrough/vtd/iommu.c
> +++ b/xen/drivers/passthrough/vtd/iommu.c
> @@ -2491,6 +2491,7 @@ const struct iommu_ops intel_iommu_ops = {
>      .crash_shutdown = vtd_crash_shutdown,
>      .iotlb_flush = intel_iommu_iotlb_flush,
>      .iotlb_flush_all = intel_iommu_iotlb_flush_all,
> +    .get_reserved_device_memory = intel_iommu_get_reserved_device_memory,
>      .dump_p2m_table = vtd_dump_p2m_table,
>  };
> 
> diff --git a/xen/include/public/memory.h b/xen/include/public/memory.h
> index 832559a..7b25275 100644
> --- a/xen/include/public/memory.h
> +++ b/xen/include/public/memory.h
> @@ -573,7 +573,37 @@ struct xen_vnuma_topology_info {
>  typedef struct xen_vnuma_topology_info xen_vnuma_topology_info_t;
>  DEFINE_XEN_GUEST_HANDLE(xen_vnuma_topology_info_t);
> 
> -/* Next available subop number is 27 */
> +/*
> + * With some legacy devices, certain guest-physical addresses cannot safely
> + * be used for other purposes, e.g. to map guest RAM.  This hypercall
> + * enumerates those regions so the toolstack can avoid using them.
> + */
> +#define XENMEM_reserved_device_memory_map   27
> +struct xen_reserved_device_memory {
> +    xen_pfn_t start_pfn;
> +    xen_ulong_t nr_pages;
> +};
> +typedef struct xen_reserved_device_memory xen_reserved_device_memory_t;
> +DEFINE_XEN_GUEST_HANDLE(xen_reserved_device_memory_t);
> +
> +struct xen_reserved_device_memory_map {
> +    /* IN */
> +    /* Currently just one bit to indicate checkng all Reserved Device Memory. */
> +#define PCI_DEV_RDM_ALL   0x1
> +    uint32_t        flag;
> +    /* IN */
> +    uint16_t        seg;
> +    uint8_t         bus;
> +    uint8_t         devfn;
> +    /* IN/OUT */
> +    unsigned int    nr_entries;
> +    /* OUT */
> +    XEN_GUEST_HANDLE(xen_reserved_device_memory_t) buffer;
> +};
> +typedef struct xen_reserved_device_memory_map
> xen_reserved_device_memory_map_t;
> +DEFINE_XEN_GUEST_HANDLE(xen_reserved_device_memory_map_t);
> +
> +/* Next available subop number is 28 */
> 
>  #endif /* __XEN_PUBLIC_MEMORY_H__ */
> 
> diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
> index b30bf41..e2f584d 100644
> --- a/xen/include/xen/iommu.h
> +++ b/xen/include/xen/iommu.h
> @@ -126,6 +126,14 @@ int iommu_do_dt_domctl(struct xen_domctl *, struct domain *,
> 
>  struct page_info;
> 
> +/*
> + * Any non-zero value returned from callbacks of this type will cause the
> + * function the callback was handed to terminate its iteration. Assigning
> + * meaning of these non-zero values is left to the top level caller /
> + * callback pair.
> + */
> +typedef int iommu_grdm_t(xen_pfn_t start, xen_ulong_t nr, u32 id, void *ctxt);
> +
>  struct iommu_ops {
>      int (*init)(struct domain *d);
>      void (*hwdom_init)(struct domain *d);
> @@ -157,12 +165,14 @@ struct iommu_ops {
>      void (*crash_shutdown)(void);
>      void (*iotlb_flush)(struct domain *d, unsigned long gfn, unsigned int page_count);
>      void (*iotlb_flush_all)(struct domain *d);
> +    int (*get_reserved_device_memory)(iommu_grdm_t *, void *);
>      void (*dump_p2m_table)(struct domain *d);
>  };
> 
>  void iommu_suspend(void);
>  void iommu_resume(void);
>  void iommu_crash_shutdown(void);
> +int iommu_get_reserved_device_memory(iommu_grdm_t *, void *);
> 
>  void iommu_share_p2m_table(struct domain *d);
> 
> diff --git a/xen/include/xen/pci.h b/xen/include/xen/pci.h
> index 3908146..d176e8b 100644
> --- a/xen/include/xen/pci.h
> +++ b/xen/include/xen/pci.h
> @@ -33,6 +33,8 @@
>  #define PCI_DEVFN2(bdf) ((bdf) & 0xff)
>  #define PCI_BDF(b,d,f)  ((((b) & 0xff) << 8) | PCI_DEVFN(d,f))
>  #define PCI_BDF2(b,df)  ((((b) & 0xff) << 8) | ((df) & 0xff))
> +#define PCI_SBDF(s,bdf) (((s & 0xffff) << 16) | (bdf & 0xffff))
> +#define PCI_SBDF2(s,b,df) (((s & 0xffff) << 16) | PCI_BDF2(b,df))
> 
>  struct pci_dev_info {
>      bool_t is_extfn;
> diff --git a/xen/include/xlat.lst b/xen/include/xlat.lst
> index 9c9fd9a..dd23559 100644
> --- a/xen/include/xlat.lst
> +++ b/xen/include/xlat.lst
> @@ -61,9 +61,10 @@
>  !	memory_exchange			memory.h
>  !	memory_map			memory.h
>  !	memory_reservation		memory.h
> -?	mem_access_op		memory.h
> +?	mem_access_op			memory.h
>  !	pod_target			memory.h
>  !	remove_from_physmap		memory.h
> +!	reserved_device_memory_map	memory.h
>  ?	vmemrange			memory.h
>  !	vnuma_topology_info		memory.h
>  ?	physdev_eoi			physdev.h
> --
> 1.9.1