Re: [PATCH 11/24] Implement foreignmemory on NetBSD

[Roger Pau Monné <roger.pau@xxxxxxxxxx>]

On Mon, Dec 14, 2020 at 05:36:10PM +0100, Manuel Bouyer wrote:
> ---
>  tools/libs/foreignmemory/Makefile  |  2 +-
>  tools/libs/foreignmemory/netbsd.c  | 76 ++++++++++++++++++++++++++----
>  tools/libs/foreignmemory/private.h | 10 +++-
>  3 files changed, 75 insertions(+), 13 deletions(-)
> 
> diff --git a/tools/libs/foreignmemory/Makefile 
> b/tools/libs/foreignmemory/Makefile
> index 13850f7988..f191cdbed0 100644
> --- a/tools/libs/foreignmemory/Makefile
> +++ b/tools/libs/foreignmemory/Makefile
> @@ -8,7 +8,7 @@ SRCS-y                 += core.c
>  SRCS-$(CONFIG_Linux)   += linux.c
>  SRCS-$(CONFIG_FreeBSD) += freebsd.c
>  SRCS-$(CONFIG_SunOS)   += compat.c solaris.c
> -SRCS-$(CONFIG_NetBSD)  += compat.c netbsd.c
> +SRCS-$(CONFIG_NetBSD)  += netbsd.c
>  SRCS-$(CONFIG_MiniOS)  += minios.c
>  
>  include $(XEN_ROOT)/tools/libs/libs.mk
> diff --git a/tools/libs/foreignmemory/netbsd.c 
> b/tools/libs/foreignmemory/netbsd.c
> index 54a418ebd6..6d740ec2a3 100644
> --- a/tools/libs/foreignmemory/netbsd.c
> +++ b/tools/libs/foreignmemory/netbsd.c
> @@ -19,7 +19,9 @@
>  
>  #include <unistd.h>
>  #include <fcntl.h>
> +#include <errno.h>
>  #include <sys/mman.h>
> +#include <sys/ioctl.h>
>  
>  #include "private.h"
>  
> @@ -66,15 +68,17 @@ int osdep_xenforeignmemory_close(xenforeignmemory_handle 
> *fmem)
>      return close(fd);
>  }
>  
> -void *osdep_map_foreign_batch(xenforeignmem_handle *fmem, uint32_t dom,
> -                              void *addr, int prot, int flags,
> -                              xen_pfn_t *arr, int num)
> +void *osdep_xenforeignmemory_map(xenforeignmemory_handle *fmem,
> +                                 uint32_t dom, void *addr,
> +                              int prot, int flags, size_t num,
> +                              const xen_pfn_t arr[/*num*/], int err[/*num*/])
> +
>  {
>      int fd = fmem->fd;
> -    privcmd_mmapbatch_t ioctlx;
> -    addr = mmap(addr, num*XC_PAGE_SIZE, prot, flags | MAP_ANON | MAP_SHARED, 
> -1, 0);
> +    privcmd_mmapbatch_v2_t ioctlx;
> +    addr = mmap(addr, num*PAGE_SIZE, prot, flags | MAP_ANON | MAP_SHARED, 
> -1, 0);
>      if ( addr == MAP_FAILED ) {
> -        PERROR("osdep_map_foreign_batch: mmap failed");
> +        PERROR("osdep_xenforeignmemory_map: mmap failed");
>          return NULL;
>      }
>  
> @@ -82,11 +86,12 @@ void *osdep_map_foreign_batch(xenforeignmem_handle *fmem, 
> uint32_t dom,
>      ioctlx.dom=dom;
>      ioctlx.addr=(unsigned long)addr;
>      ioctlx.arr=arr;
> -    if ( ioctl(fd, IOCTL_PRIVCMD_MMAPBATCH, &ioctlx) < 0 )
> +    ioctlx.err=err;
> +    if ( ioctl(fd, IOCTL_PRIVCMD_MMAPBATCH_V2, &ioctlx) < 0 )
>      {
>          int saved_errno = errno;
> -        PERROR("osdep_map_foreign_batch: ioctl failed");
> -        (void)munmap(addr, num*XC_PAGE_SIZE);
> +        PERROR("osdep_xenforeignmemory_map: ioctl failed");
> +        (void)munmap(addr, num*PAGE_SIZE);
>          errno = saved_errno;
>          return NULL;
>      }
> @@ -97,7 +102,58 @@ void *osdep_map_foreign_batch(xenforeignmem_handle *fmem, 
> uint32_t dom,
>  int osdep_xenforeignmemory_unmap(xenforeignmemory_handle *fmem,
>                                   void *addr, size_t num)
>  {
> -    return munmap(addr, num*XC_PAGE_SIZE);
> +    return munmap(addr, num*PAGE_SIZE);
> +}
> +
> +int osdep_xenforeignmemory_restrict(xenforeignmemory_handle *fmem,
> +                                    domid_t domid)
> +{
> +    return 0;

Returning 0 here is wrong, since you are not implementing it. You
should return -1 and set errno to EOPNOTSUPP.

> +}
> +
> +int osdep_xenforeignmemory_unmap_resource(
> +    xenforeignmemory_handle *fmem, xenforeignmemory_resource_handle *fres)
> +{
> +    return fres ? munmap(fres->addr, fres->nr_frames << PAGE_SHIFT) : 0;
> +}
> +
> +int osdep_xenforeignmemory_map_resource(
> +    xenforeignmemory_handle *fmem, xenforeignmemory_resource_handle *fres)
> +{
> +    privcmd_mmap_resource_t mr = {
> +        .dom = fres->domid,
> +        .type = fres->type,
> +        .id = fres->id,
> +        .idx = fres->frame,
> +        .num = fres->nr_frames,
> +    };
> +    int rc;
> +
> +    fres->addr = mmap(fres->addr, fres->nr_frames << PAGE_SHIFT,
> +                      fres->prot, fres->flags | MAP_ANON | MAP_SHARED, -1, 
> 0);
> +    if ( fres->addr == MAP_FAILED )
> +        return -1;
> +
> +    mr.addr = (uintptr_t)fres->addr;
> +
> +    rc = ioctl(fmem->fd, IOCTL_PRIVCMD_MMAP_RESOURCE, &mr);
> +    if ( rc )
> +    {
> +        int saved_errno;
> +
> +        if ( errno != fmem->unimpl_errno && errno != EOPNOTSUPP )

Maybe this is set in another patch, but I don't seem to spot where
fmem->unimpl_errno is set on NetBSD (seems to be set only for Linux
AFAICT).

> +            PERROR("ioctl failed");
> +        else
> +            errno = EOPNOTSUPP;
> +
> +        saved_errno = errno;
> +        (void)osdep_xenforeignmemory_unmap_resource(fmem, fres);
> +        errno = saved_errno;
> +
> +        return -1;
> +    }
> +
> +    return 0;
>  }
>  
>  /*
> diff --git a/tools/libs/foreignmemory/private.h 
> b/tools/libs/foreignmemory/private.h
> index 8f1bf081ed..abeceb8720 100644
> --- a/tools/libs/foreignmemory/private.h
> +++ b/tools/libs/foreignmemory/private.h
> @@ -8,7 +8,13 @@
>  #include <xentoolcore_internal.h>
>  
>  #include <xen/xen.h>
> +
> +#ifdef __NetBSD__
> +#include <xen/xen.h>
> +#include <xen/xenio.h>
> +#else
>  #include <xen/sys/privcmd.h>
> +#endif
>  
>  #ifndef PAGE_SHIFT /* Mini-os, Yukk */
>  #define PAGE_SHIFT           12
> @@ -38,7 +44,7 @@ int osdep_xenforeignmemory_unmap(xenforeignmemory_handle 
> *fmem,
>  
>  #if defined(__NetBSD__) || defined(__sun__)
>  /* Strictly compat for those two only only */
> -void *compat_mapforeign_batch(xenforeignmem_handle *fmem, uint32_t dom,
> +void *osdep_map_foreign_batch(xenforeignmemory_handle *fmem, uint32_t dom,
>                                void *addr, int prot, int flags,
>                                xen_pfn_t *arr, int num);

You will have to split this into NetBSD and Solaris variants now if
this is really required, but AFAICT you replace
osdep_map_foreign_batch with osdep_xenforeignmemory_map, so this
prototype is stale?

Also a little bit below these prototypes are the dummy implementations
of osdep_xenforeignmemory_restrict,
osdep_xenforeignmemory_map_resource and
osdep_xenforeignmemory_unmap_resource. I think you at least need to
modify the condition below so that on NetBSD the dummy inlines are not
used?

Thanks, Roger.