| Message ID | 1342624074-24650-7-git-send-email-stefanha@linux.vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
On Wed, Jul 18, 2012 at 04:07:33PM +0100, Stefan Hajnoczi wrote: > Support >4 GB physical memory accesses. > > Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Need some sane APIs, this is just too scary. > --- > hw/virtio-blk.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c > index abd9386..99654f1 100644 > --- a/hw/virtio-blk.c > +++ b/hw/virtio-blk.c > @@ -64,6 +64,13 @@ static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev) > */ > static inline void *phys_to_host(VirtIOBlock *s, target_phys_addr_t phys) > { > + /* Adjust for 3.6-4 GB PCI memory range */ > + if (phys >= 0x100000000) { > + phys -= 0x100000000 - 0xe0000000; > + } else if (phys >= 0xe0000000) { > + fprintf(stderr, "phys_to_host bad physical address in PCI range %#lx\n", phys); > + exit(1); > + } > return s->phys_mem_zero_host_ptr + phys; > } > > -- > 1.7.10.4
On Wed, Jul 18, 2012 at 7:29 PM, Michael S. Tsirkin <mst@redhat.com> wrote: > On Wed, Jul 18, 2012 at 04:07:33PM +0100, Stefan Hajnoczi wrote: >> Support >4 GB physical memory accesses. >> >> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> > > Need some sane APIs, this is just too scary. Yes, this prototype has (at least) two layering violations: 1. Bypassing QEMU's memory subsystem because it isn't thread-safe. 2. Bypassing block layer and extracting the underlying fd out of a raw-posix file, allowing us to do our own Linux AIO. Stefan
On Thu, Jul 19, 2012 at 10:14 AM, Stefan Hajnoczi <stefanha@gmail.com> wrote: > On Wed, Jul 18, 2012 at 7:29 PM, Michael S. Tsirkin <mst@redhat.com> wrote: >> On Wed, Jul 18, 2012 at 04:07:33PM +0100, Stefan Hajnoczi wrote: >>> Support >4 GB physical memory accesses. >>> >>> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> >> >> Need some sane APIs, this is just too scary. > > Yes, this prototype has (at least) two layering violations: > 1. Bypassing QEMU's memory subsystem because it isn't thread-safe. Maybe we can use MemoryListener to fix this, although we need to take care of thread-safety. Stefan
On 07/19/2012 12:16 PM, Stefan Hajnoczi wrote: > On Thu, Jul 19, 2012 at 10:14 AM, Stefan Hajnoczi <stefanha@gmail.com> wrote: >> On Wed, Jul 18, 2012 at 7:29 PM, Michael S. Tsirkin <mst@redhat.com> wrote: >>> On Wed, Jul 18, 2012 at 04:07:33PM +0100, Stefan Hajnoczi wrote: >>>> Support >4 GB physical memory accesses. >>>> >>>> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> >>> >>> Need some sane APIs, this is just too scary. >> >> Yes, this prototype has (at least) two layering violations: >> 1. Bypassing QEMU's memory subsystem because it isn't thread-safe. > > Maybe we can use MemoryListener to fix this, although we need to take > care of thread-safety. Better to fix up the memory core. It should be relatively easy to rcu-ify it, as it already works by building a new memory map instead of updating it in place. Currently it has one root pointer, all that is needed is to build it into a temporary pointer, then use rcu_assign_pointer() to atomically switch the memory map.
diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c index abd9386..99654f1 100644 --- a/hw/virtio-blk.c +++ b/hw/virtio-blk.c @@ -64,6 +64,13 @@ static VirtIOBlock *to_virtio_blk(VirtIODevice *vdev) */ static inline void *phys_to_host(VirtIOBlock *s, target_phys_addr_t phys) { + /* Adjust for 3.6-4 GB PCI memory range */ + if (phys >= 0x100000000) { + phys -= 0x100000000 - 0xe0000000; + } else if (phys >= 0xe0000000) { + fprintf(stderr, "phys_to_host bad physical address in PCI range %#lx\n", phys); + exit(1); + } return s->phys_mem_zero_host_ptr + phys; }
Support >4 GB physical memory accesses. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> --- hw/virtio-blk.c | 7 +++++++ 1 file changed, 7 insertions(+)