qdisk - hw/block/xen_disk: grant copy implementation

Copy data operated on during request from/to local buffers to/from
the grant references.

Before grant copy operation local buffers must be allocated what is
done by calling ioreq_init_copy_buffers. For the 'read' operation,
first, the qemu device invokes the read operation on local buffers
and on the completion grant copy is called and buffers are freed.
For the 'write' operation grant copy is performed before invoking
write by qemu device.

A new value 'feature_grant_copy' is added to recognize when the
grant copy operation is supported by a guest.

Signed-off-by: Paulina Szubarczyk <paulinaszubarczyk@gmail.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Anthony PERARD <anthony.perard@citrix.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
This commit is contained in:
Paulina Szubarczyk 2016-09-14 21:10:03 +02:00 committed by Stefano Stabellini
parent 25930ed60a
commit b6eb9b45f7
3 changed files with 217 additions and 5 deletions

55
configure vendored
View file

@ -1952,6 +1952,61 @@ EOF
# Xen unstable
elif
cat > $TMPC <<EOF &&
/*
* If we have stable libs the we don't want the libxc compat
* layers, regardless of what CFLAGS we may have been given.
*
* Also, check if xengnttab_grant_copy_segment_t is defined and
* grant copy operation is implemented.
*/
#undef XC_WANT_COMPAT_EVTCHN_API
#undef XC_WANT_COMPAT_GNTTAB_API
#undef XC_WANT_COMPAT_MAP_FOREIGN_API
#include <xenctrl.h>
#include <xenstore.h>
#include <xenevtchn.h>
#include <xengnttab.h>
#include <xenforeignmemory.h>
#include <stdint.h>
#include <xen/hvm/hvm_info_table.h>
#if !defined(HVM_MAX_VCPUS)
# error HVM_MAX_VCPUS not defined
#endif
int main(void) {
xc_interface *xc = NULL;
xenforeignmemory_handle *xfmem;
xenevtchn_handle *xe;
xengnttab_handle *xg;
xen_domain_handle_t handle;
xengnttab_grant_copy_segment_t* seg = NULL;
xs_daemon_open();
xc = xc_interface_open(0, 0, 0);
xc_hvm_set_mem_type(0, 0, HVMMEM_ram_ro, 0, 0);
xc_domain_add_to_physmap(0, 0, XENMAPSPACE_gmfn, 0, 0);
xc_hvm_inject_msi(xc, 0, 0xf0000000, 0x00000000);
xc_hvm_create_ioreq_server(xc, 0, HVM_IOREQSRV_BUFIOREQ_ATOMIC, NULL);
xc_domain_create(xc, 0, handle, 0, NULL, NULL);
xfmem = xenforeignmemory_open(0, 0);
xenforeignmemory_map(xfmem, 0, 0, 0, 0, 0);
xe = xenevtchn_open(0, 0);
xenevtchn_fd(xe);
xg = xengnttab_open(0, 0);
xengnttab_grant_copy(xg, 0, seg);
return 0;
}
EOF
compile_prog "" "$xen_libs $xen_stable_libs"
then
xen_ctrl_version=480
xen=yes
elif
cat > $TMPC <<EOF &&
/*
* If we have stable libs the we don't want the libxc compat
* layers, regardless of what CFLAGS we may have been given.