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author | Stefano Stabellini <stefano.stabellini@eu.citrix.com> | 2014-09-11 00:49:30 +0200 |
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committer | Stefano Stabellini <stefano.stabellini@eu.citrix.com> | 2014-09-11 20:11:52 +0200 |
commit | 5ebc77de83c7b74543de774afa7395b3b790e65e (patch) | |
tree | ed73142a80e34fc36e66ac52231b66446ca9f72a /arch/arm/xen/enlighten.c | |
parent | x86/xen: don't copy bogus duplicate entries into kernel page tables (diff) | |
download | linux-5ebc77de83c7b74543de774afa7395b3b790e65e.tar.xz linux-5ebc77de83c7b74543de774afa7395b3b790e65e.zip |
xen/arm: introduce XENFEAT_grant_map_identity
The flag tells us that the hypervisor maps a grant page to guest
physical address == machine address of the page in addition to the
normal grant mapping address. It is needed to properly issue cache
maintenance operation at the completion of a DMA operation involving a
foreign grant.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Tested-by: Denis Schneider <v1ne2go@gmail.com>
Diffstat (limited to 'arch/arm/xen/enlighten.c')
-rw-r--r-- | arch/arm/xen/enlighten.c | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 98544c5f86e9..0e15f011f9c8 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -260,6 +260,12 @@ static int __init xen_guest_init(void) xen_domain_type = XEN_HVM_DOMAIN; xen_setup_features(); + + if (!xen_feature(XENFEAT_grant_map_identity)) { + pr_warn("Please upgrade your Xen.\n" + "If your platform has any non-coherent DMA devices, they won't work properly.\n"); + } + if (xen_feature(XENFEAT_dom0)) xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED; else |