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| author | Stefano Stabellini <stefano.stabellini@eu.citrix.com> | 2014-09-10 22:49:30 +0000 |
|---|---|---|
| committer | Stefano Stabellini <stefano.stabellini@eu.citrix.com> | 2014-09-11 18:11:52 +0000 |
| commit | 5ebc77de83c7b74543de774afa7395b3b790e65e (patch) | |
| tree | ed73142a80e34fc36e66ac52231b66446ca9f72a | |
| parent | 0b5a50635fc916cf46e3de0b819a61fc3f17e7ee (diff) | |
| download | linux-5ebc77de83c7b74543de774afa7395b3b790e65e.tar.bz2 | |
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>
| -rw-r--r-- | arch/arm/xen/enlighten.c | 6 | ||||
| -rw-r--r-- | include/xen/interface/features.h | 3 |
2 files changed, 9 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 diff --git a/include/xen/interface/features.h b/include/xen/interface/features.h index 131a6ccdba25..14334d0161d5 100644 --- a/include/xen/interface/features.h +++ b/include/xen/interface/features.h @@ -53,6 +53,9 @@ /* operation as Dom0 is supported */ #define XENFEAT_dom0 11 +/* Xen also maps grant references at pfn = mfn */ +#define XENFEAT_grant_map_identity 12 + #define XENFEAT_NR_SUBMAPS 1 #endif /* __XEN_PUBLIC_FEATURES_H__ */ |