From: Gleb Natapov <gleb@xxxxxxxxxx> Introduce kvm_read_guest_cached() function in addition to write one we already have. [ by glauber: export function signature in kvm header ] Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx> Signed-off-by: Glauber Costa <glommer@xxxxxxxxxx> Acked-by: Rik van Riel <riel@xxxxxxxxxx> Tested-by: Eric Munson <emunson@xxxxxxxxx> --- include/linux/kvm_host.h | 2 ++ virt/kvm/kvm_main.c | 20 ++++++++++++++++++++ 2 files changed, 22 insertions(+), 0 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 31ebb59..f7df0a3 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -381,6 +381,8 @@ int kvm_read_guest_page(struct kvm *kvm, gfn_t gfn, void *data, int offset, int kvm_read_guest_atomic(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len); int kvm_read_guest(struct kvm *kvm, gpa_t gpa, void *data, unsigned long len); +int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, + void *data, unsigned long len); int kvm_write_guest_page(struct kvm *kvm, gfn_t gfn, const void *data, int offset, int len); int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data, diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 11d2783..d5ef9eb 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1418,6 +1418,26 @@ int kvm_write_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, } EXPORT_SYMBOL_GPL(kvm_write_guest_cached); +int kvm_read_guest_cached(struct kvm *kvm, struct gfn_to_hva_cache *ghc, + void *data, unsigned long len) +{ + struct kvm_memslots *slots = kvm_memslots(kvm); + int r; + + if (slots->generation != ghc->generation) + kvm_gfn_to_hva_cache_init(kvm, ghc, ghc->gpa); + + if (kvm_is_error_hva(ghc->hva)) + return -EFAULT; + + r = __copy_from_user(data, (void __user *)ghc->hva, len); + if (r) + return -EFAULT; + + return 0; +} +EXPORT_SYMBOL_GPL(kvm_read_guest_cached); + int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len) { return kvm_write_guest_page(kvm, gfn, (const void *) empty_zero_page, -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html