From e03b644fe68b1c6401465b02724d261538dba10f Mon Sep 17 00:00:00 2001 From: Gleb Natapov Date: Mon, 11 Jul 2011 15:28:11 -0400 Subject: [PATCH] KVM: introduce kvm_read_guest_cached 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 Signed-off-by: Glauber Costa Acked-by: Rik van Riel Tested-by: Eric Munson Signed-off-by: Avi Kivity --- include/linux/kvm_host.h | 2 ++ virt/kvm/kvm_main.c | 20 ++++++++++++++++++++ 2 files changed, 22 insertions(+) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 31ebb59cbd2f..f7df0a3b031d 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 11d2783eb9df..d5ef9ebcaff7 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, -- 2.34.1