diff mbox

[v5,1/9] introduce kvm_read_guest_cached

Message ID 1309793548-16714-2-git-send-email-glommer@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Glauber Costa July 4, 2011, 3:32 p.m. UTC 
From: Gleb Natapov <gleb@redhat.com>

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@redhat.com>
Signed-off-by: Glauber Costa <glommer@redhat.com>
---
 include/linux/kvm_host.h |    2 ++
 virt/kvm/kvm_main.c      |   20 ++++++++++++++++++++
 2 files changed, 22 insertions(+), 0 deletions(-)

Comments

Eric B Munson July 5, 2011, 7:35 p.m. UTC | #1 
On Mon, 04 Jul 2011, Glauber Costa wrote:

> From: Gleb Natapov <gleb@redhat.com>
> 
> 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@redhat.com>
> Signed-off-by: Glauber Costa <glommer@redhat.com>

Tested-by: Eric B Munson <emunson@mgebm.net>
Rik van Riel July 6, 2011, 3:45 a.m. UTC | #2 
On 07/04/2011 11:32 AM, Glauber Costa wrote:
> From: Gleb Natapov<gleb@redhat.com>
>
> 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@redhat.com>
> Signed-off-by: Glauber Costa<glommer@redhat.com>

Acked-by: Rik van Riel <riel@redhat.com>
diff mbox

Patch

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,