plugin: do not fail crosvm_vcpu_get_msrs() if we failed to fetch some

KVM_GET_MSRS may return less MSRs that were requested; do not fail but
instead let callers to know how many were fetched.

BUG=None
TEST=cargo test --features plugin

Change-Id: Ie14a3d38b66bfe34f5279543bea9c6c78423527e
Signed-off-by: Dmitry Torokhov <dtor@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1192232
Reviewed-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: Dylan Reid <dgreid@chromium.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/crosvm_plugin/crosvm.h b/crosvm_plugin/crosvm.h
index c2139b3..39c2453 100644
--- a/crosvm_plugin/crosvm.h
+++ b/crosvm_plugin/crosvm.h
@@ -509,7 +509,8 @@ int crosvm_vcpu_set_xcrs(struct crosvm_vcpu*, const struct kvm_xcrs*);
 
 /* Gets the MSRs of the vcpu indicated by the index field of each entry. */
 int crosvm_vcpu_get_msrs(struct crosvm_vcpu*, uint32_t __msr_count,
-                         struct kvm_msr_entry *__msr_entries);
+                         struct kvm_msr_entry *__msr_entries,
+                         uint32_t *__out_count);
 /* Sets the MSRs of the vcpu indicated by the index field of each entry. */
 int crosvm_vcpu_set_msrs(struct crosvm_vcpu*, uint32_t __msr_count,
                          const struct kvm_msr_entry *__msr_entries);