[1/2] kvm: libkvm: Add a wrapper for an ioctl for the KVM_SET_CPUID2 interface

Commit Message

Amit Shah Jan. 13, 2009, 10:47 a.m. UTC

kvm_set_cpuid2() builds on top of kvm_set_cpuid() and correctly populates
cpuid functions that have sub-leaves.

Signed-off-by: Amit Shah <[e-mail]>
---
 libkvm/libkvm-x86.c |   18 ++++++++++++++++++
 libkvm/libkvm.h     |   16 ++++++++++++++++
 2 files changed, 34 insertions(+), 0 deletions(-)

Comments

Avi Kivity Jan. 14, 2009, 2:52 p.m. UTC | #1

Amit Shah wrote:
> kvm_set_cpuid2() builds on top of kvm_set_cpuid() and correctly populates
> cpuid functions that have sub-leaves.
>
> Signed-off-by: Amit Shah <[e-mail]>
> ---
>  libkvm/libkvm-x86.c |   18 ++++++++++++++++++
>  libkvm/libkvm.h     |   16 ++++++++++++++++
>  2 files changed, 34 insertions(+), 0 deletions(-)
>
> diff --git a/libkvm/libkvm-x86.c b/libkvm/libkvm-x86.c
> index a8cca15..93a9c4e 100644
> --- a/libkvm/libkvm-x86.c
> +++ b/libkvm/libkvm-x86.c
> @@ -475,6 +475,24 @@ int kvm_setup_cpuid(kvm_context_t kvm, int vcpu, int nent,
>  	return r;
>  }
>  
> +int kvm_setup_cpuid2(kvm_context_t kvm, int vcpu, int nent,
> +		     struct kvm_cpuid_entry2 *entries)
> +{
> +	struct kvm_cpuid2 *cpuid;
> +	int r;
> +
> +	cpuid = malloc(sizeof(*cpuid) + nent * sizeof(*entries));
> +	if (!cpuid)
> +		return -ENOMEM;
> +
> +	cpuid->nent = nent;
> +	memcpy(cpuid->entries, entries, nent * sizeof(*entries));
> +	r = ioctl(kvm->vcpu_fd[vcpu], KVM_SET_CPUID2, cpuid);
> +
> +	free(cpuid);
> +	return r;
> +}
>   

Should return -errno, not -EPERM, if the ioctl fails.

Patch

diff --git a/libkvm/libkvm-x86.c b/libkvm/libkvm-x86.c
index a8cca15..93a9c4e 100644
--- a/libkvm/libkvm-x86.c
+++ b/libkvm/libkvm-x86.c
@@ -475,6 +475,24 @@  int kvm_setup_cpuid(kvm_context_t kvm, int vcpu, int nent,
 	return r;
 }
 
+int kvm_setup_cpuid2(kvm_context_t kvm, int vcpu, int nent,
+		     struct kvm_cpuid_entry2 *entries)
+{
+	struct kvm_cpuid2 *cpuid;
+	int r;
+
+	cpuid = malloc(sizeof(*cpuid) + nent * sizeof(*entries));
+	if (!cpuid)
+		return -ENOMEM;
+
+	cpuid->nent = nent;
+	memcpy(cpuid->entries, entries, nent * sizeof(*entries));
+	r = ioctl(kvm->vcpu_fd[vcpu], KVM_SET_CPUID2, cpuid);
+
+	free(cpuid);
+	return r;
+}
+
 int kvm_set_shadow_pages(kvm_context_t kvm, unsigned int nrshadow_pages)
 {
 #ifdef KVM_CAP_MMU_SHADOW_CACHE_CONTROL
diff --git a/libkvm/libkvm.h b/libkvm/libkvm.h
index ee1ba68..5728b1c 100644
--- a/libkvm/libkvm.h
+++ b/libkvm/libkvm.h
@@ -373,6 +373,22 @@  int kvm_setup_cpuid(kvm_context_t kvm, int vcpu, int nent,
 		    struct kvm_cpuid_entry *entries);
 
 /*!
+ * \brief Setup a vcpu's cpuid instruction emulation
+ *
+ * Set up a table of cpuid function to cpuid outputs.
+ * This call replaces the older kvm_setup_cpuid interface by adding a few
+ * parameters to support cpuid functions that have sub-leaf values.
+ *
+ * \param kvm Pointer to the current kvm_context
+ * \param vcpu Which virtual CPU should be initialized
+ * \param nent number of entries to be installed
+ * \param entries cpuid function entries table
+ * \return 0 on success, or -errno on error
+ */
+int kvm_setup_cpuid2(kvm_context_t kvm, int vcpu, int nent,
+		     struct kvm_cpuid_entry2 *entries);
+
+/*!
  * \brief Setting the number of shadow pages to be allocated to the vm
  *
  * \param kvm pointer to kvm_context